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diff --git a/vendor/github.com/klauspost/compress/fse/README.md b/vendor/github.com/klauspost/compress/fse/README.md new file mode 100644 index 000000000..ea7324da6 --- /dev/null +++ b/vendor/github.com/klauspost/compress/fse/README.md @@ -0,0 +1,79 @@ +# Finite State Entropy
+
+This package provides Finite State Entropy encoding and decoding.
+
+Finite State Entropy (also referenced as [tANS](https://en.wikipedia.org/wiki/Asymmetric_numeral_systems#tANS))
+encoding provides a fast near-optimal symbol encoding/decoding
+for byte blocks as implemented in [zstandard](https://github.com/facebook/zstd).
+
+This can be used for compressing input with a lot of similar input values to the smallest number of bytes.
+This does not perform any multi-byte [dictionary coding](https://en.wikipedia.org/wiki/Dictionary_coder) as LZ coders,
+but it can be used as a secondary step to compressors (like Snappy) that does not do entropy encoding.
+
+* [Godoc documentation](https://godoc.org/github.com/klauspost/compress/fse)
+
+## News
+
+ * Feb 2018: First implementation released. Consider this beta software for now.
+
+# Usage
+
+This package provides a low level interface that allows to compress single independent blocks.
+
+Each block is separate, and there is no built in integrity checks.
+This means that the caller should keep track of block sizes and also do checksums if needed.
+
+Compressing a block is done via the [`Compress`](https://godoc.org/github.com/klauspost/compress/fse#Compress) function.
+You must provide input and will receive the output and maybe an error.
+
+These error values can be returned:
+
+| Error | Description |
+|---------------------|-----------------------------------------------------------------------------|
+| `<nil>` | Everything ok, output is returned |
+| `ErrIncompressible` | Returned when input is judged to be too hard to compress |
+| `ErrUseRLE` | Returned from the compressor when the input is a single byte value repeated |
+| `(error)` | An internal error occurred. |
+
+As can be seen above there are errors that will be returned even under normal operation so it is important to handle these.
+
+To reduce allocations you can provide a [`Scratch`](https://godoc.org/github.com/klauspost/compress/fse#Scratch) object
+that can be re-used for successive calls. Both compression and decompression accepts a `Scratch` object, and the same
+object can be used for both.
+
+Be aware, that when re-using a `Scratch` object that the *output* buffer is also re-used, so if you are still using this
+you must set the `Out` field in the scratch to nil. The same buffer is used for compression and decompression output.
+
+Decompressing is done by calling the [`Decompress`](https://godoc.org/github.com/klauspost/compress/fse#Decompress) function.
+You must provide the output from the compression stage, at exactly the size you got back. If you receive an error back
+your input was likely corrupted.
+
+It is important to note that a successful decoding does *not* mean your output matches your original input.
+There are no integrity checks, so relying on errors from the decompressor does not assure your data is valid.
+
+For more detailed usage, see examples in the [godoc documentation](https://godoc.org/github.com/klauspost/compress/fse#pkg-examples).
+
+# Performance
+
+A lot of factors are affecting speed. Block sizes and compressibility of the material are primary factors.
+All compression functions are currently only running on the calling goroutine so only one core will be used per block.
+
+The compressor is significantly faster if symbols are kept as small as possible. The highest byte value of the input
+is used to reduce some of the processing, so if all your input is above byte value 64 for instance, it may be
+beneficial to transpose all your input values down by 64.
+
+With moderate block sizes around 64k speed are typically 200MB/s per core for compression and
+around 300MB/s decompression speed.
+
+The same hardware typically does Huffman (deflate) encoding at 125MB/s and decompression at 100MB/s.
+
+# Plans
+
+At one point, more internals will be exposed to facilitate more "expert" usage of the components.
+
+A streaming interface is also likely to be implemented. Likely compatible with [FSE stream format](https://github.com/Cyan4973/FiniteStateEntropy/blob/dev/programs/fileio.c#L261).
+
+# Contributing
+
+Contributions are always welcome. Be aware that adding public functions will require good justification and breaking
+changes will likely not be accepted. If in doubt open an issue before writing the PR.
\ No newline at end of file diff --git a/vendor/github.com/klauspost/compress/fse/bitreader.go b/vendor/github.com/klauspost/compress/fse/bitreader.go new file mode 100644 index 000000000..b9db204f5 --- /dev/null +++ b/vendor/github.com/klauspost/compress/fse/bitreader.go @@ -0,0 +1,107 @@ +// Copyright 2018 Klaus Post. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. +// Based on work Copyright (c) 2013, Yann Collet, released under BSD License. + +package fse + +import ( + "errors" + "io" +) + +// bitReader reads a bitstream in reverse. +// The last set bit indicates the start of the stream and is used +// for aligning the input. +type bitReader struct { + in []byte + off uint // next byte to read is at in[off - 1] + value uint64 + bitsRead uint8 +} + +// init initializes and resets the bit reader. +func (b *bitReader) init(in []byte) error { + if len(in) < 1 { + return errors.New("corrupt stream: too short") + } + b.in = in + b.off = uint(len(in)) + // The highest bit of the last byte indicates where to start + v := in[len(in)-1] + if v == 0 { + return errors.New("corrupt stream, did not find end of stream") + } + b.bitsRead = 64 + b.value = 0 + b.fill() + b.fill() + b.bitsRead += 8 - uint8(highBits(uint32(v))) + return nil +} + +// getBits will return n bits. n can be 0. +func (b *bitReader) getBits(n uint8) uint16 { + if n == 0 || b.bitsRead >= 64 { + return 0 + } + return b.getBitsFast(n) +} + +// getBitsFast requires that at least one bit is requested every time. +// There are no checks if the buffer is filled. +func (b *bitReader) getBitsFast(n uint8) uint16 { + const regMask = 64 - 1 + v := uint16((b.value << (b.bitsRead & regMask)) >> ((regMask + 1 - n) & regMask)) + b.bitsRead += n + return v +} + +// fillFast() will make sure at least 32 bits are available. +// There must be at least 4 bytes available. +func (b *bitReader) fillFast() { + if b.bitsRead < 32 { + return + } + // Do single re-slice to avoid bounds checks. + v := b.in[b.off-4 : b.off] + low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24) + b.value = (b.value << 32) | uint64(low) + b.bitsRead -= 32 + b.off -= 4 +} + +// fill() will make sure at least 32 bits are available. +func (b *bitReader) fill() { + if b.bitsRead < 32 { + return + } + if b.off > 4 { + v := b.in[b.off-4 : b.off] + low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24) + b.value = (b.value << 32) | uint64(low) + b.bitsRead -= 32 + b.off -= 4 + return + } + for b.off > 0 { + b.value = (b.value << 8) | uint64(b.in[b.off-1]) + b.bitsRead -= 8 + b.off-- + } +} + +// finished returns true if all bits have been read from the bit stream. +func (b *bitReader) finished() bool { + return b.off == 0 && b.bitsRead >= 64 +} + +// close the bitstream and returns an error if out-of-buffer reads occurred. +func (b *bitReader) close() error { + // Release reference. + b.in = nil + if b.bitsRead > 64 { + return io.ErrUnexpectedEOF + } + return nil +} diff --git a/vendor/github.com/klauspost/compress/fse/bitwriter.go b/vendor/github.com/klauspost/compress/fse/bitwriter.go new file mode 100644 index 000000000..43e463611 --- /dev/null +++ b/vendor/github.com/klauspost/compress/fse/bitwriter.go @@ -0,0 +1,168 @@ +// Copyright 2018 Klaus Post. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. +// Based on work Copyright (c) 2013, Yann Collet, released under BSD License. + +package fse + +import "fmt" + +// bitWriter will write bits. +// First bit will be LSB of the first byte of output. +type bitWriter struct { + bitContainer uint64 + nBits uint8 + out []byte +} + +// bitMask16 is bitmasks. Has extra to avoid bounds check. +var bitMask16 = [32]uint16{ + 0, 1, 3, 7, 0xF, 0x1F, + 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, + 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0xFFFF, + 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, + 0xFFFF, 0xFFFF} /* up to 16 bits */ + +// addBits16NC will add up to 16 bits. +// It will not check if there is space for them, +// so the caller must ensure that it has flushed recently. +func (b *bitWriter) addBits16NC(value uint16, bits uint8) { + b.bitContainer |= uint64(value&bitMask16[bits&31]) << (b.nBits & 63) + b.nBits += bits +} + +// addBits16Clean will add up to 16 bits. value may not contain more set bits than indicated. +// It will not check if there is space for them, so the caller must ensure that it has flushed recently. +func (b *bitWriter) addBits16Clean(value uint16, bits uint8) { + b.bitContainer |= uint64(value) << (b.nBits & 63) + b.nBits += bits +} + +// addBits16ZeroNC will add up to 16 bits. +// It will not check if there is space for them, +// so the caller must ensure that it has flushed recently. +// This is fastest if bits can be zero. +func (b *bitWriter) addBits16ZeroNC(value uint16, bits uint8) { + if bits == 0 { + return + } + value <<= (16 - bits) & 15 + value >>= (16 - bits) & 15 + b.bitContainer |= uint64(value) << (b.nBits & 63) + b.nBits += bits +} + +// flush will flush all pending full bytes. +// There will be at least 56 bits available for writing when this has been called. +// Using flush32 is faster, but leaves less space for writing. +func (b *bitWriter) flush() { + v := b.nBits >> 3 + switch v { + case 0: + case 1: + b.out = append(b.out, + byte(b.bitContainer), + ) + case 2: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + ) + case 3: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + ) + case 4: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + ) + case 5: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + ) + case 6: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + byte(b.bitContainer>>40), + ) + case 7: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + byte(b.bitContainer>>40), + byte(b.bitContainer>>48), + ) + case 8: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + byte(b.bitContainer>>40), + byte(b.bitContainer>>48), + byte(b.bitContainer>>56), + ) + default: + panic(fmt.Errorf("bits (%d) > 64", b.nBits)) + } + b.bitContainer >>= v << 3 + b.nBits &= 7 +} + +// flush32 will flush out, so there are at least 32 bits available for writing. +func (b *bitWriter) flush32() { + if b.nBits < 32 { + return + } + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24)) + b.nBits -= 32 + b.bitContainer >>= 32 +} + +// flushAlign will flush remaining full bytes and align to next byte boundary. +func (b *bitWriter) flushAlign() { + nbBytes := (b.nBits + 7) >> 3 + for i := uint8(0); i < nbBytes; i++ { + b.out = append(b.out, byte(b.bitContainer>>(i*8))) + } + b.nBits = 0 + b.bitContainer = 0 +} + +// close will write the alignment bit and write the final byte(s) +// to the output. +func (b *bitWriter) close() error { + // End mark + b.addBits16Clean(1, 1) + // flush until next byte. + b.flushAlign() + return nil +} + +// reset and continue writing by appending to out. +func (b *bitWriter) reset(out []byte) { + b.bitContainer = 0 + b.nBits = 0 + b.out = out +} diff --git a/vendor/github.com/klauspost/compress/fse/bytereader.go b/vendor/github.com/klauspost/compress/fse/bytereader.go new file mode 100644 index 000000000..f228a46cd --- /dev/null +++ b/vendor/github.com/klauspost/compress/fse/bytereader.go @@ -0,0 +1,56 @@ +// Copyright 2018 Klaus Post. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. +// Based on work Copyright (c) 2013, Yann Collet, released under BSD License. + +package fse + +// byteReader provides a byte reader that reads +// little endian values from a byte stream. +// The input stream is manually advanced. +// The reader performs no bounds checks. +type byteReader struct { + b []byte + off int +} + +// init will initialize the reader and set the input. +func (b *byteReader) init(in []byte) { + b.b = in + b.off = 0 +} + +// advance the stream b n bytes. +func (b *byteReader) advance(n uint) { + b.off += int(n) +} + +// Int32 returns a little endian int32 starting at current offset. +func (b byteReader) Int32() int32 { + b2 := b.b[b.off : b.off+4 : b.off+4] + v3 := int32(b2[3]) + v2 := int32(b2[2]) + v1 := int32(b2[1]) + v0 := int32(b2[0]) + return v0 | (v1 << 8) | (v2 << 16) | (v3 << 24) +} + +// Uint32 returns a little endian uint32 starting at current offset. +func (b byteReader) Uint32() uint32 { + b2 := b.b[b.off : b.off+4 : b.off+4] + v3 := uint32(b2[3]) + v2 := uint32(b2[2]) + v1 := uint32(b2[1]) + v0 := uint32(b2[0]) + return v0 | (v1 << 8) | (v2 << 16) | (v3 << 24) +} + +// unread returns the unread portion of the input. +func (b byteReader) unread() []byte { + return b.b[b.off:] +} + +// remain will return the number of bytes remaining. +func (b byteReader) remain() int { + return len(b.b) - b.off +} diff --git a/vendor/github.com/klauspost/compress/fse/compress.go b/vendor/github.com/klauspost/compress/fse/compress.go new file mode 100644 index 000000000..b69237c9b --- /dev/null +++ b/vendor/github.com/klauspost/compress/fse/compress.go @@ -0,0 +1,684 @@ +// Copyright 2018 Klaus Post. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. +// Based on work Copyright (c) 2013, Yann Collet, released under BSD License. + +package fse + +import ( + "errors" + "fmt" +) + +// Compress the input bytes. Input must be < 2GB. +// Provide a Scratch buffer to avoid memory allocations. +// Note that the output is also kept in the scratch buffer. +// If input is too hard to compress, ErrIncompressible is returned. +// If input is a single byte value repeated ErrUseRLE is returned. +func Compress(in []byte, s *Scratch) ([]byte, error) { + if len(in) <= 1 { + return nil, ErrIncompressible + } + if len(in) > (2<<30)-1 { + return nil, errors.New("input too big, must be < 2GB") + } + s, err := s.prepare(in) + if err != nil { + return nil, err + } + + // Create histogram, if none was provided. + maxCount := s.maxCount + if maxCount == 0 { + maxCount = s.countSimple(in) + } + // Reset for next run. + s.clearCount = true + s.maxCount = 0 + if maxCount == len(in) { + // One symbol, use RLE + return nil, ErrUseRLE + } + if maxCount == 1 || maxCount < (len(in)>>7) { + // Each symbol present maximum once or too well distributed. + return nil, ErrIncompressible + } + s.optimalTableLog() + err = s.normalizeCount() + if err != nil { + return nil, err + } + err = s.writeCount() + if err != nil { + return nil, err + } + + if false { + err = s.validateNorm() + if err != nil { + return nil, err + } + } + + err = s.buildCTable() + if err != nil { + return nil, err + } + err = s.compress(in) + if err != nil { + return nil, err + } + s.Out = s.bw.out + // Check if we compressed. + if len(s.Out) >= len(in) { + return nil, ErrIncompressible + } + return s.Out, nil +} + +// cState contains the compression state of a stream. +type cState struct { + bw *bitWriter + stateTable []uint16 + state uint16 +} + +// init will initialize the compression state to the first symbol of the stream. +func (c *cState) init(bw *bitWriter, ct *cTable, tableLog uint8, first symbolTransform) { + c.bw = bw + c.stateTable = ct.stateTable + + nbBitsOut := (first.deltaNbBits + (1 << 15)) >> 16 + im := int32((nbBitsOut << 16) - first.deltaNbBits) + lu := (im >> nbBitsOut) + first.deltaFindState + c.state = c.stateTable[lu] + return +} + +// encode the output symbol provided and write it to the bitstream. +func (c *cState) encode(symbolTT symbolTransform) { + nbBitsOut := (uint32(c.state) + symbolTT.deltaNbBits) >> 16 + dstState := int32(c.state>>(nbBitsOut&15)) + symbolTT.deltaFindState + c.bw.addBits16NC(c.state, uint8(nbBitsOut)) + c.state = c.stateTable[dstState] +} + +// encode the output symbol provided and write it to the bitstream. +func (c *cState) encodeZero(symbolTT symbolTransform) { + nbBitsOut := (uint32(c.state) + symbolTT.deltaNbBits) >> 16 + dstState := int32(c.state>>(nbBitsOut&15)) + symbolTT.deltaFindState + c.bw.addBits16ZeroNC(c.state, uint8(nbBitsOut)) + c.state = c.stateTable[dstState] +} + +// flush will write the tablelog to the output and flush the remaining full bytes. +func (c *cState) flush(tableLog uint8) { + c.bw.flush32() + c.bw.addBits16NC(c.state, tableLog) + c.bw.flush() +} + +// compress is the main compression loop that will encode the input from the last byte to the first. +func (s *Scratch) compress(src []byte) error { + if len(src) <= 2 { + return errors.New("compress: src too small") + } + tt := s.ct.symbolTT[:256] + s.bw.reset(s.Out) + + // Our two states each encodes every second byte. + // Last byte encoded (first byte decoded) will always be encoded by c1. + var c1, c2 cState + + // Encode so remaining size is divisible by 4. + ip := len(src) + if ip&1 == 1 { + c1.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-1]]) + c2.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-2]]) + c1.encodeZero(tt[src[ip-3]]) + ip -= 3 + } else { + c2.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-1]]) + c1.init(&s.bw, &s.ct, s.actualTableLog, tt[src[ip-2]]) + ip -= 2 + } + if ip&2 != 0 { + c2.encodeZero(tt[src[ip-1]]) + c1.encodeZero(tt[src[ip-2]]) + ip -= 2 + } + + // Main compression loop. + switch { + case !s.zeroBits && s.actualTableLog <= 8: + // We can encode 4 symbols without requiring a flush. + // We do not need to check if any output is 0 bits. + for ip >= 4 { + s.bw.flush32() + v3, v2, v1, v0 := src[ip-4], src[ip-3], src[ip-2], src[ip-1] + c2.encode(tt[v0]) + c1.encode(tt[v1]) + c2.encode(tt[v2]) + c1.encode(tt[v3]) + ip -= 4 + } + case !s.zeroBits: + // We do not need to check if any output is 0 bits. + for ip >= 4 { + s.bw.flush32() + v3, v2, v1, v0 := src[ip-4], src[ip-3], src[ip-2], src[ip-1] + c2.encode(tt[v0]) + c1.encode(tt[v1]) + s.bw.flush32() + c2.encode(tt[v2]) + c1.encode(tt[v3]) + ip -= 4 + } + case s.actualTableLog <= 8: + // We can encode 4 symbols without requiring a flush + for ip >= 4 { + s.bw.flush32() + v3, v2, v1, v0 := src[ip-4], src[ip-3], src[ip-2], src[ip-1] + c2.encodeZero(tt[v0]) + c1.encodeZero(tt[v1]) + c2.encodeZero(tt[v2]) + c1.encodeZero(tt[v3]) + ip -= 4 + } + default: + for ip >= 4 { + s.bw.flush32() + v3, v2, v1, v0 := src[ip-4], src[ip-3], src[ip-2], src[ip-1] + c2.encodeZero(tt[v0]) + c1.encodeZero(tt[v1]) + s.bw.flush32() + c2.encodeZero(tt[v2]) + c1.encodeZero(tt[v3]) + ip -= 4 + } + } + + // Flush final state. + // Used to initialize state when decoding. + c2.flush(s.actualTableLog) + c1.flush(s.actualTableLog) + + return s.bw.close() +} + +// writeCount will write the normalized histogram count to header. +// This is read back by readNCount. +func (s *Scratch) writeCount() error { + var ( + tableLog = s.actualTableLog + tableSize = 1 << tableLog + previous0 bool + charnum uint16 + + maxHeaderSize = ((int(s.symbolLen) * int(tableLog)) >> 3) + 3 + + // Write Table Size + bitStream = uint32(tableLog - minTablelog) + bitCount = uint(4) + remaining = int16(tableSize + 1) /* +1 for extra accuracy */ + threshold = int16(tableSize) + nbBits = uint(tableLog + 1) + ) + if cap(s.Out) < maxHeaderSize { + s.Out = make([]byte, 0, s.br.remain()+maxHeaderSize) + } + outP := uint(0) + out := s.Out[:maxHeaderSize] + + // stops at 1 + for remaining > 1 { + if previous0 { + start := charnum + for s.norm[charnum] == 0 { + charnum++ + } + for charnum >= start+24 { + start += 24 + bitStream += uint32(0xFFFF) << bitCount + out[outP] = byte(bitStream) + out[outP+1] = byte(bitStream >> 8) + outP += 2 + bitStream >>= 16 + } + for charnum >= start+3 { + start += 3 + bitStream += 3 << bitCount + bitCount += 2 + } + bitStream += uint32(charnum-start) << bitCount + bitCount += 2 + if bitCount > 16 { + out[outP] = byte(bitStream) + out[outP+1] = byte(bitStream >> 8) + outP += 2 + bitStream >>= 16 + bitCount -= 16 + } + } + + count := s.norm[charnum] + charnum++ + max := (2*threshold - 1) - remaining + if count < 0 { + remaining += count + } else { + remaining -= count + } + count++ // +1 for extra accuracy + if count >= threshold { + count += max // [0..max[ [max..threshold[ (...) [threshold+max 2*threshold[ + } + bitStream += uint32(count) << bitCount + bitCount += nbBits + if count < max { + bitCount-- + } + + previous0 = count == 1 + if remaining < 1 { + return errors.New("internal error: remaining<1") + } + for remaining < threshold { + nbBits-- + threshold >>= 1 + } + + if bitCount > 16 { + out[outP] = byte(bitStream) + out[outP+1] = byte(bitStream >> 8) + outP += 2 + bitStream >>= 16 + bitCount -= 16 + } + } + + out[outP] = byte(bitStream) + out[outP+1] = byte(bitStream >> 8) + outP += (bitCount + 7) / 8 + + if uint16(charnum) > s.symbolLen { + return errors.New("internal error: charnum > s.symbolLen") + } + s.Out = out[:outP] + return nil +} + +// symbolTransform contains the state transform for a symbol. +type symbolTransform struct { + deltaFindState int32 + deltaNbBits uint32 +} + +// String prints values as a human readable string. +func (s symbolTransform) String() string { + return fmt.Sprintf("dnbits: %08x, fs:%d", s.deltaNbBits, s.deltaFindState) +} + +// cTable contains tables used for compression. +type cTable struct { + tableSymbol []byte + stateTable []uint16 + symbolTT []symbolTransform +} + +// allocCtable will allocate tables needed for compression. +// If existing tables a re big enough, they are simply re-used. +func (s *Scratch) allocCtable() { + tableSize := 1 << s.actualTableLog + // get tableSymbol that is big enough. + if cap(s.ct.tableSymbol) < int(tableSize) { + s.ct.tableSymbol = make([]byte, tableSize) + } + s.ct.tableSymbol = s.ct.tableSymbol[:tableSize] + + ctSize := tableSize + if cap(s.ct.stateTable) < ctSize { + s.ct.stateTable = make([]uint16, ctSize) + } + s.ct.stateTable = s.ct.stateTable[:ctSize] + + if cap(s.ct.symbolTT) < 256 { + s.ct.symbolTT = make([]symbolTransform, 256) + } + s.ct.symbolTT = s.ct.symbolTT[:256] +} + +// buildCTable will populate the compression table so it is ready to be used. +func (s *Scratch) buildCTable() error { + tableSize := uint32(1 << s.actualTableLog) + highThreshold := tableSize - 1 + var cumul [maxSymbolValue + 2]int16 + + s.allocCtable() + tableSymbol := s.ct.tableSymbol[:tableSize] + // symbol start positions + { + cumul[0] = 0 + for ui, v := range s.norm[:s.symbolLen-1] { + u := byte(ui) // one less than reference + if v == -1 { + // Low proba symbol + cumul[u+1] = cumul[u] + 1 + tableSymbol[highThreshold] = u + highThreshold-- + } else { + cumul[u+1] = cumul[u] + v + } + } + // Encode last symbol separately to avoid overflowing u + u := int(s.symbolLen - 1) + v := s.norm[s.symbolLen-1] + if v == -1 { + // Low proba symbol + cumul[u+1] = cumul[u] + 1 + tableSymbol[highThreshold] = byte(u) + highThreshold-- + } else { + cumul[u+1] = cumul[u] + v + } + if uint32(cumul[s.symbolLen]) != tableSize { + return fmt.Errorf("internal error: expected cumul[s.symbolLen] (%d) == tableSize (%d)", cumul[s.symbolLen], tableSize) + } + cumul[s.symbolLen] = int16(tableSize) + 1 + } + // Spread symbols + s.zeroBits = false + { + step := tableStep(tableSize) + tableMask := tableSize - 1 + var position uint32 + // if any symbol > largeLimit, we may have 0 bits output. + largeLimit := int16(1 << (s.actualTableLog - 1)) + for ui, v := range s.norm[:s.symbolLen] { + symbol := byte(ui) + if v > largeLimit { + s.zeroBits = true + } + for nbOccurrences := int16(0); nbOccurrences < v; nbOccurrences++ { + tableSymbol[position] = symbol + position = (position + step) & tableMask + for position > highThreshold { + position = (position + step) & tableMask + } /* Low proba area */ + } + } + + // Check if we have gone through all positions + if position != 0 { + return errors.New("position!=0") + } + } + + // Build table + table := s.ct.stateTable + { + tsi := int(tableSize) + for u, v := range tableSymbol { + // TableU16 : sorted by symbol order; gives next state value + table[cumul[v]] = uint16(tsi + u) + cumul[v]++ + } + } + + // Build Symbol Transformation Table + { + total := int16(0) + symbolTT := s.ct.symbolTT[:s.symbolLen] + tableLog := s.actualTableLog + tl := (uint32(tableLog) << 16) - (1 << tableLog) + for i, v := range s.norm[:s.symbolLen] { + switch v { + case 0: + case -1, 1: + symbolTT[i].deltaNbBits = tl + symbolTT[i].deltaFindState = int32(total - 1) + total++ + default: + maxBitsOut := uint32(tableLog) - highBits(uint32(v-1)) + minStatePlus := uint32(v) << maxBitsOut + symbolTT[i].deltaNbBits = (maxBitsOut << 16) - minStatePlus + symbolTT[i].deltaFindState = int32(total - v) + total += v + } + } + if total != int16(tableSize) { + return fmt.Errorf("total mismatch %d (got) != %d (want)", total, tableSize) + } + } + return nil +} + +// countSimple will create a simple histogram in s.count. +// Returns the biggest count. +// Does not update s.clearCount. +func (s *Scratch) countSimple(in []byte) (max int) { + for _, v := range in { + s.count[v]++ + } + m := uint32(0) + for i, v := range s.count[:] { + if v > m { + m = v + } + if v > 0 { + s.symbolLen = uint16(i) + 1 + } + } + return int(m) +} + +// minTableLog provides the minimum logSize to safely represent a distribution. +func (s *Scratch) minTableLog() uint8 { + minBitsSrc := highBits(uint32(s.br.remain()-1)) + 1 + minBitsSymbols := highBits(uint32(s.symbolLen-1)) + 2 + if minBitsSrc < minBitsSymbols { + return uint8(minBitsSrc) + } + return uint8(minBitsSymbols) +} + +// optimalTableLog calculates and sets the optimal tableLog in s.actualTableLog +func (s *Scratch) optimalTableLog() { + tableLog := s.TableLog + minBits := s.minTableLog() + maxBitsSrc := uint8(highBits(uint32(s.br.remain()-1))) - 2 + if maxBitsSrc < tableLog { + // Accuracy can be reduced + tableLog = maxBitsSrc + } + if minBits > tableLog { + tableLog = minBits + } + // Need a minimum to safely represent all symbol values + if tableLog < minTablelog { + tableLog = minTablelog + } + if tableLog > maxTableLog { + tableLog = maxTableLog + } + s.actualTableLog = tableLog +} + +var rtbTable = [...]uint32{0, 473195, 504333, 520860, 550000, 700000, 750000, 830000} + +// normalizeCount will normalize the count of the symbols so +// the total is equal to the table size. +func (s *Scratch) normalizeCount() error { + var ( + tableLog = s.actualTableLog + scale = 62 - uint64(tableLog) + step = (1 << 62) / uint64(s.br.remain()) + vStep = uint64(1) << (scale - 20) + stillToDistribute = int16(1 << tableLog) + largest int + largestP int16 + lowThreshold = (uint32)(s.br.remain() >> tableLog) + ) + + for i, cnt := range s.count[:s.symbolLen] { + // already handled + // if (count[s] == s.length) return 0; /* rle special case */ + + if cnt == 0 { + s.norm[i] = 0 + continue + } + if cnt <= lowThreshold { + s.norm[i] = -1 + stillToDistribute-- + } else { + proba := (int16)((uint64(cnt) * step) >> scale) + if proba < 8 { + restToBeat := vStep * uint64(rtbTable[proba]) + v := uint64(cnt)*step - (uint64(proba) << scale) + if v > restToBeat { + proba++ + } + } + if proba > largestP { + largestP = proba + largest = i + } + s.norm[i] = proba + stillToDistribute -= proba + } + } + + if -stillToDistribute >= (s.norm[largest] >> 1) { + // corner case, need another normalization method + return s.normalizeCount2() + } + s.norm[largest] += stillToDistribute + return nil +} + +// Secondary normalization method. +// To be used when primary method fails. +func (s *Scratch) normalizeCount2() error { + const notYetAssigned = -2 + var ( + distributed uint32 + total = uint32(s.br.remain()) + tableLog = s.actualTableLog + lowThreshold = uint32(total >> tableLog) + lowOne = uint32((total * 3) >> (tableLog + 1)) + ) + for i, cnt := range s.count[:s.symbolLen] { + if cnt == 0 { + s.norm[i] = 0 + continue + } + if cnt <= lowThreshold { + s.norm[i] = -1 + distributed++ + total -= cnt + continue + } + if cnt <= lowOne { + s.norm[i] = 1 + distributed++ + total -= cnt + continue + } + s.norm[i] = notYetAssigned + } + toDistribute := (1 << tableLog) - distributed + + if (total / toDistribute) > lowOne { + // risk of rounding to zero + lowOne = uint32((total * 3) / (toDistribute * 2)) + for i, cnt := range s.count[:s.symbolLen] { + if (s.norm[i] == notYetAssigned) && (cnt <= lowOne) { + s.norm[i] = 1 + distributed++ + total -= cnt + continue + } + } + toDistribute = (1 << tableLog) - distributed + } + if distributed == uint32(s.symbolLen)+1 { + // all values are pretty poor; + // probably incompressible data (should have already been detected); + // find max, then give all remaining points to max + var maxV int + var maxC uint32 + for i, cnt := range s.count[:s.symbolLen] { + if cnt > maxC { + maxV = i + maxC = cnt + } + } + s.norm[maxV] += int16(toDistribute) + return nil + } + + if total == 0 { + // all of the symbols were low enough for the lowOne or lowThreshold + for i := uint32(0); toDistribute > 0; i = (i + 1) % (uint32(s.symbolLen)) { + if s.norm[i] > 0 { + toDistribute-- + s.norm[i]++ + } + } + return nil + } + + var ( + vStepLog = 62 - uint64(tableLog) + mid = uint64((1 << (vStepLog - 1)) - 1) + rStep = (((1 << vStepLog) * uint64(toDistribute)) + mid) / uint64(total) // scale on remaining + tmpTotal = mid + ) + for i, cnt := range s.count[:s.symbolLen] { + if s.norm[i] == notYetAssigned { + var ( + end = tmpTotal + uint64(cnt)*rStep + sStart = uint32(tmpTotal >> vStepLog) + sEnd = uint32(end >> vStepLog) + weight = sEnd - sStart + ) + if weight < 1 { + return errors.New("weight < 1") + } + s.norm[i] = int16(weight) + tmpTotal = end + } + } + return nil +} + +// validateNorm validates the normalized histogram table. +func (s *Scratch) validateNorm() (err error) { + var total int + for _, v := range s.norm[:s.symbolLen] { + if v >= 0 { + total += int(v) + } else { + total -= int(v) + } + } + defer func() { + if err == nil { + return + } + fmt.Printf("selected TableLog: %d, Symbol length: %d\n", s.actualTableLog, s.symbolLen) + for i, v := range s.norm[:s.symbolLen] { + fmt.Printf("%3d: %5d -> %4d \n", i, s.count[i], v) + } + }() + if total != (1 << s.actualTableLog) { + return fmt.Errorf("warning: Total == %d != %d", total, 1<<s.actualTableLog) + } + for i, v := range s.count[s.symbolLen:] { + if v != 0 { + return fmt.Errorf("warning: Found symbol out of range, %d after cut", i) + } + } + return nil +} diff --git a/vendor/github.com/klauspost/compress/fse/decompress.go b/vendor/github.com/klauspost/compress/fse/decompress.go new file mode 100644 index 000000000..202f36a99 --- /dev/null +++ b/vendor/github.com/klauspost/compress/fse/decompress.go @@ -0,0 +1,370 @@ +package fse + +import ( + "errors" + "fmt" +) + +const ( + tablelogAbsoluteMax = 15 +) + +// Decompress a block of data. +// You can provide a scratch buffer to avoid allocations. +// If nil is provided a temporary one will be allocated. +// It is possible, but by no way guaranteed that corrupt data will +// return an error. +// It is up to the caller to verify integrity of the returned data. +// Use a predefined Scrach to set maximum acceptable output size. +func Decompress(b []byte, s *Scratch) ([]byte, error) { + s, err := s.prepare(b) + if err != nil { + return nil, err + } + s.Out = s.Out[:0] + err = s.readNCount() + if err != nil { + return nil, err + } + err = s.buildDtable() + if err != nil { + return nil, err + } + err = s.decompress() + if err != nil { + return nil, err + } + + return s.Out, nil +} + +// readNCount will read the symbol distribution so decoding tables can be constructed. +func (s *Scratch) readNCount() error { + var ( + charnum uint16 + previous0 bool + b = &s.br + ) + iend := b.remain() + if iend < 4 { + return errors.New("input too small") + } + bitStream := b.Uint32() + nbBits := uint((bitStream & 0xF) + minTablelog) // extract tableLog + if nbBits > tablelogAbsoluteMax { + return errors.New("tableLog too large") + } + bitStream >>= 4 + bitCount := uint(4) + + s.actualTableLog = uint8(nbBits) + remaining := int32((1 << nbBits) + 1) + threshold := int32(1 << nbBits) + gotTotal := int32(0) + nbBits++ + + for remaining > 1 { + if previous0 { + n0 := charnum + for (bitStream & 0xFFFF) == 0xFFFF { + n0 += 24 + if b.off < iend-5 { + b.advance(2) + bitStream = b.Uint32() >> bitCount + } else { + bitStream >>= 16 + bitCount += 16 + } + } + for (bitStream & 3) == 3 { + n0 += 3 + bitStream >>= 2 + bitCount += 2 + } + n0 += uint16(bitStream & 3) + bitCount += 2 + if n0 > maxSymbolValue { + return errors.New("maxSymbolValue too small") + } + for charnum < n0 { + s.norm[charnum&0xff] = 0 + charnum++ + } + + if b.off <= iend-7 || b.off+int(bitCount>>3) <= iend-4 { + b.advance(bitCount >> 3) + bitCount &= 7 + bitStream = b.Uint32() >> bitCount + } else { + bitStream >>= 2 + } + } + + max := (2*(threshold) - 1) - (remaining) + var count int32 + + if (int32(bitStream) & (threshold - 1)) < max { + count = int32(bitStream) & (threshold - 1) + bitCount += nbBits - 1 + } else { + count = int32(bitStream) & (2*threshold - 1) + if count >= threshold { + count -= max + } + bitCount += nbBits + } + + count-- // extra accuracy + if count < 0 { + // -1 means +1 + remaining += count + gotTotal -= count + } else { + remaining -= count + gotTotal += count + } + s.norm[charnum&0xff] = int16(count) + charnum++ + previous0 = count == 0 + for remaining < threshold { + nbBits-- + threshold >>= 1 + } + if b.off <= iend-7 || b.off+int(bitCount>>3) <= iend-4 { + b.advance(bitCount >> 3) + bitCount &= 7 + } else { + bitCount -= (uint)(8 * (len(b.b) - 4 - b.off)) + b.off = len(b.b) - 4 + } + bitStream = b.Uint32() >> (bitCount & 31) + } + s.symbolLen = charnum + + if s.symbolLen <= 1 { + return fmt.Errorf("symbolLen (%d) too small", s.symbolLen) + } + if s.symbolLen > maxSymbolValue+1 { + return fmt.Errorf("symbolLen (%d) too big", s.symbolLen) + } + if remaining != 1 { + return fmt.Errorf("corruption detected (remaining %d != 1)", remaining) + } + if bitCount > 32 { + return fmt.Errorf("corruption detected (bitCount %d > 32)", bitCount) + } + if gotTotal != 1<<s.actualTableLog { + return fmt.Errorf("corruption detected (total %d != %d)", gotTotal, 1<<s.actualTableLog) + } + b.advance((bitCount + 7) >> 3) + return nil +} + +// decSymbol contains information about a state entry, +// Including the state offset base, the output symbol and +// the number of bits to read for the low part of the destination state. +type decSymbol struct { + newState uint16 + symbol uint8 + nbBits uint8 +} + +// allocDtable will allocate decoding tables if they are not big enough. +func (s *Scratch) allocDtable() { + tableSize := 1 << s.actualTableLog + if cap(s.decTable) < int(tableSize) { + s.decTable = make([]decSymbol, tableSize) + } + s.decTable = s.decTable[:tableSize] + + if cap(s.ct.tableSymbol) < 256 { + s.ct.tableSymbol = make([]byte, 256) + } + s.ct.tableSymbol = s.ct.tableSymbol[:256] + + if cap(s.ct.stateTable) < 256 { + s.ct.stateTable = make([]uint16, 256) + } + s.ct.stateTable = s.ct.stateTable[:256] +} + +// buildDtable will build the decoding table. +func (s *Scratch) buildDtable() error { + tableSize := uint32(1 << s.actualTableLog) + highThreshold := tableSize - 1 + s.allocDtable() + symbolNext := s.ct.stateTable[:256] + + // Init, lay down lowprob symbols + s.zeroBits = false + { + largeLimit := int16(1 << (s.actualTableLog - 1)) + for i, v := range s.norm[:s.symbolLen] { + if v == -1 { + s.decTable[highThreshold].symbol = uint8(i) + highThreshold-- + symbolNext[i] = 1 + } else { + if v >= largeLimit { + s.zeroBits = true + } + symbolNext[i] = uint16(v) + } + } + } + // Spread symbols + { + tableMask := tableSize - 1 + step := tableStep(tableSize) + position := uint32(0) + for ss, v := range s.norm[:s.symbolLen] { + for i := 0; i < int(v); i++ { + s.decTable[position].symbol = uint8(ss) + position = (position + step) & tableMask + for position > highThreshold { + // lowprob area + position = (position + step) & tableMask + } + } + } + if position != 0 { + // position must reach all cells once, otherwise normalizedCounter is incorrect + return errors.New("corrupted input (position != 0)") + } + } + + // Build Decoding table + { + tableSize := uint16(1 << s.actualTableLog) + for u, v := range s.decTable { + symbol := v.symbol + nextState := symbolNext[symbol] + symbolNext[symbol] = nextState + 1 + nBits := s.actualTableLog - byte(highBits(uint32(nextState))) + s.decTable[u].nbBits = nBits + newState := (nextState << nBits) - tableSize + if newState > tableSize { + return fmt.Errorf("newState (%d) outside table size (%d)", newState, tableSize) + } + if newState == uint16(u) && nBits == 0 { + // Seems weird that this is possible with nbits > 0. + return fmt.Errorf("newState (%d) == oldState (%d) and no bits", newState, u) + } + s.decTable[u].newState = newState + } + } + return nil +} + +// decompress will decompress the bitstream. +// If the buffer is over-read an error is returned. +func (s *Scratch) decompress() error { + br := &s.bits + br.init(s.br.unread()) + + var s1, s2 decoder + // Initialize and decode first state and symbol. + s1.init(br, s.decTable, s.actualTableLog) + s2.init(br, s.decTable, s.actualTableLog) + + // Use temp table to avoid bound checks/append penalty. + var tmp = s.ct.tableSymbol[:256] + var off uint8 + + // Main part + if !s.zeroBits { + for br.off >= 8 { + br.fillFast() + tmp[off+0] = s1.nextFast() + tmp[off+1] = s2.nextFast() + br.fillFast() + tmp[off+2] = s1.nextFast() + tmp[off+3] = s2.nextFast() + off += 4 + if off == 0 { + s.Out = append(s.Out, tmp...) + } + } + } else { + for br.off >= 8 { + br.fillFast() + tmp[off+0] = s1.next() + tmp[off+1] = s2.next() + br.fillFast() + tmp[off+2] = s1.next() + tmp[off+3] = s2.next() + off += 4 + if off == 0 { + s.Out = append(s.Out, tmp...) + off = 0 + if len(s.Out) >= s.DecompressLimit { + return fmt.Errorf("output size (%d) > DecompressLimit (%d)", len(s.Out), s.DecompressLimit) + } + } + } + } + s.Out = append(s.Out, tmp[:off]...) + + // Final bits, a bit more expensive check + for { + if s1.finished() { + s.Out = append(s.Out, s1.final(), s2.final()) + break + } + br.fill() + s.Out = append(s.Out, s1.next()) + if s2.finished() { + s.Out = append(s.Out, s2.final(), s1.final()) + break + } + s.Out = append(s.Out, s2.next()) + if len(s.Out) >= s.DecompressLimit { + return fmt.Errorf("output size (%d) > DecompressLimit (%d)", len(s.Out), s.DecompressLimit) + } + } + return br.close() +} + +// decoder keeps track of the current state and updates it from the bitstream. +type decoder struct { + state uint16 + br *bitReader + dt []decSymbol +} + +// init will initialize the decoder and read the first state from the stream. +func (d *decoder) init(in *bitReader, dt []decSymbol, tableLog uint8) { + d.dt = dt + d.br = in + d.state = uint16(in.getBits(tableLog)) +} + +// next returns the next symbol and sets the next state. +// At least tablelog bits must be available in the bit reader. +func (d *decoder) next() uint8 { + n := &d.dt[d.state] + lowBits := d.br.getBits(n.nbBits) + d.state = n.newState + lowBits + return n.symbol +} + +// finished returns true if all bits have been read from the bitstream +// and the next state would require reading bits from the input. +func (d *decoder) finished() bool { + return d.br.finished() && d.dt[d.state].nbBits > 0 +} + +// final returns the current state symbol without decoding the next. +func (d *decoder) final() uint8 { + return d.dt[d.state].symbol +} + +// nextFast returns the next symbol and sets the next state. +// This can only be used if no symbols are 0 bits. +// At least tablelog bits must be available in the bit reader. +func (d *decoder) nextFast() uint8 { + n := d.dt[d.state] + lowBits := d.br.getBitsFast(n.nbBits) + d.state = n.newState + lowBits + return n.symbol +} diff --git a/vendor/github.com/klauspost/compress/fse/fse.go b/vendor/github.com/klauspost/compress/fse/fse.go new file mode 100644 index 000000000..075357b5b --- /dev/null +++ b/vendor/github.com/klauspost/compress/fse/fse.go @@ -0,0 +1,143 @@ +// Copyright 2018 Klaus Post. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. +// Based on work Copyright (c) 2013, Yann Collet, released under BSD License. + +// Package fse provides Finite State Entropy encoding and decoding. +// +// Finite State Entropy encoding provides a fast near-optimal symbol encoding/decoding +// for byte blocks as implemented in zstd. +// +// See https://github.com/klauspost/compress/tree/master/fse for more information. +package fse + +import ( + "errors" + "fmt" + "math/bits" +) + +const ( + /*!MEMORY_USAGE : + * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.) + * Increasing memory usage improves compression ratio + * Reduced memory usage can improve speed, due to cache effect + * Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */ + maxMemoryUsage = 14 + defaultMemoryUsage = 13 + + maxTableLog = maxMemoryUsage - 2 + maxTablesize = 1 << maxTableLog + defaultTablelog = defaultMemoryUsage - 2 + minTablelog = 5 + maxSymbolValue = 255 +) + +var ( + // ErrIncompressible is returned when input is judged to be too hard to compress. + ErrIncompressible = errors.New("input is not compressible") + + // ErrUseRLE is returned from the compressor when the input is a single byte value repeated. + ErrUseRLE = errors.New("input is single value repeated") +) + +// Scratch provides temporary storage for compression and decompression. +type Scratch struct { + // Private + count [maxSymbolValue + 1]uint32 + norm [maxSymbolValue + 1]int16 + symbolLen uint16 // Length of active part of the symbol table. + actualTableLog uint8 // Selected tablelog. + br byteReader + bits bitReader + bw bitWriter + ct cTable // Compression tables. + decTable []decSymbol // Decompression table. + zeroBits bool // no bits has prob > 50%. + clearCount bool // clear count + maxCount int // count of the most probable symbol + + // Per block parameters. + // These can be used to override compression parameters of the block. + // Do not touch, unless you know what you are doing. + + // Out is output buffer. + // If the scratch is re-used before the caller is done processing the output, + // set this field to nil. + // Otherwise the output buffer will be re-used for next Compression/Decompression step + // and allocation will be avoided. + Out []byte + + // MaxSymbolValue will override the maximum symbol value of the next block. + MaxSymbolValue uint8 + + // TableLog will attempt to override the tablelog for the next block. + TableLog uint8 + + // DecompressLimit limits the maximum decoded size acceptable. + // If > 0 decompression will stop when approximately this many bytes + // has been decoded. + // If 0, maximum size will be 2GB. + DecompressLimit int +} + +// Histogram allows to populate the histogram and skip that step in the compression, +// It otherwise allows to inspect the histogram when compression is done. +// To indicate that you have populated the histogram call HistogramFinished +// with the value of the highest populated symbol, as well as the number of entries +// in the most populated entry. These are accepted at face value. +// The returned slice will always be length 256. +func (s *Scratch) Histogram() []uint32 { + return s.count[:] +} + +// HistogramFinished can be called to indicate that the histogram has been populated. +// maxSymbol is the index of the highest set symbol of the next data segment. +// maxCount is the number of entries in the most populated entry. +// These are accepted at face value. +func (s *Scratch) HistogramFinished(maxSymbol uint8, maxCount int) { + s.maxCount = maxCount + s.symbolLen = uint16(maxSymbol) + 1 + s.clearCount = maxCount != 0 +} + +// prepare will prepare and allocate scratch tables used for both compression and decompression. +func (s *Scratch) prepare(in []byte) (*Scratch, error) { + if s == nil { + s = &Scratch{} + } + if s.MaxSymbolValue == 0 { + s.MaxSymbolValue = 255 + } + if s.TableLog == 0 { + s.TableLog = defaultTablelog + } + if s.TableLog > maxTableLog { + return nil, fmt.Errorf("tableLog (%d) > maxTableLog (%d)", s.TableLog, maxTableLog) + } + if cap(s.Out) == 0 { + s.Out = make([]byte, 0, len(in)) + } + if s.clearCount && s.maxCount == 0 { + for i := range s.count { + s.count[i] = 0 + } + s.clearCount = false + } + s.br.init(in) + if s.DecompressLimit == 0 { + // Max size 2GB. + s.DecompressLimit = (2 << 30) - 1 + } + + return s, nil +} + +// tableStep returns the next table index. +func tableStep(tableSize uint32) uint32 { + return (tableSize >> 1) + (tableSize >> 3) + 3 +} + +func highBits(val uint32) (n uint32) { + return uint32(bits.Len32(val) - 1) +} diff --git a/vendor/github.com/klauspost/compress/huff0/.gitignore b/vendor/github.com/klauspost/compress/huff0/.gitignore new file mode 100644 index 000000000..b3d262958 --- /dev/null +++ b/vendor/github.com/klauspost/compress/huff0/.gitignore @@ -0,0 +1 @@ +/huff0-fuzz.zip diff --git a/vendor/github.com/klauspost/compress/huff0/README.md b/vendor/github.com/klauspost/compress/huff0/README.md new file mode 100644 index 000000000..0a8448ce9 --- /dev/null +++ b/vendor/github.com/klauspost/compress/huff0/README.md @@ -0,0 +1,87 @@ +# Huff0 entropy compression
+
+This package provides Huff0 encoding and decoding as used in zstd.
+
+[Huff0](https://github.com/Cyan4973/FiniteStateEntropy#new-generation-entropy-coders),
+a Huffman codec designed for modern CPU, featuring OoO (Out of Order) operations on multiple ALU
+(Arithmetic Logic Unit), achieving extremely fast compression and decompression speeds.
+
+This can be used for compressing input with a lot of similar input values to the smallest number of bytes.
+This does not perform any multi-byte [dictionary coding](https://en.wikipedia.org/wiki/Dictionary_coder) as LZ coders,
+but it can be used as a secondary step to compressors (like Snappy) that does not do entropy encoding.
+
+* [Godoc documentation](https://godoc.org/github.com/klauspost/compress/huff0)
+
+THIS PACKAGE IS NOT CONSIDERED STABLE AND API OR ENCODING MAY CHANGE IN THE FUTURE.
+
+## News
+
+ * Mar 2018: First implementation released. Consider this beta software for now.
+
+# Usage
+
+This package provides a low level interface that allows to compress single independent blocks.
+
+Each block is separate, and there is no built in integrity checks.
+This means that the caller should keep track of block sizes and also do checksums if needed.
+
+Compressing a block is done via the [`Compress1X`](https://godoc.org/github.com/klauspost/compress/huff0#Compress1X) and
+[`Compress4X`](https://godoc.org/github.com/klauspost/compress/huff0#Compress4X) functions.
+You must provide input and will receive the output and maybe an error.
+
+These error values can be returned:
+
+| Error | Description |
+|---------------------|-----------------------------------------------------------------------------|
+| `<nil>` | Everything ok, output is returned |
+| `ErrIncompressible` | Returned when input is judged to be too hard to compress |
+| `ErrUseRLE` | Returned from the compressor when the input is a single byte value repeated |
+| `ErrTooBig` | Returned if the input block exceeds the maximum allowed size (128 Kib) |
+| `(error)` | An internal error occurred. |
+
+
+As can be seen above some of there are errors that will be returned even under normal operation so it is important to handle these.
+
+To reduce allocations you can provide a [`Scratch`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch) object
+that can be re-used for successive calls. Both compression and decompression accepts a `Scratch` object, and the same
+object can be used for both.
+
+Be aware, that when re-using a `Scratch` object that the *output* buffer is also re-used, so if you are still using this
+you must set the `Out` field in the scratch to nil. The same buffer is used for compression and decompression output.
+
+The `Scratch` object will retain state that allows to re-use previous tables for encoding and decoding.
+
+## Tables and re-use
+
+Huff0 allows for reusing tables from the previous block to save space if that is expected to give better/faster results.
+
+The Scratch object allows you to set a [`ReusePolicy`](https://godoc.org/github.com/klauspost/compress/huff0#ReusePolicy)
+that controls this behaviour. See the documentation for details. This can be altered between each block.
+
+Do however note that this information is *not* stored in the output block and it is up to the users of the package to
+record whether [`ReadTable`](https://godoc.org/github.com/klauspost/compress/huff0#ReadTable) should be called,
+based on the boolean reported back from the CompressXX call.
+
+If you want to store the table separate from the data, you can access them as `OutData` and `OutTable` on the
+[`Scratch`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch) object.
+
+## Decompressing
+
+The first part of decoding is to initialize the decoding table through [`ReadTable`](https://godoc.org/github.com/klauspost/compress/huff0#ReadTable).
+This will initialize the decoding tables.
+You can supply the complete block to `ReadTable` and it will return the data part of the block
+which can be given to the decompressor.
+
+Decompressing is done by calling the [`Decompress1X`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch.Decompress1X)
+or [`Decompress4X`](https://godoc.org/github.com/klauspost/compress/huff0#Scratch.Decompress4X) function.
+
+You must provide the output from the compression stage, at exactly the size you got back. If you receive an error back
+your input was likely corrupted.
+
+It is important to note that a successful decoding does *not* mean your output matches your original input.
+There are no integrity checks, so relying on errors from the decompressor does not assure your data is valid.
+
+# Contributing
+
+Contributions are always welcome. Be aware that adding public functions will require good justification and breaking
+changes will likely not be accepted. If in doubt open an issue before writing the PR.
\ No newline at end of file diff --git a/vendor/github.com/klauspost/compress/huff0/bitreader.go b/vendor/github.com/klauspost/compress/huff0/bitreader.go new file mode 100644 index 000000000..7d0903c70 --- /dev/null +++ b/vendor/github.com/klauspost/compress/huff0/bitreader.go @@ -0,0 +1,115 @@ +// Copyright 2018 Klaus Post. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. +// Based on work Copyright (c) 2013, Yann Collet, released under BSD License. + +package huff0 + +import ( + "errors" + "io" +) + +// bitReader reads a bitstream in reverse. +// The last set bit indicates the start of the stream and is used +// for aligning the input. +type bitReader struct { + in []byte + off uint // next byte to read is at in[off - 1] + value uint64 + bitsRead uint8 +} + +// init initializes and resets the bit reader. +func (b *bitReader) init(in []byte) error { + if len(in) < 1 { + return errors.New("corrupt stream: too short") + } + b.in = in + b.off = uint(len(in)) + // The highest bit of the last byte indicates where to start + v := in[len(in)-1] + if v == 0 { + return errors.New("corrupt stream, did not find end of stream") + } + b.bitsRead = 64 + b.value = 0 + b.fill() + b.fill() + b.bitsRead += 8 - uint8(highBit32(uint32(v))) + return nil +} + +// getBits will return n bits. n can be 0. +func (b *bitReader) getBits(n uint8) uint16 { + if n == 0 || b.bitsRead >= 64 { + return 0 + } + return b.getBitsFast(n) +} + +// getBitsFast requires that at least one bit is requested every time. +// There are no checks if the buffer is filled. +func (b *bitReader) getBitsFast(n uint8) uint16 { + const regMask = 64 - 1 + v := uint16((b.value << (b.bitsRead & regMask)) >> ((regMask + 1 - n) & regMask)) + b.bitsRead += n + return v +} + +// peekBitsFast requires that at least one bit is requested every time. +// There are no checks if the buffer is filled. +func (b *bitReader) peekBitsFast(n uint8) uint16 { + const regMask = 64 - 1 + v := uint16((b.value << (b.bitsRead & regMask)) >> ((regMask + 1 - n) & regMask)) + return v +} + +// fillFast() will make sure at least 32 bits are available. +// There must be at least 4 bytes available. +func (b *bitReader) fillFast() { + if b.bitsRead < 32 { + return + } + // Do single re-slice to avoid bounds checks. + v := b.in[b.off-4 : b.off] + low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24) + b.value = (b.value << 32) | uint64(low) + b.bitsRead -= 32 + b.off -= 4 +} + +// fill() will make sure at least 32 bits are available. +func (b *bitReader) fill() { + if b.bitsRead < 32 { + return + } + if b.off > 4 { + v := b.in[b.off-4 : b.off] + low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24) + b.value = (b.value << 32) | uint64(low) + b.bitsRead -= 32 + b.off -= 4 + return + } + for b.off > 0 { + b.value = (b.value << 8) | uint64(b.in[b.off-1]) + b.bitsRead -= 8 + b.off-- + } +} + +// finished returns true if all bits have been read from the bit stream. +func (b *bitReader) finished() bool { + return b.off == 0 && b.bitsRead >= 64 +} + +// close the bitstream and returns an error if out-of-buffer reads occurred. +func (b *bitReader) close() error { + // Release reference. + b.in = nil + if b.bitsRead > 64 { + return io.ErrUnexpectedEOF + } + return nil +} diff --git a/vendor/github.com/klauspost/compress/huff0/bitwriter.go b/vendor/github.com/klauspost/compress/huff0/bitwriter.go new file mode 100644 index 000000000..ec0c3fc53 --- /dev/null +++ b/vendor/github.com/klauspost/compress/huff0/bitwriter.go @@ -0,0 +1,186 @@ +// Copyright 2018 Klaus Post. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. +// Based on work Copyright (c) 2013, Yann Collet, released under BSD License. + +package huff0 + +import "fmt" + +// bitWriter will write bits. +// First bit will be LSB of the first byte of output. +type bitWriter struct { + bitContainer uint64 + nBits uint8 + out []byte +} + +// bitMask16 is bitmasks. Has extra to avoid bounds check. +var bitMask16 = [32]uint16{ + 0, 1, 3, 7, 0xF, 0x1F, + 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, + 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0xFFFF, + 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, + 0xFFFF, 0xFFFF} /* up to 16 bits */ + +// addBits16NC will add up to 16 bits. +// It will not check if there is space for them, +// so the caller must ensure that it has flushed recently. +func (b *bitWriter) addBits16NC(value uint16, bits uint8) { + b.bitContainer |= uint64(value&bitMask16[bits&31]) << (b.nBits & 63) + b.nBits += bits +} + +// addBits16Clean will add up to 16 bits. value may not contain more set bits than indicated. +// It will not check if there is space for them, so the caller must ensure that it has flushed recently. +func (b *bitWriter) addBits16Clean(value uint16, bits uint8) { + b.bitContainer |= uint64(value) << (b.nBits & 63) + b.nBits += bits +} + +// addBits16Clean will add up to 16 bits. value may not contain more set bits than indicated. +// It will not check if there is space for them, so the caller must ensure that it has flushed recently. +func (b *bitWriter) encSymbol(ct cTable, symbol byte) { + enc := ct[symbol] + b.bitContainer |= uint64(enc.val) << (b.nBits & 63) + b.nBits += enc.nBits +} + +// addBits16ZeroNC will add up to 16 bits. +// It will not check if there is space for them, +// so the caller must ensure that it has flushed recently. +// This is fastest if bits can be zero. +func (b *bitWriter) addBits16ZeroNC(value uint16, bits uint8) { + if bits == 0 { + return + } + value <<= (16 - bits) & 15 + value >>= (16 - bits) & 15 + b.bitContainer |= uint64(value) << (b.nBits & 63) + b.nBits += bits +} + +// flush will flush all pending full bytes. +// There will be at least 56 bits available for writing when this has been called. +// Using flush32 is faster, but leaves less space for writing. +func (b *bitWriter) flush() { + v := b.nBits >> 3 + switch v { + case 0: + return + case 1: + b.out = append(b.out, + byte(b.bitContainer), + ) + b.bitContainer >>= 1 << 3 + case 2: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + ) + b.bitContainer >>= 2 << 3 + case 3: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + ) + b.bitContainer >>= 3 << 3 + case 4: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + ) + b.bitContainer >>= 4 << 3 + case 5: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + ) + b.bitContainer >>= 5 << 3 + case 6: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + byte(b.bitContainer>>40), + ) + b.bitContainer >>= 6 << 3 + case 7: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + byte(b.bitContainer>>40), + byte(b.bitContainer>>48), + ) + b.bitContainer >>= 7 << 3 + case 8: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + byte(b.bitContainer>>40), + byte(b.bitContainer>>48), + byte(b.bitContainer>>56), + ) + b.bitContainer = 0 + b.nBits = 0 + return + default: + panic(fmt.Errorf("bits (%d) > 64", b.nBits)) + } + b.nBits &= 7 +} + +// flush32 will flush out, so there are at least 32 bits available for writing. +func (b *bitWriter) flush32() { + if b.nBits < 32 { + return + } + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24)) + b.nBits -= 32 + b.bitContainer >>= 32 +} + +// flushAlign will flush remaining full bytes and align to next byte boundary. +func (b *bitWriter) flushAlign() { + nbBytes := (b.nBits + 7) >> 3 + for i := uint8(0); i < nbBytes; i++ { + b.out = append(b.out, byte(b.bitContainer>>(i*8))) + } + b.nBits = 0 + b.bitContainer = 0 +} + +// close will write the alignment bit and write the final byte(s) +// to the output. +func (b *bitWriter) close() error { + // End mark + b.addBits16Clean(1, 1) + // flush until next byte. + b.flushAlign() + return nil +} + +// reset and continue writing by appending to out. +func (b *bitWriter) reset(out []byte) { + b.bitContainer = 0 + b.nBits = 0 + b.out = out +} diff --git a/vendor/github.com/klauspost/compress/huff0/bytereader.go b/vendor/github.com/klauspost/compress/huff0/bytereader.go new file mode 100644 index 000000000..50bcdf6ea --- /dev/null +++ b/vendor/github.com/klauspost/compress/huff0/bytereader.go @@ -0,0 +1,54 @@ +// Copyright 2018 Klaus Post. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. +// Based on work Copyright (c) 2013, Yann Collet, released under BSD License. + +package huff0 + +// byteReader provides a byte reader that reads +// little endian values from a byte stream. +// The input stream is manually advanced. +// The reader performs no bounds checks. +type byteReader struct { + b []byte + off int +} + +// init will initialize the reader and set the input. +func (b *byteReader) init(in []byte) { + b.b = in + b.off = 0 +} + +// advance the stream b n bytes. +func (b *byteReader) advance(n uint) { + b.off += int(n) +} + +// Int32 returns a little endian int32 starting at current offset. +func (b byteReader) Int32() int32 { + v3 := int32(b.b[b.off+3]) + v2 := int32(b.b[b.off+2]) + v1 := int32(b.b[b.off+1]) + v0 := int32(b.b[b.off]) + return (v3 << 24) | (v2 << 16) | (v1 << 8) | v0 +} + +// Uint32 returns a little endian uint32 starting at current offset. +func (b byteReader) Uint32() uint32 { + v3 := uint32(b.b[b.off+3]) + v2 := uint32(b.b[b.off+2]) + v1 := uint32(b.b[b.off+1]) + v0 := uint32(b.b[b.off]) + return (v3 << 24) | (v2 << 16) | (v1 << 8) | v0 +} + +// unread returns the unread portion of the input. +func (b byteReader) unread() []byte { + return b.b[b.off:] +} + +// remain will return the number of bytes remaining. +func (b byteReader) remain() int { + return len(b.b) - b.off +} diff --git a/vendor/github.com/klauspost/compress/huff0/compress.go b/vendor/github.com/klauspost/compress/huff0/compress.go new file mode 100644 index 000000000..dd4f7fefb --- /dev/null +++ b/vendor/github.com/klauspost/compress/huff0/compress.go @@ -0,0 +1,618 @@ +package huff0 + +import ( + "fmt" + "runtime" + "sync" +) + +// Compress1X will compress the input. +// The output can be decoded using Decompress1X. +// Supply a Scratch object. The scratch object contains state about re-use, +// So when sharing across independent encodes, be sure to set the re-use policy. +func Compress1X(in []byte, s *Scratch) (out []byte, reUsed bool, err error) { + s, err = s.prepare(in) + if err != nil { + return nil, false, err + } + return compress(in, s, s.compress1X) +} + +// Compress4X will compress the input. The input is split into 4 independent blocks +// and compressed similar to Compress1X. +// The output can be decoded using Decompress4X. +// Supply a Scratch object. The scratch object contains state about re-use, +// So when sharing across independent encodes, be sure to set the re-use policy. +func Compress4X(in []byte, s *Scratch) (out []byte, reUsed bool, err error) { + s, err = s.prepare(in) + if err != nil { + return nil, false, err + } + if false { + // TODO: compress4Xp only slightly faster. + const parallelThreshold = 8 << 10 + if len(in) < parallelThreshold || runtime.GOMAXPROCS(0) == 1 { + return compress(in, s, s.compress4X) + } + return compress(in, s, s.compress4Xp) + } + return compress(in, s, s.compress4X) +} + +func compress(in []byte, s *Scratch, compressor func(src []byte) ([]byte, error)) (out []byte, reUsed bool, err error) { + // Nuke previous table if we cannot reuse anyway. + if s.Reuse == ReusePolicyNone { + s.prevTable = s.prevTable[:0] + } + + // Create histogram, if none was provided. + maxCount := s.maxCount + var canReuse = false + if maxCount == 0 { + maxCount, canReuse = s.countSimple(in) + } else { + canReuse = s.canUseTable(s.prevTable) + } + + // Reset for next run. + s.clearCount = true + s.maxCount = 0 + if maxCount >= len(in) { + if maxCount > len(in) { + return nil, false, fmt.Errorf("maxCount (%d) > length (%d)", maxCount, len(in)) + } + if len(in) == 1 { + return nil, false, ErrIncompressible + } + // One symbol, use RLE + return nil, false, ErrUseRLE + } + if maxCount == 1 || maxCount < (len(in)>>7) { + // Each symbol present maximum once or too well distributed. + return nil, false, ErrIncompressible + } + + if s.Reuse == ReusePolicyPrefer && canReuse { + keepTable := s.cTable + s.cTable = s.prevTable + s.Out, err = compressor(in) + s.cTable = keepTable + if err == nil && len(s.Out) < len(in) { + s.OutData = s.Out + return s.Out, true, nil + } + // Do not attempt to re-use later. + s.prevTable = s.prevTable[:0] + } + + // Calculate new table. + s.optimalTableLog() + err = s.buildCTable() + if err != nil { + return nil, false, err + } + + if false && !s.canUseTable(s.cTable) { + panic("invalid table generated") + } + + if s.Reuse == ReusePolicyAllow && canReuse { + hSize := len(s.Out) + oldSize := s.prevTable.estimateSize(s.count[:s.symbolLen]) + newSize := s.cTable.estimateSize(s.count[:s.symbolLen]) + if oldSize <= hSize+newSize || hSize+12 >= len(in) { + // Retain cTable even if we re-use. + keepTable := s.cTable + s.cTable = s.prevTable + s.Out, err = compressor(in) + s.cTable = keepTable + if len(s.Out) >= len(in) { + return nil, false, ErrIncompressible + } + s.OutData = s.Out + return s.Out, true, nil + } + } + + // Use new table + err = s.cTable.write(s) + if err != nil { + s.OutTable = nil + return nil, false, err + } + s.OutTable = s.Out + + // Compress using new table + s.Out, err = compressor(in) + if err != nil { + s.OutTable = nil + return nil, false, err + } + if len(s.Out) >= len(in) { + s.OutTable = nil + return nil, false, ErrIncompressible + } + // Move current table into previous. + s.prevTable, s.cTable = s.cTable, s.prevTable[:0] + s.OutData = s.Out[len(s.OutTable):] + return s.Out, false, nil +} + +func (s *Scratch) compress1X(src []byte) ([]byte, error) { + return s.compress1xDo(s.Out, src) +} + +func (s *Scratch) compress1xDo(dst, src []byte) ([]byte, error) { + var bw = bitWriter{out: dst} + + // N is length divisible by 4. + n := len(src) + n -= n & 3 + cTable := s.cTable[:256] + + // Encode last bytes. + for i := len(src) & 3; i > 0; i-- { + bw.encSymbol(cTable, src[n+i-1]) + } + if s.actualTableLog <= 8 { + n -= 4 + for ; n >= 0; n -= 4 { + tmp := src[n : n+4] + // tmp should be len 4 + bw.flush32() + bw.encSymbol(cTable, tmp[3]) + bw.encSymbol(cTable, tmp[2]) + bw.encSymbol(cTable, tmp[1]) + bw.encSymbol(cTable, tmp[0]) + } + } else { + n -= 4 + for ; n >= 0; n -= 4 { + tmp := src[n : n+4] + // tmp should be len 4 + bw.flush32() + bw.encSymbol(cTable, tmp[3]) + bw.encSymbol(cTable, tmp[2]) + bw.flush32() + bw.encSymbol(cTable, tmp[1]) + bw.encSymbol(cTable, tmp[0]) + } + } + err := bw.close() + return bw.out, err +} + +var sixZeros [6]byte + +func (s *Scratch) compress4X(src []byte) ([]byte, error) { + if len(src) < 12 { + return nil, ErrIncompressible + } + segmentSize := (len(src) + 3) / 4 + + // Add placeholder for output length + offsetIdx := len(s.Out) + s.Out = append(s.Out, sixZeros[:]...) + + for i := 0; i < 4; i++ { + toDo := src + if len(toDo) > segmentSize { + toDo = toDo[:segmentSize] + } + src = src[len(toDo):] + + var err error + idx := len(s.Out) + s.Out, err = s.compress1xDo(s.Out, toDo) + if err != nil { + return nil, err + } + // Write compressed length as little endian before block. + if i < 3 { + // Last length is not written. + length := len(s.Out) - idx + s.Out[i*2+offsetIdx] = byte(length) + s.Out[i*2+offsetIdx+1] = byte(length >> 8) + } + } + + return s.Out, nil +} + +// compress4Xp will compress 4 streams using separate goroutines. +func (s *Scratch) compress4Xp(src []byte) ([]byte, error) { + if len(src) < 12 { + return nil, ErrIncompressible + } + // Add placeholder for output length + s.Out = s.Out[:6] + + segmentSize := (len(src) + 3) / 4 + var wg sync.WaitGroup + var errs [4]error + wg.Add(4) + for i := 0; i < 4; i++ { + toDo := src + if len(toDo) > segmentSize { + toDo = toDo[:segmentSize] + } + src = src[len(toDo):] + + // Separate goroutine for each block. + go func(i int) { + s.tmpOut[i], errs[i] = s.compress1xDo(s.tmpOut[i][:0], toDo) + wg.Done() + }(i) + } + wg.Wait() + for i := 0; i < 4; i++ { + if errs[i] != nil { + return nil, errs[i] + } + o := s.tmpOut[i] + // Write compressed length as little endian before block. + if i < 3 { + // Last length is not written. + s.Out[i*2] = byte(len(o)) + s.Out[i*2+1] = byte(len(o) >> 8) + } + + // Write output. + s.Out = append(s.Out, o...) + } + return s.Out, nil +} + +// countSimple will create a simple histogram in s.count. +// Returns the biggest count. +// Does not update s.clearCount. +func (s *Scratch) countSimple(in []byte) (max int, reuse bool) { + reuse = true + for _, v := range in { + s.count[v]++ + } + m := uint32(0) + if len(s.prevTable) > 0 { + for i, v := range s.count[:] { + if v > m { + m = v + } + if v > 0 { + s.symbolLen = uint16(i) + 1 + if i >= len(s.prevTable) { + reuse = false + } else { + if s.prevTable[i].nBits == 0 { + reuse = false + } + } + } + } + return int(m), reuse + } + for i, v := range s.count[:] { + if v > m { + m = v + } + if v > 0 { + s.symbolLen = uint16(i) + 1 + } + } + return int(m), false +} + +func (s *Scratch) canUseTable(c cTable) bool { + if len(c) < int(s.symbolLen) { + return false + } + for i, v := range s.count[:s.symbolLen] { + if v != 0 && c[i].nBits == 0 { + return false + } + } + return true +} + +// minTableLog provides the minimum logSize to safely represent a distribution. +func (s *Scratch) minTableLog() uint8 { + minBitsSrc := highBit32(uint32(s.br.remain()-1)) + 1 + minBitsSymbols := highBit32(uint32(s.symbolLen-1)) + 2 + if minBitsSrc < minBitsSymbols { + return uint8(minBitsSrc) + } + return uint8(minBitsSymbols) +} + +// optimalTableLog calculates and sets the optimal tableLog in s.actualTableLog +func (s *Scratch) optimalTableLog() { + tableLog := s.TableLog + minBits := s.minTableLog() + maxBitsSrc := uint8(highBit32(uint32(s.br.remain()-1))) - 2 + if maxBitsSrc < tableLog { + // Accuracy can be reduced + tableLog = maxBitsSrc + } + if minBits > tableLog { + tableLog = minBits + } + // Need a minimum to safely represent all symbol values + if tableLog < minTablelog { + tableLog = minTablelog + } + if tableLog > tableLogMax { + tableLog = tableLogMax + } + s.actualTableLog = tableLog +} + +type cTableEntry struct { + val uint16 + nBits uint8 + // We have 8 bits extra +} + +const huffNodesMask = huffNodesLen - 1 + +func (s *Scratch) buildCTable() error { + s.huffSort() + if cap(s.cTable) < maxSymbolValue+1 { + s.cTable = make([]cTableEntry, s.symbolLen, maxSymbolValue+1) + } else { + s.cTable = s.cTable[:s.symbolLen] + for i := range s.cTable { + s.cTable[i] = cTableEntry{} + } + } + + var startNode = int16(s.symbolLen) + nonNullRank := s.symbolLen - 1 + + nodeNb := int16(startNode) + huffNode := s.nodes[1 : huffNodesLen+1] + + // This overlays the slice above, but allows "-1" index lookups. + // Different from reference implementation. + huffNode0 := s.nodes[0 : huffNodesLen+1] + + for huffNode[nonNullRank].count == 0 { + nonNullRank-- + } + + lowS := int16(nonNullRank) + nodeRoot := nodeNb + lowS - 1 + lowN := nodeNb + huffNode[nodeNb].count = huffNode[lowS].count + huffNode[lowS-1].count + huffNode[lowS].parent, huffNode[lowS-1].parent = uint16(nodeNb), uint16(nodeNb) + nodeNb++ + lowS -= 2 + for n := nodeNb; n <= nodeRoot; n++ { + huffNode[n].count = 1 << 30 + } + // fake entry, strong barrier + huffNode0[0].count = 1 << 31 + + // create parents + for nodeNb <= nodeRoot { + var n1, n2 int16 + if huffNode0[lowS+1].count < huffNode0[lowN+1].count { + n1 = lowS + lowS-- + } else { + n1 = lowN + lowN++ + } + if huffNode0[lowS+1].count < huffNode0[lowN+1].count { + n2 = lowS + lowS-- + } else { + n2 = lowN + lowN++ + } + + huffNode[nodeNb].count = huffNode0[n1+1].count + huffNode0[n2+1].count + huffNode0[n1+1].parent, huffNode0[n2+1].parent = uint16(nodeNb), uint16(nodeNb) + nodeNb++ + } + + // distribute weights (unlimited tree height) + huffNode[nodeRoot].nbBits = 0 + for n := nodeRoot - 1; n >= startNode; n-- { + huffNode[n].nbBits = huffNode[huffNode[n].parent].nbBits + 1 + } + for n := uint16(0); n <= nonNullRank; n++ { + huffNode[n].nbBits = huffNode[huffNode[n].parent].nbBits + 1 + } + s.actualTableLog = s.setMaxHeight(int(nonNullRank)) + maxNbBits := s.actualTableLog + + // fill result into tree (val, nbBits) + if maxNbBits > tableLogMax { + return fmt.Errorf("internal error: maxNbBits (%d) > tableLogMax (%d)", maxNbBits, tableLogMax) + } + var nbPerRank [tableLogMax + 1]uint16 + var valPerRank [tableLogMax + 1]uint16 + for _, v := range huffNode[:nonNullRank+1] { + nbPerRank[v.nbBits]++ + } + // determine stating value per rank + { + min := uint16(0) + for n := maxNbBits; n > 0; n-- { + // get starting value within each rank + valPerRank[n] = min + min += nbPerRank[n] + min >>= 1 + } + } + + // push nbBits per symbol, symbol order + // TODO: changed `s.symbolLen` -> `nonNullRank+1` (micro-opt) + for _, v := range huffNode[:nonNullRank+1] { + s.cTable[v.symbol].nBits = v.nbBits + } + + // assign value within rank, symbol order + for n, val := range s.cTable[:s.symbolLen] { + v := valPerRank[val.nBits] + s.cTable[n].val = v + valPerRank[val.nBits] = v + 1 + } + + return nil +} + +// huffSort will sort symbols, decreasing order. +func (s *Scratch) huffSort() { + type rankPos struct { + base uint32 + current uint32 + } + + // Clear nodes + nodes := s.nodes[:huffNodesLen+1] + s.nodes = nodes + nodes = nodes[1 : huffNodesLen+1] + + // Sort into buckets based on length of symbol count. + var rank [32]rankPos + for _, v := range s.count[:s.symbolLen] { + r := highBit32(v+1) & 31 + rank[r].base++ + } + for n := 30; n > 0; n-- { + rank[n-1].base += rank[n].base + } + for n := range rank[:] { + rank[n].current = rank[n].base + } + for n, c := range s.count[:s.symbolLen] { + r := (highBit32(c+1) + 1) & 31 + pos := rank[r].current + rank[r].current++ + prev := nodes[(pos-1)&huffNodesMask] + for pos > rank[r].base && c > prev.count { + nodes[pos&huffNodesMask] = prev + pos-- + prev = nodes[(pos-1)&huffNodesMask] + } + nodes[pos&huffNodesMask] = nodeElt{count: c, symbol: byte(n)} + } + return +} + +func (s *Scratch) setMaxHeight(lastNonNull int) uint8 { + maxNbBits := s.TableLog + huffNode := s.nodes[1 : huffNodesLen+1] + //huffNode = huffNode[: huffNodesLen] + + largestBits := huffNode[lastNonNull].nbBits + + // early exit : no elt > maxNbBits + if largestBits <= maxNbBits { + return largestBits + } + totalCost := int(0) + baseCost := int(1) << (largestBits - maxNbBits) + n := uint32(lastNonNull) + + for huffNode[n].nbBits > maxNbBits { + totalCost += baseCost - (1 << (largestBits - huffNode[n].nbBits)) + huffNode[n].nbBits = maxNbBits + n-- + } + // n stops at huffNode[n].nbBits <= maxNbBits + + for huffNode[n].nbBits == maxNbBits { + n-- + } + // n end at index of smallest symbol using < maxNbBits + + // renorm totalCost + totalCost >>= largestBits - maxNbBits /* note : totalCost is necessarily a multiple of baseCost */ + + // repay normalized cost + { + const noSymbol = 0xF0F0F0F0 + var rankLast [tableLogMax + 2]uint32 + + for i := range rankLast[:] { + rankLast[i] = noSymbol + } + + // Get pos of last (smallest) symbol per rank + { + currentNbBits := uint8(maxNbBits) + for pos := int(n); pos >= 0; pos-- { + if huffNode[pos].nbBits >= currentNbBits { + continue + } + currentNbBits = huffNode[pos].nbBits // < maxNbBits + rankLast[maxNbBits-currentNbBits] = uint32(pos) + } + } + + for totalCost > 0 { + nBitsToDecrease := uint8(highBit32(uint32(totalCost))) + 1 + + for ; nBitsToDecrease > 1; nBitsToDecrease-- { + highPos := rankLast[nBitsToDecrease] + lowPos := rankLast[nBitsToDecrease-1] + if highPos == noSymbol { + continue + } + if lowPos == noSymbol { + break + } + highTotal := huffNode[highPos].count + lowTotal := 2 * huffNode[lowPos].count + if highTotal <= lowTotal { + break + } + } + // only triggered when no more rank 1 symbol left => find closest one (note : there is necessarily at least one !) + // HUF_MAX_TABLELOG test just to please gcc 5+; but it should not be necessary + // FIXME: try to remove + for (nBitsToDecrease <= tableLogMax) && (rankLast[nBitsToDecrease] == noSymbol) { + nBitsToDecrease++ + } + totalCost -= 1 << (nBitsToDecrease - 1) + if rankLast[nBitsToDecrease-1] == noSymbol { + // this rank is no longer empty + rankLast[nBitsToDecrease-1] = rankLast[nBitsToDecrease] + } + huffNode[rankLast[nBitsToDecrease]].nbBits++ + if rankLast[nBitsToDecrease] == 0 { + /* special case, reached largest symbol */ + rankLast[nBitsToDecrease] = noSymbol + } else { + rankLast[nBitsToDecrease]-- + if huffNode[rankLast[nBitsToDecrease]].nbBits != maxNbBits-nBitsToDecrease { + rankLast[nBitsToDecrease] = noSymbol /* this rank is now empty */ + } + } + } + + for totalCost < 0 { /* Sometimes, cost correction overshoot */ + if rankLast[1] == noSymbol { /* special case : no rank 1 symbol (using maxNbBits-1); let's create one from largest rank 0 (using maxNbBits) */ + for huffNode[n].nbBits == maxNbBits { + n-- + } + huffNode[n+1].nbBits-- + rankLast[1] = n + 1 + totalCost++ + continue + } + huffNode[rankLast[1]+1].nbBits-- + rankLast[1]++ + totalCost++ + } + } + return maxNbBits +} + +type nodeElt struct { + count uint32 + parent uint16 + symbol byte + nbBits uint8 +} diff --git a/vendor/github.com/klauspost/compress/huff0/decompress.go b/vendor/github.com/klauspost/compress/huff0/decompress.go new file mode 100644 index 000000000..261c54274 --- /dev/null +++ b/vendor/github.com/klauspost/compress/huff0/decompress.go @@ -0,0 +1,397 @@ +package huff0 + +import ( + "errors" + "fmt" + "io" + + "github.com/klauspost/compress/fse" +) + +type dTable struct { + single []dEntrySingle + double []dEntryDouble +} + +// single-symbols decoding +type dEntrySingle struct { + byte uint8 + nBits uint8 +} + +// double-symbols decoding +type dEntryDouble struct { + seq uint16 + nBits uint8 + len uint8 +} + +// ReadTable will read a table from the input. +// The size of the input may be larger than the table definition. +// Any content remaining after the table definition will be returned. +// If no Scratch is provided a new one is allocated. +// The returned Scratch can be used for decoding input using this table. +func ReadTable(in []byte, s *Scratch) (s2 *Scratch, remain []byte, err error) { + s, err = s.prepare(in) + if err != nil { + return s, nil, err + } + if len(in) <= 1 { + return s, nil, errors.New("input too small for table") + } + iSize := in[0] + in = in[1:] + if iSize >= 128 { + // Uncompressed + oSize := iSize - 127 + iSize = (oSize + 1) / 2 + if int(iSize) > len(in) { + return s, nil, errors.New("input too small for table") + } + for n := uint8(0); n < oSize; n += 2 { + v := in[n/2] + s.huffWeight[n] = v >> 4 + s.huffWeight[n+1] = v & 15 + } + s.symbolLen = uint16(oSize) + in = in[iSize:] + } else { + if len(in) <= int(iSize) { + return s, nil, errors.New("input too small for table") + } + // FSE compressed weights + s.fse.DecompressLimit = 255 + hw := s.huffWeight[:] + s.fse.Out = hw + b, err := fse.Decompress(in[:iSize], s.fse) + s.fse.Out = nil + if err != nil { + return s, nil, err + } + if len(b) > 255 { + return s, nil, errors.New("corrupt input: output table too large") + } + s.symbolLen = uint16(len(b)) + in = in[iSize:] + } + + // collect weight stats + var rankStats [tableLogMax + 1]uint32 + weightTotal := uint32(0) + for _, v := range s.huffWeight[:s.symbolLen] { + if v > tableLogMax { + return s, nil, errors.New("corrupt input: weight too large") + } + rankStats[v]++ + weightTotal += (1 << (v & 15)) >> 1 + } + if weightTotal == 0 { + return s, nil, errors.New("corrupt input: weights zero") + } + + // get last non-null symbol weight (implied, total must be 2^n) + { + tableLog := highBit32(weightTotal) + 1 + if tableLog > tableLogMax { + return s, nil, errors.New("corrupt input: tableLog too big") + } + s.actualTableLog = uint8(tableLog) + // determine last weight + { + total := uint32(1) << tableLog + rest := total - weightTotal + verif := uint32(1) << highBit32(rest) + lastWeight := highBit32(rest) + 1 + if verif != rest { + // last value must be a clean power of 2 + return s, nil, errors.New("corrupt input: last value not power of two") + } + s.huffWeight[s.symbolLen] = uint8(lastWeight) + s.symbolLen++ + rankStats[lastWeight]++ + } + } + + if (rankStats[1] < 2) || (rankStats[1]&1 != 0) { + // by construction : at least 2 elts of rank 1, must be even + return s, nil, errors.New("corrupt input: min elt size, even check failed ") + } + + // TODO: Choose between single/double symbol decoding + + // Calculate starting value for each rank + { + var nextRankStart uint32 + for n := uint8(1); n < s.actualTableLog+1; n++ { + current := nextRankStart + nextRankStart += rankStats[n] << (n - 1) + rankStats[n] = current + } + } + + // fill DTable (always full size) + tSize := 1 << tableLogMax + if len(s.dt.single) != tSize { + s.dt.single = make([]dEntrySingle, tSize) + } + + for n, w := range s.huffWeight[:s.symbolLen] { + length := (uint32(1) << w) >> 1 + d := dEntrySingle{ + byte: uint8(n), + nBits: s.actualTableLog + 1 - w, + } + for u := rankStats[w]; u < rankStats[w]+length; u++ { + s.dt.single[u] = d + } + rankStats[w] += length + } + return s, in, nil +} + +// Decompress1X will decompress a 1X encoded stream. +// The length of the supplied input must match the end of a block exactly. +// Before this is called, the table must be initialized with ReadTable unless +// the encoder re-used the table. +func (s *Scratch) Decompress1X(in []byte) (out []byte, err error) { + if len(s.dt.single) == 0 { + return nil, errors.New("no table loaded") + } + var br bitReader + err = br.init(in) + if err != nil { + return nil, err + } + s.Out = s.Out[:0] + + decode := func() byte { + val := br.peekBitsFast(s.actualTableLog) /* note : actualTableLog >= 1 */ + v := s.dt.single[val] + br.bitsRead += v.nBits + return v.byte + } + hasDec := func(v dEntrySingle) byte { + br.bitsRead += v.nBits + return v.byte + } + + // Avoid bounds check by always having full sized table. + const tlSize = 1 << tableLogMax + const tlMask = tlSize - 1 + dt := s.dt.single[:tlSize] + + // Use temp table to avoid bound checks/append penalty. + var tmp = s.huffWeight[:256] + var off uint8 + + for br.off >= 8 { + br.fillFast() + tmp[off+0] = hasDec(dt[br.peekBitsFast(s.actualTableLog)&tlMask]) + tmp[off+1] = hasDec(dt[br.peekBitsFast(s.actualTableLog)&tlMask]) + br.fillFast() + tmp[off+2] = hasDec(dt[br.peekBitsFast(s.actualTableLog)&tlMask]) + tmp[off+3] = hasDec(dt[br.peekBitsFast(s.actualTableLog)&tlMask]) + off += 4 + if off == 0 { + s.Out = append(s.Out, tmp...) + } + } + + s.Out = append(s.Out, tmp[:off]...) + + for !br.finished() { + br.fill() + s.Out = append(s.Out, decode()) + } + return s.Out, br.close() +} + +// Decompress4X will decompress a 4X encoded stream. +// Before this is called, the table must be initialized with ReadTable unless +// the encoder re-used the table. +// The length of the supplied input must match the end of a block exactly. +// The destination size of the uncompressed data must be known and provided. +func (s *Scratch) Decompress4X(in []byte, dstSize int) (out []byte, err error) { + if len(s.dt.single) == 0 { + return nil, errors.New("no table loaded") + } + if len(in) < 6+(4*1) { + return nil, errors.New("input too small") + } + // TODO: We do not detect when we overrun a buffer, except if the last one does. + + var br [4]bitReader + start := 6 + for i := 0; i < 3; i++ { + length := int(in[i*2]) | (int(in[i*2+1]) << 8) + if start+length >= len(in) { + return nil, errors.New("truncated input (or invalid offset)") + } + err = br[i].init(in[start : start+length]) + if err != nil { + return nil, err + } + start += length + } + err = br[3].init(in[start:]) + if err != nil { + return nil, err + } + + // Prepare output + if cap(s.Out) < dstSize { + s.Out = make([]byte, 0, dstSize) + } + s.Out = s.Out[:dstSize] + // destination, offset to match first output + dstOut := s.Out + dstEvery := (dstSize + 3) / 4 + + decode := func(br *bitReader) byte { + val := br.peekBitsFast(s.actualTableLog) /* note : actualTableLog >= 1 */ + v := s.dt.single[val] + br.bitsRead += v.nBits + return v.byte + } + + // Use temp table to avoid bound checks/append penalty. + var tmp = s.huffWeight[:256] + var off uint8 + + // Decode 2 values from each decoder/loop. + const bufoff = 256 / 4 +bigloop: + for { + for i := range br { + if br[i].off < 4 { + break bigloop + } + br[i].fillFast() + } + tmp[off] = decode(&br[0]) + tmp[off+bufoff] = decode(&br[1]) + tmp[off+bufoff*2] = decode(&br[2]) + tmp[off+bufoff*3] = decode(&br[3]) + tmp[off+1] = decode(&br[0]) + tmp[off+1+bufoff] = decode(&br[1]) + tmp[off+1+bufoff*2] = decode(&br[2]) + tmp[off+1+bufoff*3] = decode(&br[3]) + off += 2 + if off == bufoff { + if bufoff > dstEvery { + return nil, errors.New("corruption detected: stream overrun") + } + copy(dstOut, tmp[:bufoff]) + copy(dstOut[dstEvery:], tmp[bufoff:bufoff*2]) + copy(dstOut[dstEvery*2:], tmp[bufoff*2:bufoff*3]) + copy(dstOut[dstEvery*3:], tmp[bufoff*3:bufoff*4]) + off = 0 + dstOut = dstOut[bufoff:] + // There must at least be 3 buffers left. + if len(dstOut) < dstEvery*3+3 { + return nil, errors.New("corruption detected: stream overrun") + } + } + } + if off > 0 { + ioff := int(off) + if len(dstOut) < dstEvery*3+ioff { + return nil, errors.New("corruption detected: stream overrun") + } + copy(dstOut, tmp[:off]) + copy(dstOut[dstEvery:dstEvery+ioff], tmp[bufoff:bufoff*2]) + copy(dstOut[dstEvery*2:dstEvery*2+ioff], tmp[bufoff*2:bufoff*3]) + copy(dstOut[dstEvery*3:dstEvery*3+ioff], tmp[bufoff*3:bufoff*4]) + dstOut = dstOut[off:] + } + + for i := range br { + offset := dstEvery * i + br := &br[i] + for !br.finished() { + br.fill() + if offset >= len(dstOut) { + return nil, errors.New("corruption detected: stream overrun") + } + dstOut[offset] = decode(br) + offset++ + } + err = br.close() + if err != nil { + return nil, err + } + } + + return s.Out, nil +} + +// matches will compare a decoding table to a coding table. +// Errors are written to the writer. +// Nothing will be written if table is ok. +func (s *Scratch) matches(ct cTable, w io.Writer) { + if s == nil || len(s.dt.single) == 0 { + return + } + dt := s.dt.single[:1<<s.actualTableLog] + tablelog := s.actualTableLog + ok := 0 + broken := 0 + for sym, enc := range ct { + errs := 0 + broken++ + if enc.nBits == 0 { + for _, dec := range dt { + if dec.byte == byte(sym) { + fmt.Fprintf(w, "symbol %x has decoder, but no encoder\n", sym) + errs++ + break + } + } + if errs == 0 { + broken-- + } + continue + } + // Unused bits in input + ub := tablelog - enc.nBits + top := enc.val << ub + // decoder looks at top bits. + dec := dt[top] + if dec.nBits != enc.nBits { + fmt.Fprintf(w, "symbol 0x%x bit size mismatch (enc: %d, dec:%d).\n", sym, enc.nBits, dec.nBits) + errs++ + } + if dec.byte != uint8(sym) { + fmt.Fprintf(w, "symbol 0x%x decoder output mismatch (enc: %d, dec:%d).\n", sym, sym, dec.byte) + errs++ + } + if errs > 0 { + fmt.Fprintf(w, "%d errros in base, stopping\n", errs) + continue + } + // Ensure that all combinations are covered. + for i := uint16(0); i < (1 << ub); i++ { + vval := top | i + dec := dt[vval] + if dec.nBits != enc.nBits { + fmt.Fprintf(w, "symbol 0x%x bit size mismatch (enc: %d, dec:%d).\n", vval, enc.nBits, dec.nBits) + errs++ + } + if dec.byte != uint8(sym) { + fmt.Fprintf(w, "symbol 0x%x decoder output mismatch (enc: %d, dec:%d).\n", vval, sym, dec.byte) + errs++ + } + if errs > 20 { + fmt.Fprintf(w, "%d errros, stopping\n", errs) + break + } + } + if errs == 0 { + ok++ + broken-- + } + } + if broken > 0 { + fmt.Fprintf(w, "%d broken, %d ok\n", broken, ok) + } +} diff --git a/vendor/github.com/klauspost/compress/huff0/huff0.go b/vendor/github.com/klauspost/compress/huff0/huff0.go new file mode 100644 index 000000000..50d02e440 --- /dev/null +++ b/vendor/github.com/klauspost/compress/huff0/huff0.go @@ -0,0 +1,241 @@ +// Package huff0 provides fast huffman encoding as used in zstd. +// +// See README.md at https://github.com/klauspost/compress/tree/master/huff0 for details. +package huff0 + +import ( + "errors" + "fmt" + "math" + "math/bits" + + "github.com/klauspost/compress/fse" +) + +const ( + maxSymbolValue = 255 + + // zstandard limits tablelog to 11, see: + // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#huffman-tree-description + tableLogMax = 11 + tableLogDefault = 11 + minTablelog = 5 + huffNodesLen = 512 + + // BlockSizeMax is maximum input size for a single block uncompressed. + BlockSizeMax = 1<<18 - 1 +) + +var ( + // ErrIncompressible is returned when input is judged to be too hard to compress. + ErrIncompressible = errors.New("input is not compressible") + + // ErrUseRLE is returned from the compressor when the input is a single byte value repeated. + ErrUseRLE = errors.New("input is single value repeated") + + // ErrTooBig is return if input is too large for a single block. + ErrTooBig = errors.New("input too big") +) + +type ReusePolicy uint8 + +const ( + // ReusePolicyAllow will allow reuse if it produces smaller output. + ReusePolicyAllow ReusePolicy = iota + + // ReusePolicyPrefer will re-use aggressively if possible. + // This will not check if a new table will produce smaller output, + // except if the current table is impossible to use or + // compressed output is bigger than input. + ReusePolicyPrefer + + // ReusePolicyNone will disable re-use of tables. + // This is slightly faster than ReusePolicyAllow but may produce larger output. + ReusePolicyNone +) + +type Scratch struct { + count [maxSymbolValue + 1]uint32 + + // Per block parameters. + // These can be used to override compression parameters of the block. + // Do not touch, unless you know what you are doing. + + // Out is output buffer. + // If the scratch is re-used before the caller is done processing the output, + // set this field to nil. + // Otherwise the output buffer will be re-used for next Compression/Decompression step + // and allocation will be avoided. + Out []byte + + // OutTable will contain the table data only, if a new table has been generated. + // Slice of the returned data. + OutTable []byte + + // OutData will contain the compressed data. + // Slice of the returned data. + OutData []byte + + // MaxSymbolValue will override the maximum symbol value of the next block. + MaxSymbolValue uint8 + + // TableLog will attempt to override the tablelog for the next block. + // Must be <= 11. + TableLog uint8 + + // Reuse will specify the reuse policy + Reuse ReusePolicy + + br byteReader + symbolLen uint16 // Length of active part of the symbol table. + maxCount int // count of the most probable symbol + clearCount bool // clear count + actualTableLog uint8 // Selected tablelog. + prevTable cTable // Table used for previous compression. + cTable cTable // compression table + dt dTable // decompression table + nodes []nodeElt + tmpOut [4][]byte + fse *fse.Scratch + huffWeight [maxSymbolValue + 1]byte +} + +func (s *Scratch) prepare(in []byte) (*Scratch, error) { + if len(in) > BlockSizeMax { + return nil, ErrTooBig + } + if s == nil { + s = &Scratch{} + } + if s.MaxSymbolValue == 0 { + s.MaxSymbolValue = maxSymbolValue + } + if s.TableLog == 0 { + s.TableLog = tableLogDefault + } + if s.TableLog > tableLogMax { + return nil, fmt.Errorf("tableLog (%d) > maxTableLog (%d)", s.TableLog, tableLogMax) + } + if s.clearCount && s.maxCount == 0 { + for i := range s.count { + s.count[i] = 0 + } + s.clearCount = false + } + if cap(s.Out) == 0 { + s.Out = make([]byte, 0, len(in)) + } + s.Out = s.Out[:0] + + s.OutTable = nil + s.OutData = nil + if cap(s.nodes) < huffNodesLen+1 { + s.nodes = make([]nodeElt, 0, huffNodesLen+1) + } + s.nodes = s.nodes[:0] + if s.fse == nil { + s.fse = &fse.Scratch{} + } + s.br.init(in) + + return s, nil +} + +type cTable []cTableEntry + +func (c cTable) write(s *Scratch) error { + var ( + // precomputed conversion table + bitsToWeight [tableLogMax + 1]byte + huffLog = s.actualTableLog + // last weight is not saved. + maxSymbolValue = uint8(s.symbolLen - 1) + huffWeight = s.huffWeight[:256] + ) + const ( + maxFSETableLog = 6 + ) + // convert to weight + bitsToWeight[0] = 0 + for n := uint8(1); n < huffLog+1; n++ { + bitsToWeight[n] = huffLog + 1 - n + } + + // Acquire histogram for FSE. + hist := s.fse.Histogram() + hist = hist[:256] + for i := range hist[:16] { + hist[i] = 0 + } + for n := uint8(0); n < maxSymbolValue; n++ { + v := bitsToWeight[c[n].nBits] & 15 + huffWeight[n] = v + hist[v]++ + } + + // FSE compress if feasible. + if maxSymbolValue >= 2 { + huffMaxCnt := uint32(0) + huffMax := uint8(0) + for i, v := range hist[:16] { + if v == 0 { + continue + } + huffMax = byte(i) + if v > huffMaxCnt { + huffMaxCnt = v + } + } + s.fse.HistogramFinished(huffMax, int(huffMaxCnt)) + s.fse.TableLog = maxFSETableLog + b, err := fse.Compress(huffWeight[:maxSymbolValue], s.fse) + if err == nil && len(b) < int(s.symbolLen>>1) { + s.Out = append(s.Out, uint8(len(b))) + s.Out = append(s.Out, b...) + return nil + } + // Unable to compress (RLE/uncompressible) + } + // write raw values as 4-bits (max : 15) + if maxSymbolValue > (256 - 128) { + // should not happen : likely means source cannot be compressed + return ErrIncompressible + } + op := s.Out + // special case, pack weights 4 bits/weight. + op = append(op, 128|(maxSymbolValue-1)) + // be sure it doesn't cause msan issue in final combination + huffWeight[maxSymbolValue] = 0 + for n := uint16(0); n < uint16(maxSymbolValue); n += 2 { + op = append(op, (huffWeight[n]<<4)|huffWeight[n+1]) + } + s.Out = op + return nil +} + +// estimateSize returns the estimated size in bytes of the input represented in the +// histogram supplied. +func (c cTable) estimateSize(hist []uint32) int { + nbBits := uint32(7) + for i, v := range c[:len(hist)] { + nbBits += uint32(v.nBits) * hist[i] + } + return int(nbBits >> 3) +} + +// minSize returns the minimum possible size considering the shannon limit. +func (s *Scratch) minSize(total int) int { + nbBits := float64(7) + fTotal := float64(total) + for _, v := range s.count[:s.symbolLen] { + n := float64(v) + if n > 0 { + nbBits += math.Log2(fTotal/n) * n + } + } + return int(nbBits) >> 3 +} + +func highBit32(val uint32) (n uint32) { + return uint32(bits.Len32(val) - 1) +} diff --git a/vendor/github.com/klauspost/compress/snappy/.gitignore b/vendor/github.com/klauspost/compress/snappy/.gitignore new file mode 100644 index 000000000..042091d9b --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/.gitignore @@ -0,0 +1,16 @@ +cmd/snappytool/snappytool +testdata/bench + +# These explicitly listed benchmark data files are for an obsolete version of +# snappy_test.go. +testdata/alice29.txt +testdata/asyoulik.txt +testdata/fireworks.jpeg +testdata/geo.protodata +testdata/html +testdata/html_x_4 +testdata/kppkn.gtb +testdata/lcet10.txt +testdata/paper-100k.pdf +testdata/plrabn12.txt +testdata/urls.10K diff --git a/vendor/github.com/klauspost/compress/snappy/AUTHORS b/vendor/github.com/klauspost/compress/snappy/AUTHORS new file mode 100644 index 000000000..bcfa19520 --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/AUTHORS @@ -0,0 +1,15 @@ +# This is the official list of Snappy-Go authors for copyright purposes. +# This file is distinct from the CONTRIBUTORS files. +# See the latter for an explanation. + +# Names should be added to this file as +# Name or Organization <email address> +# The email address is not required for organizations. + +# Please keep the list sorted. + +Damian Gryski <dgryski@gmail.com> +Google Inc. +Jan Mercl <0xjnml@gmail.com> +Rodolfo Carvalho <rhcarvalho@gmail.com> +Sebastien Binet <seb.binet@gmail.com> diff --git a/vendor/github.com/klauspost/compress/snappy/CONTRIBUTORS b/vendor/github.com/klauspost/compress/snappy/CONTRIBUTORS new file mode 100644 index 000000000..931ae3160 --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/CONTRIBUTORS @@ -0,0 +1,37 @@ +# This is the official list of people who can contribute +# (and typically have contributed) code to the Snappy-Go repository. +# The AUTHORS file lists the copyright holders; this file +# lists people. For example, Google employees are listed here +# but not in AUTHORS, because Google holds the copyright. +# +# The submission process automatically checks to make sure +# that people submitting code are listed in this file (by email address). +# +# Names should be added to this file only after verifying that +# the individual or the individual's organization has agreed to +# the appropriate Contributor License Agreement, found here: +# +# http://code.google.com/legal/individual-cla-v1.0.html +# http://code.google.com/legal/corporate-cla-v1.0.html +# +# The agreement for individuals can be filled out on the web. +# +# When adding J Random Contributor's name to this file, +# either J's name or J's organization's name should be +# added to the AUTHORS file, depending on whether the +# individual or corporate CLA was used. + +# Names should be added to this file like so: +# Name <email address> + +# Please keep the list sorted. + +Damian Gryski <dgryski@gmail.com> +Jan Mercl <0xjnml@gmail.com> +Kai Backman <kaib@golang.org> +Marc-Antoine Ruel <maruel@chromium.org> +Nigel Tao <nigeltao@golang.org> +Rob Pike <r@golang.org> +Rodolfo Carvalho <rhcarvalho@gmail.com> +Russ Cox <rsc@golang.org> +Sebastien Binet <seb.binet@gmail.com> diff --git a/vendor/github.com/klauspost/compress/snappy/LICENSE b/vendor/github.com/klauspost/compress/snappy/LICENSE new file mode 100644 index 000000000..6050c10f4 --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/LICENSE @@ -0,0 +1,27 @@ +Copyright (c) 2011 The Snappy-Go Authors. All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + + * Redistributions of source code must retain the above copyright +notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above +copyright notice, this list of conditions and the following disclaimer +in the documentation and/or other materials provided with the +distribution. + * Neither the name of Google Inc. nor the names of its +contributors may be used to endorse or promote products derived from +this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/vendor/github.com/klauspost/compress/snappy/README b/vendor/github.com/klauspost/compress/snappy/README new file mode 100644 index 000000000..cea12879a --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/README @@ -0,0 +1,107 @@ +The Snappy compression format in the Go programming language. + +To download and install from source: +$ go get github.com/golang/snappy + +Unless otherwise noted, the Snappy-Go source files are distributed +under the BSD-style license found in the LICENSE file. + + + +Benchmarks. + +The golang/snappy benchmarks include compressing (Z) and decompressing (U) ten +or so files, the same set used by the C++ Snappy code (github.com/google/snappy +and note the "google", not "golang"). On an "Intel(R) Core(TM) i7-3770 CPU @ +3.40GHz", Go's GOARCH=amd64 numbers as of 2016-05-29: + +"go test -test.bench=." + +_UFlat0-8 2.19GB/s ± 0% html +_UFlat1-8 1.41GB/s ± 0% urls +_UFlat2-8 23.5GB/s ± 2% jpg +_UFlat3-8 1.91GB/s ± 0% jpg_200 +_UFlat4-8 14.0GB/s ± 1% pdf +_UFlat5-8 1.97GB/s ± 0% html4 +_UFlat6-8 814MB/s ± 0% txt1 +_UFlat7-8 785MB/s ± 0% txt2 +_UFlat8-8 857MB/s ± 0% txt3 +_UFlat9-8 719MB/s ± 1% txt4 +_UFlat10-8 2.84GB/s ± 0% pb +_UFlat11-8 1.05GB/s ± 0% gaviota + +_ZFlat0-8 1.04GB/s ± 0% html +_ZFlat1-8 534MB/s ± 0% urls +_ZFlat2-8 15.7GB/s ± 1% jpg +_ZFlat3-8 740MB/s ± 3% jpg_200 +_ZFlat4-8 9.20GB/s ± 1% pdf +_ZFlat5-8 991MB/s ± 0% html4 +_ZFlat6-8 379MB/s ± 0% txt1 +_ZFlat7-8 352MB/s ± 0% txt2 +_ZFlat8-8 396MB/s ± 1% txt3 +_ZFlat9-8 327MB/s ± 1% txt4 +_ZFlat10-8 1.33GB/s ± 1% pb +_ZFlat11-8 605MB/s ± 1% gaviota + + + +"go test -test.bench=. -tags=noasm" + +_UFlat0-8 621MB/s ± 2% html +_UFlat1-8 494MB/s ± 1% urls +_UFlat2-8 23.2GB/s ± 1% jpg +_UFlat3-8 1.12GB/s ± 1% jpg_200 +_UFlat4-8 4.35GB/s ± 1% pdf +_UFlat5-8 609MB/s ± 0% html4 +_UFlat6-8 296MB/s ± 0% txt1 +_UFlat7-8 288MB/s ± 0% txt2 +_UFlat8-8 309MB/s ± 1% txt3 +_UFlat9-8 280MB/s ± 1% txt4 +_UFlat10-8 753MB/s ± 0% pb +_UFlat11-8 400MB/s ± 0% gaviota + +_ZFlat0-8 409MB/s ± 1% html +_ZFlat1-8 250MB/s ± 1% urls +_ZFlat2-8 12.3GB/s ± 1% jpg +_ZFlat3-8 132MB/s ± 0% jpg_200 +_ZFlat4-8 2.92GB/s ± 0% pdf +_ZFlat5-8 405MB/s ± 1% html4 +_ZFlat6-8 179MB/s ± 1% txt1 +_ZFlat7-8 170MB/s ± 1% txt2 +_ZFlat8-8 189MB/s ± 1% txt3 +_ZFlat9-8 164MB/s ± 1% txt4 +_ZFlat10-8 479MB/s ± 1% pb +_ZFlat11-8 270MB/s ± 1% gaviota + + + +For comparison (Go's encoded output is byte-for-byte identical to C++'s), here +are the numbers from C++ Snappy's + +make CXXFLAGS="-O2 -DNDEBUG -g" clean snappy_unittest.log && cat snappy_unittest.log + +BM_UFlat/0 2.4GB/s html +BM_UFlat/1 1.4GB/s urls +BM_UFlat/2 21.8GB/s jpg +BM_UFlat/3 1.5GB/s jpg_200 +BM_UFlat/4 13.3GB/s pdf +BM_UFlat/5 2.1GB/s html4 +BM_UFlat/6 1.0GB/s txt1 +BM_UFlat/7 959.4MB/s txt2 +BM_UFlat/8 1.0GB/s txt3 +BM_UFlat/9 864.5MB/s txt4 +BM_UFlat/10 2.9GB/s pb +BM_UFlat/11 1.2GB/s gaviota + +BM_ZFlat/0 944.3MB/s html (22.31 %) +BM_ZFlat/1 501.6MB/s urls (47.78 %) +BM_ZFlat/2 14.3GB/s jpg (99.95 %) +BM_ZFlat/3 538.3MB/s jpg_200 (73.00 %) +BM_ZFlat/4 8.3GB/s pdf (83.30 %) +BM_ZFlat/5 903.5MB/s html4 (22.52 %) +BM_ZFlat/6 336.0MB/s txt1 (57.88 %) +BM_ZFlat/7 312.3MB/s txt2 (61.91 %) +BM_ZFlat/8 353.1MB/s txt3 (54.99 %) +BM_ZFlat/9 289.9MB/s txt4 (66.26 %) +BM_ZFlat/10 1.2GB/s pb (19.68 %) +BM_ZFlat/11 527.4MB/s gaviota (37.72 %) diff --git a/vendor/github.com/klauspost/compress/snappy/decode.go b/vendor/github.com/klauspost/compress/snappy/decode.go new file mode 100644 index 000000000..72efb0353 --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/decode.go @@ -0,0 +1,237 @@ +// Copyright 2011 The Snappy-Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package snappy + +import ( + "encoding/binary" + "errors" + "io" +) + +var ( + // ErrCorrupt reports that the input is invalid. + ErrCorrupt = errors.New("snappy: corrupt input") + // ErrTooLarge reports that the uncompressed length is too large. + ErrTooLarge = errors.New("snappy: decoded block is too large") + // ErrUnsupported reports that the input isn't supported. + ErrUnsupported = errors.New("snappy: unsupported input") + + errUnsupportedLiteralLength = errors.New("snappy: unsupported literal length") +) + +// DecodedLen returns the length of the decoded block. +func DecodedLen(src []byte) (int, error) { + v, _, err := decodedLen(src) + return v, err +} + +// decodedLen returns the length of the decoded block and the number of bytes +// that the length header occupied. +func decodedLen(src []byte) (blockLen, headerLen int, err error) { + v, n := binary.Uvarint(src) + if n <= 0 || v > 0xffffffff { + return 0, 0, ErrCorrupt + } + + const wordSize = 32 << (^uint(0) >> 32 & 1) + if wordSize == 32 && v > 0x7fffffff { + return 0, 0, ErrTooLarge + } + return int(v), n, nil +} + +const ( + decodeErrCodeCorrupt = 1 + decodeErrCodeUnsupportedLiteralLength = 2 +) + +// Decode returns the decoded form of src. The returned slice may be a sub- +// slice of dst if dst was large enough to hold the entire decoded block. +// Otherwise, a newly allocated slice will be returned. +// +// The dst and src must not overlap. It is valid to pass a nil dst. +func Decode(dst, src []byte) ([]byte, error) { + dLen, s, err := decodedLen(src) + if err != nil { + return nil, err + } + if dLen <= len(dst) { + dst = dst[:dLen] + } else { + dst = make([]byte, dLen) + } + switch decode(dst, src[s:]) { + case 0: + return dst, nil + case decodeErrCodeUnsupportedLiteralLength: + return nil, errUnsupportedLiteralLength + } + return nil, ErrCorrupt +} + +// NewReader returns a new Reader that decompresses from r, using the framing +// format described at +// https://github.com/google/snappy/blob/master/framing_format.txt +func NewReader(r io.Reader) *Reader { + return &Reader{ + r: r, + decoded: make([]byte, maxBlockSize), + buf: make([]byte, maxEncodedLenOfMaxBlockSize+checksumSize), + } +} + +// Reader is an io.Reader that can read Snappy-compressed bytes. +type Reader struct { + r io.Reader + err error + decoded []byte + buf []byte + // decoded[i:j] contains decoded bytes that have not yet been passed on. + i, j int + readHeader bool +} + +// Reset discards any buffered data, resets all state, and switches the Snappy +// reader to read from r. This permits reusing a Reader rather than allocating +// a new one. +func (r *Reader) Reset(reader io.Reader) { + r.r = reader + r.err = nil + r.i = 0 + r.j = 0 + r.readHeader = false +} + +func (r *Reader) readFull(p []byte, allowEOF bool) (ok bool) { + if _, r.err = io.ReadFull(r.r, p); r.err != nil { + if r.err == io.ErrUnexpectedEOF || (r.err == io.EOF && !allowEOF) { + r.err = ErrCorrupt + } + return false + } + return true +} + +// Read satisfies the io.Reader interface. +func (r *Reader) Read(p []byte) (int, error) { + if r.err != nil { + return 0, r.err + } + for { + if r.i < r.j { + n := copy(p, r.decoded[r.i:r.j]) + r.i += n + return n, nil + } + if !r.readFull(r.buf[:4], true) { + return 0, r.err + } + chunkType := r.buf[0] + if !r.readHeader { + if chunkType != chunkTypeStreamIdentifier { + r.err = ErrCorrupt + return 0, r.err + } + r.readHeader = true + } + chunkLen := int(r.buf[1]) | int(r.buf[2])<<8 | int(r.buf[3])<<16 + if chunkLen > len(r.buf) { + r.err = ErrUnsupported + return 0, r.err + } + + // The chunk types are specified at + // https://github.com/google/snappy/blob/master/framing_format.txt + switch chunkType { + case chunkTypeCompressedData: + // Section 4.2. Compressed data (chunk type 0x00). + if chunkLen < checksumSize { + r.err = ErrCorrupt + return 0, r.err + } + buf := r.buf[:chunkLen] + if !r.readFull(buf, false) { + return 0, r.err + } + checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24 + buf = buf[checksumSize:] + + n, err := DecodedLen(buf) + if err != nil { + r.err = err + return 0, r.err + } + if n > len(r.decoded) { + r.err = ErrCorrupt + return 0, r.err + } + if _, err := Decode(r.decoded, buf); err != nil { + r.err = err + return 0, r.err + } + if crc(r.decoded[:n]) != checksum { + r.err = ErrCorrupt + return 0, r.err + } + r.i, r.j = 0, n + continue + + case chunkTypeUncompressedData: + // Section 4.3. Uncompressed data (chunk type 0x01). + if chunkLen < checksumSize { + r.err = ErrCorrupt + return 0, r.err + } + buf := r.buf[:checksumSize] + if !r.readFull(buf, false) { + return 0, r.err + } + checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24 + // Read directly into r.decoded instead of via r.buf. + n := chunkLen - checksumSize + if n > len(r.decoded) { + r.err = ErrCorrupt + return 0, r.err + } + if !r.readFull(r.decoded[:n], false) { + return 0, r.err + } + if crc(r.decoded[:n]) != checksum { + r.err = ErrCorrupt + return 0, r.err + } + r.i, r.j = 0, n + continue + + case chunkTypeStreamIdentifier: + // Section 4.1. Stream identifier (chunk type 0xff). + if chunkLen != len(magicBody) { + r.err = ErrCorrupt + return 0, r.err + } + if !r.readFull(r.buf[:len(magicBody)], false) { + return 0, r.err + } + for i := 0; i < len(magicBody); i++ { + if r.buf[i] != magicBody[i] { + r.err = ErrCorrupt + return 0, r.err + } + } + continue + } + + if chunkType <= 0x7f { + // Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f). + r.err = ErrUnsupported + return 0, r.err + } + // Section 4.4 Padding (chunk type 0xfe). + // Section 4.6. Reserved skippable chunks (chunk types 0x80-0xfd). + if !r.readFull(r.buf[:chunkLen], false) { + return 0, r.err + } + } +} diff --git a/vendor/github.com/klauspost/compress/snappy/decode_amd64.go b/vendor/github.com/klauspost/compress/snappy/decode_amd64.go new file mode 100644 index 000000000..fcd192b84 --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/decode_amd64.go @@ -0,0 +1,14 @@ +// Copyright 2016 The Snappy-Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !appengine +// +build gc +// +build !noasm + +package snappy + +// decode has the same semantics as in decode_other.go. +// +//go:noescape +func decode(dst, src []byte) int diff --git a/vendor/github.com/klauspost/compress/snappy/decode_amd64.s b/vendor/github.com/klauspost/compress/snappy/decode_amd64.s new file mode 100644 index 000000000..e6179f65e --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/decode_amd64.s @@ -0,0 +1,490 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !appengine +// +build gc +// +build !noasm + +#include "textflag.h" + +// The asm code generally follows the pure Go code in decode_other.go, except +// where marked with a "!!!". + +// func decode(dst, src []byte) int +// +// All local variables fit into registers. The non-zero stack size is only to +// spill registers and push args when issuing a CALL. The register allocation: +// - AX scratch +// - BX scratch +// - CX length or x +// - DX offset +// - SI &src[s] +// - DI &dst[d] +// + R8 dst_base +// + R9 dst_len +// + R10 dst_base + dst_len +// + R11 src_base +// + R12 src_len +// + R13 src_base + src_len +// - R14 used by doCopy +// - R15 used by doCopy +// +// The registers R8-R13 (marked with a "+") are set at the start of the +// function, and after a CALL returns, and are not otherwise modified. +// +// The d variable is implicitly DI - R8, and len(dst)-d is R10 - DI. +// The s variable is implicitly SI - R11, and len(src)-s is R13 - SI. +TEXT ·decode(SB), NOSPLIT, $48-56 + // Initialize SI, DI and R8-R13. + MOVQ dst_base+0(FP), R8 + MOVQ dst_len+8(FP), R9 + MOVQ R8, DI + MOVQ R8, R10 + ADDQ R9, R10 + MOVQ src_base+24(FP), R11 + MOVQ src_len+32(FP), R12 + MOVQ R11, SI + MOVQ R11, R13 + ADDQ R12, R13 + +loop: + // for s < len(src) + CMPQ SI, R13 + JEQ end + + // CX = uint32(src[s]) + // + // switch src[s] & 0x03 + MOVBLZX (SI), CX + MOVL CX, BX + ANDL $3, BX + CMPL BX, $1 + JAE tagCopy + + // ---------------------------------------- + // The code below handles literal tags. + + // case tagLiteral: + // x := uint32(src[s] >> 2) + // switch + SHRL $2, CX + CMPL CX, $60 + JAE tagLit60Plus + + // case x < 60: + // s++ + INCQ SI + +doLit: + // This is the end of the inner "switch", when we have a literal tag. + // + // We assume that CX == x and x fits in a uint32, where x is the variable + // used in the pure Go decode_other.go code. + + // length = int(x) + 1 + // + // Unlike the pure Go code, we don't need to check if length <= 0 because + // CX can hold 64 bits, so the increment cannot overflow. + INCQ CX + + // Prepare to check if copying length bytes will run past the end of dst or + // src. + // + // AX = len(dst) - d + // BX = len(src) - s + MOVQ R10, AX + SUBQ DI, AX + MOVQ R13, BX + SUBQ SI, BX + + // !!! Try a faster technique for short (16 or fewer bytes) copies. + // + // if length > 16 || len(dst)-d < 16 || len(src)-s < 16 { + // goto callMemmove // Fall back on calling runtime·memmove. + // } + // + // The C++ snappy code calls this TryFastAppend. It also checks len(src)-s + // against 21 instead of 16, because it cannot assume that all of its input + // is contiguous in memory and so it needs to leave enough source bytes to + // read the next tag without refilling buffers, but Go's Decode assumes + // contiguousness (the src argument is a []byte). + CMPQ CX, $16 + JGT callMemmove + CMPQ AX, $16 + JLT callMemmove + CMPQ BX, $16 + JLT callMemmove + + // !!! Implement the copy from src to dst as a 16-byte load and store. + // (Decode's documentation says that dst and src must not overlap.) + // + // This always copies 16 bytes, instead of only length bytes, but that's + // OK. If the input is a valid Snappy encoding then subsequent iterations + // will fix up the overrun. Otherwise, Decode returns a nil []byte (and a + // non-nil error), so the overrun will be ignored. + // + // Note that on amd64, it is legal and cheap to issue unaligned 8-byte or + // 16-byte loads and stores. This technique probably wouldn't be as + // effective on architectures that are fussier about alignment. + MOVOU 0(SI), X0 + MOVOU X0, 0(DI) + + // d += length + // s += length + ADDQ CX, DI + ADDQ CX, SI + JMP loop + +callMemmove: + // if length > len(dst)-d || length > len(src)-s { etc } + CMPQ CX, AX + JGT errCorrupt + CMPQ CX, BX + JGT errCorrupt + + // copy(dst[d:], src[s:s+length]) + // + // This means calling runtime·memmove(&dst[d], &src[s], length), so we push + // DI, SI and CX as arguments. Coincidentally, we also need to spill those + // three registers to the stack, to save local variables across the CALL. + MOVQ DI, 0(SP) + MOVQ SI, 8(SP) + MOVQ CX, 16(SP) + MOVQ DI, 24(SP) + MOVQ SI, 32(SP) + MOVQ CX, 40(SP) + CALL runtime·memmove(SB) + + // Restore local variables: unspill registers from the stack and + // re-calculate R8-R13. + MOVQ 24(SP), DI + MOVQ 32(SP), SI + MOVQ 40(SP), CX + MOVQ dst_base+0(FP), R8 + MOVQ dst_len+8(FP), R9 + MOVQ R8, R10 + ADDQ R9, R10 + MOVQ src_base+24(FP), R11 + MOVQ src_len+32(FP), R12 + MOVQ R11, R13 + ADDQ R12, R13 + + // d += length + // s += length + ADDQ CX, DI + ADDQ CX, SI + JMP loop + +tagLit60Plus: + // !!! This fragment does the + // + // s += x - 58; if uint(s) > uint(len(src)) { etc } + // + // checks. In the asm version, we code it once instead of once per switch case. + ADDQ CX, SI + SUBQ $58, SI + MOVQ SI, BX + SUBQ R11, BX + CMPQ BX, R12 + JA errCorrupt + + // case x == 60: + CMPL CX, $61 + JEQ tagLit61 + JA tagLit62Plus + + // x = uint32(src[s-1]) + MOVBLZX -1(SI), CX + JMP doLit + +tagLit61: + // case x == 61: + // x = uint32(src[s-2]) | uint32(src[s-1])<<8 + MOVWLZX -2(SI), CX + JMP doLit + +tagLit62Plus: + CMPL CX, $62 + JA tagLit63 + + // case x == 62: + // x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16 + MOVWLZX -3(SI), CX + MOVBLZX -1(SI), BX + SHLL $16, BX + ORL BX, CX + JMP doLit + +tagLit63: + // case x == 63: + // x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24 + MOVL -4(SI), CX + JMP doLit + +// The code above handles literal tags. +// ---------------------------------------- +// The code below handles copy tags. + +tagCopy4: + // case tagCopy4: + // s += 5 + ADDQ $5, SI + + // if uint(s) > uint(len(src)) { etc } + MOVQ SI, BX + SUBQ R11, BX + CMPQ BX, R12 + JA errCorrupt + + // length = 1 + int(src[s-5])>>2 + SHRQ $2, CX + INCQ CX + + // offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24) + MOVLQZX -4(SI), DX + JMP doCopy + +tagCopy2: + // case tagCopy2: + // s += 3 + ADDQ $3, SI + + // if uint(s) > uint(len(src)) { etc } + MOVQ SI, BX + SUBQ R11, BX + CMPQ BX, R12 + JA errCorrupt + + // length = 1 + int(src[s-3])>>2 + SHRQ $2, CX + INCQ CX + + // offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8) + MOVWQZX -2(SI), DX + JMP doCopy + +tagCopy: + // We have a copy tag. We assume that: + // - BX == src[s] & 0x03 + // - CX == src[s] + CMPQ BX, $2 + JEQ tagCopy2 + JA tagCopy4 + + // case tagCopy1: + // s += 2 + ADDQ $2, SI + + // if uint(s) > uint(len(src)) { etc } + MOVQ SI, BX + SUBQ R11, BX + CMPQ BX, R12 + JA errCorrupt + + // offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1])) + MOVQ CX, DX + ANDQ $0xe0, DX + SHLQ $3, DX + MOVBQZX -1(SI), BX + ORQ BX, DX + + // length = 4 + int(src[s-2])>>2&0x7 + SHRQ $2, CX + ANDQ $7, CX + ADDQ $4, CX + +doCopy: + // This is the end of the outer "switch", when we have a copy tag. + // + // We assume that: + // - CX == length && CX > 0 + // - DX == offset + + // if offset <= 0 { etc } + CMPQ DX, $0 + JLE errCorrupt + + // if d < offset { etc } + MOVQ DI, BX + SUBQ R8, BX + CMPQ BX, DX + JLT errCorrupt + + // if length > len(dst)-d { etc } + MOVQ R10, BX + SUBQ DI, BX + CMPQ CX, BX + JGT errCorrupt + + // forwardCopy(dst[d:d+length], dst[d-offset:]); d += length + // + // Set: + // - R14 = len(dst)-d + // - R15 = &dst[d-offset] + MOVQ R10, R14 + SUBQ DI, R14 + MOVQ DI, R15 + SUBQ DX, R15 + + // !!! Try a faster technique for short (16 or fewer bytes) forward copies. + // + // First, try using two 8-byte load/stores, similar to the doLit technique + // above. Even if dst[d:d+length] and dst[d-offset:] can overlap, this is + // still OK if offset >= 8. Note that this has to be two 8-byte load/stores + // and not one 16-byte load/store, and the first store has to be before the + // second load, due to the overlap if offset is in the range [8, 16). + // + // if length > 16 || offset < 8 || len(dst)-d < 16 { + // goto slowForwardCopy + // } + // copy 16 bytes + // d += length + CMPQ CX, $16 + JGT slowForwardCopy + CMPQ DX, $8 + JLT slowForwardCopy + CMPQ R14, $16 + JLT slowForwardCopy + MOVQ 0(R15), AX + MOVQ AX, 0(DI) + MOVQ 8(R15), BX + MOVQ BX, 8(DI) + ADDQ CX, DI + JMP loop + +slowForwardCopy: + // !!! If the forward copy is longer than 16 bytes, or if offset < 8, we + // can still try 8-byte load stores, provided we can overrun up to 10 extra + // bytes. As above, the overrun will be fixed up by subsequent iterations + // of the outermost loop. + // + // The C++ snappy code calls this technique IncrementalCopyFastPath. Its + // commentary says: + // + // ---- + // + // The main part of this loop is a simple copy of eight bytes at a time + // until we've copied (at least) the requested amount of bytes. However, + // if d and d-offset are less than eight bytes apart (indicating a + // repeating pattern of length < 8), we first need to expand the pattern in + // order to get the correct results. For instance, if the buffer looks like + // this, with the eight-byte <d-offset> and <d> patterns marked as + // intervals: + // + // abxxxxxxxxxxxx + // [------] d-offset + // [------] d + // + // a single eight-byte copy from <d-offset> to <d> will repeat the pattern + // once, after which we can move <d> two bytes without moving <d-offset>: + // + // ababxxxxxxxxxx + // [------] d-offset + // [------] d + // + // and repeat the exercise until the two no longer overlap. + // + // This allows us to do very well in the special case of one single byte + // repeated many times, without taking a big hit for more general cases. + // + // The worst case of extra writing past the end of the match occurs when + // offset == 1 and length == 1; the last copy will read from byte positions + // [0..7] and write to [4..11], whereas it was only supposed to write to + // position 1. Thus, ten excess bytes. + // + // ---- + // + // That "10 byte overrun" worst case is confirmed by Go's + // TestSlowForwardCopyOverrun, which also tests the fixUpSlowForwardCopy + // and finishSlowForwardCopy algorithm. + // + // if length > len(dst)-d-10 { + // goto verySlowForwardCopy + // } + SUBQ $10, R14 + CMPQ CX, R14 + JGT verySlowForwardCopy + +makeOffsetAtLeast8: + // !!! As above, expand the pattern so that offset >= 8 and we can use + // 8-byte load/stores. + // + // for offset < 8 { + // copy 8 bytes from dst[d-offset:] to dst[d:] + // length -= offset + // d += offset + // offset += offset + // // The two previous lines together means that d-offset, and therefore + // // R15, is unchanged. + // } + CMPQ DX, $8 + JGE fixUpSlowForwardCopy + MOVQ (R15), BX + MOVQ BX, (DI) + SUBQ DX, CX + ADDQ DX, DI + ADDQ DX, DX + JMP makeOffsetAtLeast8 + +fixUpSlowForwardCopy: + // !!! Add length (which might be negative now) to d (implied by DI being + // &dst[d]) so that d ends up at the right place when we jump back to the + // top of the loop. Before we do that, though, we save DI to AX so that, if + // length is positive, copying the remaining length bytes will write to the + // right place. + MOVQ DI, AX + ADDQ CX, DI + +finishSlowForwardCopy: + // !!! Repeat 8-byte load/stores until length <= 0. Ending with a negative + // length means that we overrun, but as above, that will be fixed up by + // subsequent iterations of the outermost loop. + CMPQ CX, $0 + JLE loop + MOVQ (R15), BX + MOVQ BX, (AX) + ADDQ $8, R15 + ADDQ $8, AX + SUBQ $8, CX + JMP finishSlowForwardCopy + +verySlowForwardCopy: + // verySlowForwardCopy is a simple implementation of forward copy. In C + // parlance, this is a do/while loop instead of a while loop, since we know + // that length > 0. In Go syntax: + // + // for { + // dst[d] = dst[d - offset] + // d++ + // length-- + // if length == 0 { + // break + // } + // } + MOVB (R15), BX + MOVB BX, (DI) + INCQ R15 + INCQ DI + DECQ CX + JNZ verySlowForwardCopy + JMP loop + +// The code above handles copy tags. +// ---------------------------------------- + +end: + // This is the end of the "for s < len(src)". + // + // if d != len(dst) { etc } + CMPQ DI, R10 + JNE errCorrupt + + // return 0 + MOVQ $0, ret+48(FP) + RET + +errCorrupt: + // return decodeErrCodeCorrupt + MOVQ $1, ret+48(FP) + RET diff --git a/vendor/github.com/klauspost/compress/snappy/decode_other.go b/vendor/github.com/klauspost/compress/snappy/decode_other.go new file mode 100644 index 000000000..8c9f2049b --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/decode_other.go @@ -0,0 +1,101 @@ +// Copyright 2016 The Snappy-Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !amd64 appengine !gc noasm + +package snappy + +// decode writes the decoding of src to dst. It assumes that the varint-encoded +// length of the decompressed bytes has already been read, and that len(dst) +// equals that length. +// +// It returns 0 on success or a decodeErrCodeXxx error code on failure. +func decode(dst, src []byte) int { + var d, s, offset, length int + for s < len(src) { + switch src[s] & 0x03 { + case tagLiteral: + x := uint32(src[s] >> 2) + switch { + case x < 60: + s++ + case x == 60: + s += 2 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + return decodeErrCodeCorrupt + } + x = uint32(src[s-1]) + case x == 61: + s += 3 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + return decodeErrCodeCorrupt + } + x = uint32(src[s-2]) | uint32(src[s-1])<<8 + case x == 62: + s += 4 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + return decodeErrCodeCorrupt + } + x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16 + case x == 63: + s += 5 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + return decodeErrCodeCorrupt + } + x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24 + } + length = int(x) + 1 + if length <= 0 { + return decodeErrCodeUnsupportedLiteralLength + } + if length > len(dst)-d || length > len(src)-s { + return decodeErrCodeCorrupt + } + copy(dst[d:], src[s:s+length]) + d += length + s += length + continue + + case tagCopy1: + s += 2 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + return decodeErrCodeCorrupt + } + length = 4 + int(src[s-2])>>2&0x7 + offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1])) + + case tagCopy2: + s += 3 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + return decodeErrCodeCorrupt + } + length = 1 + int(src[s-3])>>2 + offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8) + + case tagCopy4: + s += 5 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + return decodeErrCodeCorrupt + } + length = 1 + int(src[s-5])>>2 + offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24) + } + + if offset <= 0 || d < offset || length > len(dst)-d { + return decodeErrCodeCorrupt + } + // Copy from an earlier sub-slice of dst to a later sub-slice. Unlike + // the built-in copy function, this byte-by-byte copy always runs + // forwards, even if the slices overlap. Conceptually, this is: + // + // d += forwardCopy(dst[d:d+length], dst[d-offset:]) + for end := d + length; d != end; d++ { + dst[d] = dst[d-offset] + } + } + if d != len(dst) { + return decodeErrCodeCorrupt + } + return 0 +} diff --git a/vendor/github.com/klauspost/compress/snappy/encode.go b/vendor/github.com/klauspost/compress/snappy/encode.go new file mode 100644 index 000000000..8d393e904 --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/encode.go @@ -0,0 +1,285 @@ +// Copyright 2011 The Snappy-Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package snappy + +import ( + "encoding/binary" + "errors" + "io" +) + +// Encode returns the encoded form of src. The returned slice may be a sub- +// slice of dst if dst was large enough to hold the entire encoded block. +// Otherwise, a newly allocated slice will be returned. +// +// The dst and src must not overlap. It is valid to pass a nil dst. +func Encode(dst, src []byte) []byte { + if n := MaxEncodedLen(len(src)); n < 0 { + panic(ErrTooLarge) + } else if len(dst) < n { + dst = make([]byte, n) + } + + // The block starts with the varint-encoded length of the decompressed bytes. + d := binary.PutUvarint(dst, uint64(len(src))) + + for len(src) > 0 { + p := src + src = nil + if len(p) > maxBlockSize { + p, src = p[:maxBlockSize], p[maxBlockSize:] + } + if len(p) < minNonLiteralBlockSize { + d += emitLiteral(dst[d:], p) + } else { + d += encodeBlock(dst[d:], p) + } + } + return dst[:d] +} + +// inputMargin is the minimum number of extra input bytes to keep, inside +// encodeBlock's inner loop. On some architectures, this margin lets us +// implement a fast path for emitLiteral, where the copy of short (<= 16 byte) +// literals can be implemented as a single load to and store from a 16-byte +// register. That literal's actual length can be as short as 1 byte, so this +// can copy up to 15 bytes too much, but that's OK as subsequent iterations of +// the encoding loop will fix up the copy overrun, and this inputMargin ensures +// that we don't overrun the dst and src buffers. +const inputMargin = 16 - 1 + +// minNonLiteralBlockSize is the minimum size of the input to encodeBlock that +// could be encoded with a copy tag. This is the minimum with respect to the +// algorithm used by encodeBlock, not a minimum enforced by the file format. +// +// The encoded output must start with at least a 1 byte literal, as there are +// no previous bytes to copy. A minimal (1 byte) copy after that, generated +// from an emitCopy call in encodeBlock's main loop, would require at least +// another inputMargin bytes, for the reason above: we want any emitLiteral +// calls inside encodeBlock's main loop to use the fast path if possible, which +// requires being able to overrun by inputMargin bytes. Thus, +// minNonLiteralBlockSize equals 1 + 1 + inputMargin. +// +// The C++ code doesn't use this exact threshold, but it could, as discussed at +// https://groups.google.com/d/topic/snappy-compression/oGbhsdIJSJ8/discussion +// The difference between Go (2+inputMargin) and C++ (inputMargin) is purely an +// optimization. It should not affect the encoded form. This is tested by +// TestSameEncodingAsCppShortCopies. +const minNonLiteralBlockSize = 1 + 1 + inputMargin + +// MaxEncodedLen returns the maximum length of a snappy block, given its +// uncompressed length. +// +// It will return a negative value if srcLen is too large to encode. +func MaxEncodedLen(srcLen int) int { + n := uint64(srcLen) + if n > 0xffffffff { + return -1 + } + // Compressed data can be defined as: + // compressed := item* literal* + // item := literal* copy + // + // The trailing literal sequence has a space blowup of at most 62/60 + // since a literal of length 60 needs one tag byte + one extra byte + // for length information. + // + // Item blowup is trickier to measure. Suppose the "copy" op copies + // 4 bytes of data. Because of a special check in the encoding code, + // we produce a 4-byte copy only if the offset is < 65536. Therefore + // the copy op takes 3 bytes to encode, and this type of item leads + // to at most the 62/60 blowup for representing literals. + // + // Suppose the "copy" op copies 5 bytes of data. If the offset is big + // enough, it will take 5 bytes to encode the copy op. Therefore the + // worst case here is a one-byte literal followed by a five-byte copy. + // That is, 6 bytes of input turn into 7 bytes of "compressed" data. + // + // This last factor dominates the blowup, so the final estimate is: + n = 32 + n + n/6 + if n > 0xffffffff { + return -1 + } + return int(n) +} + +var errClosed = errors.New("snappy: Writer is closed") + +// NewWriter returns a new Writer that compresses to w. +// +// The Writer returned does not buffer writes. There is no need to Flush or +// Close such a Writer. +// +// Deprecated: the Writer returned is not suitable for many small writes, only +// for few large writes. Use NewBufferedWriter instead, which is efficient +// regardless of the frequency and shape of the writes, and remember to Close +// that Writer when done. +func NewWriter(w io.Writer) *Writer { + return &Writer{ + w: w, + obuf: make([]byte, obufLen), + } +} + +// NewBufferedWriter returns a new Writer that compresses to w, using the +// framing format described at +// https://github.com/google/snappy/blob/master/framing_format.txt +// +// The Writer returned buffers writes. Users must call Close to guarantee all +// data has been forwarded to the underlying io.Writer. They may also call +// Flush zero or more times before calling Close. +func NewBufferedWriter(w io.Writer) *Writer { + return &Writer{ + w: w, + ibuf: make([]byte, 0, maxBlockSize), + obuf: make([]byte, obufLen), + } +} + +// Writer is an io.Writer that can write Snappy-compressed bytes. +type Writer struct { + w io.Writer + err error + + // ibuf is a buffer for the incoming (uncompressed) bytes. + // + // Its use is optional. For backwards compatibility, Writers created by the + // NewWriter function have ibuf == nil, do not buffer incoming bytes, and + // therefore do not need to be Flush'ed or Close'd. + ibuf []byte + + // obuf is a buffer for the outgoing (compressed) bytes. + obuf []byte + + // wroteStreamHeader is whether we have written the stream header. + wroteStreamHeader bool +} + +// Reset discards the writer's state and switches the Snappy writer to write to +// w. This permits reusing a Writer rather than allocating a new one. +func (w *Writer) Reset(writer io.Writer) { + w.w = writer + w.err = nil + if w.ibuf != nil { + w.ibuf = w.ibuf[:0] + } + w.wroteStreamHeader = false +} + +// Write satisfies the io.Writer interface. +func (w *Writer) Write(p []byte) (nRet int, errRet error) { + if w.ibuf == nil { + // Do not buffer incoming bytes. This does not perform or compress well + // if the caller of Writer.Write writes many small slices. This + // behavior is therefore deprecated, but still supported for backwards + // compatibility with code that doesn't explicitly Flush or Close. + return w.write(p) + } + + // The remainder of this method is based on bufio.Writer.Write from the + // standard library. + + for len(p) > (cap(w.ibuf)-len(w.ibuf)) && w.err == nil { + var n int + if len(w.ibuf) == 0 { + // Large write, empty buffer. + // Write directly from p to avoid copy. + n, _ = w.write(p) + } else { + n = copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p) + w.ibuf = w.ibuf[:len(w.ibuf)+n] + w.Flush() + } + nRet += n + p = p[n:] + } + if w.err != nil { + return nRet, w.err + } + n := copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p) + w.ibuf = w.ibuf[:len(w.ibuf)+n] + nRet += n + return nRet, nil +} + +func (w *Writer) write(p []byte) (nRet int, errRet error) { + if w.err != nil { + return 0, w.err + } + for len(p) > 0 { + obufStart := len(magicChunk) + if !w.wroteStreamHeader { + w.wroteStreamHeader = true + copy(w.obuf, magicChunk) + obufStart = 0 + } + + var uncompressed []byte + if len(p) > maxBlockSize { + uncompressed, p = p[:maxBlockSize], p[maxBlockSize:] + } else { + uncompressed, p = p, nil + } + checksum := crc(uncompressed) + + // Compress the buffer, discarding the result if the improvement + // isn't at least 12.5%. + compressed := Encode(w.obuf[obufHeaderLen:], uncompressed) + chunkType := uint8(chunkTypeCompressedData) + chunkLen := 4 + len(compressed) + obufEnd := obufHeaderLen + len(compressed) + if len(compressed) >= len(uncompressed)-len(uncompressed)/8 { + chunkType = chunkTypeUncompressedData + chunkLen = 4 + len(uncompressed) + obufEnd = obufHeaderLen + } + + // Fill in the per-chunk header that comes before the body. + w.obuf[len(magicChunk)+0] = chunkType + w.obuf[len(magicChunk)+1] = uint8(chunkLen >> 0) + w.obuf[len(magicChunk)+2] = uint8(chunkLen >> 8) + w.obuf[len(magicChunk)+3] = uint8(chunkLen >> 16) + w.obuf[len(magicChunk)+4] = uint8(checksum >> 0) + w.obuf[len(magicChunk)+5] = uint8(checksum >> 8) + w.obuf[len(magicChunk)+6] = uint8(checksum >> 16) + w.obuf[len(magicChunk)+7] = uint8(checksum >> 24) + + if _, err := w.w.Write(w.obuf[obufStart:obufEnd]); err != nil { + w.err = err + return nRet, err + } + if chunkType == chunkTypeUncompressedData { + if _, err := w.w.Write(uncompressed); err != nil { + w.err = err + return nRet, err + } + } + nRet += len(uncompressed) + } + return nRet, nil +} + +// Flush flushes the Writer to its underlying io.Writer. +func (w *Writer) Flush() error { + if w.err != nil { + return w.err + } + if len(w.ibuf) == 0 { + return nil + } + w.write(w.ibuf) + w.ibuf = w.ibuf[:0] + return w.err +} + +// Close calls Flush and then closes the Writer. +func (w *Writer) Close() error { + w.Flush() + ret := w.err + if w.err == nil { + w.err = errClosed + } + return ret +} diff --git a/vendor/github.com/klauspost/compress/snappy/encode_amd64.go b/vendor/github.com/klauspost/compress/snappy/encode_amd64.go new file mode 100644 index 000000000..150d91bc8 --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/encode_amd64.go @@ -0,0 +1,29 @@ +// Copyright 2016 The Snappy-Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !appengine +// +build gc +// +build !noasm + +package snappy + +// emitLiteral has the same semantics as in encode_other.go. +// +//go:noescape +func emitLiteral(dst, lit []byte) int + +// emitCopy has the same semantics as in encode_other.go. +// +//go:noescape +func emitCopy(dst []byte, offset, length int) int + +// extendMatch has the same semantics as in encode_other.go. +// +//go:noescape +func extendMatch(src []byte, i, j int) int + +// encodeBlock has the same semantics as in encode_other.go. +// +//go:noescape +func encodeBlock(dst, src []byte) (d int) diff --git a/vendor/github.com/klauspost/compress/snappy/encode_amd64.s b/vendor/github.com/klauspost/compress/snappy/encode_amd64.s new file mode 100644 index 000000000..adfd979fe --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/encode_amd64.s @@ -0,0 +1,730 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !appengine +// +build gc +// +build !noasm + +#include "textflag.h" + +// The XXX lines assemble on Go 1.4, 1.5 and 1.7, but not 1.6, due to a +// Go toolchain regression. See https://github.com/golang/go/issues/15426 and +// https://github.com/golang/snappy/issues/29 +// +// As a workaround, the package was built with a known good assembler, and +// those instructions were disassembled by "objdump -d" to yield the +// 4e 0f b7 7c 5c 78 movzwq 0x78(%rsp,%r11,2),%r15 +// style comments, in AT&T asm syntax. Note that rsp here is a physical +// register, not Go/asm's SP pseudo-register (see https://golang.org/doc/asm). +// The instructions were then encoded as "BYTE $0x.." sequences, which assemble +// fine on Go 1.6. + +// The asm code generally follows the pure Go code in encode_other.go, except +// where marked with a "!!!". + +// ---------------------------------------------------------------------------- + +// func emitLiteral(dst, lit []byte) int +// +// All local variables fit into registers. The register allocation: +// - AX len(lit) +// - BX n +// - DX return value +// - DI &dst[i] +// - R10 &lit[0] +// +// The 24 bytes of stack space is to call runtime·memmove. +// +// The unusual register allocation of local variables, such as R10 for the +// source pointer, matches the allocation used at the call site in encodeBlock, +// which makes it easier to manually inline this function. +TEXT ·emitLiteral(SB), NOSPLIT, $24-56 + MOVQ dst_base+0(FP), DI + MOVQ lit_base+24(FP), R10 + MOVQ lit_len+32(FP), AX + MOVQ AX, DX + MOVL AX, BX + SUBL $1, BX + + CMPL BX, $60 + JLT oneByte + CMPL BX, $256 + JLT twoBytes + +threeBytes: + MOVB $0xf4, 0(DI) + MOVW BX, 1(DI) + ADDQ $3, DI + ADDQ $3, DX + JMP memmove + +twoBytes: + MOVB $0xf0, 0(DI) + MOVB BX, 1(DI) + ADDQ $2, DI + ADDQ $2, DX + JMP memmove + +oneByte: + SHLB $2, BX + MOVB BX, 0(DI) + ADDQ $1, DI + ADDQ $1, DX + +memmove: + MOVQ DX, ret+48(FP) + + // copy(dst[i:], lit) + // + // This means calling runtime·memmove(&dst[i], &lit[0], len(lit)), so we push + // DI, R10 and AX as arguments. + MOVQ DI, 0(SP) + MOVQ R10, 8(SP) + MOVQ AX, 16(SP) + CALL runtime·memmove(SB) + RET + +// ---------------------------------------------------------------------------- + +// func emitCopy(dst []byte, offset, length int) int +// +// All local variables fit into registers. The register allocation: +// - AX length +// - SI &dst[0] +// - DI &dst[i] +// - R11 offset +// +// The unusual register allocation of local variables, such as R11 for the +// offset, matches the allocation used at the call site in encodeBlock, which +// makes it easier to manually inline this function. +TEXT ·emitCopy(SB), NOSPLIT, $0-48 + MOVQ dst_base+0(FP), DI + MOVQ DI, SI + MOVQ offset+24(FP), R11 + MOVQ length+32(FP), AX + +loop0: + // for length >= 68 { etc } + CMPL AX, $68 + JLT step1 + + // Emit a length 64 copy, encoded as 3 bytes. + MOVB $0xfe, 0(DI) + MOVW R11, 1(DI) + ADDQ $3, DI + SUBL $64, AX + JMP loop0 + +step1: + // if length > 64 { etc } + CMPL AX, $64 + JLE step2 + + // Emit a length 60 copy, encoded as 3 bytes. + MOVB $0xee, 0(DI) + MOVW R11, 1(DI) + ADDQ $3, DI + SUBL $60, AX + +step2: + // if length >= 12 || offset >= 2048 { goto step3 } + CMPL AX, $12 + JGE step3 + CMPL R11, $2048 + JGE step3 + + // Emit the remaining copy, encoded as 2 bytes. + MOVB R11, 1(DI) + SHRL $8, R11 + SHLB $5, R11 + SUBB $4, AX + SHLB $2, AX + ORB AX, R11 + ORB $1, R11 + MOVB R11, 0(DI) + ADDQ $2, DI + + // Return the number of bytes written. + SUBQ SI, DI + MOVQ DI, ret+40(FP) + RET + +step3: + // Emit the remaining copy, encoded as 3 bytes. + SUBL $1, AX + SHLB $2, AX + ORB $2, AX + MOVB AX, 0(DI) + MOVW R11, 1(DI) + ADDQ $3, DI + + // Return the number of bytes written. + SUBQ SI, DI + MOVQ DI, ret+40(FP) + RET + +// ---------------------------------------------------------------------------- + +// func extendMatch(src []byte, i, j int) int +// +// All local variables fit into registers. The register allocation: +// - DX &src[0] +// - SI &src[j] +// - R13 &src[len(src) - 8] +// - R14 &src[len(src)] +// - R15 &src[i] +// +// The unusual register allocation of local variables, such as R15 for a source +// pointer, matches the allocation used at the call site in encodeBlock, which +// makes it easier to manually inline this function. +TEXT ·extendMatch(SB), NOSPLIT, $0-48 + MOVQ src_base+0(FP), DX + MOVQ src_len+8(FP), R14 + MOVQ i+24(FP), R15 + MOVQ j+32(FP), SI + ADDQ DX, R14 + ADDQ DX, R15 + ADDQ DX, SI + MOVQ R14, R13 + SUBQ $8, R13 + +cmp8: + // As long as we are 8 or more bytes before the end of src, we can load and + // compare 8 bytes at a time. If those 8 bytes are equal, repeat. + CMPQ SI, R13 + JA cmp1 + MOVQ (R15), AX + MOVQ (SI), BX + CMPQ AX, BX + JNE bsf + ADDQ $8, R15 + ADDQ $8, SI + JMP cmp8 + +bsf: + // If those 8 bytes were not equal, XOR the two 8 byte values, and return + // the index of the first byte that differs. The BSF instruction finds the + // least significant 1 bit, the amd64 architecture is little-endian, and + // the shift by 3 converts a bit index to a byte index. + XORQ AX, BX + BSFQ BX, BX + SHRQ $3, BX + ADDQ BX, SI + + // Convert from &src[ret] to ret. + SUBQ DX, SI + MOVQ SI, ret+40(FP) + RET + +cmp1: + // In src's tail, compare 1 byte at a time. + CMPQ SI, R14 + JAE extendMatchEnd + MOVB (R15), AX + MOVB (SI), BX + CMPB AX, BX + JNE extendMatchEnd + ADDQ $1, R15 + ADDQ $1, SI + JMP cmp1 + +extendMatchEnd: + // Convert from &src[ret] to ret. + SUBQ DX, SI + MOVQ SI, ret+40(FP) + RET + +// ---------------------------------------------------------------------------- + +// func encodeBlock(dst, src []byte) (d int) +// +// All local variables fit into registers, other than "var table". The register +// allocation: +// - AX . . +// - BX . . +// - CX 56 shift (note that amd64 shifts by non-immediates must use CX). +// - DX 64 &src[0], tableSize +// - SI 72 &src[s] +// - DI 80 &dst[d] +// - R9 88 sLimit +// - R10 . &src[nextEmit] +// - R11 96 prevHash, currHash, nextHash, offset +// - R12 104 &src[base], skip +// - R13 . &src[nextS], &src[len(src) - 8] +// - R14 . len(src), bytesBetweenHashLookups, &src[len(src)], x +// - R15 112 candidate +// +// The second column (56, 64, etc) is the stack offset to spill the registers +// when calling other functions. We could pack this slightly tighter, but it's +// simpler to have a dedicated spill map independent of the function called. +// +// "var table [maxTableSize]uint16" takes up 32768 bytes of stack space. An +// extra 56 bytes, to call other functions, and an extra 64 bytes, to spill +// local variables (registers) during calls gives 32768 + 56 + 64 = 32888. +TEXT ·encodeBlock(SB), 0, $32888-56 + MOVQ dst_base+0(FP), DI + MOVQ src_base+24(FP), SI + MOVQ src_len+32(FP), R14 + + // shift, tableSize := uint32(32-8), 1<<8 + MOVQ $24, CX + MOVQ $256, DX + +calcShift: + // for ; tableSize < maxTableSize && tableSize < len(src); tableSize *= 2 { + // shift-- + // } + CMPQ DX, $16384 + JGE varTable + CMPQ DX, R14 + JGE varTable + SUBQ $1, CX + SHLQ $1, DX + JMP calcShift + +varTable: + // var table [maxTableSize]uint16 + // + // In the asm code, unlike the Go code, we can zero-initialize only the + // first tableSize elements. Each uint16 element is 2 bytes and each MOVOU + // writes 16 bytes, so we can do only tableSize/8 writes instead of the + // 2048 writes that would zero-initialize all of table's 32768 bytes. + SHRQ $3, DX + LEAQ table-32768(SP), BX + PXOR X0, X0 + +memclr: + MOVOU X0, 0(BX) + ADDQ $16, BX + SUBQ $1, DX + JNZ memclr + + // !!! DX = &src[0] + MOVQ SI, DX + + // sLimit := len(src) - inputMargin + MOVQ R14, R9 + SUBQ $15, R9 + + // !!! Pre-emptively spill CX, DX and R9 to the stack. Their values don't + // change for the rest of the function. + MOVQ CX, 56(SP) + MOVQ DX, 64(SP) + MOVQ R9, 88(SP) + + // nextEmit := 0 + MOVQ DX, R10 + + // s := 1 + ADDQ $1, SI + + // nextHash := hash(load32(src, s), shift) + MOVL 0(SI), R11 + IMULL $0x1e35a7bd, R11 + SHRL CX, R11 + +outer: + // for { etc } + + // skip := 32 + MOVQ $32, R12 + + // nextS := s + MOVQ SI, R13 + + // candidate := 0 + MOVQ $0, R15 + +inner0: + // for { etc } + + // s := nextS + MOVQ R13, SI + + // bytesBetweenHashLookups := skip >> 5 + MOVQ R12, R14 + SHRQ $5, R14 + + // nextS = s + bytesBetweenHashLookups + ADDQ R14, R13 + + // skip += bytesBetweenHashLookups + ADDQ R14, R12 + + // if nextS > sLimit { goto emitRemainder } + MOVQ R13, AX + SUBQ DX, AX + CMPQ AX, R9 + JA emitRemainder + + // candidate = int(table[nextHash]) + // XXX: MOVWQZX table-32768(SP)(R11*2), R15 + // XXX: 4e 0f b7 7c 5c 78 movzwq 0x78(%rsp,%r11,2),%r15 + BYTE $0x4e + BYTE $0x0f + BYTE $0xb7 + BYTE $0x7c + BYTE $0x5c + BYTE $0x78 + + // table[nextHash] = uint16(s) + MOVQ SI, AX + SUBQ DX, AX + + // XXX: MOVW AX, table-32768(SP)(R11*2) + // XXX: 66 42 89 44 5c 78 mov %ax,0x78(%rsp,%r11,2) + BYTE $0x66 + BYTE $0x42 + BYTE $0x89 + BYTE $0x44 + BYTE $0x5c + BYTE $0x78 + + // nextHash = hash(load32(src, nextS), shift) + MOVL 0(R13), R11 + IMULL $0x1e35a7bd, R11 + SHRL CX, R11 + + // if load32(src, s) != load32(src, candidate) { continue } break + MOVL 0(SI), AX + MOVL (DX)(R15*1), BX + CMPL AX, BX + JNE inner0 + +fourByteMatch: + // As per the encode_other.go code: + // + // A 4-byte match has been found. We'll later see etc. + + // !!! Jump to a fast path for short (<= 16 byte) literals. See the comment + // on inputMargin in encode.go. + MOVQ SI, AX + SUBQ R10, AX + CMPQ AX, $16 + JLE emitLiteralFastPath + + // ---------------------------------------- + // Begin inline of the emitLiteral call. + // + // d += emitLiteral(dst[d:], src[nextEmit:s]) + + MOVL AX, BX + SUBL $1, BX + + CMPL BX, $60 + JLT inlineEmitLiteralOneByte + CMPL BX, $256 + JLT inlineEmitLiteralTwoBytes + +inlineEmitLiteralThreeBytes: + MOVB $0xf4, 0(DI) + MOVW BX, 1(DI) + ADDQ $3, DI + JMP inlineEmitLiteralMemmove + +inlineEmitLiteralTwoBytes: + MOVB $0xf0, 0(DI) + MOVB BX, 1(DI) + ADDQ $2, DI + JMP inlineEmitLiteralMemmove + +inlineEmitLiteralOneByte: + SHLB $2, BX + MOVB BX, 0(DI) + ADDQ $1, DI + +inlineEmitLiteralMemmove: + // Spill local variables (registers) onto the stack; call; unspill. + // + // copy(dst[i:], lit) + // + // This means calling runtime·memmove(&dst[i], &lit[0], len(lit)), so we push + // DI, R10 and AX as arguments. + MOVQ DI, 0(SP) + MOVQ R10, 8(SP) + MOVQ AX, 16(SP) + ADDQ AX, DI // Finish the "d +=" part of "d += emitLiteral(etc)". + MOVQ SI, 72(SP) + MOVQ DI, 80(SP) + MOVQ R15, 112(SP) + CALL runtime·memmove(SB) + MOVQ 56(SP), CX + MOVQ 64(SP), DX + MOVQ 72(SP), SI + MOVQ 80(SP), DI + MOVQ 88(SP), R9 + MOVQ 112(SP), R15 + JMP inner1 + +inlineEmitLiteralEnd: + // End inline of the emitLiteral call. + // ---------------------------------------- + +emitLiteralFastPath: + // !!! Emit the 1-byte encoding "uint8(len(lit)-1)<<2". + MOVB AX, BX + SUBB $1, BX + SHLB $2, BX + MOVB BX, (DI) + ADDQ $1, DI + + // !!! Implement the copy from lit to dst as a 16-byte load and store. + // (Encode's documentation says that dst and src must not overlap.) + // + // This always copies 16 bytes, instead of only len(lit) bytes, but that's + // OK. Subsequent iterations will fix up the overrun. + // + // Note that on amd64, it is legal and cheap to issue unaligned 8-byte or + // 16-byte loads and stores. This technique probably wouldn't be as + // effective on architectures that are fussier about alignment. + MOVOU 0(R10), X0 + MOVOU X0, 0(DI) + ADDQ AX, DI + +inner1: + // for { etc } + + // base := s + MOVQ SI, R12 + + // !!! offset := base - candidate + MOVQ R12, R11 + SUBQ R15, R11 + SUBQ DX, R11 + + // ---------------------------------------- + // Begin inline of the extendMatch call. + // + // s = extendMatch(src, candidate+4, s+4) + + // !!! R14 = &src[len(src)] + MOVQ src_len+32(FP), R14 + ADDQ DX, R14 + + // !!! R13 = &src[len(src) - 8] + MOVQ R14, R13 + SUBQ $8, R13 + + // !!! R15 = &src[candidate + 4] + ADDQ $4, R15 + ADDQ DX, R15 + + // !!! s += 4 + ADDQ $4, SI + +inlineExtendMatchCmp8: + // As long as we are 8 or more bytes before the end of src, we can load and + // compare 8 bytes at a time. If those 8 bytes are equal, repeat. + CMPQ SI, R13 + JA inlineExtendMatchCmp1 + MOVQ (R15), AX + MOVQ (SI), BX + CMPQ AX, BX + JNE inlineExtendMatchBSF + ADDQ $8, R15 + ADDQ $8, SI + JMP inlineExtendMatchCmp8 + +inlineExtendMatchBSF: + // If those 8 bytes were not equal, XOR the two 8 byte values, and return + // the index of the first byte that differs. The BSF instruction finds the + // least significant 1 bit, the amd64 architecture is little-endian, and + // the shift by 3 converts a bit index to a byte index. + XORQ AX, BX + BSFQ BX, BX + SHRQ $3, BX + ADDQ BX, SI + JMP inlineExtendMatchEnd + +inlineExtendMatchCmp1: + // In src's tail, compare 1 byte at a time. + CMPQ SI, R14 + JAE inlineExtendMatchEnd + MOVB (R15), AX + MOVB (SI), BX + CMPB AX, BX + JNE inlineExtendMatchEnd + ADDQ $1, R15 + ADDQ $1, SI + JMP inlineExtendMatchCmp1 + +inlineExtendMatchEnd: + // End inline of the extendMatch call. + // ---------------------------------------- + + // ---------------------------------------- + // Begin inline of the emitCopy call. + // + // d += emitCopy(dst[d:], base-candidate, s-base) + + // !!! length := s - base + MOVQ SI, AX + SUBQ R12, AX + +inlineEmitCopyLoop0: + // for length >= 68 { etc } + CMPL AX, $68 + JLT inlineEmitCopyStep1 + + // Emit a length 64 copy, encoded as 3 bytes. + MOVB $0xfe, 0(DI) + MOVW R11, 1(DI) + ADDQ $3, DI + SUBL $64, AX + JMP inlineEmitCopyLoop0 + +inlineEmitCopyStep1: + // if length > 64 { etc } + CMPL AX, $64 + JLE inlineEmitCopyStep2 + + // Emit a length 60 copy, encoded as 3 bytes. + MOVB $0xee, 0(DI) + MOVW R11, 1(DI) + ADDQ $3, DI + SUBL $60, AX + +inlineEmitCopyStep2: + // if length >= 12 || offset >= 2048 { goto inlineEmitCopyStep3 } + CMPL AX, $12 + JGE inlineEmitCopyStep3 + CMPL R11, $2048 + JGE inlineEmitCopyStep3 + + // Emit the remaining copy, encoded as 2 bytes. + MOVB R11, 1(DI) + SHRL $8, R11 + SHLB $5, R11 + SUBB $4, AX + SHLB $2, AX + ORB AX, R11 + ORB $1, R11 + MOVB R11, 0(DI) + ADDQ $2, DI + JMP inlineEmitCopyEnd + +inlineEmitCopyStep3: + // Emit the remaining copy, encoded as 3 bytes. + SUBL $1, AX + SHLB $2, AX + ORB $2, AX + MOVB AX, 0(DI) + MOVW R11, 1(DI) + ADDQ $3, DI + +inlineEmitCopyEnd: + // End inline of the emitCopy call. + // ---------------------------------------- + + // nextEmit = s + MOVQ SI, R10 + + // if s >= sLimit { goto emitRemainder } + MOVQ SI, AX + SUBQ DX, AX + CMPQ AX, R9 + JAE emitRemainder + + // As per the encode_other.go code: + // + // We could immediately etc. + + // x := load64(src, s-1) + MOVQ -1(SI), R14 + + // prevHash := hash(uint32(x>>0), shift) + MOVL R14, R11 + IMULL $0x1e35a7bd, R11 + SHRL CX, R11 + + // table[prevHash] = uint16(s-1) + MOVQ SI, AX + SUBQ DX, AX + SUBQ $1, AX + + // XXX: MOVW AX, table-32768(SP)(R11*2) + // XXX: 66 42 89 44 5c 78 mov %ax,0x78(%rsp,%r11,2) + BYTE $0x66 + BYTE $0x42 + BYTE $0x89 + BYTE $0x44 + BYTE $0x5c + BYTE $0x78 + + // currHash := hash(uint32(x>>8), shift) + SHRQ $8, R14 + MOVL R14, R11 + IMULL $0x1e35a7bd, R11 + SHRL CX, R11 + + // candidate = int(table[currHash]) + // XXX: MOVWQZX table-32768(SP)(R11*2), R15 + // XXX: 4e 0f b7 7c 5c 78 movzwq 0x78(%rsp,%r11,2),%r15 + BYTE $0x4e + BYTE $0x0f + BYTE $0xb7 + BYTE $0x7c + BYTE $0x5c + BYTE $0x78 + + // table[currHash] = uint16(s) + ADDQ $1, AX + + // XXX: MOVW AX, table-32768(SP)(R11*2) + // XXX: 66 42 89 44 5c 78 mov %ax,0x78(%rsp,%r11,2) + BYTE $0x66 + BYTE $0x42 + BYTE $0x89 + BYTE $0x44 + BYTE $0x5c + BYTE $0x78 + + // if uint32(x>>8) == load32(src, candidate) { continue } + MOVL (DX)(R15*1), BX + CMPL R14, BX + JEQ inner1 + + // nextHash = hash(uint32(x>>16), shift) + SHRQ $8, R14 + MOVL R14, R11 + IMULL $0x1e35a7bd, R11 + SHRL CX, R11 + + // s++ + ADDQ $1, SI + + // break out of the inner1 for loop, i.e. continue the outer loop. + JMP outer + +emitRemainder: + // if nextEmit < len(src) { etc } + MOVQ src_len+32(FP), AX + ADDQ DX, AX + CMPQ R10, AX + JEQ encodeBlockEnd + + // d += emitLiteral(dst[d:], src[nextEmit:]) + // + // Push args. + MOVQ DI, 0(SP) + MOVQ $0, 8(SP) // Unnecessary, as the callee ignores it, but conservative. + MOVQ $0, 16(SP) // Unnecessary, as the callee ignores it, but conservative. + MOVQ R10, 24(SP) + SUBQ R10, AX + MOVQ AX, 32(SP) + MOVQ AX, 40(SP) // Unnecessary, as the callee ignores it, but conservative. + + // Spill local variables (registers) onto the stack; call; unspill. + MOVQ DI, 80(SP) + CALL ·emitLiteral(SB) + MOVQ 80(SP), DI + + // Finish the "d +=" part of "d += emitLiteral(etc)". + ADDQ 48(SP), DI + +encodeBlockEnd: + MOVQ dst_base+0(FP), AX + SUBQ AX, DI + MOVQ DI, d+48(FP) + RET diff --git a/vendor/github.com/klauspost/compress/snappy/encode_other.go b/vendor/github.com/klauspost/compress/snappy/encode_other.go new file mode 100644 index 000000000..dbcae905e --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/encode_other.go @@ -0,0 +1,238 @@ +// Copyright 2016 The Snappy-Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !amd64 appengine !gc noasm + +package snappy + +func load32(b []byte, i int) uint32 { + b = b[i : i+4 : len(b)] // Help the compiler eliminate bounds checks on the next line. + return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24 +} + +func load64(b []byte, i int) uint64 { + b = b[i : i+8 : len(b)] // Help the compiler eliminate bounds checks on the next line. + return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | + uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 +} + +// emitLiteral writes a literal chunk and returns the number of bytes written. +// +// It assumes that: +// dst is long enough to hold the encoded bytes +// 1 <= len(lit) && len(lit) <= 65536 +func emitLiteral(dst, lit []byte) int { + i, n := 0, uint(len(lit)-1) + switch { + case n < 60: + dst[0] = uint8(n)<<2 | tagLiteral + i = 1 + case n < 1<<8: + dst[0] = 60<<2 | tagLiteral + dst[1] = uint8(n) + i = 2 + default: + dst[0] = 61<<2 | tagLiteral + dst[1] = uint8(n) + dst[2] = uint8(n >> 8) + i = 3 + } + return i + copy(dst[i:], lit) +} + +// emitCopy writes a copy chunk and returns the number of bytes written. +// +// It assumes that: +// dst is long enough to hold the encoded bytes +// 1 <= offset && offset <= 65535 +// 4 <= length && length <= 65535 +func emitCopy(dst []byte, offset, length int) int { + i := 0 + // The maximum length for a single tagCopy1 or tagCopy2 op is 64 bytes. The + // threshold for this loop is a little higher (at 68 = 64 + 4), and the + // length emitted down below is is a little lower (at 60 = 64 - 4), because + // it's shorter to encode a length 67 copy as a length 60 tagCopy2 followed + // by a length 7 tagCopy1 (which encodes as 3+2 bytes) than to encode it as + // a length 64 tagCopy2 followed by a length 3 tagCopy2 (which encodes as + // 3+3 bytes). The magic 4 in the 64±4 is because the minimum length for a + // tagCopy1 op is 4 bytes, which is why a length 3 copy has to be an + // encodes-as-3-bytes tagCopy2 instead of an encodes-as-2-bytes tagCopy1. + for length >= 68 { + // Emit a length 64 copy, encoded as 3 bytes. + dst[i+0] = 63<<2 | tagCopy2 + dst[i+1] = uint8(offset) + dst[i+2] = uint8(offset >> 8) + i += 3 + length -= 64 + } + if length > 64 { + // Emit a length 60 copy, encoded as 3 bytes. + dst[i+0] = 59<<2 | tagCopy2 + dst[i+1] = uint8(offset) + dst[i+2] = uint8(offset >> 8) + i += 3 + length -= 60 + } + if length >= 12 || offset >= 2048 { + // Emit the remaining copy, encoded as 3 bytes. + dst[i+0] = uint8(length-1)<<2 | tagCopy2 + dst[i+1] = uint8(offset) + dst[i+2] = uint8(offset >> 8) + return i + 3 + } + // Emit the remaining copy, encoded as 2 bytes. + dst[i+0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1 + dst[i+1] = uint8(offset) + return i + 2 +} + +// extendMatch returns the largest k such that k <= len(src) and that +// src[i:i+k-j] and src[j:k] have the same contents. +// +// It assumes that: +// 0 <= i && i < j && j <= len(src) +func extendMatch(src []byte, i, j int) int { + for ; j < len(src) && src[i] == src[j]; i, j = i+1, j+1 { + } + return j +} + +func hash(u, shift uint32) uint32 { + return (u * 0x1e35a7bd) >> shift +} + +// encodeBlock encodes a non-empty src to a guaranteed-large-enough dst. It +// assumes that the varint-encoded length of the decompressed bytes has already +// been written. +// +// It also assumes that: +// len(dst) >= MaxEncodedLen(len(src)) && +// minNonLiteralBlockSize <= len(src) && len(src) <= maxBlockSize +func encodeBlock(dst, src []byte) (d int) { + // Initialize the hash table. Its size ranges from 1<<8 to 1<<14 inclusive. + // The table element type is uint16, as s < sLimit and sLimit < len(src) + // and len(src) <= maxBlockSize and maxBlockSize == 65536. + const ( + maxTableSize = 1 << 14 + // tableMask is redundant, but helps the compiler eliminate bounds + // checks. + tableMask = maxTableSize - 1 + ) + shift := uint32(32 - 8) + for tableSize := 1 << 8; tableSize < maxTableSize && tableSize < len(src); tableSize *= 2 { + shift-- + } + // In Go, all array elements are zero-initialized, so there is no advantage + // to a smaller tableSize per se. However, it matches the C++ algorithm, + // and in the asm versions of this code, we can get away with zeroing only + // the first tableSize elements. + var table [maxTableSize]uint16 + + // sLimit is when to stop looking for offset/length copies. The inputMargin + // lets us use a fast path for emitLiteral in the main loop, while we are + // looking for copies. + sLimit := len(src) - inputMargin + + // nextEmit is where in src the next emitLiteral should start from. + nextEmit := 0 + + // The encoded form must start with a literal, as there are no previous + // bytes to copy, so we start looking for hash matches at s == 1. + s := 1 + nextHash := hash(load32(src, s), shift) + + for { + // Copied from the C++ snappy implementation: + // + // Heuristic match skipping: If 32 bytes are scanned with no matches + // found, start looking only at every other byte. If 32 more bytes are + // scanned (or skipped), look at every third byte, etc.. When a match + // is found, immediately go back to looking at every byte. This is a + // small loss (~5% performance, ~0.1% density) for compressible data + // due to more bookkeeping, but for non-compressible data (such as + // JPEG) it's a huge win since the compressor quickly "realizes" the + // data is incompressible and doesn't bother looking for matches + // everywhere. + // + // The "skip" variable keeps track of how many bytes there are since + // the last match; dividing it by 32 (ie. right-shifting by five) gives + // the number of bytes to move ahead for each iteration. + skip := 32 + + nextS := s + candidate := 0 + for { + s = nextS + bytesBetweenHashLookups := skip >> 5 + nextS = s + bytesBetweenHashLookups + skip += bytesBetweenHashLookups + if nextS > sLimit { + goto emitRemainder + } + candidate = int(table[nextHash&tableMask]) + table[nextHash&tableMask] = uint16(s) + nextHash = hash(load32(src, nextS), shift) + if load32(src, s) == load32(src, candidate) { + break + } + } + + // A 4-byte match has been found. We'll later see if more than 4 bytes + // match. But, prior to the match, src[nextEmit:s] are unmatched. Emit + // them as literal bytes. + d += emitLiteral(dst[d:], src[nextEmit:s]) + + // Call emitCopy, and then see if another emitCopy could be our next + // move. Repeat until we find no match for the input immediately after + // what was consumed by the last emitCopy call. + // + // If we exit this loop normally then we need to call emitLiteral next, + // though we don't yet know how big the literal will be. We handle that + // by proceeding to the next iteration of the main loop. We also can + // exit this loop via goto if we get close to exhausting the input. + for { + // Invariant: we have a 4-byte match at s, and no need to emit any + // literal bytes prior to s. + base := s + + // Extend the 4-byte match as long as possible. + // + // This is an inlined version of: + // s = extendMatch(src, candidate+4, s+4) + s += 4 + for i := candidate + 4; s < len(src) && src[i] == src[s]; i, s = i+1, s+1 { + } + + d += emitCopy(dst[d:], base-candidate, s-base) + nextEmit = s + if s >= sLimit { + goto emitRemainder + } + + // We could immediately start working at s now, but to improve + // compression we first update the hash table at s-1 and at s. If + // another emitCopy is not our next move, also calculate nextHash + // at s+1. At least on GOARCH=amd64, these three hash calculations + // are faster as one load64 call (with some shifts) instead of + // three load32 calls. + x := load64(src, s-1) + prevHash := hash(uint32(x>>0), shift) + table[prevHash&tableMask] = uint16(s - 1) + currHash := hash(uint32(x>>8), shift) + candidate = int(table[currHash&tableMask]) + table[currHash&tableMask] = uint16(s) + if uint32(x>>8) != load32(src, candidate) { + nextHash = hash(uint32(x>>16), shift) + s++ + break + } + } + } + +emitRemainder: + if nextEmit < len(src) { + d += emitLiteral(dst[d:], src[nextEmit:]) + } + return d +} diff --git a/vendor/github.com/klauspost/compress/snappy/runbench.cmd b/vendor/github.com/klauspost/compress/snappy/runbench.cmd new file mode 100644 index 000000000..d24eb4b47 --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/runbench.cmd @@ -0,0 +1,2 @@ +del old.txt +go test -bench=. >>old.txt && go test -bench=. >>old.txt && go test -bench=. >>old.txt && benchstat -delta-test=ttest old.txt new.txt diff --git a/vendor/github.com/klauspost/compress/snappy/snappy.go b/vendor/github.com/klauspost/compress/snappy/snappy.go new file mode 100644 index 000000000..74a36689e --- /dev/null +++ b/vendor/github.com/klauspost/compress/snappy/snappy.go @@ -0,0 +1,98 @@ +// Copyright 2011 The Snappy-Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package snappy implements the Snappy compression format. It aims for very +// high speeds and reasonable compression. +// +// There are actually two Snappy formats: block and stream. They are related, +// but different: trying to decompress block-compressed data as a Snappy stream +// will fail, and vice versa. The block format is the Decode and Encode +// functions and the stream format is the Reader and Writer types. +// +// The block format, the more common case, is used when the complete size (the +// number of bytes) of the original data is known upfront, at the time +// compression starts. The stream format, also known as the framing format, is +// for when that isn't always true. +// +// The canonical, C++ implementation is at https://github.com/google/snappy and +// it only implements the block format. +package snappy + +import ( + "hash/crc32" +) + +/* +Each encoded block begins with the varint-encoded length of the decoded data, +followed by a sequence of chunks. Chunks begin and end on byte boundaries. The +first byte of each chunk is broken into its 2 least and 6 most significant bits +called l and m: l ranges in [0, 4) and m ranges in [0, 64). l is the chunk tag. +Zero means a literal tag. All other values mean a copy tag. + +For literal tags: + - If m < 60, the next 1 + m bytes are literal bytes. + - Otherwise, let n be the little-endian unsigned integer denoted by the next + m - 59 bytes. The next 1 + n bytes after that are literal bytes. + +For copy tags, length bytes are copied from offset bytes ago, in the style of +Lempel-Ziv compression algorithms. In particular: + - For l == 1, the offset ranges in [0, 1<<11) and the length in [4, 12). + The length is 4 + the low 3 bits of m. The high 3 bits of m form bits 8-10 + of the offset. The next byte is bits 0-7 of the offset. + - For l == 2, the offset ranges in [0, 1<<16) and the length in [1, 65). + The length is 1 + m. The offset is the little-endian unsigned integer + denoted by the next 2 bytes. + - For l == 3, this tag is a legacy format that is no longer issued by most + encoders. Nonetheless, the offset ranges in [0, 1<<32) and the length in + [1, 65). The length is 1 + m. The offset is the little-endian unsigned + integer denoted by the next 4 bytes. +*/ +const ( + tagLiteral = 0x00 + tagCopy1 = 0x01 + tagCopy2 = 0x02 + tagCopy4 = 0x03 +) + +const ( + checksumSize = 4 + chunkHeaderSize = 4 + magicChunk = "\xff\x06\x00\x00" + magicBody + magicBody = "sNaPpY" + + // maxBlockSize is the maximum size of the input to encodeBlock. It is not + // part of the wire format per se, but some parts of the encoder assume + // that an offset fits into a uint16. + // + // Also, for the framing format (Writer type instead of Encode function), + // https://github.com/google/snappy/blob/master/framing_format.txt says + // that "the uncompressed data in a chunk must be no longer than 65536 + // bytes". + maxBlockSize = 65536 + + // maxEncodedLenOfMaxBlockSize equals MaxEncodedLen(maxBlockSize), but is + // hard coded to be a const instead of a variable, so that obufLen can also + // be a const. Their equivalence is confirmed by + // TestMaxEncodedLenOfMaxBlockSize. + maxEncodedLenOfMaxBlockSize = 76490 + + obufHeaderLen = len(magicChunk) + checksumSize + chunkHeaderSize + obufLen = obufHeaderLen + maxEncodedLenOfMaxBlockSize +) + +const ( + chunkTypeCompressedData = 0x00 + chunkTypeUncompressedData = 0x01 + chunkTypePadding = 0xfe + chunkTypeStreamIdentifier = 0xff +) + +var crcTable = crc32.MakeTable(crc32.Castagnoli) + +// crc implements the checksum specified in section 3 of +// https://github.com/google/snappy/blob/master/framing_format.txt +func crc(b []byte) uint32 { + c := crc32.Update(0, crcTable, b) + return uint32(c>>15|c<<17) + 0xa282ead8 +} diff --git a/vendor/github.com/klauspost/compress/zstd/README.md b/vendor/github.com/klauspost/compress/zstd/README.md new file mode 100644 index 000000000..670f98af4 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/README.md @@ -0,0 +1,383 @@ +# zstd + +[Zstandard](https://facebook.github.io/zstd/) is a real-time compression algorithm, providing high compression ratios. +It offers a very wide range of compression / speed trade-off, while being backed by a very fast decoder. +A high performance compression algorithm is implemented. For now focused on speed. + +This package provides [compression](#Compressor) to and [decompression](#Decompressor) of Zstandard content. +Note that custom dictionaries are not supported yet, so if your code relies on that, +you cannot use the package as-is. + +This package is pure Go and without use of "unsafe". +If a significant speedup can be achieved using "unsafe", it may be added as an option later. + +The `zstd` package is provided as open source software using a Go standard license. + +Currently the package is heavily optimized for 64 bit processors and will be significantly slower on 32 bit processors. + +## Installation + +Install using `go get -u github.com/klauspost/compress`. The package is located in `github.com/klauspost/compress/zstd`. + +Godoc Documentation: https://godoc.org/github.com/klauspost/compress/zstd + + +## Compressor + +### Status: + +BETA - there may still be subtle bugs, but a wide variety of content has been tested. +There may still be implementation specific stuff in regards to error handling that could lead to edge cases. + +For now, a high speed (fastest) and medium-fast (default) compressor has been implemented. + +The "Fastest" compression ratio is roughly equivalent to zstd level 1. +The "Default" compression ration is roughly equivalent to zstd level 3 (default). + +In terms of speed, it is typically 2x as fast as the stdlib deflate/gzip in its fastest mode. The compression ratio compared to stdlib is around level 3, but usually 3x as fast. + +Compared to cgo zstd, the speed is around level 3 (default), but compression slightly worse, between level 1&2. + + +### Usage + +An Encoder can be used for either compressing a stream via the +`io.WriteCloser` interface supported by the Encoder or as multiple independent +tasks via the `EncodeAll` function. +Smaller encodes are encouraged to use the EncodeAll function. +Use `NewWriter` to create a new instance that can be used for both. + +To create a writer with default options, do like this: + +```Go +// Compress input to output. +func Compress(in io.Reader, out io.Writer) error { + w, err := NewWriter(output) + if err != nil { + return err + } + _, err := io.Copy(w, input) + if err != nil { + enc.Close() + return err + } + return enc.Close() +} +``` + +Now you can encode by writing data to `enc`. The output will be finished writing when `Close()` is called. +Even if your encode fails, you should still call `Close()` to release any resources that may be held up. + +The above is fine for big encodes. However, whenever possible try to *reuse* the writer. + +To reuse the encoder, you can use the `Reset(io.Writer)` function to change to another output. +This will allow the encoder to reuse all resources and avoid wasteful allocations. + +Currently stream encoding has 'light' concurrency, meaning up to 2 goroutines can be working on part +of a stream. This is independent of the `WithEncoderConcurrency(n)`, but that is likely to change +in the future. So if you want to limit concurrency for future updates, specify the concurrency +you would like. + +You can specify your desired compression level using `WithEncoderLevel()` option. Currently only pre-defined +compression settings can be specified. + +#### Future Compatibility Guarantees + +This will be an evolving project. When using this package it is important to note that both the compression efficiency and speed may change. + +The goal will be to keep the default efficiency at the default zstd (level 3). +However the encoding should never be assumed to remain the same, +and you should not use hashes of compressed output for similarity checks. + +The Encoder can be assumed to produce the same output from the exact same code version. +However, the may be modes in the future that break this, +although they will not be enabled without an explicit option. + +This encoder is not designed to (and will probably never) output the exact same bitstream as the reference encoder. + +Also note, that the cgo decompressor currently does not [report all errors on invalid input](https://github.com/DataDog/zstd/issues/59), +[omits error checks](https://github.com/DataDog/zstd/issues/61), [ignores checksums](https://github.com/DataDog/zstd/issues/43) +and seems to ignore concatenated streams, even though [it is part of the spec](https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#frames). + +#### Blocks + +For compressing small blocks, the returned encoder has a function called `EncodeAll(src, dst []byte) []byte`. + +`EncodeAll` will encode all input in src and append it to dst. +This function can be called concurrently, but each call will only run on a single goroutine. + +Encoded blocks can be concatenated and the result will be the combined input stream. +Data compressed with EncodeAll can be decoded with the Decoder, using either a stream or `DecodeAll`. + +Especially when encoding blocks you should take special care to reuse the encoder. +This will effectively make it run without allocations after a warmup period. +To make it run completely without allocations, supply a destination buffer with space for all content. + +```Go +import "github.com/klauspost/compress/zstd" + +// Create a writer that caches compressors. +// For this operation type we supply a nil Reader. +var encoder, _ = zstd.NewWriter(nil) + +// Compress a buffer. +// If you have a destination buffer, the allocation in the call can also be eliminated. +func Compress(src []byte) []byte { + return encoder.EncodeAll(src, make([]byte, 0, len(src))) +} +``` + +You can control the maximum number of concurrent encodes using the `WithEncoderConcurrency(n)` +option when creating the writer. + +Using the Encoder for both a stream and individual blocks concurrently is safe. + +### Performance + +I have collected some speed examples to compare speed and compression against other compressors. + +* `file` is the input file. +* `out` is the compressor used. `zskp` is this package. `gzstd` is gzip standard library. `zstd` is the Datadog cgo library. +* `level` is the compression level used. For `zskp` level 1 is "fastest", level 2 is "default". +* `insize`/`outsize` is the input/output size. +* `millis` is the number of milliseconds used for compression. +* `mb/s` is megabytes (2^20 bytes) per second. + +``` +The test data for the Large Text Compression Benchmark is the first +10^9 bytes of the English Wikipedia dump on Mar. 3, 2006. +http://mattmahoney.net/dc/textdata.html + +file out level insize outsize millis mb/s +enwik9 zskp 1 1000000000 343833033 5840 163.30 +enwik9 zskp 2 1000000000 317822183 8449 112.87 +enwik9 gzstd 1 1000000000 382578136 13627 69.98 +enwik9 gzstd 3 1000000000 349139651 22344 42.68 +enwik9 zstd 1 1000000000 357416379 4838 197.12 +enwik9 zstd 3 1000000000 313734522 7556 126.21 + +GOB stream of binary data. Highly compressible. +https://files.klauspost.com/compress/gob-stream.7z + +file out level insize outsize millis mb/s +gob-stream zskp 1 1911399616 234981983 5100 357.42 +gob-stream zskp 2 1911399616 208674003 6698 272.15 +gob-stream gzstd 1 1911399616 357382641 14727 123.78 +gob-stream gzstd 3 1911399616 327835097 17005 107.19 +gob-stream zstd 1 1911399616 250787165 4075 447.22 +gob-stream zstd 3 1911399616 208191888 5511 330.77 + +Highly compressible JSON file. Similar to logs in a lot of ways. +https://files.klauspost.com/compress/adresser.001.gz + +file out level insize outsize millis mb/s +adresser.001 zskp 1 1073741824 18510122 1477 692.83 +adresser.001 zskp 2 1073741824 19831697 1705 600.59 +adresser.001 gzstd 1 1073741824 47755503 3079 332.47 +adresser.001 gzstd 3 1073741824 40052381 3051 335.63 +adresser.001 zstd 1 1073741824 16135896 994 1030.18 +adresser.001 zstd 3 1073741824 17794465 905 1131.49 + +VM Image, Linux mint with a few installed applications: +https://files.klauspost.com/compress/rawstudio-mint14.7z + +file out level insize outsize millis mb/s +rawstudio-mint14.tar zskp 1 8558382592 3648168838 33398 244.38 +rawstudio-mint14.tar zskp 2 8558382592 3376721436 50962 160.16 +rawstudio-mint14.tar gzstd 1 8558382592 3926257486 84712 96.35 +rawstudio-mint14.tar gzstd 3 8558382592 3740711978 176344 46.28 +rawstudio-mint14.tar zstd 1 8558382592 3607859742 27903 292.51 +rawstudio-mint14.tar zstd 3 8558382592 3341710879 46700 174.77 + + +The test data is designed to test archivers in realistic backup scenarios. +http://mattmahoney.net/dc/10gb.html + +file out level insize outsize millis mb/s +10gb.tar zskp 1 10065157632 4883149814 45715 209.97 +10gb.tar zskp 2 10065157632 4638110010 60970 157.44 +10gb.tar gzstd 1 10065157632 5198296126 97769 98.18 +10gb.tar gzstd 3 10065157632 4932665487 313427 30.63 +10gb.tar zstd 1 10065157632 4940796535 40391 237.65 +10gb.tar zstd 3 10065157632 4638618579 52911 181.42 + +Silesia Corpus: +http://sun.aei.polsl.pl/~sdeor/corpus/silesia.zip + +file out level insize outsize millis mb/s +silesia.tar zskp 1 211947520 73025800 1108 182.26 +silesia.tar zskp 2 211947520 67674684 1599 126.41 +silesia.tar gzstd 1 211947520 80007735 2515 80.37 +silesia.tar gzstd 3 211947520 73133380 4259 47.45 +silesia.tar zstd 1 211947520 73513991 933 216.64 +silesia.tar zstd 3 211947520 66793301 1377 146.79 +``` + +### Converters + +As part of the development process a *Snappy* -> *Zstandard* converter was also built. + +This can convert a *framed* [Snappy Stream](https://godoc.org/github.com/golang/snappy#Writer) to a zstd stream. Note that a single block is not framed. + +Conversion is done by converting the stream directly from Snappy without intermediate full decoding. +Therefore the compression ratio is much less than what can be done by a full decompression +and compression, and a faulty Snappy stream may lead to a faulty Zstandard stream without +any errors being generated. +No CRC value is being generated and not all CRC values of the Snappy stream are checked. +However, it provides really fast re-compression of Snappy streams. + + +``` +BenchmarkSnappy_ConvertSilesia-8 1 1156001600 ns/op 183.35 MB/s +Snappy len 103008711 -> zstd len 82687318 + +BenchmarkSnappy_Enwik9-8 1 6472998400 ns/op 154.49 MB/s +Snappy len 508028601 -> zstd len 390921079 +``` + + +```Go + s := zstd.SnappyConverter{} + n, err = s.Convert(input, output) + if err != nil { + fmt.Println("Re-compressed stream to", n, "bytes") + } +``` + +The converter `s` can be reused to avoid allocations, even after errors. + + +## Decompressor + +STATUS: Release Candidate - there may still be subtle bugs, but a wide variety of content has been tested. + + +### Usage + +The package has been designed for two main usages, big streams of data and smaller in-memory buffers. +There are two main usages of the package for these. Both of them are accessed by creating a `Decoder`. + +For streaming use a simple setup could look like this: + +```Go +import "github.com/klauspost/compress/zstd" + +func Decompress(in io.Reader, out io.Writer) error { + d, err := zstd.NewReader(input) + if err != nil { + return err + } + defer d.Close() + + // Copy content... + _, err := io.Copy(out, d) + return err +} +``` + +It is important to use the "Close" function when you no longer need the Reader to stop running goroutines. +See "Allocation-less operation" below. + +For decoding buffers, it could look something like this: + +```Go +import "github.com/klauspost/compress/zstd" + +// Create a reader that caches decompressors. +// For this operation type we supply a nil Reader. +var decoder, _ = zstd.NewReader(nil) + +// Decompress a buffer. We don't supply a destination buffer, +// so it will be allocated by the decoder. +func Decompress(src []byte) ([]byte, error) { + return decoder.DecodeAll(src, nil) +} +``` + +Both of these cases should provide the functionality needed. +The decoder can be used for *concurrent* decompression of multiple buffers. +It will only allow a certain number of concurrent operations to run. +To tweak that yourself use the `WithDecoderConcurrency(n)` option when creating the decoder. + +### Allocation-less operation + +The decoder has been designed to operate without allocations after a warmup. + +This means that you should *store* the decoder for best performance. +To re-use a stream decoder, use the `Reset(r io.Reader) error` to switch to another stream. +A decoder can safely be re-used even if the previous stream failed. + +To release the resources, you must call the `Close()` function on a decoder. +After this it can *no longer be reused*, but all running goroutines will be stopped. +So you *must* use this if you will no longer need the Reader. + +For decompressing smaller buffers a single decoder can be used. +When decoding buffers, you can supply a destination slice with length 0 and your expected capacity. +In this case no unneeded allocations should be made. + +### Concurrency + +The buffer decoder does everything on the same goroutine and does nothing concurrently. +It can however decode several buffers concurrently. Use `WithDecoderConcurrency(n)` to limit that. + +The stream decoder operates on + +* One goroutine reads input and splits the input to several block decoders. +* A number of decoders will decode blocks. +* A goroutine coordinates these blocks and sends history from one to the next. + +So effectively this also means the decoder will "read ahead" and prepare data to always be available for output. + +Since "blocks" are quite dependent on the output of the previous block stream decoding will only have limited concurrency. + +In practice this means that concurrency is often limited to utilizing about 2 cores effectively. + + +### Benchmarks + +These are some examples of performance compared to [datadog cgo library](https://github.com/DataDog/zstd). + +The first two are streaming decodes and the last are smaller inputs. + +``` +BenchmarkDecoderSilesia-8 20 642550210 ns/op 329.85 MB/s 3101 B/op 8 allocs/op +BenchmarkDecoderSilesiaCgo-8 100 384930000 ns/op 550.61 MB/s 451878 B/op 9713 allocs/op + +BenchmarkDecoderEnwik9-2 10 3146000080 ns/op 317.86 MB/s 2649 B/op 9 allocs/op +BenchmarkDecoderEnwik9Cgo-2 20 1905900000 ns/op 524.69 MB/s 1125120 B/op 45785 allocs/op + +BenchmarkDecoder_DecodeAll/z000000.zst-8 200 7049994 ns/op 138.26 MB/s 40 B/op 2 allocs/op +BenchmarkDecoder_DecodeAll/z000001.zst-8 100000 19560 ns/op 97.49 MB/s 40 B/op 2 allocs/op +BenchmarkDecoder_DecodeAll/z000002.zst-8 5000 297599 ns/op 236.99 MB/s 40 B/op 2 allocs/op +BenchmarkDecoder_DecodeAll/z000003.zst-8 2000 725502 ns/op 141.17 MB/s 40 B/op 2 allocs/op +BenchmarkDecoder_DecodeAll/z000004.zst-8 200000 9314 ns/op 54.54 MB/s 40 B/op 2 allocs/op +BenchmarkDecoder_DecodeAll/z000005.zst-8 10000 137500 ns/op 104.72 MB/s 40 B/op 2 allocs/op +BenchmarkDecoder_DecodeAll/z000006.zst-8 500 2316009 ns/op 206.06 MB/s 40 B/op 2 allocs/op +BenchmarkDecoder_DecodeAll/z000007.zst-8 20000 64499 ns/op 344.90 MB/s 40 B/op 2 allocs/op +BenchmarkDecoder_DecodeAll/z000008.zst-8 50000 24900 ns/op 219.56 MB/s 40 B/op 2 allocs/op +BenchmarkDecoder_DecodeAll/z000009.zst-8 1000 2348999 ns/op 154.01 MB/s 40 B/op 2 allocs/op + +BenchmarkDecoder_DecodeAllCgo/z000000.zst-8 500 4268005 ns/op 228.38 MB/s 1228849 B/op 3 allocs/op +BenchmarkDecoder_DecodeAllCgo/z000001.zst-8 100000 15250 ns/op 125.05 MB/s 2096 B/op 3 allocs/op +BenchmarkDecoder_DecodeAllCgo/z000002.zst-8 10000 147399 ns/op 478.49 MB/s 73776 B/op 3 allocs/op +BenchmarkDecoder_DecodeAllCgo/z000003.zst-8 5000 320798 ns/op 319.27 MB/s 139312 B/op 3 allocs/op +BenchmarkDecoder_DecodeAllCgo/z000004.zst-8 200000 10004 ns/op 50.77 MB/s 560 B/op 3 allocs/op +BenchmarkDecoder_DecodeAllCgo/z000005.zst-8 20000 73599 ns/op 195.64 MB/s 19120 B/op 3 allocs/op +BenchmarkDecoder_DecodeAllCgo/z000006.zst-8 1000 1119003 ns/op 426.48 MB/s 557104 B/op 3 allocs/op +BenchmarkDecoder_DecodeAllCgo/z000007.zst-8 20000 103450 ns/op 215.04 MB/s 71296 B/op 9 allocs/op +BenchmarkDecoder_DecodeAllCgo/z000008.zst-8 100000 20130 ns/op 271.58 MB/s 6192 B/op 3 allocs/op +BenchmarkDecoder_DecodeAllCgo/z000009.zst-8 2000 1123500 ns/op 322.00 MB/s 368688 B/op 3 allocs/op +``` + +This reflects the performance around May 2019, but this may be out of date. + +# Contributions + +Contributions are always welcome. +For new features/fixes, remember to add tests and for performance enhancements include benchmarks. + +For sending files for reproducing errors use a service like [goobox](https://goobox.io/#/upload) or similar to share your files. + +For general feedback and experience reports, feel free to open an issue or write me on [Twitter](https://twitter.com/sh0dan). + +This package includes the excellent [`github.com/cespare/xxhash`](https://github.com/cespare/xxhash) package Copyright (c) 2016 Caleb Spare.
\ No newline at end of file diff --git a/vendor/github.com/klauspost/compress/zstd/bitreader.go b/vendor/github.com/klauspost/compress/zstd/bitreader.go new file mode 100644 index 000000000..15d79d439 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/bitreader.go @@ -0,0 +1,121 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "errors" + "io" + "math/bits" +) + +// bitReader reads a bitstream in reverse. +// The last set bit indicates the start of the stream and is used +// for aligning the input. +type bitReader struct { + in []byte + off uint // next byte to read is at in[off - 1] + value uint64 // Maybe use [16]byte, but shifting is awkward. + bitsRead uint8 +} + +// init initializes and resets the bit reader. +func (b *bitReader) init(in []byte) error { + if len(in) < 1 { + return errors.New("corrupt stream: too short") + } + b.in = in + b.off = uint(len(in)) + // The highest bit of the last byte indicates where to start + v := in[len(in)-1] + if v == 0 { + return errors.New("corrupt stream, did not find end of stream") + } + b.bitsRead = 64 + b.value = 0 + b.fill() + b.fill() + b.bitsRead += 8 - uint8(highBits(uint32(v))) + return nil +} + +// getBits will return n bits. n can be 0. +func (b *bitReader) getBits(n uint8) int { + if n == 0 /*|| b.bitsRead >= 64 */ { + return 0 + } + return b.getBitsFast(n) +} + +// getBitsFast requires that at least one bit is requested every time. +// There are no checks if the buffer is filled. +func (b *bitReader) getBitsFast(n uint8) int { + const regMask = 64 - 1 + v := uint32((b.value << (b.bitsRead & regMask)) >> ((regMask + 1 - n) & regMask)) + b.bitsRead += n + return int(v) +} + +// fillFast() will make sure at least 32 bits are available. +// There must be at least 4 bytes available. +func (b *bitReader) fillFast() { + if b.bitsRead < 32 { + return + } + // Do single re-slice to avoid bounds checks. + v := b.in[b.off-4 : b.off] + low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24) + b.value = (b.value << 32) | uint64(low) + b.bitsRead -= 32 + b.off -= 4 +} + +// fill() will make sure at least 32 bits are available. +func (b *bitReader) fill() { + if b.bitsRead < 32 { + return + } + if b.off >= 4 { + v := b.in[b.off-4 : b.off] + low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24) + b.value = (b.value << 32) | uint64(low) + b.bitsRead -= 32 + b.off -= 4 + return + } + for b.off > 0 { + b.value = (b.value << 8) | uint64(b.in[b.off-1]) + b.bitsRead -= 8 + b.off-- + } +} + +// finished returns true if all bits have been read from the bit stream. +func (b *bitReader) finished() bool { + return b.off == 0 && b.bitsRead >= 64 +} + +// overread returns true if more bits have been requested than is on the stream. +func (b *bitReader) overread() bool { + return b.bitsRead > 64 +} + +// remain returns the number of bits remaining. +func (b *bitReader) remain() uint { + return b.off*8 + 64 - uint(b.bitsRead) +} + +// close the bitstream and returns an error if out-of-buffer reads occurred. +func (b *bitReader) close() error { + // Release reference. + b.in = nil + if b.bitsRead > 64 { + return io.ErrUnexpectedEOF + } + return nil +} + +func highBits(val uint32) (n uint32) { + return uint32(bits.Len32(val) - 1) +} diff --git a/vendor/github.com/klauspost/compress/zstd/bitwriter.go b/vendor/github.com/klauspost/compress/zstd/bitwriter.go new file mode 100644 index 000000000..303ae90f9 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/bitwriter.go @@ -0,0 +1,169 @@ +// Copyright 2018 Klaus Post. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. +// Based on work Copyright (c) 2013, Yann Collet, released under BSD License. + +package zstd + +import "fmt" + +// bitWriter will write bits. +// First bit will be LSB of the first byte of output. +type bitWriter struct { + bitContainer uint64 + nBits uint8 + out []byte +} + +// bitMask16 is bitmasks. Has extra to avoid bounds check. +var bitMask16 = [32]uint16{ + 0, 1, 3, 7, 0xF, 0x1F, + 0x3F, 0x7F, 0xFF, 0x1FF, 0x3FF, 0x7FF, + 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, 0xFFFF, + 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF, + 0xFFFF, 0xFFFF} /* up to 16 bits */ + +var bitMask32 = [32]uint32{ + 0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF, + 0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF, + 0x1ffff, 0x3ffff, 0x7FFFF, 0xfFFFF, 0x1fFFFF, 0x3fFFFF, 0x7fFFFF, 0xffFFFF, + 0x1ffFFFF, 0x3ffFFFF, 0x7ffFFFF, 0xfffFFFF, 0x1fffFFFF, 0x3fffFFFF, 0x7fffFFFF, +} // up to 32 bits + +// addBits16NC will add up to 16 bits. +// It will not check if there is space for them, +// so the caller must ensure that it has flushed recently. +func (b *bitWriter) addBits16NC(value uint16, bits uint8) { + b.bitContainer |= uint64(value&bitMask16[bits&31]) << (b.nBits & 63) + b.nBits += bits +} + +// addBits32NC will add up to 32 bits. +// It will not check if there is space for them, +// so the caller must ensure that it has flushed recently. +func (b *bitWriter) addBits32NC(value uint32, bits uint8) { + b.bitContainer |= uint64(value&bitMask32[bits&31]) << (b.nBits & 63) + b.nBits += bits +} + +// addBits16Clean will add up to 16 bits. value may not contain more set bits than indicated. +// It will not check if there is space for them, so the caller must ensure that it has flushed recently. +func (b *bitWriter) addBits16Clean(value uint16, bits uint8) { + b.bitContainer |= uint64(value) << (b.nBits & 63) + b.nBits += bits +} + +// flush will flush all pending full bytes. +// There will be at least 56 bits available for writing when this has been called. +// Using flush32 is faster, but leaves less space for writing. +func (b *bitWriter) flush() { + v := b.nBits >> 3 + switch v { + case 0: + case 1: + b.out = append(b.out, + byte(b.bitContainer), + ) + case 2: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + ) + case 3: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + ) + case 4: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + ) + case 5: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + ) + case 6: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + byte(b.bitContainer>>40), + ) + case 7: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + byte(b.bitContainer>>40), + byte(b.bitContainer>>48), + ) + case 8: + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24), + byte(b.bitContainer>>32), + byte(b.bitContainer>>40), + byte(b.bitContainer>>48), + byte(b.bitContainer>>56), + ) + default: + panic(fmt.Errorf("bits (%d) > 64", b.nBits)) + } + b.bitContainer >>= v << 3 + b.nBits &= 7 +} + +// flush32 will flush out, so there are at least 32 bits available for writing. +func (b *bitWriter) flush32() { + if b.nBits < 32 { + return + } + b.out = append(b.out, + byte(b.bitContainer), + byte(b.bitContainer>>8), + byte(b.bitContainer>>16), + byte(b.bitContainer>>24)) + b.nBits -= 32 + b.bitContainer >>= 32 +} + +// flushAlign will flush remaining full bytes and align to next byte boundary. +func (b *bitWriter) flushAlign() { + nbBytes := (b.nBits + 7) >> 3 + for i := uint8(0); i < nbBytes; i++ { + b.out = append(b.out, byte(b.bitContainer>>(i*8))) + } + b.nBits = 0 + b.bitContainer = 0 +} + +// close will write the alignment bit and write the final byte(s) +// to the output. +func (b *bitWriter) close() error { + // End mark + b.addBits16Clean(1, 1) + // flush until next byte. + b.flushAlign() + return nil +} + +// reset and continue writing by appending to out. +func (b *bitWriter) reset(out []byte) { + b.bitContainer = 0 + b.nBits = 0 + b.out = out +} diff --git a/vendor/github.com/klauspost/compress/zstd/blockdec.go b/vendor/github.com/klauspost/compress/zstd/blockdec.go new file mode 100644 index 000000000..aca1cb85d --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/blockdec.go @@ -0,0 +1,708 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "errors" + "fmt" + "io" + "sync" + + "github.com/klauspost/compress/huff0" +) + +type blockType uint8 + +//go:generate stringer -type=blockType,literalsBlockType,seqCompMode,tableIndex + +const ( + blockTypeRaw blockType = iota + blockTypeRLE + blockTypeCompressed + blockTypeReserved +) + +type literalsBlockType uint8 + +const ( + literalsBlockRaw literalsBlockType = iota + literalsBlockRLE + literalsBlockCompressed + literalsBlockTreeless +) + +const ( + // maxCompressedBlockSize is the biggest allowed compressed block size (128KB) + maxCompressedBlockSize = 128 << 10 + + // Maximum possible block size (all Raw+Uncompressed). + maxBlockSize = (1 << 21) - 1 + + // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#literals_section_header + maxCompressedLiteralSize = 1 << 18 + maxRLELiteralSize = 1 << 20 + maxMatchLen = 131074 + maxSequences = 0x7f00 + 0xffff + + // We support slightly less than the reference decoder to be able to + // use ints on 32 bit archs. + maxOffsetBits = 30 +) + +var ( + huffDecoderPool = sync.Pool{New: func() interface{} { + return &huff0.Scratch{} + }} + + fseDecoderPool = sync.Pool{New: func() interface{} { + return &fseDecoder{} + }} +) + +type blockDec struct { + // Raw source data of the block. + data []byte + + // Destination of the decoded data. + dst []byte + + // Buffer for literals data. + literalBuf []byte + + // Window size of the block. + WindowSize uint64 + Type blockType + RLESize uint32 + + // Is this the last block of a frame? + Last bool + + // Use less memory + lowMem bool + history chan *history + input chan struct{} + result chan decodeOutput + sequenceBuf []seq + tmp [4]byte + err error +} + +func (b *blockDec) String() string { + if b == nil { + return "<nil>" + } + return fmt.Sprintf("Steam Size: %d, Type: %v, Last: %t, Window: %d", len(b.data), b.Type, b.Last, b.WindowSize) +} + +func newBlockDec(lowMem bool) *blockDec { + b := blockDec{ + lowMem: lowMem, + result: make(chan decodeOutput, 1), + input: make(chan struct{}, 1), + history: make(chan *history, 1), + } + go b.startDecoder() + return &b +} + +// reset will reset the block. +// Input must be a start of a block and will be at the end of the block when returned. +func (b *blockDec) reset(br byteBuffer, windowSize uint64) error { + b.WindowSize = windowSize + tmp := br.readSmall(3) + if tmp == nil { + if debug { + println("Reading block header:", io.ErrUnexpectedEOF) + } + return io.ErrUnexpectedEOF + } + bh := uint32(tmp[0]) | (uint32(tmp[1]) << 8) | (uint32(tmp[2]) << 16) + b.Last = bh&1 != 0 + b.Type = blockType((bh >> 1) & 3) + // find size. + cSize := int(bh >> 3) + switch b.Type { + case blockTypeReserved: + return ErrReservedBlockType + case blockTypeRLE: + b.RLESize = uint32(cSize) + cSize = 1 + case blockTypeCompressed: + if debug { + println("Data size on stream:", cSize) + } + b.RLESize = 0 + if cSize > maxCompressedBlockSize || uint64(cSize) > b.WindowSize { + if debug { + printf("compressed block too big: csize:%d block: %+v\n", uint64(cSize), b) + } + return ErrCompressedSizeTooBig + } + default: + b.RLESize = 0 + } + + // Read block data. + if cap(b.data) < cSize { + if b.lowMem { + b.data = make([]byte, 0, cSize) + } else { + b.data = make([]byte, 0, maxBlockSize) + } + } + if cap(b.dst) <= maxBlockSize { + b.dst = make([]byte, 0, maxBlockSize+1) + } + var err error + b.data, err = br.readBig(cSize, b.data[:0]) + if err != nil { + if debug { + println("Reading block:", err) + } + return err + } + return nil +} + +// sendEOF will make the decoder send EOF on this frame. +func (b *blockDec) sendErr(err error) { + b.Last = true + b.Type = blockTypeReserved + b.err = err + b.input <- struct{}{} +} + +// Close will release resources. +// Closed blockDec cannot be reset. +func (b *blockDec) Close() { + close(b.input) + close(b.history) + close(b.result) +} + +// decodeAsync will prepare decoding the block when it receives input. +// This will separate output and history. +func (b *blockDec) startDecoder() { + for range b.input { + //println("blockDec: Got block input") + switch b.Type { + case blockTypeRLE: + if cap(b.dst) < int(b.RLESize) { + if b.lowMem { + b.dst = make([]byte, b.RLESize) + } else { + b.dst = make([]byte, maxBlockSize) + } + } + o := decodeOutput{ + d: b, + b: b.dst[:b.RLESize], + err: nil, + } + v := b.data[0] + for i := range o.b { + o.b[i] = v + } + hist := <-b.history + hist.append(o.b) + b.result <- o + case blockTypeRaw: + o := decodeOutput{ + d: b, + b: b.data, + err: nil, + } + hist := <-b.history + hist.append(o.b) + b.result <- o + case blockTypeCompressed: + b.dst = b.dst[:0] + err := b.decodeCompressed(nil) + o := decodeOutput{ + d: b, + b: b.dst, + err: err, + } + if debug { + println("Decompressed to", len(b.dst), "bytes, error:", err) + } + b.result <- o + case blockTypeReserved: + // Used for returning errors. + <-b.history + b.result <- decodeOutput{ + d: b, + b: nil, + err: b.err, + } + default: + panic("Invalid block type") + } + if debug { + println("blockDec: Finished block") + } + } +} + +// decodeAsync will prepare decoding the block when it receives the history. +// If history is provided, it will not fetch it from the channel. +func (b *blockDec) decodeBuf(hist *history) error { + switch b.Type { + case blockTypeRLE: + if cap(b.dst) < int(b.RLESize) { + if b.lowMem { + b.dst = make([]byte, b.RLESize) + } else { + b.dst = make([]byte, maxBlockSize) + } + } + b.dst = b.dst[:b.RLESize] + v := b.data[0] + for i := range b.dst { + b.dst[i] = v + } + hist.appendKeep(b.dst) + return nil + case blockTypeRaw: + hist.appendKeep(b.data) + return nil + case blockTypeCompressed: + saved := b.dst + b.dst = hist.b + hist.b = nil + err := b.decodeCompressed(hist) + if debug { + println("Decompressed to total", len(b.dst), "bytes, error:", err) + } + hist.b = b.dst + b.dst = saved + return err + case blockTypeReserved: + // Used for returning errors. + return b.err + default: + panic("Invalid block type") + } +} + +// decodeCompressed will start decompressing a block. +// If no history is supplied the decoder will decodeAsync as much as possible +// before fetching from blockDec.history +func (b *blockDec) decodeCompressed(hist *history) error { + in := b.data + delayedHistory := hist == nil + + if delayedHistory { + // We must always grab history. + defer func() { + if hist == nil { + <-b.history + } + }() + } + // There must be at least one byte for Literals_Block_Type and one for Sequences_Section_Header + if len(in) < 2 { + return ErrBlockTooSmall + } + litType := literalsBlockType(in[0] & 3) + var litRegenSize int + var litCompSize int + sizeFormat := (in[0] >> 2) & 3 + var fourStreams bool + switch litType { + case literalsBlockRaw, literalsBlockRLE: + switch sizeFormat { + case 0, 2: + // Regenerated_Size uses 5 bits (0-31). Literals_Section_Header uses 1 byte. + litRegenSize = int(in[0] >> 3) + in = in[1:] + case 1: + // Regenerated_Size uses 12 bits (0-4095). Literals_Section_Header uses 2 bytes. + litRegenSize = int(in[0]>>4) + (int(in[1]) << 4) + in = in[2:] + case 3: + // Regenerated_Size uses 20 bits (0-1048575). Literals_Section_Header uses 3 bytes. + if len(in) < 3 { + println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in)) + return ErrBlockTooSmall + } + litRegenSize = int(in[0]>>4) + (int(in[1]) << 4) + (int(in[2]) << 12) + in = in[3:] + } + case literalsBlockCompressed, literalsBlockTreeless: + switch sizeFormat { + case 0, 1: + // Both Regenerated_Size and Compressed_Size use 10 bits (0-1023). + if len(in) < 3 { + println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in)) + return ErrBlockTooSmall + } + n := uint64(in[0]>>4) + (uint64(in[1]) << 4) + (uint64(in[2]) << 12) + litRegenSize = int(n & 1023) + litCompSize = int(n >> 10) + fourStreams = sizeFormat == 1 + in = in[3:] + case 2: + fourStreams = true + if len(in) < 4 { + println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in)) + return ErrBlockTooSmall + } + n := uint64(in[0]>>4) + (uint64(in[1]) << 4) + (uint64(in[2]) << 12) + (uint64(in[3]) << 20) + litRegenSize = int(n & 16383) + litCompSize = int(n >> 14) + in = in[4:] + case 3: + fourStreams = true + if len(in) < 5 { + println("too small: litType:", litType, " sizeFormat", sizeFormat, len(in)) + return ErrBlockTooSmall + } + n := uint64(in[0]>>4) + (uint64(in[1]) << 4) + (uint64(in[2]) << 12) + (uint64(in[3]) << 20) + (uint64(in[4]) << 28) + litRegenSize = int(n & 262143) + litCompSize = int(n >> 18) + in = in[5:] + } + } + if debug { + println("literals type:", litType, "litRegenSize:", litRegenSize, "litCompSize", litCompSize) + } + var literals []byte + var huff *huff0.Scratch + switch litType { + case literalsBlockRaw: + if len(in) < litRegenSize { + println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", litRegenSize) + return ErrBlockTooSmall + } + literals = in[:litRegenSize] + in = in[litRegenSize:] + //printf("Found %d uncompressed literals\n", litRegenSize) + case literalsBlockRLE: + if len(in) < 1 { + println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", 1) + return ErrBlockTooSmall + } + if cap(b.literalBuf) < litRegenSize { + if b.lowMem { + b.literalBuf = make([]byte, litRegenSize) + } else { + if litRegenSize > maxCompressedLiteralSize { + // Exceptional + b.literalBuf = make([]byte, litRegenSize) + } else { + b.literalBuf = make([]byte, litRegenSize, maxCompressedLiteralSize) + + } + } + } + literals = b.literalBuf[:litRegenSize] + v := in[0] + for i := range literals { + literals[i] = v + } + in = in[1:] + if debug { + printf("Found %d RLE compressed literals\n", litRegenSize) + } + case literalsBlockTreeless: + if len(in) < litCompSize { + println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", litCompSize) + return ErrBlockTooSmall + } + // Store compressed literals, so we defer decoding until we get history. + literals = in[:litCompSize] + in = in[litCompSize:] + if debug { + printf("Found %d compressed literals\n", litCompSize) + } + case literalsBlockCompressed: + if len(in) < litCompSize { + println("too small: litType:", litType, " sizeFormat", sizeFormat, "remain:", len(in), "want:", litCompSize) + return ErrBlockTooSmall + } + literals = in[:litCompSize] + in = in[litCompSize:] + + huff = huffDecoderPool.Get().(*huff0.Scratch) + var err error + // Ensure we have space to store it. + if cap(b.literalBuf) < litRegenSize { + if b.lowMem { + b.literalBuf = make([]byte, 0, litRegenSize) + } else { + b.literalBuf = make([]byte, 0, maxCompressedLiteralSize) + } + } + if huff == nil { + huff = &huff0.Scratch{} + } + huff.Out = b.literalBuf[:0] + huff, literals, err = huff0.ReadTable(literals, huff) + if err != nil { + println("reading huffman table:", err) + return err + } + // Use our out buffer. + huff.Out = b.literalBuf[:0] + if fourStreams { + literals, err = huff.Decompress4X(literals, litRegenSize) + } else { + literals, err = huff.Decompress1X(literals) + } + if err != nil { + println("decoding compressed literals:", err) + return err + } + // Make sure we don't leak our literals buffer + huff.Out = nil + if len(literals) != litRegenSize { + return fmt.Errorf("literal output size mismatch want %d, got %d", litRegenSize, len(literals)) + } + if debug { + printf("Decompressed %d literals into %d bytes\n", litCompSize, litRegenSize) + } + } + + // Decode Sequences + // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#sequences-section + if len(in) < 1 { + return ErrBlockTooSmall + } + seqHeader := in[0] + nSeqs := 0 + switch { + case seqHeader == 0: + in = in[1:] + case seqHeader < 128: + nSeqs = int(seqHeader) + in = in[1:] + case seqHeader < 255: + if len(in) < 2 { + return ErrBlockTooSmall + } + nSeqs = int(seqHeader-128)<<8 | int(in[1]) + in = in[2:] + case seqHeader == 255: + if len(in) < 3 { + return ErrBlockTooSmall + } + nSeqs = 0x7f00 + int(in[1]) + (int(in[2]) << 8) + in = in[3:] + } + // Allocate sequences + if cap(b.sequenceBuf) < nSeqs { + if b.lowMem { + b.sequenceBuf = make([]seq, nSeqs) + } else { + // Allocate max + b.sequenceBuf = make([]seq, nSeqs, maxSequences) + } + } else { + // Reuse buffer + b.sequenceBuf = b.sequenceBuf[:nSeqs] + } + var seqs = &sequenceDecs{} + if nSeqs > 0 { + if len(in) < 1 { + return ErrBlockTooSmall + } + br := byteReader{b: in, off: 0} + compMode := br.Uint8() + br.advance(1) + if debug { + printf("Compression modes: 0b%b", compMode) + } + for i := uint(0); i < 3; i++ { + mode := seqCompMode((compMode >> (6 - i*2)) & 3) + if debug { + println("Table", tableIndex(i), "is", mode) + } + var seq *sequenceDec + switch tableIndex(i) { + case tableLiteralLengths: + seq = &seqs.litLengths + case tableOffsets: + seq = &seqs.offsets + case tableMatchLengths: + seq = &seqs.matchLengths + default: + panic("unknown table") + } + switch mode { + case compModePredefined: + seq.fse = &fsePredef[i] + case compModeRLE: + if br.remain() < 1 { + return ErrBlockTooSmall + } + v := br.Uint8() + br.advance(1) + dec := fseDecoderPool.Get().(*fseDecoder) + symb, err := decSymbolValue(v, symbolTableX[i]) + if err != nil { + printf("RLE Transform table (%v) error: %v", tableIndex(i), err) + return err + } + dec.setRLE(symb) + seq.fse = dec + if debug { + printf("RLE set to %+v, code: %v", symb, v) + } + case compModeFSE: + println("Reading table for", tableIndex(i)) + dec := fseDecoderPool.Get().(*fseDecoder) + err := dec.readNCount(&br, uint16(maxTableSymbol[i])) + if err != nil { + println("Read table error:", err) + return err + } + err = dec.transform(symbolTableX[i]) + if err != nil { + println("Transform table error:", err) + return err + } + if debug { + println("Read table ok", "symbolLen:", dec.symbolLen) + } + seq.fse = dec + case compModeRepeat: + seq.repeat = true + } + if br.overread() { + return io.ErrUnexpectedEOF + } + } + in = br.unread() + } + + // Wait for history. + // All time spent after this is critical since it is strictly sequential. + if hist == nil { + hist = <-b.history + if hist.error { + return ErrDecoderClosed + } + } + + // Decode treeless literal block. + if litType == literalsBlockTreeless { + // TODO: We could send the history early WITHOUT the stream history. + // This would allow decoding treeless literials before the byte history is available. + // Silencia stats: Treeless 4393, with: 32775, total: 37168, 11% treeless. + // So not much obvious gain here. + + if hist.huffTree == nil { + return errors.New("literal block was treeless, but no history was defined") + } + // Ensure we have space to store it. + if cap(b.literalBuf) < litRegenSize { + if b.lowMem { + b.literalBuf = make([]byte, 0, litRegenSize) + } else { + b.literalBuf = make([]byte, 0, maxCompressedLiteralSize) + } + } + var err error + // Use our out buffer. + huff = hist.huffTree + huff.Out = b.literalBuf[:0] + if fourStreams { + literals, err = huff.Decompress4X(literals, litRegenSize) + } else { + literals, err = huff.Decompress1X(literals) + } + // Make sure we don't leak our literals buffer + huff.Out = nil + if err != nil { + println("decompressing literals:", err) + return err + } + if len(literals) != litRegenSize { + return fmt.Errorf("literal output size mismatch want %d, got %d", litRegenSize, len(literals)) + } + } else { + if hist.huffTree != nil && huff != nil { + huffDecoderPool.Put(hist.huffTree) + hist.huffTree = nil + } + } + if huff != nil { + huff.Out = nil + hist.huffTree = huff + } + if debug { + println("Final literals:", len(literals), "and", nSeqs, "sequences.") + } + + if nSeqs == 0 { + // Decompressed content is defined entirely as Literals Section content. + b.dst = append(b.dst, literals...) + if delayedHistory { + hist.append(literals) + } + return nil + } + + seqs, err := seqs.mergeHistory(&hist.decoders) + if err != nil { + return err + } + if debug { + println("History merged ok") + } + br := &bitReader{} + if err := br.init(in); err != nil { + return err + } + + // TODO: Investigate if sending history without decoders are faster. + // This would allow the sequences to be decoded async and only have to construct stream history. + // If only recent offsets were not transferred, this would be an obvious win. + // Also, if first 3 sequences don't reference recent offsets, all sequences can be decoded. + + if err := seqs.initialize(br, hist, literals, b.dst); err != nil { + println("initializing sequences:", err) + return err + } + + err = seqs.decode(nSeqs, br, hist.b) + if err != nil { + return err + } + if !br.finished() { + return fmt.Errorf("%d extra bits on block, should be 0", br.remain()) + } + + err = br.close() + if err != nil { + printf("Closing sequences: %v, %+v\n", err, *br) + } + if len(b.data) > maxCompressedBlockSize { + return fmt.Errorf("compressed block size too large (%d)", len(b.data)) + } + // Set output and release references. + b.dst = seqs.out + seqs.out, seqs.literals, seqs.hist = nil, nil, nil + + if !delayedHistory { + // If we don't have delayed history, no need to update. + hist.recentOffsets = seqs.prevOffset + return nil + } + if b.Last { + // if last block we don't care about history. + println("Last block, no history returned") + hist.b = hist.b[:0] + return nil + } + hist.append(b.dst) + hist.recentOffsets = seqs.prevOffset + if debug { + println("Finished block with literals:", len(literals), "and", nSeqs, "sequences.") + } + + return nil +} diff --git a/vendor/github.com/klauspost/compress/zstd/blockenc.go b/vendor/github.com/klauspost/compress/zstd/blockenc.go new file mode 100644 index 000000000..cba24c76d --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/blockenc.go @@ -0,0 +1,754 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "errors" + "fmt" + "math" + "math/bits" + + "github.com/klauspost/compress/huff0" +) + +type blockEnc struct { + size int + literals []byte + sequences []seq + coders seqCoders + litEnc *huff0.Scratch + wr bitWriter + + extraLits int + last bool + + output []byte + recentOffsets [3]uint32 + prevRecentOffsets [3]uint32 +} + +// init should be used once the block has been created. +// If called more than once, the effect is the same as calling reset. +func (b *blockEnc) init() { + if cap(b.literals) < maxCompressedLiteralSize { + b.literals = make([]byte, 0, maxCompressedLiteralSize) + } + const defSeqs = 200 + b.literals = b.literals[:0] + if cap(b.sequences) < defSeqs { + b.sequences = make([]seq, 0, defSeqs) + } + if cap(b.output) < maxCompressedBlockSize { + b.output = make([]byte, 0, maxCompressedBlockSize) + } + if b.coders.mlEnc == nil { + b.coders.mlEnc = &fseEncoder{} + b.coders.mlPrev = &fseEncoder{} + b.coders.ofEnc = &fseEncoder{} + b.coders.ofPrev = &fseEncoder{} + b.coders.llEnc = &fseEncoder{} + b.coders.llPrev = &fseEncoder{} + } + b.litEnc = &huff0.Scratch{} + b.reset(nil) +} + +// initNewEncode can be used to reset offsets and encoders to the initial state. +func (b *blockEnc) initNewEncode() { + b.recentOffsets = [3]uint32{1, 4, 8} + b.litEnc.Reuse = huff0.ReusePolicyNone + b.coders.setPrev(nil, nil, nil) +} + +// reset will reset the block for a new encode, but in the same stream, +// meaning that state will be carried over, but the block content is reset. +// If a previous block is provided, the recent offsets are carried over. +func (b *blockEnc) reset(prev *blockEnc) { + b.extraLits = 0 + b.literals = b.literals[:0] + b.size = 0 + b.sequences = b.sequences[:0] + b.output = b.output[:0] + b.last = false + if prev != nil { + b.recentOffsets = prev.prevRecentOffsets + } +} + +// reset will reset the block for a new encode, but in the same stream, +// meaning that state will be carried over, but the block content is reset. +// If a previous block is provided, the recent offsets are carried over. +func (b *blockEnc) swapEncoders(prev *blockEnc) { + b.coders.swap(&prev.coders) + b.litEnc, prev.litEnc = prev.litEnc, b.litEnc +} + +// blockHeader contains the information for a block header. +type blockHeader uint32 + +// setLast sets the 'last' indicator on a block. +func (h *blockHeader) setLast(b bool) { + if b { + *h = *h | 1 + } else { + const mask = (1 << 24) - 2 + *h = *h & mask + } +} + +// setSize will store the compressed size of a block. +func (h *blockHeader) setSize(v uint32) { + const mask = 7 + *h = (*h)&mask | blockHeader(v<<3) +} + +// setType sets the block type. +func (h *blockHeader) setType(t blockType) { + const mask = 1 | (((1 << 24) - 1) ^ 7) + *h = (*h & mask) | blockHeader(t<<1) +} + +// appendTo will append the block header to a slice. +func (h blockHeader) appendTo(b []byte) []byte { + return append(b, uint8(h), uint8(h>>8), uint8(h>>16)) +} + +// String returns a string representation of the block. +func (h blockHeader) String() string { + return fmt.Sprintf("Type: %d, Size: %d, Last:%t", (h>>1)&3, h>>3, h&1 == 1) +} + +// literalsHeader contains literals header information. +type literalsHeader uint64 + +// setType can be used to set the type of literal block. +func (h *literalsHeader) setType(t literalsBlockType) { + const mask = math.MaxUint64 - 3 + *h = (*h & mask) | literalsHeader(t) +} + +// setSize can be used to set a single size, for uncompressed and RLE content. +func (h *literalsHeader) setSize(regenLen int) { + inBits := bits.Len32(uint32(regenLen)) + // Only retain 2 bits + const mask = 3 + lh := uint64(*h & mask) + switch { + case inBits < 5: + lh |= (uint64(regenLen) << 3) | (1 << 60) + if debug { + got := int(lh>>3) & 0xff + if got != regenLen { + panic(fmt.Sprint("litRegenSize = ", regenLen, "(want) != ", got, "(got)")) + } + } + case inBits < 12: + lh |= (1 << 2) | (uint64(regenLen) << 4) | (2 << 60) + case inBits < 20: + lh |= (3 << 2) | (uint64(regenLen) << 4) | (3 << 60) + default: + panic(fmt.Errorf("internal error: block too big (%d)", regenLen)) + } + *h = literalsHeader(lh) +} + +// setSizes will set the size of a compressed literals section and the input length. +func (h *literalsHeader) setSizes(compLen, inLen int) { + compBits, inBits := bits.Len32(uint32(compLen)), bits.Len32(uint32(inLen)) + // Only retain 2 bits + const mask = 3 + lh := uint64(*h & mask) + switch { + case compBits <= 10 && inBits <= 10: + lh |= (1 << 2) | (uint64(inLen) << 4) | (uint64(compLen) << (10 + 4)) | (3 << 60) + if debug { + const mmask = (1 << 24) - 1 + n := (lh >> 4) & mmask + if int(n&1023) != inLen { + panic(fmt.Sprint("regensize:", int(n&1023), "!=", inLen, inBits)) + } + if int(n>>10) != compLen { + panic(fmt.Sprint("compsize:", int(n>>10), "!=", compLen, compBits)) + } + } + case compBits <= 14 && inBits <= 14: + lh |= (2 << 2) | (uint64(inLen) << 4) | (uint64(compLen) << (14 + 4)) | (4 << 60) + case compBits <= 18 && inBits <= 18: + lh |= (3 << 2) | (uint64(inLen) << 4) | (uint64(compLen) << (18 + 4)) | (5 << 60) + default: + panic("internal error: block too big") + } + *h = literalsHeader(lh) +} + +// appendTo will append the literals header to a byte slice. +func (h literalsHeader) appendTo(b []byte) []byte { + size := uint8(h >> 60) + switch size { + case 1: + b = append(b, uint8(h)) + case 2: + b = append(b, uint8(h), uint8(h>>8)) + case 3: + b = append(b, uint8(h), uint8(h>>8), uint8(h>>16)) + case 4: + b = append(b, uint8(h), uint8(h>>8), uint8(h>>16), uint8(h>>24)) + case 5: + b = append(b, uint8(h), uint8(h>>8), uint8(h>>16), uint8(h>>24), uint8(h>>32)) + default: + panic(fmt.Errorf("internal error: literalsHeader has invalid size (%d)", size)) + } + return b +} + +// size returns the output size with currently set values. +func (h literalsHeader) size() int { + return int(h >> 60) +} + +func (h literalsHeader) String() string { + return fmt.Sprintf("Type: %d, SizeFormat: %d, Size: 0x%d, Bytes:%d", literalsBlockType(h&3), (h>>2)&3, h&((1<<60)-1)>>4, h>>60) +} + +// pushOffsets will push the recent offsets to the backup store. +func (b *blockEnc) pushOffsets() { + b.prevRecentOffsets = b.recentOffsets +} + +// pushOffsets will push the recent offsets to the backup store. +func (b *blockEnc) popOffsets() { + b.recentOffsets = b.prevRecentOffsets +} + +// matchOffset will adjust recent offsets and return the adjusted one, +// if it matches a previous offset. +func (b *blockEnc) matchOffset(offset, lits uint32) uint32 { + // Check if offset is one of the recent offsets. + // Adjusts the output offset accordingly. + // Gives a tiny bit of compression, typically around 1%. + if true { + if lits > 0 { + switch offset { + case b.recentOffsets[0]: + offset = 1 + case b.recentOffsets[1]: + b.recentOffsets[1] = b.recentOffsets[0] + b.recentOffsets[0] = offset + offset = 2 + case b.recentOffsets[2]: + b.recentOffsets[2] = b.recentOffsets[1] + b.recentOffsets[1] = b.recentOffsets[0] + b.recentOffsets[0] = offset + offset = 3 + default: + b.recentOffsets[2] = b.recentOffsets[1] + b.recentOffsets[1] = b.recentOffsets[0] + b.recentOffsets[0] = offset + offset += 3 + } + } else { + switch offset { + case b.recentOffsets[1]: + b.recentOffsets[1] = b.recentOffsets[0] + b.recentOffsets[0] = offset + offset = 1 + case b.recentOffsets[2]: + b.recentOffsets[2] = b.recentOffsets[1] + b.recentOffsets[1] = b.recentOffsets[0] + b.recentOffsets[0] = offset + offset = 2 + case b.recentOffsets[0] - 1: + b.recentOffsets[2] = b.recentOffsets[1] + b.recentOffsets[1] = b.recentOffsets[0] + b.recentOffsets[0] = offset + offset = 3 + default: + b.recentOffsets[2] = b.recentOffsets[1] + b.recentOffsets[1] = b.recentOffsets[0] + b.recentOffsets[0] = offset + offset += 3 + } + } + } else { + offset += 3 + } + return offset +} + +// encodeRaw can be used to set the output to a raw representation of supplied bytes. +func (b *blockEnc) encodeRaw(a []byte) { + var bh blockHeader + bh.setLast(b.last) + bh.setSize(uint32(len(a))) + bh.setType(blockTypeRaw) + b.output = bh.appendTo(b.output[:0]) + b.output = append(b.output, a...) + if debug { + println("Adding RAW block, length", len(a)) + } +} + +// encodeLits can be used if the block is only litLen. +func (b *blockEnc) encodeLits() error { + var bh blockHeader + bh.setLast(b.last) + bh.setSize(uint32(len(b.literals))) + + // Don't compress extremely small blocks + if len(b.literals) < 32 { + if debug { + println("Adding RAW block, length", len(b.literals)) + } + bh.setType(blockTypeRaw) + b.output = bh.appendTo(b.output) + b.output = append(b.output, b.literals...) + return nil + } + + // TODO: Switch to 1X when less than x bytes. + out, reUsed, err := huff0.Compress4X(b.literals, b.litEnc) + // Bail out of compression is too little. + if len(out) > (len(b.literals) - len(b.literals)>>4) { + err = huff0.ErrIncompressible + } + switch err { + case huff0.ErrIncompressible: + if debug { + println("Adding RAW block, length", len(b.literals)) + } + bh.setType(blockTypeRaw) + b.output = bh.appendTo(b.output) + b.output = append(b.output, b.literals...) + return nil + case huff0.ErrUseRLE: + if debug { + println("Adding RLE block, length", len(b.literals)) + } + bh.setType(blockTypeRLE) + b.output = bh.appendTo(b.output) + b.output = append(b.output, b.literals[0]) + return nil + default: + return err + case nil: + } + // Compressed... + // Now, allow reuse + b.litEnc.Reuse = huff0.ReusePolicyAllow + bh.setType(blockTypeCompressed) + var lh literalsHeader + if reUsed { + if debug { + println("Reused tree, compressed to", len(out)) + } + lh.setType(literalsBlockTreeless) + } else { + if debug { + println("New tree, compressed to", len(out), "tree size:", len(b.litEnc.OutTable)) + } + lh.setType(literalsBlockCompressed) + } + // Set sizes + lh.setSizes(len(out), len(b.literals)) + bh.setSize(uint32(len(out) + lh.size() + 1)) + + // Write block headers. + b.output = bh.appendTo(b.output) + b.output = lh.appendTo(b.output) + // Add compressed data. + b.output = append(b.output, out...) + // No sequences. + b.output = append(b.output, 0) + return nil +} + +// encode will encode the block and put the output in b.output. +func (b *blockEnc) encode() error { + if len(b.sequences) == 0 { + return b.encodeLits() + } + // We want some difference + if len(b.literals) > (b.size - (b.size >> 5)) { + return errIncompressible + } + + var bh blockHeader + var lh literalsHeader + bh.setLast(b.last) + bh.setType(blockTypeCompressed) + b.output = bh.appendTo(b.output) + + var ( + out []byte + reUsed bool + err error + ) + if len(b.literals) > 32 { + // TODO: Switch to 1X on small blocks. + out, reUsed, err = huff0.Compress4X(b.literals, b.litEnc) + if len(out) > len(b.literals)-len(b.literals)>>4 { + err = huff0.ErrIncompressible + } + } else { + err = huff0.ErrIncompressible + } + switch err { + case huff0.ErrIncompressible: + lh.setType(literalsBlockRaw) + lh.setSize(len(b.literals)) + b.output = lh.appendTo(b.output) + b.output = append(b.output, b.literals...) + if debug { + println("Adding literals RAW, length", len(b.literals)) + } + case huff0.ErrUseRLE: + lh.setType(literalsBlockRLE) + lh.setSize(len(b.literals)) + b.output = lh.appendTo(b.output) + b.output = append(b.output, b.literals[0]) + if debug { + println("Adding literals RLE") + } + default: + if debug { + println("Adding literals ERROR:", err) + } + return err + case nil: + // Compressed litLen... + if reUsed { + if debug { + println("reused tree") + } + lh.setType(literalsBlockTreeless) + } else { + if debug { + println("new tree, size:", len(b.litEnc.OutTable)) + } + lh.setType(literalsBlockCompressed) + if debug { + _, _, err := huff0.ReadTable(out, nil) + if err != nil { + panic(err) + } + } + } + lh.setSizes(len(out), len(b.literals)) + if debug { + printf("Compressed %d literals to %d bytes", len(b.literals), len(out)) + println("Adding literal header:", lh) + } + b.output = lh.appendTo(b.output) + b.output = append(b.output, out...) + b.litEnc.Reuse = huff0.ReusePolicyAllow + if debug { + println("Adding literals compressed") + } + } + // Sequence compression + + // Write the number of sequences + switch { + case len(b.sequences) < 128: + b.output = append(b.output, uint8(len(b.sequences))) + case len(b.sequences) < 0x7f00: // TODO: this could be wrong + n := len(b.sequences) + b.output = append(b.output, 128+uint8(n>>8), uint8(n)) + default: + n := len(b.sequences) - 0x7f00 + b.output = append(b.output, 255, uint8(n), uint8(n>>8)) + } + if debug { + println("Encoding", len(b.sequences), "sequences") + } + b.genCodes() + llEnc := b.coders.llEnc + ofEnc := b.coders.ofEnc + mlEnc := b.coders.mlEnc + err = llEnc.normalizeCount(len(b.sequences)) + if err != nil { + return err + } + err = ofEnc.normalizeCount(len(b.sequences)) + if err != nil { + return err + } + err = mlEnc.normalizeCount(len(b.sequences)) + if err != nil { + return err + } + + // Choose the best compression mode for each type. + // Will evaluate the new vs predefined and previous. + chooseComp := func(cur, prev, preDef *fseEncoder) (*fseEncoder, seqCompMode) { + // See if predefined/previous is better + hist := cur.count[:cur.symbolLen] + nSize := cur.approxSize(hist) + cur.maxHeaderSize() + predefSize := preDef.approxSize(hist) + prevSize := prev.approxSize(hist) + + // Add a small penalty for new encoders. + // Don't bother with extremely small (<2 byte gains). + nSize = nSize + (nSize+2*8*16)>>4 + switch { + case predefSize <= prevSize && predefSize <= nSize || forcePreDef: + if debug { + println("Using predefined", predefSize>>3, "<=", nSize>>3) + } + return preDef, compModePredefined + case prevSize <= nSize: + if debug { + println("Using previous", prevSize>>3, "<=", nSize>>3) + } + return prev, compModeRepeat + default: + if debug { + println("Using new, predef", predefSize>>3, ". previous:", prevSize>>3, ">", nSize>>3, "header max:", cur.maxHeaderSize()>>3, "bytes") + println("tl:", cur.actualTableLog, "symbolLen:", cur.symbolLen, "norm:", cur.norm[:cur.symbolLen], "hist", cur.count[:cur.symbolLen]) + } + return cur, compModeFSE + } + } + + // Write compression mode + var mode uint8 + if llEnc.useRLE { + mode |= uint8(compModeRLE) << 6 + llEnc.setRLE(b.sequences[0].llCode) + if debug { + println("llEnc.useRLE") + } + } else { + var m seqCompMode + llEnc, m = chooseComp(llEnc, b.coders.llPrev, &fsePredefEnc[tableLiteralLengths]) + mode |= uint8(m) << 6 + } + if ofEnc.useRLE { + mode |= uint8(compModeRLE) << 4 + ofEnc.setRLE(b.sequences[0].ofCode) + if debug { + println("ofEnc.useRLE") + } + } else { + var m seqCompMode + ofEnc, m = chooseComp(ofEnc, b.coders.ofPrev, &fsePredefEnc[tableOffsets]) + mode |= uint8(m) << 4 + } + + if mlEnc.useRLE { + mode |= uint8(compModeRLE) << 2 + mlEnc.setRLE(b.sequences[0].mlCode) + if debug { + println("mlEnc.useRLE, code: ", b.sequences[0].mlCode, "value", b.sequences[0].matchLen) + } + } else { + var m seqCompMode + mlEnc, m = chooseComp(mlEnc, b.coders.mlPrev, &fsePredefEnc[tableMatchLengths]) + mode |= uint8(m) << 2 + } + b.output = append(b.output, mode) + if debug { + printf("Compression modes: 0b%b", mode) + } + b.output, err = llEnc.writeCount(b.output) + if err != nil { + return err + } + start := len(b.output) + b.output, err = ofEnc.writeCount(b.output) + if err != nil { + return err + } + if false { + println("block:", b.output[start:], "tablelog", ofEnc.actualTableLog, "maxcount:", ofEnc.maxCount) + fmt.Printf("selected TableLog: %d, Symbol length: %d\n", ofEnc.actualTableLog, ofEnc.symbolLen) + for i, v := range ofEnc.norm[:ofEnc.symbolLen] { + fmt.Printf("%3d: %5d -> %4d \n", i, ofEnc.count[i], v) + } + } + b.output, err = mlEnc.writeCount(b.output) + if err != nil { + return err + } + + // Maybe in block? + wr := &b.wr + wr.reset(b.output) + + var ll, of, ml cState + + // Current sequence + seq := len(b.sequences) - 1 + s := b.sequences[seq] + llEnc.setBits(llBitsTable[:]) + mlEnc.setBits(mlBitsTable[:]) + ofEnc.setBits(nil) + + llTT, ofTT, mlTT := llEnc.ct.symbolTT[:256], ofEnc.ct.symbolTT[:256], mlEnc.ct.symbolTT[:256] + + // We have 3 bounds checks here (and in the loop). + // Since we are iterating backwards it is kinda hard to avoid. + llB, ofB, mlB := llTT[s.llCode], ofTT[s.ofCode], mlTT[s.mlCode] + ll.init(wr, &llEnc.ct, llB) + of.init(wr, &ofEnc.ct, ofB) + wr.flush32() + ml.init(wr, &mlEnc.ct, mlB) + + // Each of these lookups also generates a bounds check. + wr.addBits32NC(s.litLen, llB.outBits) + wr.addBits32NC(s.matchLen, mlB.outBits) + wr.flush32() + wr.addBits32NC(s.offset, ofB.outBits) + if debugSequences { + println("Encoded seq", seq, s, "codes:", s.llCode, s.mlCode, s.ofCode, "states:", ll.state, ml.state, of.state, "bits:", llB, mlB, ofB) + } + seq-- + if llEnc.maxBits+mlEnc.maxBits+ofEnc.maxBits <= 32 { + // No need to flush (common) + for seq >= 0 { + s = b.sequences[seq] + wr.flush32() + llB, ofB, mlB := llTT[s.llCode], ofTT[s.ofCode], mlTT[s.mlCode] + // tabelog max is 8 for all. + of.encode(ofB) + ml.encode(mlB) + ll.encode(llB) + wr.flush32() + + // We checked that all can stay within 32 bits + wr.addBits32NC(s.litLen, llB.outBits) + wr.addBits32NC(s.matchLen, mlB.outBits) + wr.addBits32NC(s.offset, ofB.outBits) + + if debugSequences { + println("Encoded seq", seq, s) + } + + seq-- + } + } else { + for seq >= 0 { + s = b.sequences[seq] + wr.flush32() + llB, ofB, mlB := llTT[s.llCode], ofTT[s.ofCode], mlTT[s.mlCode] + // tabelog max is below 8 for each. + of.encode(ofB) + ml.encode(mlB) + ll.encode(llB) + wr.flush32() + + // ml+ll = max 32 bits total + wr.addBits32NC(s.litLen, llB.outBits) + wr.addBits32NC(s.matchLen, mlB.outBits) + wr.flush32() + wr.addBits32NC(s.offset, ofB.outBits) + + if debugSequences { + println("Encoded seq", seq, s) + } + + seq-- + } + } + ml.flush(mlEnc.actualTableLog) + of.flush(ofEnc.actualTableLog) + ll.flush(llEnc.actualTableLog) + err = wr.close() + if err != nil { + return err + } + b.output = wr.out + + if len(b.output)-3 >= b.size { + // Maybe even add a bigger margin. + b.litEnc.Reuse = huff0.ReusePolicyNone + return errIncompressible + } + + // Size is output minus block header. + bh.setSize(uint32(len(b.output)) - 3) + if debug { + println("Rewriting block header", bh) + } + _ = bh.appendTo(b.output[:0]) + b.coders.setPrev(llEnc, mlEnc, ofEnc) + return nil +} + +var errIncompressible = errors.New("uncompressible") + +func (b *blockEnc) genCodes() { + if len(b.sequences) == 0 { + // nothing to do + return + } + + if len(b.sequences) > math.MaxUint16 { + panic("can only encode up to 64K sequences") + } + // No bounds checks after here: + llH := b.coders.llEnc.Histogram()[:256] + ofH := b.coders.ofEnc.Histogram()[:256] + mlH := b.coders.mlEnc.Histogram()[:256] + for i := range llH { + llH[i] = 0 + } + for i := range ofH { + ofH[i] = 0 + } + for i := range mlH { + mlH[i] = 0 + } + + var llMax, ofMax, mlMax uint8 + for i, seq := range b.sequences { + v := llCode(seq.litLen) + seq.llCode = v + llH[v]++ + if v > llMax { + llMax = v + } + + v = ofCode(seq.offset) + seq.ofCode = v + ofH[v]++ + if v > ofMax { + ofMax = v + } + + v = mlCode(seq.matchLen) + seq.mlCode = v + mlH[v]++ + if v > mlMax { + mlMax = v + if debug && mlMax > maxMatchLengthSymbol { + panic(fmt.Errorf("mlMax > maxMatchLengthSymbol (%d), matchlen: %d", mlMax, seq.matchLen)) + } + } + b.sequences[i] = seq + } + maxCount := func(a []uint32) int { + var max uint32 + for _, v := range a { + if v > max { + max = v + } + } + return int(max) + } + if mlMax > maxMatchLengthSymbol { + panic(fmt.Errorf("mlMax > maxMatchLengthSymbol (%d)", mlMax)) + } + if ofMax > maxOffsetBits { + panic(fmt.Errorf("ofMax > maxOffsetBits (%d)", ofMax)) + } + if llMax > maxLiteralLengthSymbol { + panic(fmt.Errorf("llMax > maxLiteralLengthSymbol (%d)", llMax)) + } + + b.coders.mlEnc.HistogramFinished(mlMax, maxCount(mlH[:mlMax+1])) + b.coders.ofEnc.HistogramFinished(ofMax, maxCount(ofH[:ofMax+1])) + b.coders.llEnc.HistogramFinished(llMax, maxCount(llH[:llMax+1])) +} diff --git a/vendor/github.com/klauspost/compress/zstd/blocktype_string.go b/vendor/github.com/klauspost/compress/zstd/blocktype_string.go new file mode 100644 index 000000000..01a01e486 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/blocktype_string.go @@ -0,0 +1,85 @@ +// Code generated by "stringer -type=blockType,literalsBlockType,seqCompMode,tableIndex"; DO NOT EDIT. + +package zstd + +import "strconv" + +func _() { + // An "invalid array index" compiler error signifies that the constant values have changed. + // Re-run the stringer command to generate them again. + var x [1]struct{} + _ = x[blockTypeRaw-0] + _ = x[blockTypeRLE-1] + _ = x[blockTypeCompressed-2] + _ = x[blockTypeReserved-3] +} + +const _blockType_name = "blockTypeRawblockTypeRLEblockTypeCompressedblockTypeReserved" + +var _blockType_index = [...]uint8{0, 12, 24, 43, 60} + +func (i blockType) String() string { + if i >= blockType(len(_blockType_index)-1) { + return "blockType(" + strconv.FormatInt(int64(i), 10) + ")" + } + return _blockType_name[_blockType_index[i]:_blockType_index[i+1]] +} +func _() { + // An "invalid array index" compiler error signifies that the constant values have changed. + // Re-run the stringer command to generate them again. + var x [1]struct{} + _ = x[literalsBlockRaw-0] + _ = x[literalsBlockRLE-1] + _ = x[literalsBlockCompressed-2] + _ = x[literalsBlockTreeless-3] +} + +const _literalsBlockType_name = "literalsBlockRawliteralsBlockRLEliteralsBlockCompressedliteralsBlockTreeless" + +var _literalsBlockType_index = [...]uint8{0, 16, 32, 55, 76} + +func (i literalsBlockType) String() string { + if i >= literalsBlockType(len(_literalsBlockType_index)-1) { + return "literalsBlockType(" + strconv.FormatInt(int64(i), 10) + ")" + } + return _literalsBlockType_name[_literalsBlockType_index[i]:_literalsBlockType_index[i+1]] +} +func _() { + // An "invalid array index" compiler error signifies that the constant values have changed. + // Re-run the stringer command to generate them again. + var x [1]struct{} + _ = x[compModePredefined-0] + _ = x[compModeRLE-1] + _ = x[compModeFSE-2] + _ = x[compModeRepeat-3] +} + +const _seqCompMode_name = "compModePredefinedcompModeRLEcompModeFSEcompModeRepeat" + +var _seqCompMode_index = [...]uint8{0, 18, 29, 40, 54} + +func (i seqCompMode) String() string { + if i >= seqCompMode(len(_seqCompMode_index)-1) { + return "seqCompMode(" + strconv.FormatInt(int64(i), 10) + ")" + } + return _seqCompMode_name[_seqCompMode_index[i]:_seqCompMode_index[i+1]] +} +func _() { + // An "invalid array index" compiler error signifies that the constant values have changed. + // Re-run the stringer command to generate them again. + var x [1]struct{} + _ = x[tableLiteralLengths-0] + _ = x[tableOffsets-1] + _ = x[tableMatchLengths-2] +} + +const _tableIndex_name = "tableLiteralLengthstableOffsetstableMatchLengths" + +var _tableIndex_index = [...]uint8{0, 19, 31, 48} + +func (i tableIndex) String() string { + if i >= tableIndex(len(_tableIndex_index)-1) { + return "tableIndex(" + strconv.FormatInt(int64(i), 10) + ")" + } + return _tableIndex_name[_tableIndex_index[i]:_tableIndex_index[i+1]] +} diff --git a/vendor/github.com/klauspost/compress/zstd/bytebuf.go b/vendor/github.com/klauspost/compress/zstd/bytebuf.go new file mode 100644 index 000000000..4a8460476 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/bytebuf.go @@ -0,0 +1,121 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "fmt" + "io" + "io/ioutil" +) + +type byteBuffer interface { + // Read up to 8 bytes. + // Returns nil if no more input is available. + readSmall(n int) []byte + + // Read >8 bytes. + // MAY use the destination slice. + readBig(n int, dst []byte) ([]byte, error) + + // Read a single byte. + readByte() (byte, error) + + // Skip n bytes. + skipN(n int) error +} + +// in-memory buffer +type byteBuf []byte + +func (b *byteBuf) readSmall(n int) []byte { + if debug && n > 8 { + panic(fmt.Errorf("small read > 8 (%d). use readBig", n)) + } + bb := *b + if len(bb) < n { + return nil + } + r := bb[:n] + *b = bb[n:] + return r +} + +func (b *byteBuf) readBig(n int, dst []byte) ([]byte, error) { + bb := *b + if len(bb) < n { + return nil, io.ErrUnexpectedEOF + } + r := bb[:n] + *b = bb[n:] + return r, nil +} + +func (b *byteBuf) remain() []byte { + return *b +} + +func (b *byteBuf) readByte() (byte, error) { + bb := *b + if len(bb) < 1 { + return 0, nil + } + r := bb[0] + *b = bb[1:] + return r, nil +} + +func (b *byteBuf) skipN(n int) error { + bb := *b + if len(bb) < n { + return io.ErrUnexpectedEOF + } + *b = bb[n:] + return nil +} + +// wrapper around a reader. +type readerWrapper struct { + r io.Reader + tmp [8]byte +} + +func (r *readerWrapper) readSmall(n int) []byte { + if debug && n > 8 { + panic(fmt.Errorf("small read > 8 (%d). use readBig", n)) + } + n2, err := io.ReadFull(r.r, r.tmp[:n]) + // We only really care about the actual bytes read. + if n2 != n { + if debug { + println("readSmall: got", n2, "want", n, "err", err) + } + return nil + } + return r.tmp[:n] +} + +func (r *readerWrapper) readBig(n int, dst []byte) ([]byte, error) { + if cap(dst) < n { + dst = make([]byte, n) + } + n2, err := io.ReadFull(r.r, dst[:n]) + return dst[:n2], err +} + +func (r *readerWrapper) readByte() (byte, error) { + n2, err := r.r.Read(r.tmp[:1]) + if err != nil { + return 0, err + } + if n2 != 1 { + return 0, io.ErrUnexpectedEOF + } + return r.tmp[0], nil +} + +func (r *readerWrapper) skipN(n int) error { + _, err := io.CopyN(ioutil.Discard, r.r, int64(n)) + return err +} diff --git a/vendor/github.com/klauspost/compress/zstd/bytereader.go b/vendor/github.com/klauspost/compress/zstd/bytereader.go new file mode 100644 index 000000000..dc4378b64 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/bytereader.go @@ -0,0 +1,74 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +// byteReader provides a byte reader that reads +// little endian values from a byte stream. +// The input stream is manually advanced. +// The reader performs no bounds checks. +type byteReader struct { + b []byte + off int +} + +// init will initialize the reader and set the input. +func (b *byteReader) init(in []byte) { + b.b = in + b.off = 0 +} + +// advance the stream b n bytes. +func (b *byteReader) advance(n uint) { + b.off += int(n) +} + +// overread returns whether we have advanced too far. +func (b *byteReader) overread() bool { + return b.off > len(b.b) +} + +// Int32 returns a little endian int32 starting at current offset. +func (b byteReader) Int32() int32 { + b2 := b.b[b.off : b.off+4 : b.off+4] + v3 := int32(b2[3]) + v2 := int32(b2[2]) + v1 := int32(b2[1]) + v0 := int32(b2[0]) + return v0 | (v1 << 8) | (v2 << 16) | (v3 << 24) +} + +// Uint8 returns the next byte +func (b *byteReader) Uint8() uint8 { + v := b.b[b.off] + return v +} + +// Uint32 returns a little endian uint32 starting at current offset. +func (b byteReader) Uint32() uint32 { + if r := b.remain(); r < 4 { + // Very rare + v := uint32(0) + for i := 1; i <= r; i++ { + v = (v << 8) | uint32(b.b[len(b.b)-i]) + } + return v + } + b2 := b.b[b.off : b.off+4 : b.off+4] + v3 := uint32(b2[3]) + v2 := uint32(b2[2]) + v1 := uint32(b2[1]) + v0 := uint32(b2[0]) + return v0 | (v1 << 8) | (v2 << 16) | (v3 << 24) +} + +// unread returns the unread portion of the input. +func (b byteReader) unread() []byte { + return b.b[b.off:] +} + +// remain will return the number of bytes remaining. +func (b byteReader) remain() int { + return len(b.b) - b.off +} diff --git a/vendor/github.com/klauspost/compress/zstd/decoder.go b/vendor/github.com/klauspost/compress/zstd/decoder.go new file mode 100644 index 000000000..f06bff6f6 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/decoder.go @@ -0,0 +1,437 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "bytes" + "errors" + "io" + "sync" +) + +// Decoder provides decoding of zstandard streams. +// The decoder has been designed to operate without allocations after a warmup. +// This means that you should store the decoder for best performance. +// To re-use a stream decoder, use the Reset(r io.Reader) error to switch to another stream. +// A decoder can safely be re-used even if the previous stream failed. +// To release the resources, you must call the Close() function on a decoder. +type Decoder struct { + o decoderOptions + + // Unreferenced decoders, ready for use. + decoders chan *blockDec + + // Unreferenced decoders, ready for use. + frames chan *frameDec + + // Streams ready to be decoded. + stream chan decodeStream + + // Current read position used for Reader functionality. + current decoderState + + // Custom dictionaries + dicts map[uint32]struct{} + + // streamWg is the waitgroup for all streams + streamWg sync.WaitGroup +} + +// decoderState is used for maintaining state when the decoder +// is used for streaming. +type decoderState struct { + // current block being written to stream. + decodeOutput + + // output in order to be written to stream. + output chan decodeOutput + + // cancel remaining output. + cancel chan struct{} + + flushed bool +} + +var ( + // Check the interfaces we want to support. + _ = io.WriterTo(&Decoder{}) + _ = io.Reader(&Decoder{}) +) + +// NewReader creates a new decoder. +// A nil Reader can be provided in which case Reset can be used to start a decode. +// +// A Decoder can be used in two modes: +// +// 1) As a stream, or +// 2) For stateless decoding using DecodeAll or DecodeBuffer. +// +// Only a single stream can be decoded concurrently, but the same decoder +// can run multiple concurrent stateless decodes. It is even possible to +// use stateless decodes while a stream is being decoded. +// +// The Reset function can be used to initiate a new stream, which is will considerably +// reduce the allocations normally caused by NewReader. +func NewReader(r io.Reader, opts ...DOption) (*Decoder, error) { + var d Decoder + d.o.setDefault() + for _, o := range opts { + err := o(&d.o) + if err != nil { + return nil, err + } + } + d.current.output = make(chan decodeOutput, d.o.concurrent) + d.current.flushed = true + + // Create decoders + d.decoders = make(chan *blockDec, d.o.concurrent) + d.frames = make(chan *frameDec, d.o.concurrent) + for i := 0; i < d.o.concurrent; i++ { + d.frames <- newFrameDec(d.o) + d.decoders <- newBlockDec(d.o.lowMem) + } + + if r == nil { + return &d, nil + } + return &d, d.Reset(r) +} + +// Read bytes from the decompressed stream into p. +// Returns the number of bytes written and any error that occurred. +// When the stream is done, io.EOF will be returned. +func (d *Decoder) Read(p []byte) (int, error) { + if d.stream == nil { + return 0, errors.New("no input has been initialized") + } + var n int + for { + if len(d.current.b) > 0 { + filled := copy(p, d.current.b) + p = p[filled:] + d.current.b = d.current.b[filled:] + n += filled + } + if len(p) == 0 { + break + } + if len(d.current.b) == 0 { + // We have an error and no more data + if d.current.err != nil { + break + } + d.nextBlock() + } + } + if len(d.current.b) > 0 { + // Only return error at end of block + return n, nil + } + if d.current.err != nil { + d.drainOutput() + } + if debug { + println("returning", n, d.current.err, len(d.decoders)) + } + return n, d.current.err +} + +// Reset will reset the decoder the supplied stream after the current has finished processing. +// Note that this functionality cannot be used after Close has been called. +func (d *Decoder) Reset(r io.Reader) error { + if d.current.err == ErrDecoderClosed { + return d.current.err + } + if r == nil { + return errors.New("nil Reader sent as input") + } + + if d.stream == nil { + d.stream = make(chan decodeStream, 1) + d.streamWg.Add(1) + go d.startStreamDecoder(d.stream) + } + + d.drainOutput() + + // If bytes buffer and < 1MB, do sync decoding anyway. + if bb, ok := r.(*bytes.Buffer); ok && bb.Len() < 1<<20 { + b := bb.Bytes() + dst, err := d.DecodeAll(b, nil) + if err == nil { + err = io.EOF + } + d.current.b = dst + d.current.err = err + d.current.flushed = true + return nil + } + + // Remove current block. + d.current.decodeOutput = decodeOutput{} + d.current.err = nil + d.current.cancel = make(chan struct{}) + d.current.flushed = false + d.current.d = nil + + d.stream <- decodeStream{ + r: r, + output: d.current.output, + cancel: d.current.cancel, + } + return nil +} + +// drainOutput will drain the output until errEndOfStream is sent. +func (d *Decoder) drainOutput() { + if d.current.cancel != nil { + println("cancelling current") + close(d.current.cancel) + d.current.cancel = nil + } + if d.current.d != nil { + println("re-adding current decoder", d.current.d, len(d.decoders)) + d.decoders <- d.current.d + d.current.d = nil + d.current.b = nil + } + if d.current.output == nil || d.current.flushed { + println("current already flushed") + return + } + for { + select { + case v := <-d.current.output: + if v.d != nil { + println("got decoder", v.d) + d.decoders <- v.d + } + if v.err == errEndOfStream { + println("current flushed") + d.current.flushed = true + return + } + } + } +} + +// WriteTo writes data to w until there's no more data to write or when an error occurs. +// The return value n is the number of bytes written. +// Any error encountered during the write is also returned. +func (d *Decoder) WriteTo(w io.Writer) (int64, error) { + if d.stream == nil { + return 0, errors.New("no input has been initialized") + } + var n int64 + for { + if len(d.current.b) > 0 { + n2, err2 := w.Write(d.current.b) + n += int64(n2) + if err2 != nil && d.current.err == nil { + d.current.err = err2 + break + } + } + if d.current.err != nil { + break + } + d.nextBlock() + } + err := d.current.err + if err != nil { + d.drainOutput() + } + if err == io.EOF { + err = nil + } + return n, err +} + +// DecodeAll allows stateless decoding of a blob of bytes. +// Output will be appended to dst, so if the destination size is known +// you can pre-allocate the destination slice to avoid allocations. +// DecodeAll can be used concurrently. +// The Decoder concurrency limits will be respected. +func (d *Decoder) DecodeAll(input, dst []byte) ([]byte, error) { + if d.current.err == ErrDecoderClosed { + return dst, ErrDecoderClosed + } + //println(len(d.frames), len(d.decoders), d.current) + block, frame := <-d.decoders, <-d.frames + defer func() { + d.decoders <- block + frame.rawInput = nil + d.frames <- frame + }() + if cap(dst) == 0 { + // Allocate 1MB by default. + dst = make([]byte, 0, 1<<20) + } + br := byteBuf(input) + for { + err := frame.reset(&br) + if err == io.EOF { + return dst, nil + } + if err != nil { + return dst, err + } + if frame.FrameContentSize > d.o.maxDecodedSize-uint64(len(dst)) { + return dst, ErrDecoderSizeExceeded + } + if frame.FrameContentSize > 0 && frame.FrameContentSize < 1<<30 { + // Never preallocate moe than 1 GB up front. + if uint64(cap(dst)) < frame.FrameContentSize { + dst2 := make([]byte, len(dst), len(dst)+int(frame.FrameContentSize)) + copy(dst2, dst) + dst = dst2 + } + } + dst, err = frame.runDecoder(dst, block) + if err != nil { + return dst, err + } + if len(br) == 0 { + break + } + } + return dst, nil +} + +// nextBlock returns the next block. +// If an error occurs d.err will be set. +func (d *Decoder) nextBlock() { + if d.current.d != nil { + d.decoders <- d.current.d + d.current.d = nil + } + if d.current.err != nil { + // Keep error state. + return + } + d.current.decodeOutput = <-d.current.output + if debug { + println("got", len(d.current.b), "bytes, error:", d.current.err) + } +} + +// Close will release all resources. +// It is NOT possible to reuse the decoder after this. +func (d *Decoder) Close() { + if d.current.err == ErrDecoderClosed { + return + } + d.drainOutput() + if d.stream != nil { + close(d.stream) + d.streamWg.Wait() + d.stream = nil + } + if d.decoders != nil { + close(d.decoders) + for dec := range d.decoders { + dec.Close() + } + d.decoders = nil + } + if d.current.d != nil { + d.current.d.Close() + d.current.d = nil + } + d.current.err = ErrDecoderClosed +} + +type decodeOutput struct { + d *blockDec + b []byte + err error +} + +type decodeStream struct { + r io.Reader + + // Blocks ready to be written to output. + output chan decodeOutput + + // cancel reading from the input + cancel chan struct{} +} + +// errEndOfStream indicates that everything from the stream was read. +var errEndOfStream = errors.New("end-of-stream") + +// Create Decoder: +// Spawn n block decoders. These accept tasks to decode a block. +// Create goroutine that handles stream processing, this will send history to decoders as they are available. +// Decoders update the history as they decode. +// When a block is returned: +// a) history is sent to the next decoder, +// b) content written to CRC. +// c) return data to WRITER. +// d) wait for next block to return data. +// Once WRITTEN, the decoders reused by the writer frame decoder for re-use. +func (d *Decoder) startStreamDecoder(inStream chan decodeStream) { + defer d.streamWg.Done() + frame := newFrameDec(d.o) + for stream := range inStream { + br := readerWrapper{r: stream.r} + decodeStream: + for { + err := frame.reset(&br) + if debug && err != nil { + println("Frame decoder returned", err) + } + if err != nil { + stream.output <- decodeOutput{ + err: err, + } + break + } + if debug { + println("starting frame decoder") + } + + // This goroutine will forward history between frames. + frame.frameDone.Add(1) + frame.initAsync() + + go frame.startDecoder(stream.output) + decodeFrame: + // Go through all blocks of the frame. + for { + dec := <-d.decoders + select { + case <-stream.cancel: + if !frame.sendErr(dec, io.EOF) { + // To not let the decoder dangle, send it back. + stream.output <- decodeOutput{d: dec} + } + break decodeStream + default: + } + err := frame.next(dec) + switch err { + case io.EOF: + // End of current frame, no error + println("EOF on next block") + break decodeFrame + case nil: + continue + default: + println("block decoder returned", err) + break decodeStream + } + } + // All blocks have started decoding, check if there are more frames. + println("waiting for done") + frame.frameDone.Wait() + println("done waiting...") + } + frame.frameDone.Wait() + println("Sending EOS") + stream.output <- decodeOutput{err: errEndOfStream} + } +} diff --git a/vendor/github.com/klauspost/compress/zstd/decoder_options.go b/vendor/github.com/klauspost/compress/zstd/decoder_options.go new file mode 100644 index 000000000..52c1eb066 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/decoder_options.go @@ -0,0 +1,66 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "errors" + "fmt" + "runtime" +) + +// DOption is an option for creating a decoder. +type DOption func(*decoderOptions) error + +// options retains accumulated state of multiple options. +type decoderOptions struct { + lowMem bool + concurrent int + maxDecodedSize uint64 +} + +func (o *decoderOptions) setDefault() { + *o = decoderOptions{ + // use less ram: true for now, but may change. + lowMem: true, + concurrent: runtime.GOMAXPROCS(0), + } + o.maxDecodedSize = 1 << 63 +} + +// WithDecoderLowmem will set whether to use a lower amount of memory, +// but possibly have to allocate more while running. +func WithDecoderLowmem(b bool) DOption { + return func(o *decoderOptions) error { o.lowMem = b; return nil } +} + +// WithDecoderConcurrency will set the concurrency, +// meaning the maximum number of decoders to run concurrently. +// The value supplied must be at least 1. +// By default this will be set to GOMAXPROCS. +func WithDecoderConcurrency(n int) DOption { + return func(o *decoderOptions) error { + if n <= 0 { + return fmt.Errorf("Concurrency must be at least 1") + } + o.concurrent = n + return nil + } +} + +// WithDecoderMaxMemory allows to set a maximum decoded size for in-memory +// (non-streaming) operations. +// Maxmimum and default is 1 << 63 bytes. +func WithDecoderMaxMemory(n uint64) DOption { + return func(o *decoderOptions) error { + if n == 0 { + return errors.New("WithDecoderMaxmemory must be at least 1") + } + if n > 1<<63 { + return fmt.Errorf("WithDecoderMaxmemorymust be less than 1 << 63") + } + o.maxDecodedSize = n + return nil + } +} diff --git a/vendor/github.com/klauspost/compress/zstd/enc_dfast.go b/vendor/github.com/klauspost/compress/zstd/enc_dfast.go new file mode 100644 index 000000000..02c79814f --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/enc_dfast.go @@ -0,0 +1,410 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +const ( + dFastLongTableBits = 17 // Bits used in the long match table + dFastLongTableSize = 1 << dFastLongTableBits // Size of the table + dFastLongTableMask = dFastLongTableSize - 1 // Mask for table indices. Redundant, but can eliminate bounds checks. + + dFastShortTableBits = tableBits // Bits used in the short match table + dFastShortTableSize = 1 << dFastShortTableBits // Size of the table + dFastShortTableMask = dFastShortTableSize - 1 // Mask for table indices. Redundant, but can eliminate bounds checks. +) + +type doubleFastEncoder struct { + fastEncoder + longTable [dFastLongTableSize]tableEntry +} + +// Encode mimmics functionality in zstd_dfast.c +func (e *doubleFastEncoder) Encode(blk *blockEnc, src []byte) { + const ( + // Input margin is the number of bytes we read (8) + // and the maximum we will read ahead (2) + inputMargin = 8 + 2 + minNonLiteralBlockSize = 16 + ) + + // Protect against e.cur wraparound. + for e.cur > (1<<30)+e.maxMatchOff { + if len(e.hist) == 0 { + for i := range e.table[:] { + e.table[i] = tableEntry{} + } + for i := range e.longTable[:] { + e.longTable[i] = tableEntry{} + } + e.cur = e.maxMatchOff + break + } + // Shift down everything in the table that isn't already too far away. + minOff := e.cur + int32(len(e.hist)) - e.maxMatchOff + for i := range e.table[:] { + v := e.table[i].offset + if v < minOff { + v = 0 + } else { + v = v - e.cur + e.maxMatchOff + } + e.table[i].offset = v + } + for i := range e.longTable[:] { + v := e.longTable[i].offset + if v < minOff { + v = 0 + } else { + v = v - e.cur + e.maxMatchOff + } + e.longTable[i].offset = v + } + e.cur = e.maxMatchOff + } + + s := e.addBlock(src) + blk.size = len(src) + if len(src) < minNonLiteralBlockSize { + blk.extraLits = len(src) + blk.literals = blk.literals[:len(src)] + copy(blk.literals, src) + return + } + + // Override src + src = e.hist + sLimit := int32(len(src)) - inputMargin + // stepSize is the number of bytes to skip on every main loop iteration. + // It should be >= 1. + stepSize := int32(e.o.targetLength) + if stepSize == 0 { + stepSize++ + } + + // TEMPLATE + + const kSearchStrength = 8 + + // nextEmit is where in src the next emitLiteral should start from. + nextEmit := s + cv := load6432(src, s) + // nextHash is the hash at s + nextHashS := hash5(cv, dFastShortTableBits) + nextHashL := hash8(cv, dFastLongTableBits) + + // Relative offsets + offset1 := int32(blk.recentOffsets[0]) + offset2 := int32(blk.recentOffsets[1]) + + addLiterals := func(s *seq, until int32) { + if until == nextEmit { + return + } + blk.literals = append(blk.literals, src[nextEmit:until]...) + s.litLen = uint32(until - nextEmit) + } + if debug { + println("recent offsets:", blk.recentOffsets) + } + +encodeLoop: + for { + var t int32 + // We allow the encoder to optionally turn off repeat offsets across blocks + canRepeat := len(blk.sequences) > 2 + + for { + if debug && canRepeat && offset1 == 0 { + panic("offset0 was 0") + } + + nextHashS = nextHashS & dFastShortTableMask + nextHashL = nextHashL & dFastLongTableMask + candidateL := e.longTable[nextHashL] + candidateS := e.table[nextHashS] + + const repOff = 1 + repIndex := s - offset1 + repOff + entry := tableEntry{offset: s + e.cur, val: uint32(cv)} + e.longTable[nextHashL] = entry + e.table[nextHashS] = entry + + if canRepeat { + if repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>(repOff*8)) { + // Consider history as well. + var seq seq + lenght := 4 + e.matchlen(s+4+repOff, repIndex+4, src) + + seq.matchLen = uint32(lenght - zstdMinMatch) + + // We might be able to match backwards. + // Extend as long as we can. + start := s + repOff + // We end the search early, so we don't risk 0 literals + // and have to do special offset treatment. + startLimit := nextEmit + 1 + + tMin := s - e.maxMatchOff + if tMin < 0 { + tMin = 0 + } + for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 { + repIndex-- + start-- + seq.matchLen++ + } + addLiterals(&seq, start) + + // rep 0 + seq.offset = 1 + if debugSequences { + println("repeat sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + s += lenght + repOff + nextEmit = s + if s >= sLimit { + if debug { + println("repeat ended", s, lenght) + + } + break encodeLoop + } + cv = load6432(src, s) + nextHashS = hash5(cv, dFastShortTableBits) + nextHashL = hash8(cv, dFastLongTableBits) + continue + } + const repOff2 = 1 + // We deviate from the reference encoder and also check offset 2. + // Slower and not consistently better, so disabled. + // repIndex = s - offset2 + repOff2 + if false && repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>(repOff2*8)) { + // Consider history as well. + var seq seq + lenght := 4 + e.matchlen(s+4+repOff2, repIndex+4, src) + + seq.matchLen = uint32(lenght - zstdMinMatch) + + // We might be able to match backwards. + // Extend as long as we can. + start := s + repOff2 + // We end the search early, so we don't risk 0 literals + // and have to do special offset treatment. + startLimit := nextEmit + 1 + + tMin := s - e.maxMatchOff + if tMin < 0 { + tMin = 0 + } + for repIndex > tMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch-1 { + repIndex-- + start-- + seq.matchLen++ + } + addLiterals(&seq, start) + + // rep 2 + seq.offset = 2 + if debugSequences { + println("repeat sequence 2", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + s += lenght + repOff2 + nextEmit = s + if s >= sLimit { + if debug { + println("repeat ended", s, lenght) + + } + break encodeLoop + } + cv = load6432(src, s) + nextHashS = hash5(cv, dFastShortTableBits) + nextHashL = hash8(cv, dFastLongTableBits) + // Swap offsets + offset1, offset2 = offset2, offset1 + continue + } + } + // Find the offsets of our two matches. + coffsetL := s - (candidateL.offset - e.cur) + coffsetS := s - (candidateS.offset - e.cur) + + // Check if we have a long match. + if coffsetL < e.maxMatchOff && uint32(cv) == candidateL.val { + // Found a long match, likely at least 8 bytes. + // Reference encoder checks all 8 bytes, we only check 4, + // but the likelihood of both the first 4 bytes and the hash matching should be enough. + t = candidateL.offset - e.cur + if debug && s <= t { + panic("s <= t") + } + if debug && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + if debug { + println("long match") + } + break + } + + // Check if we have a short match. + if coffsetS < e.maxMatchOff && uint32(cv) == candidateS.val { + // found a regular match + // See if we can find a long match at s+1 + const checkAt = 1 + cv := load6432(src, s+checkAt) + nextHashL = hash8(cv, dFastLongTableBits) + candidateL = e.longTable[nextHashL] + coffsetL = s - (candidateL.offset - e.cur) + checkAt + + // We can store it, since we have at least a 4 byte match. + e.longTable[nextHashL] = tableEntry{offset: s + checkAt + e.cur, val: uint32(cv)} + if coffsetL < e.maxMatchOff && uint32(cv) == candidateL.val { + // Found a long match, likely at least 8 bytes. + // Reference encoder checks all 8 bytes, we only check 4, + // but the likelihood of both the first 4 bytes and the hash matching should be enough. + t = candidateL.offset - e.cur + s += checkAt + if debug { + println("long match (after short)") + } + break + } + + t = candidateS.offset - e.cur + if debug && s <= t { + panic("s <= t") + } + if debug && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + if debug && t < 0 { + panic("t<0") + } + if debug { + println("short match") + } + break + } + + // No match found, move forward in input. + s += stepSize + ((s - nextEmit) >> (kSearchStrength - 1)) + if s >= sLimit { + break encodeLoop + } + cv = load6432(src, s) + nextHashS = hash5(cv, dFastShortTableBits) + nextHashL = hash8(cv, dFastLongTableBits) + } + + // A 4-byte match has been found. Update recent offsets. + // We'll later see if more than 4 bytes. + offset2 = offset1 + offset1 = s - t + + if debug && s <= t { + panic("s <= t") + } + + if debug && canRepeat && int(offset1) > len(src) { + panic("invalid offset") + } + + // Extend the 4-byte match as long as possible. + l := e.matchlen(s+4, t+4, src) + 4 + + // Extend backwards + tMin := s - e.maxMatchOff + if tMin < 0 { + tMin = 0 + } + for t > tMin && s > nextEmit && src[t-1] == src[s-1] && l < maxMatchLength { + s-- + t-- + l++ + } + + // Write our sequence + var seq seq + seq.litLen = uint32(s - nextEmit) + seq.matchLen = uint32(l - zstdMinMatch) + if seq.litLen > 0 { + blk.literals = append(blk.literals, src[nextEmit:s]...) + } + seq.offset = uint32(s-t) + 3 + s += l + if debugSequences { + println("sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + nextEmit = s + if s >= sLimit { + break encodeLoop + } + + // Index match start + 2 and end - 2 + index0 := s - l + 2 + index1 := s - 2 + if l == 4 { + // if l is 4, we would check the same place twice, so index s-1 instead. + index1++ + } + + cv0 := load6432(src, index0) + cv1 := load6432(src, index1) + entry0 := tableEntry{offset: index0 + e.cur, val: uint32(cv0)} + entry1 := tableEntry{offset: index1 + e.cur, val: uint32(cv1)} + e.table[hash5(cv0, dFastShortTableBits)&dFastShortTableMask] = entry0 + e.longTable[hash8(cv0, dFastLongTableBits)&dFastLongTableMask] = entry0 + e.table[hash5(cv1, dFastShortTableBits)&dFastShortTableMask] = entry1 + e.longTable[hash8(cv1, dFastLongTableBits)&dFastLongTableMask] = entry1 + + cv = load6432(src, s) + nextHashS = hash5(cv, dFastShortTableBits) + nextHashL = hash8(cv, dFastLongTableBits) + + // Check offset 2 + if o2 := s - offset2; canRepeat && o2 > 0 && load3232(src, o2) == uint32(cv) { + // We have at least 4 byte match. + // No need to check backwards. We come straight from a match + l := 4 + e.matchlen(s+4, o2+4, src) + // Store this, since we have it. + entry := tableEntry{offset: s + e.cur, val: uint32(cv)} + e.longTable[nextHashL&dFastLongTableMask] = entry + e.table[nextHashS&dFastShortTableMask] = entry + seq.matchLen = uint32(l) - zstdMinMatch + seq.litLen = 0 + // Since litlen is always 0, this is offset 1. + seq.offset = 1 + s += l + nextEmit = s + if debugSequences { + println("sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + + // Swap offset 1 and 2. + offset1, offset2 = offset2, offset1 + if s >= sLimit { + break encodeLoop + } + // Prepare next loop. + cv = load6432(src, s) + nextHashS = hash5(cv, dFastShortTableBits) + nextHashL = hash8(cv, dFastLongTableBits) + } + } + + if int(nextEmit) < len(src) { + blk.literals = append(blk.literals, src[nextEmit:]...) + blk.extraLits = len(src) - int(nextEmit) + } + blk.recentOffsets[0] = uint32(offset1) + blk.recentOffsets[1] = uint32(offset2) + if debug { + println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits) + } +} diff --git a/vendor/github.com/klauspost/compress/zstd/enc_fast.go b/vendor/github.com/klauspost/compress/zstd/enc_fast.go new file mode 100644 index 000000000..a8edaa888 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/enc_fast.go @@ -0,0 +1,416 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "math/bits" + + "github.com/klauspost/compress/zstd/internal/xxhash" +) + +const ( + tableBits = 15 // Bits used in the table + tableSize = 1 << tableBits // Size of the table + tableMask = tableSize - 1 // Mask for table indices. Redundant, but can eliminate bounds checks. + maxMatchLength = 131074 +) + +type tableEntry struct { + val uint32 + offset int32 +} + +type fastEncoder struct { + o encParams + // cur is the offset at the start of hist + cur int32 + // maximum offset. Should be at least 2x block size. + maxMatchOff int32 + hist []byte + crc *xxhash.Digest + table [tableSize]tableEntry + tmp [8]byte + blk *blockEnc +} + +// CRC returns the underlying CRC writer. +func (e *fastEncoder) CRC() *xxhash.Digest { + return e.crc +} + +// AppendCRC will append the CRC to the destination slice and return it. +func (e *fastEncoder) AppendCRC(dst []byte) []byte { + crc := e.crc.Sum(e.tmp[:0]) + dst = append(dst, crc[7], crc[6], crc[5], crc[4]) + return dst +} + +// WindowSize returns the window size of the encoder, +// or a window size small enough to contain the input size, if > 0. +func (e *fastEncoder) WindowSize(size int) int32 { + if size > 0 && size < int(e.maxMatchOff) { + b := int32(1) << uint(bits.Len(uint(size))) + // Keep minimum window. + if b < 1024 { + b = 1024 + } + return b + } + return e.maxMatchOff +} + +// Block returns the current block. +func (e *fastEncoder) Block() *blockEnc { + return e.blk +} + +// Encode mimmics functionality in zstd_fast.c +func (e *fastEncoder) Encode(blk *blockEnc, src []byte) { + const ( + inputMargin = 8 + minNonLiteralBlockSize = 1 + 1 + inputMargin + ) + + // Protect against e.cur wraparound. + for e.cur > (1<<30)+e.maxMatchOff { + if len(e.hist) == 0 { + for i := range e.table[:] { + e.table[i] = tableEntry{} + } + e.cur = e.maxMatchOff + break + } + // Shift down everything in the table that isn't already too far away. + minOff := e.cur + int32(len(e.hist)) - e.maxMatchOff + for i := range e.table[:] { + v := e.table[i].offset + if v < minOff { + v = 0 + } else { + v = v - e.cur + e.maxMatchOff + } + e.table[i].offset = v + } + e.cur = e.maxMatchOff + } + + s := e.addBlock(src) + blk.size = len(src) + if len(src) < minNonLiteralBlockSize { + blk.extraLits = len(src) + blk.literals = blk.literals[:len(src)] + copy(blk.literals, src) + return + } + + // Override src + src = e.hist + sLimit := int32(len(src)) - inputMargin + // stepSize is the number of bytes to skip on every main loop iteration. + // It should be >= 2. + stepSize := int32(e.o.targetLength) + if stepSize == 0 { + stepSize++ + } + stepSize++ + + // TEMPLATE + const hashLog = tableBits + // seems global, but would be nice to tweak. + const kSearchStrength = 8 + + // nextEmit is where in src the next emitLiteral should start from. + nextEmit := s + cv := load6432(src, s) + // nextHash is the hash at s + nextHash := hash6(cv, hashLog) + + // Relative offsets + offset1 := int32(blk.recentOffsets[0]) + offset2 := int32(blk.recentOffsets[1]) + + addLiterals := func(s *seq, until int32) { + if until == nextEmit { + return + } + blk.literals = append(blk.literals, src[nextEmit:until]...) + s.litLen = uint32(until - nextEmit) + } + if debug { + println("recent offsets:", blk.recentOffsets) + } + +encodeLoop: + for { + // t will contain the match offset when we find one. + // When existing the search loop, we have already checked 4 bytes. + var t int32 + + // We will not use repeat offsets across blocks. + // By not using them for the first 3 matches + canRepeat := len(blk.sequences) > 2 + + for { + if debug && canRepeat && offset1 == 0 { + panic("offset0 was 0") + } + + nextHash2 := hash6(cv>>8, hashLog) & tableMask + nextHash = nextHash & tableMask + candidate := e.table[nextHash] + candidate2 := e.table[nextHash2] + repIndex := s - offset1 + 2 + + e.table[nextHash] = tableEntry{offset: s + e.cur, val: uint32(cv)} + e.table[nextHash2] = tableEntry{offset: s + e.cur + 1, val: uint32(cv >> 8)} + + if canRepeat && repIndex >= 0 && load3232(src, repIndex) == uint32(cv>>16) { + // Consider history as well. + var seq seq + lenght := 4 + e.matchlen(s+6, repIndex+4, src) + + seq.matchLen = uint32(lenght - zstdMinMatch) + + // We might be able to match backwards. + // Extend as long as we can. + start := s + 2 + // We end the search early, so we don't risk 0 literals + // and have to do special offset treatment. + startLimit := nextEmit + 1 + + sMin := s - e.maxMatchOff + if sMin < 0 { + sMin = 0 + } + for repIndex > sMin && start > startLimit && src[repIndex-1] == src[start-1] && seq.matchLen < maxMatchLength-zstdMinMatch { + repIndex-- + start-- + seq.matchLen++ + } + addLiterals(&seq, start) + + // rep 0 + seq.offset = 1 + if debugSequences { + println("repeat sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + s += lenght + 2 + nextEmit = s + if s >= sLimit { + if debug { + println("repeat ended", s, lenght) + + } + break encodeLoop + } + cv = load6432(src, s) + //nextHash = hashLen(cv, hashLog, mls) + nextHash = hash6(cv, hashLog) + continue + } + coffset0 := s - (candidate.offset - e.cur) + coffset1 := s - (candidate2.offset - e.cur) + 1 + if coffset0 < e.maxMatchOff && uint32(cv) == candidate.val { + // found a regular match + t = candidate.offset - e.cur + if debug && s <= t { + panic("s <= t") + } + if debug && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + break + } + + if coffset1 < e.maxMatchOff && uint32(cv>>8) == candidate2.val { + // found a regular match + t = candidate2.offset - e.cur + s++ + if debug && s <= t { + panic("s <= t") + } + if debug && s-t > e.maxMatchOff { + panic("s - t >e.maxMatchOff") + } + if debug && t < 0 { + panic("t<0") + } + break + } + s += stepSize + ((s - nextEmit) >> (kSearchStrength - 1)) + if s >= sLimit { + break encodeLoop + } + cv = load6432(src, s) + nextHash = hash6(cv, hashLog) + } + // A 4-byte match has been found. We'll later see if more than 4 bytes. + offset2 = offset1 + offset1 = s - t + + if debug && s <= t { + panic("s <= t") + } + + if debug && canRepeat && int(offset1) > len(src) { + panic("invalid offset") + } + + // Extend the 4-byte match as long as possible. + l := e.matchlen(s+4, t+4, src) + 4 + + // Extend backwards + tMin := s - e.maxMatchOff + if tMin < 0 { + tMin = 0 + } + for t > tMin && s > nextEmit && src[t-1] == src[s-1] && l < maxMatchLength { + s-- + t-- + l++ + } + + // Write our sequence. + var seq seq + seq.litLen = uint32(s - nextEmit) + seq.matchLen = uint32(l - zstdMinMatch) + if seq.litLen > 0 { + blk.literals = append(blk.literals, src[nextEmit:s]...) + } + // Don't use repeat offsets + seq.offset = uint32(s-t) + 3 + s += l + if debugSequences { + println("sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + nextEmit = s + if s >= sLimit { + break encodeLoop + } + cv = load6432(src, s) + nextHash = hash6(cv, hashLog) + + // Check offset 2 + if o2 := s - offset2; canRepeat && o2 > 0 && load3232(src, o2) == uint32(cv) { + // We have at least 4 byte match. + // No need to check backwards. We come straight from a match + l := 4 + e.matchlen(s+4, o2+4, src) + // Store this, since we have it. + e.table[nextHash&tableMask] = tableEntry{offset: s + e.cur, val: uint32(cv)} + seq.matchLen = uint32(l) - zstdMinMatch + seq.litLen = 0 + // Since litlen is always 0, this is offset 1. + seq.offset = 1 + s += l + nextEmit = s + if debugSequences { + println("sequence", seq, "next s:", s) + } + blk.sequences = append(blk.sequences, seq) + + // Swap offset 1 and 2. + offset1, offset2 = offset2, offset1 + if s >= sLimit { + break encodeLoop + } + // Prepare next loop. + cv = load6432(src, s) + nextHash = hash6(cv, hashLog) + } + } + + if int(nextEmit) < len(src) { + blk.literals = append(blk.literals, src[nextEmit:]...) + blk.extraLits = len(src) - int(nextEmit) + } + blk.recentOffsets[0] = uint32(offset1) + blk.recentOffsets[1] = uint32(offset2) + if debug { + println("returning, recent offsets:", blk.recentOffsets, "extra literals:", blk.extraLits) + } +} + +func (e *fastEncoder) addBlock(src []byte) int32 { + // check if we have space already + if len(e.hist)+len(src) > cap(e.hist) { + if cap(e.hist) == 0 { + l := e.maxMatchOff * 2 + // Make it at least 1MB. + if l < 1<<20 { + l = 1 << 20 + } + e.hist = make([]byte, 0, l) + } else { + if cap(e.hist) < int(e.maxMatchOff*2) { + panic("unexpected buffer size") + } + // Move down + offset := int32(len(e.hist)) - e.maxMatchOff + copy(e.hist[0:e.maxMatchOff], e.hist[offset:]) + e.cur += offset + e.hist = e.hist[:e.maxMatchOff] + } + } + s := int32(len(e.hist)) + e.hist = append(e.hist, src...) + return s +} + +// useBlock will replace the block with the provided one, +// but transfer recent offsets from the previous. +func (e *fastEncoder) UseBlock(enc *blockEnc) { + enc.reset(e.blk) + e.blk = enc +} + +func (e *fastEncoder) matchlen(s, t int32, src []byte) int32 { + if debug { + if s < 0 { + panic("s<0") + } + if t < 0 { + panic("t<0") + } + if s-t > e.maxMatchOff { + panic(s - t) + } + } + s1 := int(s) + maxMatchLength - 4 + if s1 > len(src) { + s1 = len(src) + } + + // Extend the match to be as long as possible. + return int32(matchLen(src[s:s1], src[t:])) +} + +// Reset the encoding table. +func (e *fastEncoder) Reset() { + if e.blk == nil { + e.blk = &blockEnc{} + e.blk.init() + } else { + e.blk.reset(nil) + } + e.blk.initNewEncode() + if e.crc == nil { + e.crc = xxhash.New() + } else { + e.crc.Reset() + } + if cap(e.hist) < int(e.maxMatchOff*2) { + l := e.maxMatchOff * 2 + // Make it at least 1MB. + if l < 1<<20 { + l = 1 << 20 + } + e.hist = make([]byte, 0, l) + } + // We offset current position so everything will be out of reach + e.cur += e.maxMatchOff + int32(len(e.hist)) + e.hist = e.hist[:0] +} diff --git a/vendor/github.com/klauspost/compress/zstd/enc_params.go b/vendor/github.com/klauspost/compress/zstd/enc_params.go new file mode 100644 index 000000000..b6779ecb6 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/enc_params.go @@ -0,0 +1,154 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +type encParams struct { + // largest match distance : larger == more compression, more memory needed during decompression + windowLog uint8 + + // fully searched segment : larger == more compression, slower, more memory (useless for fast) + chainLog uint8 + + // dispatch table : larger == faster, more memory + hashLog uint8 + + // < nb of searches : larger == more compression, slower + searchLog uint8 + + // < match length searched : larger == faster decompression, sometimes less compression + minMatch uint8 + + // acceptable match size for optimal parser (only) : larger == more compression, slower + targetLength uint32 + + // see ZSTD_strategy definition above + strategy strategy +} + +// strategy defines the algorithm to use when generating sequences. +type strategy uint8 + +const ( + // Compression strategies, listed from fastest to strongest + strategyFast strategy = iota + 1 + strategyDfast + strategyGreedy + strategyLazy + strategyLazy2 + strategyBtlazy2 + strategyBtopt + strategyBtultra + strategyBtultra2 + // note : new strategies _might_ be added in the future. + // Only the order (from fast to strong) is guaranteed + +) + +var defEncParams = [4][]encParams{ + { // "default" - for any srcSize > 256 KB + // W, C, H, S, L, TL, strat + {19, 12, 13, 1, 6, 1, strategyFast}, // base for negative levels + {19, 13, 14, 1, 7, 0, strategyFast}, // level 1 + {20, 15, 16, 1, 6, 0, strategyFast}, // level 2 + {21, 16, 17, 1, 5, 1, strategyDfast}, // level 3 + {21, 18, 18, 1, 5, 1, strategyDfast}, // level 4 + {21, 18, 19, 2, 5, 2, strategyGreedy}, // level 5 + {21, 19, 19, 3, 5, 4, strategyGreedy}, // level 6 + {21, 19, 19, 3, 5, 8, strategyLazy}, // level 7 + {21, 19, 19, 3, 5, 16, strategyLazy2}, // level 8 + {21, 19, 20, 4, 5, 16, strategyLazy2}, // level 9 + {22, 20, 21, 4, 5, 16, strategyLazy2}, // level 10 + {22, 21, 22, 4, 5, 16, strategyLazy2}, // level 11 + {22, 21, 22, 5, 5, 16, strategyLazy2}, // level 12 + {22, 21, 22, 5, 5, 32, strategyBtlazy2}, // level 13 + {22, 22, 23, 5, 5, 32, strategyBtlazy2}, // level 14 + {22, 23, 23, 6, 5, 32, strategyBtlazy2}, // level 15 + {22, 22, 22, 5, 5, 48, strategyBtopt}, // level 16 + {23, 23, 22, 5, 4, 64, strategyBtopt}, // level 17 + {23, 23, 22, 6, 3, 64, strategyBtultra}, // level 18 + {23, 24, 22, 7, 3, 256, strategyBtultra2}, // level 19 + {25, 25, 23, 7, 3, 256, strategyBtultra2}, // level 20 + {26, 26, 24, 7, 3, 512, strategyBtultra2}, // level 21 + {27, 27, 25, 9, 3, 999, strategyBtultra2}, // level 22 + }, + { // for srcSize <= 256 KB + // W, C, H, S, L, T, strat + {18, 12, 13, 1, 5, 1, strategyFast}, // base for negative levels + {18, 13, 14, 1, 6, 0, strategyFast}, // level 1 + {18, 14, 14, 1, 5, 1, strategyDfast}, // level 2 + {18, 16, 16, 1, 4, 1, strategyDfast}, // level 3 + {18, 16, 17, 2, 5, 2, strategyGreedy}, // level 4. + {18, 18, 18, 3, 5, 2, strategyGreedy}, // level 5. + {18, 18, 19, 3, 5, 4, strategyLazy}, // level 6. + {18, 18, 19, 4, 4, 4, strategyLazy}, // level 7 + {18, 18, 19, 4, 4, 8, strategyLazy2}, // level 8 + {18, 18, 19, 5, 4, 8, strategyLazy2}, // level 9 + {18, 18, 19, 6, 4, 8, strategyLazy2}, // level 10 + {18, 18, 19, 5, 4, 12, strategyBtlazy2}, // level 11. + {18, 19, 19, 7, 4, 12, strategyBtlazy2}, // level 12. + {18, 18, 19, 4, 4, 16, strategyBtopt}, // level 13 + {18, 18, 19, 4, 3, 32, strategyBtopt}, // level 14. + {18, 18, 19, 6, 3, 128, strategyBtopt}, // level 15. + {18, 19, 19, 6, 3, 128, strategyBtultra}, // level 16. + {18, 19, 19, 8, 3, 256, strategyBtultra}, // level 17. + {18, 19, 19, 6, 3, 128, strategyBtultra2}, // level 18. + {18, 19, 19, 8, 3, 256, strategyBtultra2}, // level 19. + {18, 19, 19, 10, 3, 512, strategyBtultra2}, // level 20. + {18, 19, 19, 12, 3, 512, strategyBtultra2}, // level 21. + {18, 19, 19, 13, 3, 999, strategyBtultra2}, // level 22. + }, + { // for srcSize <= 128 KB + // W, C, H, S, L, T, strat + {17, 12, 12, 1, 5, 1, strategyFast}, // base for negative levels + {17, 12, 13, 1, 6, 0, strategyFast}, // level 1 + {17, 13, 15, 1, 5, 0, strategyFast}, // level 2 + {17, 15, 16, 2, 5, 1, strategyDfast}, // level 3 + {17, 17, 17, 2, 4, 1, strategyDfast}, // level 4 + {17, 16, 17, 3, 4, 2, strategyGreedy}, // level 5 + {17, 17, 17, 3, 4, 4, strategyLazy}, // level 6 + {17, 17, 17, 3, 4, 8, strategyLazy2}, // level 7 + {17, 17, 17, 4, 4, 8, strategyLazy2}, // level 8 + {17, 17, 17, 5, 4, 8, strategyLazy2}, // level 9 + {17, 17, 17, 6, 4, 8, strategyLazy2}, // level 10 + {17, 17, 17, 5, 4, 8, strategyBtlazy2}, // level 11 + {17, 18, 17, 7, 4, 12, strategyBtlazy2}, // level 12 + {17, 18, 17, 3, 4, 12, strategyBtopt}, // level 13. + {17, 18, 17, 4, 3, 32, strategyBtopt}, // level 14. + {17, 18, 17, 6, 3, 256, strategyBtopt}, // level 15. + {17, 18, 17, 6, 3, 128, strategyBtultra}, // level 16. + {17, 18, 17, 8, 3, 256, strategyBtultra}, // level 17. + {17, 18, 17, 10, 3, 512, strategyBtultra}, // level 18. + {17, 18, 17, 5, 3, 256, strategyBtultra2}, // level 19. + {17, 18, 17, 7, 3, 512, strategyBtultra2}, // level 20. + {17, 18, 17, 9, 3, 512, strategyBtultra2}, // level 21. + {17, 18, 17, 11, 3, 999, strategyBtultra2}, // level 22. + }, + { // for srcSize <= 16 KB + // W, C, H, S, L, T, strat + {14, 12, 13, 1, 5, 1, strategyFast}, // base for negative levels + {14, 14, 15, 1, 5, 0, strategyFast}, // level 1 + {14, 14, 15, 1, 4, 0, strategyFast}, // level 2 + {14, 14, 15, 2, 4, 1, strategyDfast}, // level 3 + {14, 14, 14, 4, 4, 2, strategyGreedy}, // level 4 + {14, 14, 14, 3, 4, 4, strategyLazy}, // level 5. + {14, 14, 14, 4, 4, 8, strategyLazy2}, // level 6 + {14, 14, 14, 6, 4, 8, strategyLazy2}, // level 7 + {14, 14, 14, 8, 4, 8, strategyLazy2}, // level 8. + {14, 15, 14, 5, 4, 8, strategyBtlazy2}, // level 9. + {14, 15, 14, 9, 4, 8, strategyBtlazy2}, // level 10. + {14, 15, 14, 3, 4, 12, strategyBtopt}, // level 11. + {14, 15, 14, 4, 3, 24, strategyBtopt}, // level 12. + {14, 15, 14, 5, 3, 32, strategyBtultra}, // level 13. + {14, 15, 15, 6, 3, 64, strategyBtultra}, // level 14. + {14, 15, 15, 7, 3, 256, strategyBtultra}, // level 15. + {14, 15, 15, 5, 3, 48, strategyBtultra2}, // level 16. + {14, 15, 15, 6, 3, 128, strategyBtultra2}, // level 17. + {14, 15, 15, 7, 3, 256, strategyBtultra2}, // level 18. + {14, 15, 15, 8, 3, 256, strategyBtultra2}, // level 19. + {14, 15, 15, 8, 3, 512, strategyBtultra2}, // level 20. + {14, 15, 15, 9, 3, 512, strategyBtultra2}, // level 21. + {14, 15, 15, 10, 3, 999, strategyBtultra2}, // level 22. + }, +} diff --git a/vendor/github.com/klauspost/compress/zstd/encoder.go b/vendor/github.com/klauspost/compress/zstd/encoder.go new file mode 100644 index 000000000..ed028f5a7 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/encoder.go @@ -0,0 +1,472 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "crypto/rand" + "fmt" + "io" + rdebug "runtime/debug" + "sync" + + "github.com/klauspost/compress/zstd/internal/xxhash" +) + +// Encoder provides encoding to Zstandard. +// An Encoder can be used for either compressing a stream via the +// io.WriteCloser interface supported by the Encoder or as multiple independent +// tasks via the EncodeAll function. +// Smaller encodes are encouraged to use the EncodeAll function. +// Use NewWriter to create a new instance. +type Encoder struct { + o encoderOptions + encoders chan encoder + state encoderState + init sync.Once +} + +type encoder interface { + Encode(blk *blockEnc, src []byte) + Block() *blockEnc + CRC() *xxhash.Digest + AppendCRC([]byte) []byte + WindowSize(size int) int32 + UseBlock(*blockEnc) + Reset() +} + +type encoderState struct { + w io.Writer + filling []byte + current []byte + previous []byte + encoder encoder + writing *blockEnc + err error + writeErr error + nWritten int64 + headerWritten bool + eofWritten bool + + // This waitgroup indicates an encode is running. + wg sync.WaitGroup + // This waitgroup indicates we have a block encoding/writing. + wWg sync.WaitGroup +} + +// NewWriter will create a new Zstandard encoder. +// If the encoder will be used for encoding blocks a nil writer can be used. +func NewWriter(w io.Writer, opts ...EOption) (*Encoder, error) { + var e Encoder + e.o.setDefault() + for _, o := range opts { + err := o(&e.o) + if err != nil { + return nil, err + } + } + if w != nil { + e.Reset(w) + } else { + e.init.Do(func() { + e.initialize() + }) + } + return &e, nil +} + +func (e *Encoder) initialize() { + e.encoders = make(chan encoder, e.o.concurrent) + for i := 0; i < e.o.concurrent; i++ { + e.encoders <- e.o.encoder() + } +} + +// Reset will re-initialize the writer and new writes will encode to the supplied writer +// as a new, independent stream. +func (e *Encoder) Reset(w io.Writer) { + e.init.Do(func() { + e.initialize() + }) + s := &e.state + s.wg.Wait() + s.wWg.Wait() + if cap(s.filling) == 0 { + s.filling = make([]byte, 0, e.o.blockSize) + } + if cap(s.current) == 0 { + s.current = make([]byte, 0, e.o.blockSize) + } + if cap(s.previous) == 0 { + s.previous = make([]byte, 0, e.o.blockSize) + } + if s.encoder == nil { + s.encoder = e.o.encoder() + } + if s.writing == nil { + s.writing = &blockEnc{} + s.writing.init() + } + s.writing.initNewEncode() + s.filling = s.filling[:0] + s.current = s.current[:0] + s.previous = s.previous[:0] + s.encoder.Reset() + s.headerWritten = false + s.eofWritten = false + s.w = w + s.err = nil + s.nWritten = 0 + s.writeErr = nil +} + +// Write data to the encoder. +// Input data will be buffered and as the buffer fills up +// content will be compressed and written to the output. +// When done writing, use Close to flush the remaining output +// and write CRC if requested. +func (e *Encoder) Write(p []byte) (n int, err error) { + s := &e.state + for len(p) > 0 { + if len(p)+len(s.filling) < e.o.blockSize { + if e.o.crc { + _, _ = s.encoder.CRC().Write(p) + } + s.filling = append(s.filling, p...) + return n + len(p), nil + } + add := p + if len(p)+len(s.filling) > e.o.blockSize { + add = add[:e.o.blockSize-len(s.filling)] + } + if e.o.crc { + _, _ = s.encoder.CRC().Write(add) + } + s.filling = append(s.filling, add...) + p = p[len(add):] + n += len(add) + if len(s.filling) < e.o.blockSize { + return n, nil + } + err := e.nextBlock(false) + if err != nil { + return n, err + } + if debug && len(s.filling) > 0 { + panic(len(s.filling)) + } + } + return n, nil +} + +// nextBlock will synchronize and start compressing input in e.state.filling. +// If an error has occurred during encoding it will be returned. +func (e *Encoder) nextBlock(final bool) error { + s := &e.state + // Wait for current block. + s.wg.Wait() + if s.err != nil { + return s.err + } + if len(s.filling) > e.o.blockSize { + return fmt.Errorf("block > maxStoreBlockSize") + } + if !s.headerWritten { + var tmp [maxHeaderSize]byte + fh := frameHeader{ + ContentSize: 0, + WindowSize: uint32(s.encoder.WindowSize(0)), + SingleSegment: false, + Checksum: e.o.crc, + DictID: 0, + } + dst, err := fh.appendTo(tmp[:0]) + if err != nil { + return err + } + s.headerWritten = true + s.wWg.Wait() + var n2 int + n2, s.err = s.w.Write(dst) + if s.err != nil { + return s.err + } + s.nWritten += int64(n2) + } + if s.eofWritten { + // Ensure we only write it once. + final = false + } + + if len(s.filling) == 0 { + // Final block, but no data. + if final { + enc := s.encoder + blk := enc.Block() + blk.reset(nil) + blk.last = true + blk.encodeRaw(nil) + s.wWg.Wait() + _, s.err = s.w.Write(blk.output) + s.nWritten += int64(len(blk.output)) + } + return s.err + } + + // Move blocks forward. + s.filling, s.current, s.previous = s.previous[:0], s.filling, s.current + s.wg.Add(1) + go func(src []byte) { + if debug { + println("Adding block,", len(src), "bytes, final:", final) + } + defer func() { + if r := recover(); r != nil { + s.err = fmt.Errorf("panic while encoding: %v", r) + rdebug.PrintStack() + } + s.wg.Done() + }() + enc := s.encoder + blk := enc.Block() + enc.Encode(blk, src) + blk.last = final + if final { + s.eofWritten = true + } + // Wait for pending writes. + s.wWg.Wait() + if s.writeErr != nil { + s.err = s.writeErr + return + } + // Transfer encoders from previous write block. + blk.swapEncoders(s.writing) + // Transfer recent offsets to next. + enc.UseBlock(s.writing) + s.writing = blk + s.wWg.Add(1) + go func() { + defer func() { + if r := recover(); r != nil { + s.writeErr = fmt.Errorf("panic while encoding/writing: %v", r) + rdebug.PrintStack() + } + s.wWg.Done() + }() + err := blk.encode() + switch err { + case errIncompressible: + if debug { + println("Storing incompressible block as raw") + } + blk.encodeRaw(src) + // In fast mode, we do not transfer offsets, so we don't have to deal with changing the. + case nil: + default: + s.writeErr = err + return + } + _, s.writeErr = s.w.Write(blk.output) + s.nWritten += int64(len(blk.output)) + }() + }(s.current) + return nil +} + +// ReadFrom reads data from r until EOF or error. +// The return value n is the number of bytes read. +// Any error except io.EOF encountered during the read is also returned. +// +// The Copy function uses ReaderFrom if available. +func (e *Encoder) ReadFrom(r io.Reader) (n int64, err error) { + if debug { + println("Using ReadFrom") + } + // Maybe handle stuff queued? + e.state.filling = e.state.filling[:e.o.blockSize] + src := e.state.filling + for { + n2, err := r.Read(src) + _, _ = e.state.encoder.CRC().Write(src[:n2]) + // src is now the unfilled part... + src = src[n2:] + n += int64(n2) + switch err { + case io.EOF: + e.state.filling = e.state.filling[:len(e.state.filling)-len(src)] + if debug { + println("ReadFrom: got EOF final block:", len(e.state.filling)) + } + return n, e.nextBlock(true) + default: + if debug { + println("ReadFrom: got error:", err) + } + e.state.err = err + return n, err + case nil: + } + if len(src) > 0 { + if debug { + println("ReadFrom: got space left in source:", len(src)) + } + continue + } + err = e.nextBlock(false) + if err != nil { + return n, err + } + e.state.filling = e.state.filling[:e.o.blockSize] + src = e.state.filling + } +} + +// Flush will send the currently written data to output +// and block until everything has been written. +// This should only be used on rare occasions where pushing the currently queued data is critical. +func (e *Encoder) Flush() error { + s := &e.state + if len(s.filling) > 0 { + err := e.nextBlock(false) + if err != nil { + return err + } + } + s.wg.Wait() + s.wWg.Wait() + if s.err != nil { + return s.err + } + return s.writeErr +} + +// Close will flush the final output and close the stream. +// The function will block until everything has been written. +// The Encoder can still be re-used after calling this. +func (e *Encoder) Close() error { + s := &e.state + if s.encoder == nil { + return nil + } + err := e.nextBlock(true) + if err != nil { + return err + } + s.wg.Wait() + s.wWg.Wait() + + if s.err != nil { + return s.err + } + if s.writeErr != nil { + return s.writeErr + } + + // Write CRC + if e.o.crc && s.err == nil { + // heap alloc. + var tmp [4]byte + _, s.err = s.w.Write(s.encoder.AppendCRC(tmp[:0])) + s.nWritten += 4 + } + + // Add padding with content from crypto/rand.Reader + if s.err == nil && e.o.pad > 0 { + add := calcSkippableFrame(s.nWritten, int64(e.o.pad)) + frame, err := skippableFrame(s.filling[:0], add, rand.Reader) + if err != nil { + return err + } + _, s.err = s.w.Write(frame) + } + return s.err +} + +// EncodeAll will encode all input in src and append it to dst. +// This function can be called concurrently, but each call will only run on a single goroutine. +// If empty input is given, nothing is returned. +// Encoded blocks can be concatenated and the result will be the combined input stream. +// Data compressed with EncodeAll can be decoded with the Decoder, +// using either a stream or DecodeAll. +func (e *Encoder) EncodeAll(src, dst []byte) []byte { + if len(src) == 0 { + return dst + } + e.init.Do(func() { + e.o.setDefault() + e.initialize() + }) + enc := <-e.encoders + defer func() { + // Release encoder reference to last block. + enc.Reset() + e.encoders <- enc + }() + enc.Reset() + blk := enc.Block() + single := len(src) > 1<<20 + if e.o.single != nil { + single = *e.o.single + } + fh := frameHeader{ + ContentSize: uint64(len(src)), + WindowSize: uint32(enc.WindowSize(len(src))), + SingleSegment: single, + Checksum: e.o.crc, + DictID: 0, + } + + // If less than 1MB, allocate a buffer up front. + if len(dst) == 0 && cap(dst) == 0 && len(src) < 1<<20 { + dst = make([]byte, 0, len(src)) + } + dst, err := fh.appendTo(dst) + if err != nil { + panic(err) + } + + for len(src) > 0 { + todo := src + if len(todo) > e.o.blockSize { + todo = todo[:e.o.blockSize] + } + src = src[len(todo):] + if e.o.crc { + _, _ = enc.CRC().Write(todo) + } + blk.reset(nil) + blk.pushOffsets() + enc.Encode(blk, todo) + if len(src) == 0 { + blk.last = true + } + err := blk.encode() + switch err { + case errIncompressible: + if debug { + println("Storing incompressible block as raw") + } + blk.encodeRaw(todo) + blk.popOffsets() + case nil: + default: + panic(err) + } + dst = append(dst, blk.output...) + } + if e.o.crc { + dst = enc.AppendCRC(dst) + } + // Add padding with content from crypto/rand.Reader + if e.o.pad > 0 { + add := calcSkippableFrame(int64(len(dst)), int64(e.o.pad)) + dst, err = skippableFrame(dst, add, rand.Reader) + if err != nil { + panic(err) + } + } + return dst +} diff --git a/vendor/github.com/klauspost/compress/zstd/encoder_options.go b/vendor/github.com/klauspost/compress/zstd/encoder_options.go new file mode 100644 index 000000000..6e210c4a0 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/encoder_options.go @@ -0,0 +1,184 @@ +package zstd + +import ( + "fmt" + "runtime" + "strings" +) + +// DOption is an option for creating a encoder. +type EOption func(*encoderOptions) error + +// options retains accumulated state of multiple options. +type encoderOptions struct { + concurrent int + crc bool + single *bool + pad int + blockSize int + windowSize int + level EncoderLevel +} + +func (o *encoderOptions) setDefault() { + *o = encoderOptions{ + // use less ram: true for now, but may change. + concurrent: runtime.GOMAXPROCS(0), + crc: true, + single: nil, + blockSize: 1 << 16, + windowSize: 1 << 22, + level: SpeedDefault, + } +} + +// encoder returns an encoder with the selected options. +func (o encoderOptions) encoder() encoder { + switch o.level { + case SpeedDefault: + return &doubleFastEncoder{fastEncoder: fastEncoder{maxMatchOff: int32(o.windowSize)}} + case SpeedFastest: + return &fastEncoder{maxMatchOff: int32(o.windowSize)} + } + panic("unknown compression level") +} + +// WithEncoderCRC will add CRC value to output. +// Output will be 4 bytes larger. +func WithEncoderCRC(b bool) EOption { + return func(o *encoderOptions) error { o.crc = b; return nil } +} + +// WithEncoderConcurrency will set the concurrency, +// meaning the maximum number of decoders to run concurrently. +// The value supplied must be at least 1. +// By default this will be set to GOMAXPROCS. +func WithEncoderConcurrency(n int) EOption { + return func(o *encoderOptions) error { + if n <= 0 { + return fmt.Errorf("concurrency must be at least 1") + } + o.concurrent = n + return nil + } +} + +// WithEncoderPadding will add padding to all output so the size will be a multiple of n. +// This can be used to obfuscate the exact output size or make blocks of a certain size. +// The contents will be a skippable frame, so it will be invisible by the decoder. +// n must be > 0 and <= 1GB, 1<<30 bytes. +// The padded area will be filled with data from crypto/rand.Reader. +// If `EncodeAll` is used with data already in the destination, the total size will be multiple of this. +func WithEncoderPadding(n int) EOption { + return func(o *encoderOptions) error { + if n <= 0 { + return fmt.Errorf("padding must be at least 1") + } + // No need to waste our time. + if n == 1 { + o.pad = 0 + } + if n > 1<<30 { + return fmt.Errorf("padding must less than 1GB (1<<30 bytes) ") + } + o.pad = n + return nil + } +} + +// EncoderLevel predefines encoder compression levels. +// Only use the constants made available, since the actual mapping +// of these values are very likely to change and your compression could change +// unpredictably when upgrading the library. +type EncoderLevel int + +const ( + speedNotSet EncoderLevel = iota + + // SpeedFastest will choose the fastest reasonable compression. + // This is roughly equivalent to the fastest Zstandard mode. + SpeedFastest + + // SpeedDefault is the default "pretty fast" compression option. + // This is roughly equivalent to the default Zstandard mode (level 3). + SpeedDefault + + // speedLast should be kept as the last actual compression option. + // The is not for external usage, but is used to keep track of the valid options. + speedLast + + // SpeedBetterCompression will (in the future) yield better compression than the default, + // but at approximately 4x the CPU usage of the default. + // For now this is not implemented. + SpeedBetterCompression = SpeedDefault + + // SpeedBestCompression will choose the best available compression option. + // For now this is not implemented. + SpeedBestCompression = SpeedDefault +) + +// EncoderLevelFromString will convert a string representation of an encoding level back +// to a compression level. The compare is not case sensitive. +// If the string wasn't recognized, (false, SpeedDefault) will be returned. +func EncoderLevelFromString(s string) (bool, EncoderLevel) { + for l := EncoderLevel(speedNotSet + 1); l < speedLast; l++ { + if strings.EqualFold(s, l.String()) { + return true, l + } + } + return false, SpeedDefault +} + +// EncoderLevelFromZstd will return an encoder level that closest matches the compression +// ratio of a specific zstd compression level. +// Many input values will provide the same compression level. +func EncoderLevelFromZstd(level int) EncoderLevel { + switch { + case level < 3: + return SpeedFastest + case level >= 3: + return SpeedDefault + } + return SpeedDefault +} + +// String provides a string representation of the compression level. +func (e EncoderLevel) String() string { + switch e { + case SpeedFastest: + return "fastest" + case SpeedDefault: + return "default" + default: + return "invalid" + } +} + +// WithEncoderLevel specifies a predefined compression level. +func WithEncoderLevel(l EncoderLevel) EOption { + return func(o *encoderOptions) error { + switch { + case l <= speedNotSet || l >= speedLast: + return fmt.Errorf("unknown encoder level") + } + o.level = l + return nil + } +} + +// WithSingleSegment will set the "single segment" flag when EncodeAll is used. +// If this flag is set, data must be regenerated within a single continuous memory segment. +// In this case, Window_Descriptor byte is skipped, but Frame_Content_Size is necessarily present. +// As a consequence, the decoder must allocate a memory segment of size equal or larger than size of your content. +// In order to preserve the decoder from unreasonable memory requirements, +// a decoder is allowed to reject a compressed frame which requests a memory size beyond decoder's authorized range. +// For broader compatibility, decoders are recommended to support memory sizes of at least 8 MB. +// This is only a recommendation, each decoder is free to support higher or lower limits, depending on local limitations. +// If this is not specified, block encodes will automatically choose this based on the input size. +// This setting has no effect on streamed encodes. +func WithSingleSegment(b bool) EOption { + return func(o *encoderOptions) error { + o.single = &b + return nil + } +} diff --git a/vendor/github.com/klauspost/compress/zstd/framedec.go b/vendor/github.com/klauspost/compress/zstd/framedec.go new file mode 100644 index 000000000..8fa264fc2 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/framedec.go @@ -0,0 +1,473 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "bytes" + "encoding/hex" + "errors" + "hash" + "io" + "sync" + + "github.com/klauspost/compress/zstd/internal/xxhash" +) + +type frameDec struct { + o decoderOptions + crc hash.Hash64 + frameDone sync.WaitGroup + offset int64 + + WindowSize uint64 + DictionaryID uint32 + FrameContentSize uint64 + HasCheckSum bool + SingleSegment bool + + // maxWindowSize is the maximum windows size to support. + // should never be bigger than max-int. + maxWindowSize uint64 + + // In order queue of blocks being decoded. + decoding chan *blockDec + + // Frame history passed between blocks + history history + + rawInput byteBuffer + + // asyncRunning indicates whether the async routine processes input on 'decoding'. + asyncRunning bool + asyncRunningMu sync.Mutex +} + +const ( + // The minimum Window_Size is 1 KB. + minWindowSize = 1 << 10 +) + +var ( + frameMagic = []byte{0x28, 0xb5, 0x2f, 0xfd} + skippableFrameMagic = []byte{0x2a, 0x4d, 0x18} +) + +func newFrameDec(o decoderOptions) *frameDec { + d := frameDec{ + o: o, + maxWindowSize: 1 << 30, + } + return &d +} + +// reset will read the frame header and prepare for block decoding. +// If nothing can be read from the input, io.EOF will be returned. +// Any other error indicated that the stream contained data, but +// there was a problem. +func (d *frameDec) reset(br byteBuffer) error { + d.HasCheckSum = false + d.WindowSize = 0 + var b []byte + for { + b = br.readSmall(4) + if b == nil { + return io.EOF + } + if !bytes.Equal(b[1:4], skippableFrameMagic) || b[0]&0xf0 != 0x50 { + if debug { + println("Not skippable", hex.EncodeToString(b), hex.EncodeToString(skippableFrameMagic)) + } + // Break if not skippable frame. + break + } + // Read size to skip + b = br.readSmall(4) + if b == nil { + println("Reading Frame Size EOF") + return io.ErrUnexpectedEOF + } + n := uint32(b[0]) | (uint32(b[1]) << 8) | (uint32(b[2]) << 16) | (uint32(b[3]) << 24) + println("Skipping frame with", n, "bytes.") + err := br.skipN(int(n)) + if err != nil { + if debug { + println("Reading discarded frame", err) + } + return err + } + } + if !bytes.Equal(b, frameMagic) { + println("Got magic numbers: ", b, "want:", frameMagic) + return ErrMagicMismatch + } + + // Read Frame_Header_Descriptor + fhd, err := br.readByte() + if err != nil { + println("Reading Frame_Header_Descriptor", err) + return err + } + d.SingleSegment = fhd&(1<<5) != 0 + + if fhd&(1<<3) != 0 { + return errors.New("Reserved bit set on frame header") + } + + // Read Window_Descriptor + // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#window_descriptor + d.WindowSize = 0 + if !d.SingleSegment { + wd, err := br.readByte() + if err != nil { + println("Reading Window_Descriptor", err) + return err + } + printf("raw: %x, mantissa: %d, exponent: %d\n", wd, wd&7, wd>>3) + windowLog := 10 + (wd >> 3) + windowBase := uint64(1) << windowLog + windowAdd := (windowBase / 8) * uint64(wd&0x7) + d.WindowSize = windowBase + windowAdd + } + + // Read Dictionary_ID + // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#dictionary_id + d.DictionaryID = 0 + if size := fhd & 3; size != 0 { + if size == 3 { + size = 4 + } + b = br.readSmall(int(size)) + if b == nil { + if debug { + println("Reading Dictionary_ID", io.ErrUnexpectedEOF) + } + return io.ErrUnexpectedEOF + } + switch size { + case 1: + d.DictionaryID = uint32(b[0]) + case 2: + d.DictionaryID = uint32(b[0]) | (uint32(b[1]) << 8) + case 4: + d.DictionaryID = uint32(b[0]) | (uint32(b[1]) << 8) | (uint32(b[2]) << 16) | (uint32(b[3]) << 24) + } + if debug { + println("Dict size", size, "ID:", d.DictionaryID) + } + if d.DictionaryID != 0 { + return ErrUnknownDictionary + } + } + + // Read Frame_Content_Size + // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#frame_content_size + var fcsSize int + v := fhd >> 6 + switch v { + case 0: + if d.SingleSegment { + fcsSize = 1 + } + default: + fcsSize = 1 << v + } + d.FrameContentSize = 0 + if fcsSize > 0 { + b := br.readSmall(fcsSize) + if b == nil { + println("Reading Frame content", io.ErrUnexpectedEOF) + return io.ErrUnexpectedEOF + } + switch fcsSize { + case 1: + d.FrameContentSize = uint64(b[0]) + case 2: + // When FCS_Field_Size is 2, the offset of 256 is added. + d.FrameContentSize = uint64(b[0]) | (uint64(b[1]) << 8) + 256 + case 4: + d.FrameContentSize = uint64(b[0]) | (uint64(b[1]) << 8) | (uint64(b[2]) << 16) | (uint64(b[3] << 24)) + case 8: + d1 := uint32(b[0]) | (uint32(b[1]) << 8) | (uint32(b[2]) << 16) | (uint32(b[3]) << 24) + d2 := uint32(b[4]) | (uint32(b[5]) << 8) | (uint32(b[6]) << 16) | (uint32(b[7]) << 24) + d.FrameContentSize = uint64(d1) | (uint64(d2) << 32) + } + if debug { + println("field size bits:", v, "fcsSize:", fcsSize, "FrameContentSize:", d.FrameContentSize, hex.EncodeToString(b[:fcsSize])) + } + } + // Move this to shared. + d.HasCheckSum = fhd&(1<<2) != 0 + if d.HasCheckSum { + if d.crc == nil { + d.crc = xxhash.New() + } + d.crc.Reset() + } + + if d.WindowSize == 0 && d.SingleSegment { + // We may not need window in this case. + d.WindowSize = d.FrameContentSize + if d.WindowSize < minWindowSize { + d.WindowSize = minWindowSize + } + } + + if d.WindowSize > d.maxWindowSize { + printf("window size %d > max %d\n", d.WindowSize, d.maxWindowSize) + return ErrWindowSizeExceeded + } + // The minimum Window_Size is 1 KB. + if d.WindowSize < minWindowSize { + println("got window size: ", d.WindowSize) + return ErrWindowSizeTooSmall + } + d.history.windowSize = int(d.WindowSize) + d.history.maxSize = d.history.windowSize + maxBlockSize + // history contains input - maybe we do something + d.rawInput = br + return nil +} + +// next will start decoding the next block from stream. +func (d *frameDec) next(block *blockDec) error { + println("decoding new block") + err := block.reset(d.rawInput, d.WindowSize) + if err != nil { + println("block error:", err) + // Signal the frame decoder we have a problem. + d.sendErr(block, err) + return err + } + block.input <- struct{}{} + if debug { + println("next block:", block) + } + d.asyncRunningMu.Lock() + defer d.asyncRunningMu.Unlock() + if !d.asyncRunning { + return nil + } + if block.Last { + // We indicate the frame is done by sending io.EOF + d.decoding <- block + return io.EOF + } + d.decoding <- block + return nil +} + +// sendEOF will queue an error block on the frame. +// This will cause the frame decoder to return when it encounters the block. +// Returns true if the decoder was added. +func (d *frameDec) sendErr(block *blockDec, err error) bool { + d.asyncRunningMu.Lock() + defer d.asyncRunningMu.Unlock() + if !d.asyncRunning { + return false + } + + println("sending error", err.Error()) + block.sendErr(err) + d.decoding <- block + return true +} + +// checkCRC will check the checksum if the frame has one. +// Will return ErrCRCMismatch if crc check failed, otherwise nil. +func (d *frameDec) checkCRC() error { + if !d.HasCheckSum { + return nil + } + var tmp [8]byte + gotB := d.crc.Sum(tmp[:0]) + // Flip to match file order. + gotB[0] = gotB[7] + gotB[1] = gotB[6] + gotB[2] = gotB[5] + gotB[3] = gotB[4] + + // We can overwrite upper tmp now + want := d.rawInput.readSmall(4) + if want == nil { + println("CRC missing?") + return io.ErrUnexpectedEOF + } + + if !bytes.Equal(gotB[:4], want) { + println("CRC Check Failed:", gotB[:4], "!=", want) + return ErrCRCMismatch + } + println("CRC ok") + return nil +} + +func (d *frameDec) initAsync() { + if !d.o.lowMem && !d.SingleSegment { + // set max extra size history to 20MB. + d.history.maxSize = d.history.windowSize + maxBlockSize*10 + } + // re-alloc if more than one extra block size. + if d.o.lowMem && cap(d.history.b) > d.history.maxSize+maxBlockSize { + d.history.b = make([]byte, 0, d.history.maxSize) + } + if cap(d.history.b) < d.history.maxSize { + d.history.b = make([]byte, 0, d.history.maxSize) + } + if cap(d.decoding) < d.o.concurrent { + d.decoding = make(chan *blockDec, d.o.concurrent) + } + if debug { + h := d.history + printf("history init. len: %d, cap: %d", len(h.b), cap(h.b)) + } + d.asyncRunningMu.Lock() + d.asyncRunning = true + d.asyncRunningMu.Unlock() +} + +// startDecoder will start decoding blocks and write them to the writer. +// The decoder will stop as soon as an error occurs or at end of frame. +// When the frame has finished decoding the *bufio.Reader +// containing the remaining input will be sent on frameDec.frameDone. +func (d *frameDec) startDecoder(output chan decodeOutput) { + // TODO: Init to dictionary + d.history.reset() + written := int64(0) + + defer func() { + d.asyncRunningMu.Lock() + d.asyncRunning = false + d.asyncRunningMu.Unlock() + + // Drain the currently decoding. + d.history.error = true + flushdone: + for { + select { + case b := <-d.decoding: + b.history <- &d.history + output <- <-b.result + default: + break flushdone + } + } + println("frame decoder done, signalling done") + d.frameDone.Done() + }() + // Get decoder for first block. + block := <-d.decoding + block.history <- &d.history + for { + var next *blockDec + // Get result + r := <-block.result + if r.err != nil { + println("Result contained error", r.err) + output <- r + return + } + if debug { + println("got result, from ", d.offset, "to", d.offset+int64(len(r.b))) + d.offset += int64(len(r.b)) + } + if !block.Last { + // Send history to next block + select { + case next = <-d.decoding: + if debug { + println("Sending ", len(d.history.b), "bytes as history") + } + next.history <- &d.history + default: + // Wait until we have sent the block, so + // other decoders can potentially get the decoder. + next = nil + } + } + + // Add checksum, async to decoding. + if d.HasCheckSum { + n, err := d.crc.Write(r.b) + if err != nil { + r.err = err + if n != len(r.b) { + r.err = io.ErrShortWrite + } + output <- r + return + } + } + written += int64(len(r.b)) + if d.SingleSegment && uint64(written) > d.FrameContentSize { + r.err = ErrFrameSizeExceeded + output <- r + return + } + if block.Last { + r.err = d.checkCRC() + output <- r + return + } + output <- r + if next == nil { + // There was no decoder available, we wait for one now that we have sent to the writer. + if debug { + println("Sending ", len(d.history.b), " bytes as history") + } + next = <-d.decoding + next.history <- &d.history + } + block = next + } +} + +// runDecoder will create a sync decoder that will decodeAsync a block of data. +func (d *frameDec) runDecoder(dst []byte, dec *blockDec) ([]byte, error) { + // TODO: Init to dictionary + d.history.reset() + saved := d.history.b + + // We use the history for output to avoid copying it. + d.history.b = dst + // Store input length, so we only check new data. + crcStart := len(dst) + var err error + for { + err = dec.reset(d.rawInput, d.WindowSize) + if err != nil { + break + } + if debug { + println("next block:", dec) + } + err = dec.decodeBuf(&d.history) + if err != nil || dec.Last { + break + } + if uint64(len(d.history.b)) > d.o.maxDecodedSize { + err = ErrDecoderSizeExceeded + break + } + if d.SingleSegment && uint64(len(d.history.b)) > d.o.maxDecodedSize { + err = ErrFrameSizeExceeded + break + } + } + dst = d.history.b + if err == nil { + if d.HasCheckSum { + var n int + n, err = d.crc.Write(dst[crcStart:]) + if err == nil { + if n != len(dst)-crcStart { + err = io.ErrShortWrite + } + } + err = d.checkCRC() + } + } + d.history.b = saved + return dst, err +} diff --git a/vendor/github.com/klauspost/compress/zstd/frameenc.go b/vendor/github.com/klauspost/compress/zstd/frameenc.go new file mode 100644 index 000000000..acac32527 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/frameenc.go @@ -0,0 +1,118 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "errors" + "fmt" + "io" + "math" + "math/bits" +) + +type frameHeader struct { + ContentSize uint64 + WindowSize uint32 + SingleSegment bool + Checksum bool + DictID uint32 // Not stored. +} + +const maxHeaderSize = 14 + +func (f frameHeader) appendTo(dst []byte) ([]byte, error) { + dst = append(dst, frameMagic...) + var fhd uint8 + if f.Checksum { + fhd |= 1 << 2 + } + if f.SingleSegment { + fhd |= 1 << 5 + } + var fcs uint8 + if f.ContentSize >= 256 { + fcs++ + } + if f.ContentSize >= 65536+256 { + fcs++ + } + if f.ContentSize >= 0xffffffff { + fcs++ + } + fhd |= fcs << 6 + + dst = append(dst, fhd) + if !f.SingleSegment { + const winLogMin = 10 + windowLog := (bits.Len32(f.WindowSize-1) - winLogMin) << 3 + dst = append(dst, uint8(windowLog)) + } + if f.SingleSegment && f.ContentSize == 0 { + return nil, errors.New("single segment, but no size set") + } + switch fcs { + case 0: + if f.SingleSegment { + dst = append(dst, uint8(f.ContentSize)) + } + // Unless SingleSegment is set, framessizes < 256 are nto stored. + case 1: + f.ContentSize -= 256 + dst = append(dst, uint8(f.ContentSize), uint8(f.ContentSize>>8)) + case 2: + dst = append(dst, uint8(f.ContentSize), uint8(f.ContentSize>>8), uint8(f.ContentSize>>16), uint8(f.ContentSize>>24)) + case 3: + dst = append(dst, uint8(f.ContentSize), uint8(f.ContentSize>>8), uint8(f.ContentSize>>16), uint8(f.ContentSize>>24), + uint8(f.ContentSize>>32), uint8(f.ContentSize>>40), uint8(f.ContentSize>>48), uint8(f.ContentSize>>56)) + default: + panic("invalid fcs") + } + return dst, nil +} + +const skippableFrameHeader = 4 + 4 + +// calcSkippableFrame will return a total size to be added for written +// to be divisible by multiple. +// The value will always be > skippableFrameHeader. +// The function will panic if written < 0 or wantMultiple <= 0. +func calcSkippableFrame(written, wantMultiple int64) int { + if wantMultiple <= 0 { + panic("wantMultiple <= 0") + } + if written < 0 { + panic("written < 0") + } + leftOver := written % wantMultiple + if leftOver == 0 { + return 0 + } + toAdd := wantMultiple - leftOver + for toAdd < skippableFrameHeader { + toAdd += wantMultiple + } + return int(toAdd) +} + +// skippableFrame will add a skippable frame with a total size of bytes. +// total should be >= skippableFrameHeader and < math.MaxUint32. +func skippableFrame(dst []byte, total int, r io.Reader) ([]byte, error) { + if total == 0 { + return dst, nil + } + if total < skippableFrameHeader { + return dst, fmt.Errorf("requested skippable frame (%d) < 8", total) + } + if int64(total) > math.MaxUint32 { + return dst, fmt.Errorf("requested skippable frame (%d) > max uint32", total) + } + dst = append(dst, 0x50, 0x2a, 0x4d, 0x18) + f := uint32(total - skippableFrameHeader) + dst = append(dst, uint8(f), uint8(f>>8), uint8(f>>16), uint8(f>>24)) + start := len(dst) + dst = append(dst, make([]byte, f)...) + _, err := io.ReadFull(r, dst[start:]) + return dst, err +} diff --git a/vendor/github.com/klauspost/compress/zstd/fse_decoder.go b/vendor/github.com/klauspost/compress/zstd/fse_decoder.go new file mode 100644 index 000000000..a86d00bc3 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/fse_decoder.go @@ -0,0 +1,337 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "errors" + "fmt" +) + +const ( + tablelogAbsoluteMax = 9 +) + +const ( + /*!MEMORY_USAGE : + * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.) + * Increasing memory usage improves compression ratio + * Reduced memory usage can improve speed, due to cache effect + * Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */ + maxMemoryUsage = 11 + + maxTableLog = maxMemoryUsage - 2 + maxTablesize = 1 << maxTableLog + maxTableMask = (1 << maxTableLog) - 1 + minTablelog = 5 + maxSymbolValue = 255 +) + +// fseDecoder provides temporary storage for compression and decompression. +type fseDecoder struct { + dt [maxTablesize]decSymbol // Decompression table. + symbolLen uint16 // Length of active part of the symbol table. + actualTableLog uint8 // Selected tablelog. + maxBits uint8 // Maximum number of additional bits + + // used for table creation to avoid allocations. + stateTable [256]uint16 + norm [maxSymbolValue + 1]int16 + preDefined bool +} + +// tableStep returns the next table index. +func tableStep(tableSize uint32) uint32 { + return (tableSize >> 1) + (tableSize >> 3) + 3 +} + +// readNCount will read the symbol distribution so decoding tables can be constructed. +func (s *fseDecoder) readNCount(b *byteReader, maxSymbol uint16) error { + var ( + charnum uint16 + previous0 bool + ) + if b.remain() < 4 { + return errors.New("input too small") + } + bitStream := b.Uint32() + nbBits := uint((bitStream & 0xF) + minTablelog) // extract tableLog + if nbBits > tablelogAbsoluteMax { + println("Invalid tablelog:", nbBits) + return errors.New("tableLog too large") + } + bitStream >>= 4 + bitCount := uint(4) + + s.actualTableLog = uint8(nbBits) + remaining := int32((1 << nbBits) + 1) + threshold := int32(1 << nbBits) + gotTotal := int32(0) + nbBits++ + + for remaining > 1 && charnum <= maxSymbol { + if previous0 { + //println("prev0") + n0 := charnum + for (bitStream & 0xFFFF) == 0xFFFF { + //println("24 x 0") + n0 += 24 + if r := b.remain(); r > 5 { + b.advance(2) + bitStream = b.Uint32() >> bitCount + } else { + // end of bit stream + bitStream >>= 16 + bitCount += 16 + } + } + //printf("bitstream: %d, 0b%b", bitStream&3, bitStream) + for (bitStream & 3) == 3 { + n0 += 3 + bitStream >>= 2 + bitCount += 2 + } + n0 += uint16(bitStream & 3) + bitCount += 2 + + if n0 > maxSymbolValue { + return errors.New("maxSymbolValue too small") + } + //println("inserting ", n0-charnum, "zeroes from idx", charnum, "ending before", n0) + for charnum < n0 { + s.norm[uint8(charnum)] = 0 + charnum++ + } + + if r := b.remain(); r >= 7 || r+int(bitCount>>3) >= 4 { + b.advance(bitCount >> 3) + bitCount &= 7 + bitStream = b.Uint32() >> bitCount + } else { + bitStream >>= 2 + } + } + + max := (2*threshold - 1) - remaining + var count int32 + + if int32(bitStream)&(threshold-1) < max { + count = int32(bitStream) & (threshold - 1) + if debug && nbBits < 1 { + panic("nbBits underflow") + } + bitCount += nbBits - 1 + } else { + count = int32(bitStream) & (2*threshold - 1) + if count >= threshold { + count -= max + } + bitCount += nbBits + } + + // extra accuracy + count-- + if count < 0 { + // -1 means +1 + remaining += count + gotTotal -= count + } else { + remaining -= count + gotTotal += count + } + s.norm[charnum&0xff] = int16(count) + charnum++ + previous0 = count == 0 + for remaining < threshold { + nbBits-- + threshold >>= 1 + } + + //println("b.off:", b.off, "len:", len(b.b), "bc:", bitCount, "remain:", b.remain()) + if r := b.remain(); r >= 7 || r+int(bitCount>>3) >= 4 { + b.advance(bitCount >> 3) + bitCount &= 7 + } else { + bitCount -= (uint)(8 * (len(b.b) - 4 - b.off)) + b.off = len(b.b) - 4 + //println("b.off:", b.off, "len:", len(b.b), "bc:", bitCount, "iend", iend) + } + bitStream = b.Uint32() >> (bitCount & 31) + //printf("bitstream is now: 0b%b", bitStream) + } + s.symbolLen = charnum + if s.symbolLen <= 1 { + return fmt.Errorf("symbolLen (%d) too small", s.symbolLen) + } + if s.symbolLen > maxSymbolValue+1 { + return fmt.Errorf("symbolLen (%d) too big", s.symbolLen) + } + if remaining != 1 { + return fmt.Errorf("corruption detected (remaining %d != 1)", remaining) + } + if bitCount > 32 { + return fmt.Errorf("corruption detected (bitCount %d > 32)", bitCount) + } + if gotTotal != 1<<s.actualTableLog { + return fmt.Errorf("corruption detected (total %d != %d)", gotTotal, 1<<s.actualTableLog) + } + b.advance((bitCount + 7) >> 3) + // println(s.norm[:s.symbolLen], s.symbolLen) + return s.buildDtable() +} + +// decSymbol contains information about a state entry, +// Including the state offset base, the output symbol and +// the number of bits to read for the low part of the destination state. +type decSymbol struct { + newState uint16 + addBits uint8 // Used for symbols until transformed. + nbBits uint8 + baseline uint32 +} + +// decSymbolValue returns the transformed decSymbol for the given symbol. +func decSymbolValue(symb uint8, t []baseOffset) (decSymbol, error) { + if int(symb) >= len(t) { + return decSymbol{}, fmt.Errorf("rle symbol %d >= max %d", symb, len(t)) + } + lu := t[symb] + return decSymbol{ + addBits: lu.addBits, + baseline: lu.baseLine, + }, nil +} + +// setRLE will set the decoder til RLE mode. +func (s *fseDecoder) setRLE(symbol decSymbol) { + s.actualTableLog = 0 + s.maxBits = symbol.addBits + s.dt[0] = symbol +} + +// buildDtable will build the decoding table. +func (s *fseDecoder) buildDtable() error { + tableSize := uint32(1 << s.actualTableLog) + highThreshold := tableSize - 1 + symbolNext := s.stateTable[:256] + + // Init, lay down lowprob symbols + { + for i, v := range s.norm[:s.symbolLen] { + if v == -1 { + s.dt[highThreshold].addBits = uint8(i) + highThreshold-- + symbolNext[i] = 1 + } else { + symbolNext[i] = uint16(v) + } + } + } + // Spread symbols + { + tableMask := tableSize - 1 + step := tableStep(tableSize) + position := uint32(0) + for ss, v := range s.norm[:s.symbolLen] { + for i := 0; i < int(v); i++ { + s.dt[position].addBits = uint8(ss) + position = (position + step) & tableMask + for position > highThreshold { + // lowprob area + position = (position + step) & tableMask + } + } + } + if position != 0 { + // position must reach all cells once, otherwise normalizedCounter is incorrect + return errors.New("corrupted input (position != 0)") + } + } + + // Build Decoding table + { + tableSize := uint16(1 << s.actualTableLog) + for u, v := range s.dt[:tableSize] { + symbol := v.addBits + nextState := symbolNext[symbol] + symbolNext[symbol] = nextState + 1 + nBits := s.actualTableLog - byte(highBits(uint32(nextState))) + s.dt[u&maxTableMask].nbBits = nBits + newState := (nextState << nBits) - tableSize + if newState > tableSize { + return fmt.Errorf("newState (%d) outside table size (%d)", newState, tableSize) + } + if newState == uint16(u) && nBits == 0 { + // Seems weird that this is possible with nbits > 0. + return fmt.Errorf("newState (%d) == oldState (%d) and no bits", newState, u) + } + s.dt[u&maxTableMask].newState = newState + } + } + return nil +} + +// transform will transform the decoder table into a table usable for +// decoding without having to apply the transformation while decoding. +// The state will contain the base value and the number of bits to read. +func (s *fseDecoder) transform(t []baseOffset) error { + tableSize := uint16(1 << s.actualTableLog) + s.maxBits = 0 + for i, v := range s.dt[:tableSize] { + if int(v.addBits) >= len(t) { + return fmt.Errorf("invalid decoding table entry %d, symbol %d >= max (%d)", i, v.addBits, len(t)) + } + lu := t[v.addBits] + if lu.addBits > s.maxBits { + s.maxBits = lu.addBits + } + s.dt[i&maxTableMask] = decSymbol{ + newState: v.newState, + nbBits: v.nbBits, + addBits: lu.addBits, + baseline: lu.baseLine, + } + } + return nil +} + +type fseState struct { + // TODO: Check if *[1 << maxTablelog]decSymbol is faster. + dt []decSymbol + state decSymbol +} + +// Initialize and decodeAsync first state and symbol. +func (s *fseState) init(br *bitReader, tableLog uint8, dt []decSymbol) { + s.dt = dt + br.fill() + s.state = dt[br.getBits(tableLog)] +} + +// next returns the current symbol and sets the next state. +// At least tablelog bits must be available in the bit reader. +func (s *fseState) next(br *bitReader) { + lowBits := uint16(br.getBits(s.state.nbBits)) + s.state = s.dt[s.state.newState+lowBits] +} + +// finished returns true if all bits have been read from the bitstream +// and the next state would require reading bits from the input. +func (s *fseState) finished(br *bitReader) bool { + return br.finished() && s.state.nbBits > 0 +} + +// final returns the current state symbol without decoding the next. +func (s *fseState) final() (int, uint8) { + return int(s.state.baseline), s.state.addBits +} + +// nextFast returns the next symbol and sets the next state. +// This can only be used if no symbols are 0 bits. +// At least tablelog bits must be available in the bit reader. +func (s *fseState) nextFast(br *bitReader) (uint32, uint8) { + lowBits := uint16(br.getBitsFast(s.state.nbBits)) + s.state = s.dt[s.state.newState+lowBits] + return s.state.baseline, s.state.addBits +} diff --git a/vendor/github.com/klauspost/compress/zstd/fse_encoder.go b/vendor/github.com/klauspost/compress/zstd/fse_encoder.go new file mode 100644 index 000000000..dfa6cf7ce --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/fse_encoder.go @@ -0,0 +1,717 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "errors" + "fmt" + "math" +) + +const ( + // For encoding we only support up to + maxEncTableLog = 8 + maxEncTablesize = 1 << maxTableLog + maxEncTableMask = (1 << maxTableLog) - 1 + minEncTablelog = 5 + maxEncSymbolValue = maxMatchLengthSymbol +) + +// Scratch provides temporary storage for compression and decompression. +type fseEncoder struct { + symbolLen uint16 // Length of active part of the symbol table. + actualTableLog uint8 // Selected tablelog. + ct cTable // Compression tables. + maxCount int // count of the most probable symbol + zeroBits bool // no bits has prob > 50%. + clearCount bool // clear count + useRLE bool // This encoder is for RLE + preDefined bool // This encoder is predefined. + reUsed bool // Set to know when the encoder has been reused. + rleVal uint8 // RLE Symbol + maxBits uint8 // Maximum output bits after transform. + + // TODO: Technically zstd should be fine with 64 bytes. + count [256]uint32 + norm [256]int16 +} + +// cTable contains tables used for compression. +type cTable struct { + tableSymbol []byte + stateTable []uint16 + symbolTT []symbolTransform +} + +// symbolTransform contains the state transform for a symbol. +type symbolTransform struct { + deltaNbBits uint32 + deltaFindState int16 + outBits uint8 +} + +// String prints values as a human readable string. +func (s symbolTransform) String() string { + return fmt.Sprintf("{deltabits: %08x, findstate:%d outbits:%d}", s.deltaNbBits, s.deltaFindState, s.outBits) +} + +// Histogram allows to populate the histogram and skip that step in the compression, +// It otherwise allows to inspect the histogram when compression is done. +// To indicate that you have populated the histogram call HistogramFinished +// with the value of the highest populated symbol, as well as the number of entries +// in the most populated entry. These are accepted at face value. +// The returned slice will always be length 256. +func (s *fseEncoder) Histogram() []uint32 { + return s.count[:] +} + +// HistogramFinished can be called to indicate that the histogram has been populated. +// maxSymbol is the index of the highest set symbol of the next data segment. +// maxCount is the number of entries in the most populated entry. +// These are accepted at face value. +func (s *fseEncoder) HistogramFinished(maxSymbol uint8, maxCount int) { + s.maxCount = maxCount + s.symbolLen = uint16(maxSymbol) + 1 + s.clearCount = maxCount != 0 +} + +// prepare will prepare and allocate scratch tables used for both compression and decompression. +func (s *fseEncoder) prepare() (*fseEncoder, error) { + if s == nil { + s = &fseEncoder{} + } + s.useRLE = false + if s.clearCount && s.maxCount == 0 { + for i := range s.count { + s.count[i] = 0 + } + s.clearCount = false + } + return s, nil +} + +// allocCtable will allocate tables needed for compression. +// If existing tables a re big enough, they are simply re-used. +func (s *fseEncoder) allocCtable() { + tableSize := 1 << s.actualTableLog + // get tableSymbol that is big enough. + if cap(s.ct.tableSymbol) < int(tableSize) { + s.ct.tableSymbol = make([]byte, tableSize) + } + s.ct.tableSymbol = s.ct.tableSymbol[:tableSize] + + ctSize := tableSize + if cap(s.ct.stateTable) < ctSize { + s.ct.stateTable = make([]uint16, ctSize) + } + s.ct.stateTable = s.ct.stateTable[:ctSize] + + if cap(s.ct.symbolTT) < 256 { + s.ct.symbolTT = make([]symbolTransform, 256) + } + s.ct.symbolTT = s.ct.symbolTT[:256] +} + +// buildCTable will populate the compression table so it is ready to be used. +func (s *fseEncoder) buildCTable() error { + tableSize := uint32(1 << s.actualTableLog) + highThreshold := tableSize - 1 + var cumul [256]int16 + + s.allocCtable() + tableSymbol := s.ct.tableSymbol[:tableSize] + // symbol start positions + { + cumul[0] = 0 + for ui, v := range s.norm[:s.symbolLen-1] { + u := byte(ui) // one less than reference + if v == -1 { + // Low proba symbol + cumul[u+1] = cumul[u] + 1 + tableSymbol[highThreshold] = u + highThreshold-- + } else { + cumul[u+1] = cumul[u] + v + } + } + // Encode last symbol separately to avoid overflowing u + u := int(s.symbolLen - 1) + v := s.norm[s.symbolLen-1] + if v == -1 { + // Low proba symbol + cumul[u+1] = cumul[u] + 1 + tableSymbol[highThreshold] = byte(u) + highThreshold-- + } else { + cumul[u+1] = cumul[u] + v + } + if uint32(cumul[s.symbolLen]) != tableSize { + return fmt.Errorf("internal error: expected cumul[s.symbolLen] (%d) == tableSize (%d)", cumul[s.symbolLen], tableSize) + } + cumul[s.symbolLen] = int16(tableSize) + 1 + } + // Spread symbols + s.zeroBits = false + { + step := tableStep(tableSize) + tableMask := tableSize - 1 + var position uint32 + // if any symbol > largeLimit, we may have 0 bits output. + largeLimit := int16(1 << (s.actualTableLog - 1)) + for ui, v := range s.norm[:s.symbolLen] { + symbol := byte(ui) + if v > largeLimit { + s.zeroBits = true + } + for nbOccurrences := int16(0); nbOccurrences < v; nbOccurrences++ { + tableSymbol[position] = symbol + position = (position + step) & tableMask + for position > highThreshold { + position = (position + step) & tableMask + } /* Low proba area */ + } + } + + // Check if we have gone through all positions + if position != 0 { + return errors.New("position!=0") + } + } + + // Build table + table := s.ct.stateTable + { + tsi := int(tableSize) + for u, v := range tableSymbol { + // TableU16 : sorted by symbol order; gives next state value + table[cumul[v]] = uint16(tsi + u) + cumul[v]++ + } + } + + // Build Symbol Transformation Table + { + total := int16(0) + symbolTT := s.ct.symbolTT[:s.symbolLen] + tableLog := s.actualTableLog + tl := (uint32(tableLog) << 16) - (1 << tableLog) + for i, v := range s.norm[:s.symbolLen] { + switch v { + case 0: + case -1, 1: + symbolTT[i].deltaNbBits = tl + symbolTT[i].deltaFindState = int16(total - 1) + total++ + default: + maxBitsOut := uint32(tableLog) - highBit(uint32(v-1)) + minStatePlus := uint32(v) << maxBitsOut + symbolTT[i].deltaNbBits = (maxBitsOut << 16) - minStatePlus + symbolTT[i].deltaFindState = int16(total - v) + total += v + } + } + if total != int16(tableSize) { + return fmt.Errorf("total mismatch %d (got) != %d (want)", total, tableSize) + } + } + return nil +} + +var rtbTable = [...]uint32{0, 473195, 504333, 520860, 550000, 700000, 750000, 830000} + +func (s *fseEncoder) setRLE(val byte) { + s.allocCtable() + s.actualTableLog = 0 + s.ct.stateTable = s.ct.stateTable[:1] + s.ct.symbolTT[val] = symbolTransform{ + deltaFindState: 0, + deltaNbBits: 0, + } + if debug { + println("setRLE: val", val, "symbolTT", s.ct.symbolTT[val]) + } + s.rleVal = val + s.useRLE = true +} + +// setBits will set output bits for the transform. +// if nil is provided, the number of bits is equal to the index. +func (s *fseEncoder) setBits(transform []byte) { + if s.reUsed || s.preDefined { + return + } + if s.useRLE { + if transform == nil { + s.ct.symbolTT[s.rleVal].outBits = s.rleVal + s.maxBits = s.rleVal + return + } + s.maxBits = transform[s.rleVal] + s.ct.symbolTT[s.rleVal].outBits = s.maxBits + return + } + if transform == nil { + for i := range s.ct.symbolTT[:s.symbolLen] { + s.ct.symbolTT[i].outBits = uint8(i) + } + s.maxBits = uint8(s.symbolLen - 1) + return + } + s.maxBits = 0 + for i, v := range transform[:s.symbolLen] { + s.ct.symbolTT[i].outBits = v + if v > s.maxBits { + // We could assume bits always going up, but we play safe. + s.maxBits = v + } + } +} + +// normalizeCount will normalize the count of the symbols so +// the total is equal to the table size. +// If successful, compression tables will also be made ready. +func (s *fseEncoder) normalizeCount(length int) error { + if s.reUsed { + return nil + } + s.optimalTableLog(length) + var ( + tableLog = s.actualTableLog + scale = 62 - uint64(tableLog) + step = (1 << 62) / uint64(length) + vStep = uint64(1) << (scale - 20) + stillToDistribute = int16(1 << tableLog) + largest int + largestP int16 + lowThreshold = (uint32)(length >> tableLog) + ) + if s.maxCount == length { + s.useRLE = true + return nil + } + s.useRLE = false + for i, cnt := range s.count[:s.symbolLen] { + // already handled + // if (count[s] == s.length) return 0; /* rle special case */ + + if cnt == 0 { + s.norm[i] = 0 + continue + } + if cnt <= lowThreshold { + s.norm[i] = -1 + stillToDistribute-- + } else { + proba := (int16)((uint64(cnt) * step) >> scale) + if proba < 8 { + restToBeat := vStep * uint64(rtbTable[proba]) + v := uint64(cnt)*step - (uint64(proba) << scale) + if v > restToBeat { + proba++ + } + } + if proba > largestP { + largestP = proba + largest = i + } + s.norm[i] = proba + stillToDistribute -= proba + } + } + + if -stillToDistribute >= (s.norm[largest] >> 1) { + // corner case, need another normalization method + err := s.normalizeCount2(length) + if err != nil { + return err + } + if debug { + err = s.validateNorm() + if err != nil { + return err + } + } + return s.buildCTable() + } + s.norm[largest] += stillToDistribute + if debug { + err := s.validateNorm() + if err != nil { + return err + } + } + return s.buildCTable() +} + +// Secondary normalization method. +// To be used when primary method fails. +func (s *fseEncoder) normalizeCount2(length int) error { + const notYetAssigned = -2 + var ( + distributed uint32 + total = uint32(length) + tableLog = s.actualTableLog + lowThreshold = uint32(total >> tableLog) + lowOne = uint32((total * 3) >> (tableLog + 1)) + ) + for i, cnt := range s.count[:s.symbolLen] { + if cnt == 0 { + s.norm[i] = 0 + continue + } + if cnt <= lowThreshold { + s.norm[i] = -1 + distributed++ + total -= cnt + continue + } + if cnt <= lowOne { + s.norm[i] = 1 + distributed++ + total -= cnt + continue + } + s.norm[i] = notYetAssigned + } + toDistribute := (1 << tableLog) - distributed + + if (total / toDistribute) > lowOne { + // risk of rounding to zero + lowOne = uint32((total * 3) / (toDistribute * 2)) + for i, cnt := range s.count[:s.symbolLen] { + if (s.norm[i] == notYetAssigned) && (cnt <= lowOne) { + s.norm[i] = 1 + distributed++ + total -= cnt + continue + } + } + toDistribute = (1 << tableLog) - distributed + } + if distributed == uint32(s.symbolLen)+1 { + // all values are pretty poor; + // probably incompressible data (should have already been detected); + // find max, then give all remaining points to max + var maxV int + var maxC uint32 + for i, cnt := range s.count[:s.symbolLen] { + if cnt > maxC { + maxV = i + maxC = cnt + } + } + s.norm[maxV] += int16(toDistribute) + return nil + } + + if total == 0 { + // all of the symbols were low enough for the lowOne or lowThreshold + for i := uint32(0); toDistribute > 0; i = (i + 1) % (uint32(s.symbolLen)) { + if s.norm[i] > 0 { + toDistribute-- + s.norm[i]++ + } + } + return nil + } + + var ( + vStepLog = 62 - uint64(tableLog) + mid = uint64((1 << (vStepLog - 1)) - 1) + rStep = (((1 << vStepLog) * uint64(toDistribute)) + mid) / uint64(total) // scale on remaining + tmpTotal = mid + ) + for i, cnt := range s.count[:s.symbolLen] { + if s.norm[i] == notYetAssigned { + var ( + end = tmpTotal + uint64(cnt)*rStep + sStart = uint32(tmpTotal >> vStepLog) + sEnd = uint32(end >> vStepLog) + weight = sEnd - sStart + ) + if weight < 1 { + return errors.New("weight < 1") + } + s.norm[i] = int16(weight) + tmpTotal = end + } + } + return nil +} + +// optimalTableLog calculates and sets the optimal tableLog in s.actualTableLog +func (s *fseEncoder) optimalTableLog(length int) { + tableLog := uint8(maxEncTableLog) + minBitsSrc := highBit(uint32(length)) + 1 + minBitsSymbols := highBit(uint32(s.symbolLen-1)) + 2 + minBits := uint8(minBitsSymbols) + if minBitsSrc < minBitsSymbols { + minBits = uint8(minBitsSrc) + } + + maxBitsSrc := uint8(highBit(uint32(length-1))) - 2 + if maxBitsSrc < tableLog { + // Accuracy can be reduced + tableLog = maxBitsSrc + } + if minBits > tableLog { + tableLog = minBits + } + // Need a minimum to safely represent all symbol values + if tableLog < minEncTablelog { + tableLog = minEncTablelog + } + if tableLog > maxEncTableLog { + tableLog = maxEncTableLog + } + s.actualTableLog = tableLog +} + +// validateNorm validates the normalized histogram table. +func (s *fseEncoder) validateNorm() (err error) { + var total int + for _, v := range s.norm[:s.symbolLen] { + if v >= 0 { + total += int(v) + } else { + total -= int(v) + } + } + defer func() { + if err == nil { + return + } + fmt.Printf("selected TableLog: %d, Symbol length: %d\n", s.actualTableLog, s.symbolLen) + for i, v := range s.norm[:s.symbolLen] { + fmt.Printf("%3d: %5d -> %4d \n", i, s.count[i], v) + } + }() + if total != (1 << s.actualTableLog) { + return fmt.Errorf("warning: Total == %d != %d", total, 1<<s.actualTableLog) + } + for i, v := range s.count[s.symbolLen:] { + if v != 0 { + return fmt.Errorf("warning: Found symbol out of range, %d after cut", i) + } + } + return nil +} + +// writeCount will write the normalized histogram count to header. +// This is read back by readNCount. +func (s *fseEncoder) writeCount(out []byte) ([]byte, error) { + var ( + tableLog = s.actualTableLog + tableSize = 1 << tableLog + previous0 bool + charnum uint16 + + maxHeaderSize = ((int(s.symbolLen) * int(tableLog)) >> 3) + 3 + + // Write Table Size + bitStream = uint32(tableLog - minEncTablelog) + bitCount = uint(4) + remaining = int16(tableSize + 1) /* +1 for extra accuracy */ + threshold = int16(tableSize) + nbBits = uint(tableLog + 1) + ) + if s.useRLE { + return append(out, s.rleVal), nil + } + if s.preDefined || s.reUsed { + // Never write predefined. + return out, nil + } + outP := len(out) + out = out[:outP+maxHeaderSize] + + // stops at 1 + for remaining > 1 { + if previous0 { + start := charnum + for s.norm[charnum] == 0 { + charnum++ + } + for charnum >= start+24 { + start += 24 + bitStream += uint32(0xFFFF) << bitCount + out[outP] = byte(bitStream) + out[outP+1] = byte(bitStream >> 8) + outP += 2 + bitStream >>= 16 + } + for charnum >= start+3 { + start += 3 + bitStream += 3 << bitCount + bitCount += 2 + } + bitStream += uint32(charnum-start) << bitCount + bitCount += 2 + if bitCount > 16 { + out[outP] = byte(bitStream) + out[outP+1] = byte(bitStream >> 8) + outP += 2 + bitStream >>= 16 + bitCount -= 16 + } + } + + count := s.norm[charnum] + charnum++ + max := (2*threshold - 1) - remaining + if count < 0 { + remaining += count + } else { + remaining -= count + } + count++ // +1 for extra accuracy + if count >= threshold { + count += max // [0..max[ [max..threshold[ (...) [threshold+max 2*threshold[ + } + bitStream += uint32(count) << bitCount + bitCount += nbBits + if count < max { + bitCount-- + } + + previous0 = count == 1 + if remaining < 1 { + return nil, errors.New("internal error: remaining < 1") + } + for remaining < threshold { + nbBits-- + threshold >>= 1 + } + + if bitCount > 16 { + out[outP] = byte(bitStream) + out[outP+1] = byte(bitStream >> 8) + outP += 2 + bitStream >>= 16 + bitCount -= 16 + } + } + + out[outP] = byte(bitStream) + out[outP+1] = byte(bitStream >> 8) + outP += int((bitCount + 7) / 8) + + if uint16(charnum) > s.symbolLen { + return nil, errors.New("internal error: charnum > s.symbolLen") + } + return out[:outP], nil +} + +// Approximate symbol cost, as fractional value, using fixed-point format (accuracyLog fractional bits) +// note 1 : assume symbolValue is valid (<= maxSymbolValue) +// note 2 : if freq[symbolValue]==0, @return a fake cost of tableLog+1 bits * +func (s *fseEncoder) bitCost(symbolValue uint8, accuracyLog uint32) uint32 { + minNbBits := s.ct.symbolTT[symbolValue].deltaNbBits >> 16 + threshold := (minNbBits + 1) << 16 + if debug { + if !(s.actualTableLog < 16) { + panic("!s.actualTableLog < 16") + } + // ensure enough room for renormalization double shift + if !(uint8(accuracyLog) < 31-s.actualTableLog) { + panic("!uint8(accuracyLog) < 31-s.actualTableLog") + } + } + tableSize := uint32(1) << s.actualTableLog + deltaFromThreshold := threshold - (s.ct.symbolTT[symbolValue].deltaNbBits + tableSize) + // linear interpolation (very approximate) + normalizedDeltaFromThreshold := (deltaFromThreshold << accuracyLog) >> s.actualTableLog + bitMultiplier := uint32(1) << accuracyLog + if debug { + if s.ct.symbolTT[symbolValue].deltaNbBits+tableSize > threshold { + panic("s.ct.symbolTT[symbolValue].deltaNbBits+tableSize > threshold") + } + if normalizedDeltaFromThreshold > bitMultiplier { + panic("normalizedDeltaFromThreshold > bitMultiplier") + } + } + return (minNbBits+1)*bitMultiplier - normalizedDeltaFromThreshold +} + +// Returns the cost in bits of encoding the distribution in count using ctable. +// Histogram should only be up to the last non-zero symbol. +// Returns an -1 if ctable cannot represent all the symbols in count. +func (s *fseEncoder) approxSize(hist []uint32) uint32 { + if int(s.symbolLen) < len(hist) { + // More symbols than we have. + return math.MaxUint32 + } + if s.useRLE { + // We will never reuse RLE encoders. + return math.MaxUint32 + } + const kAccuracyLog = 8 + badCost := (uint32(s.actualTableLog) + 1) << kAccuracyLog + var cost uint32 + for i, v := range hist { + if v == 0 { + continue + } + if s.norm[i] == 0 { + return math.MaxUint32 + } + bitCost := s.bitCost(uint8(i), kAccuracyLog) + if bitCost > badCost { + return math.MaxUint32 + } + cost += v * bitCost + } + return cost >> kAccuracyLog +} + +// maxHeaderSize returns the maximum header size in bits. +// This is not exact size, but we want a penalty for new tables anyway. +func (s *fseEncoder) maxHeaderSize() uint32 { + if s.preDefined { + return 0 + } + if s.useRLE { + return 8 + } + return (((uint32(s.symbolLen) * uint32(s.actualTableLog)) >> 3) + 3) * 8 +} + +// cState contains the compression state of a stream. +type cState struct { + bw *bitWriter + stateTable []uint16 + state uint16 +} + +// init will initialize the compression state to the first symbol of the stream. +func (c *cState) init(bw *bitWriter, ct *cTable, first symbolTransform) { + c.bw = bw + c.stateTable = ct.stateTable + if len(c.stateTable) == 1 { + // RLE + c.stateTable[0] = uint16(0) + c.state = 0 + return + } + nbBitsOut := (first.deltaNbBits + (1 << 15)) >> 16 + im := int32((nbBitsOut << 16) - first.deltaNbBits) + lu := (im >> nbBitsOut) + int32(first.deltaFindState) + c.state = c.stateTable[lu] + return +} + +// encode the output symbol provided and write it to the bitstream. +func (c *cState) encode(symbolTT symbolTransform) { + nbBitsOut := (uint32(c.state) + symbolTT.deltaNbBits) >> 16 + dstState := int32(c.state>>(nbBitsOut&15)) + int32(symbolTT.deltaFindState) + c.bw.addBits16NC(c.state, uint8(nbBitsOut)) + c.state = c.stateTable[dstState] +} + +// flush will write the tablelog to the output and flush the remaining full bytes. +func (c *cState) flush(tableLog uint8) { + c.bw.flush32() + c.bw.addBits16NC(c.state, tableLog) +} diff --git a/vendor/github.com/klauspost/compress/zstd/fse_predefined.go b/vendor/github.com/klauspost/compress/zstd/fse_predefined.go new file mode 100644 index 000000000..5186de802 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/fse_predefined.go @@ -0,0 +1,153 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "fmt" + "math" +) + +var ( + // fsePredef are the predefined fse tables as defined here: + // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#default-distributions + // These values are already transformed. + fsePredef [3]fseDecoder + + // fsePredefEnc are the predefined encoder based on fse tables as defined here: + // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#default-distributions + // These values are already transformed. + fsePredefEnc [3]fseEncoder + + // symbolTableX contain the transformations needed for each type as defined in + // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#the-codes-for-literals-lengths-match-lengths-and-offsets + symbolTableX [3][]baseOffset + + // maxTableSymbol is the biggest supported symbol for each table type + // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#the-codes-for-literals-lengths-match-lengths-and-offsets + maxTableSymbol = [3]uint8{tableLiteralLengths: maxLiteralLengthSymbol, tableOffsets: maxOffsetLengthSymbol, tableMatchLengths: maxMatchLengthSymbol} + + // bitTables is the bits table for each table. + bitTables = [3][]byte{tableLiteralLengths: llBitsTable[:], tableOffsets: nil, tableMatchLengths: mlBitsTable[:]} +) + +type tableIndex uint8 + +const ( + // indexes for fsePredef and symbolTableX + tableLiteralLengths tableIndex = 0 + tableOffsets tableIndex = 1 + tableMatchLengths tableIndex = 2 + + maxLiteralLengthSymbol = 35 + maxOffsetLengthSymbol = 30 + maxMatchLengthSymbol = 52 +) + +// baseOffset is used for calculating transformations. +type baseOffset struct { + baseLine uint32 + addBits uint8 +} + +// fillBase will precalculate base offsets with the given bit distributions. +func fillBase(dst []baseOffset, base uint32, bits ...uint8) { + if len(bits) != len(dst) { + panic(fmt.Sprintf("len(dst) (%d) != len(bits) (%d)", len(dst), len(bits))) + } + for i, bit := range bits { + if base > math.MaxInt32 { + panic(fmt.Sprintf("invalid decoding table, base overflows int32")) + } + + dst[i] = baseOffset{ + baseLine: base, + addBits: bit, + } + base += 1 << bit + } +} + +func init() { + // Literals length codes + tmp := make([]baseOffset, 36) + for i := range tmp[:16] { + tmp[i] = baseOffset{ + baseLine: uint32(i), + addBits: 0, + } + } + fillBase(tmp[16:], 16, 1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16) + symbolTableX[tableLiteralLengths] = tmp + + // Match length codes + tmp = make([]baseOffset, 53) + for i := range tmp[:32] { + tmp[i] = baseOffset{ + // The transformation adds the 3 length. + baseLine: uint32(i) + 3, + addBits: 0, + } + } + fillBase(tmp[32:], 35, 1, 1, 1, 1, 2, 2, 3, 3, 4, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16) + symbolTableX[tableMatchLengths] = tmp + + // Offset codes + tmp = make([]baseOffset, maxOffsetBits+1) + tmp[1] = baseOffset{ + baseLine: 1, + addBits: 1, + } + fillBase(tmp[2:], 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30) + symbolTableX[tableOffsets] = tmp + + // Fill predefined tables and transform them. + // https://github.com/facebook/zstd/blob/dev/doc/zstd_compression_format.md#default-distributions + for i := range fsePredef[:] { + f := &fsePredef[i] + switch tableIndex(i) { + case tableLiteralLengths: + // https://github.com/facebook/zstd/blob/ededcfca57366461021c922720878c81a5854a0a/lib/decompress/zstd_decompress_block.c#L243 + f.actualTableLog = 6 + copy(f.norm[:], []int16{4, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, + 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 1, 1, 1, 1, 1, + -1, -1, -1, -1}) + f.symbolLen = 36 + case tableOffsets: + // https://github.com/facebook/zstd/blob/ededcfca57366461021c922720878c81a5854a0a/lib/decompress/zstd_decompress_block.c#L281 + f.actualTableLog = 5 + copy(f.norm[:], []int16{ + 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1}) + f.symbolLen = 29 + case tableMatchLengths: + //https://github.com/facebook/zstd/blob/ededcfca57366461021c922720878c81a5854a0a/lib/decompress/zstd_decompress_block.c#L304 + f.actualTableLog = 6 + copy(f.norm[:], []int16{ + 1, 4, 3, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -1, + -1, -1, -1, -1, -1}) + f.symbolLen = 53 + } + if err := f.buildDtable(); err != nil { + panic(fmt.Errorf("building table %v: %v", tableIndex(i), err)) + } + if err := f.transform(symbolTableX[i]); err != nil { + panic(fmt.Errorf("building table %v: %v", tableIndex(i), err)) + } + f.preDefined = true + + // Create encoder as well + enc := &fsePredefEnc[i] + copy(enc.norm[:], f.norm[:]) + enc.symbolLen = f.symbolLen + enc.actualTableLog = f.actualTableLog + if err := enc.buildCTable(); err != nil { + panic(fmt.Errorf("building encoding table %v: %v", tableIndex(i), err)) + } + enc.setBits(bitTables[i]) + enc.preDefined = true + } +} diff --git a/vendor/github.com/klauspost/compress/zstd/hash.go b/vendor/github.com/klauspost/compress/zstd/hash.go new file mode 100644 index 000000000..819d87f88 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/hash.go @@ -0,0 +1,77 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +const ( + prime3bytes = 506832829 + prime4bytes = 2654435761 + prime5bytes = 889523592379 + prime6bytes = 227718039650203 + prime7bytes = 58295818150454627 + prime8bytes = 0xcf1bbcdcb7a56463 +) + +// hashLen returns a hash of the lowest l bytes of u for a size size of h bytes. +// l must be >=4 and <=8. Any other value will return hash for 4 bytes. +// h should always be <32. +// Preferably h and l should be a constant. +// FIXME: This does NOT get resolved, if 'mls' is constant, +// so this cannot be used. +func hashLen(u uint64, hashLog, mls uint8) uint32 { + switch mls { + case 5: + return hash5(u, hashLog) + case 6: + return hash6(u, hashLog) + case 7: + return hash7(u, hashLog) + case 8: + return hash8(u, hashLog) + default: + return hash4x64(u, hashLog) + } +} + +// hash3 returns the hash of the lower 3 bytes of u to fit in a hash table with h bits. +// Preferably h should be a constant and should always be <32. +func hash3(u uint32, h uint8) uint32 { + return ((u << (32 - 24)) * prime3bytes) >> ((32 - h) & 31) +} + +// hash4 returns the hash of u to fit in a hash table with h bits. +// Preferably h should be a constant and should always be <32. +func hash4(u uint32, h uint8) uint32 { + return (u * prime4bytes) >> ((32 - h) & 31) +} + +// hash4x64 returns the hash of the lowest 4 bytes of u to fit in a hash table with h bits. +// Preferably h should be a constant and should always be <32. +func hash4x64(u uint64, h uint8) uint32 { + return (uint32(u) * prime4bytes) >> ((32 - h) & 31) +} + +// hash5 returns the hash of the lowest 5 bytes of u to fit in a hash table with h bits. +// Preferably h should be a constant and should always be <64. +func hash5(u uint64, h uint8) uint32 { + return uint32(((u << (64 - 40)) * prime5bytes) >> ((64 - h) & 63)) +} + +// hash6 returns the hash of the lowest 6 bytes of u to fit in a hash table with h bits. +// Preferably h should be a constant and should always be <64. +func hash6(u uint64, h uint8) uint32 { + return uint32(((u << (64 - 48)) * prime6bytes) >> ((64 - h) & 63)) +} + +// hash6 returns the hash of the lowest 7 bytes of u to fit in a hash table with h bits. +// Preferably h should be a constant and should always be <64. +func hash7(u uint64, h uint8) uint32 { + return uint32(((u << (64 - 56)) * prime7bytes) >> ((64 - h) & 63)) +} + +// hash8 returns the hash of u to fit in a hash table with h bits. +// Preferably h should be a constant and should always be <64. +func hash8(u uint64, h uint8) uint32 { + return uint32((u * prime8bytes) >> ((64 - h) & 63)) +} diff --git a/vendor/github.com/klauspost/compress/zstd/history.go b/vendor/github.com/klauspost/compress/zstd/history.go new file mode 100644 index 000000000..e8c419bd5 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/history.go @@ -0,0 +1,73 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "github.com/klauspost/compress/huff0" +) + +// history contains the information transferred between blocks. +type history struct { + b []byte + huffTree *huff0.Scratch + recentOffsets [3]int + decoders sequenceDecs + windowSize int + maxSize int + error bool +} + +// reset will reset the history to initial state of a frame. +// The history must already have been initialized to the desired size. +func (h *history) reset() { + h.b = h.b[:0] + h.error = false + h.recentOffsets = [3]int{1, 4, 8} + if f := h.decoders.litLengths.fse; f != nil && !f.preDefined { + fseDecoderPool.Put(f) + } + if f := h.decoders.offsets.fse; f != nil && !f.preDefined { + fseDecoderPool.Put(f) + } + if f := h.decoders.matchLengths.fse; f != nil && !f.preDefined { + fseDecoderPool.Put(f) + } + h.decoders = sequenceDecs{} + if h.huffTree != nil { + huffDecoderPool.Put(h.huffTree) + } + h.huffTree = nil + //printf("history created: %+v (l: %d, c: %d)", *h, len(h.b), cap(h.b)) +} + +// append bytes to history. +// This function will make sure there is space for it, +// if the buffer has been allocated with enough extra space. +func (h *history) append(b []byte) { + if len(b) >= h.windowSize { + // Discard all history by simply overwriting + h.b = h.b[:h.windowSize] + copy(h.b, b[len(b)-h.windowSize:]) + return + } + + // If there is space, append it. + if len(b) < cap(h.b)-len(h.b) { + h.b = append(h.b, b...) + return + } + + // Move data down so we only have window size left. + // We know we have less than window size in b at this point. + discard := len(b) + len(h.b) - h.windowSize + copy(h.b, h.b[discard:]) + h.b = h.b[:h.windowSize] + copy(h.b[h.windowSize-len(b):], b) +} + +// append bytes to history without ever discarding anything. +func (h *history) appendKeep(b []byte) { + h.b = append(h.b, b...) +} diff --git a/vendor/github.com/klauspost/compress/zstd/internal/xxhash/LICENSE.txt b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/LICENSE.txt new file mode 100644 index 000000000..24b53065f --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/LICENSE.txt @@ -0,0 +1,22 @@ +Copyright (c) 2016 Caleb Spare + +MIT License + +Permission is hereby granted, free of charge, to any person obtaining +a copy of this software and associated documentation files (the +"Software"), to deal in the Software without restriction, including +without limitation the rights to use, copy, modify, merge, publish, +distribute, sublicense, and/or sell copies of the Software, and to +permit persons to whom the Software is furnished to do so, subject to +the following conditions: + +The above copyright notice and this permission notice shall be +included in all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE +LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION +WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. diff --git a/vendor/github.com/klauspost/compress/zstd/internal/xxhash/README.md b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/README.md new file mode 100644 index 000000000..69aa3bb58 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/README.md @@ -0,0 +1,58 @@ +# xxhash + +VENDORED: Go to [github.com/cespare/xxhash](https://github.com/cespare/xxhash) for original package. + + +[](https://godoc.org/github.com/cespare/xxhash) +[](https://travis-ci.org/cespare/xxhash) + +xxhash is a Go implementation of the 64-bit +[xxHash](http://cyan4973.github.io/xxHash/) algorithm, XXH64. This is a +high-quality hashing algorithm that is much faster than anything in the Go +standard library. + +This package provides a straightforward API: + +``` +func Sum64(b []byte) uint64 +func Sum64String(s string) uint64 +type Digest struct{ ... } + func New() *Digest +``` + +The `Digest` type implements hash.Hash64. Its key methods are: + +``` +func (*Digest) Write([]byte) (int, error) +func (*Digest) WriteString(string) (int, error) +func (*Digest) Sum64() uint64 +``` + +This implementation provides a fast pure-Go implementation and an even faster +assembly implementation for amd64. + +## Benchmarks + +Here are some quick benchmarks comparing the pure-Go and assembly +implementations of Sum64. + +| input size | purego | asm | +| --- | --- | --- | +| 5 B | 979.66 MB/s | 1291.17 MB/s | +| 100 B | 7475.26 MB/s | 7973.40 MB/s | +| 4 KB | 17573.46 MB/s | 17602.65 MB/s | +| 10 MB | 17131.46 MB/s | 17142.16 MB/s | + +These numbers were generated on Ubuntu 18.04 with an Intel i7-8700K CPU using +the following commands under Go 1.11.2: + +``` +$ go test -tags purego -benchtime 10s -bench '/xxhash,direct,bytes' +$ go test -benchtime 10s -bench '/xxhash,direct,bytes' +``` + +## Projects using this package + +- [InfluxDB](https://github.com/influxdata/influxdb) +- [Prometheus](https://github.com/prometheus/prometheus) +- [FreeCache](https://github.com/coocood/freecache) diff --git a/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash.go b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash.go new file mode 100644 index 000000000..426b9cac7 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash.go @@ -0,0 +1,238 @@ +// Package xxhash implements the 64-bit variant of xxHash (XXH64) as described +// at http://cyan4973.github.io/xxHash/. +// THIS IS VENDORED: Go to github.com/cespare/xxhash for original package. + +package xxhash + +import ( + "encoding/binary" + "errors" + "math/bits" +) + +const ( + prime1 uint64 = 11400714785074694791 + prime2 uint64 = 14029467366897019727 + prime3 uint64 = 1609587929392839161 + prime4 uint64 = 9650029242287828579 + prime5 uint64 = 2870177450012600261 +) + +// NOTE(caleb): I'm using both consts and vars of the primes. Using consts where +// possible in the Go code is worth a small (but measurable) performance boost +// by avoiding some MOVQs. Vars are needed for the asm and also are useful for +// convenience in the Go code in a few places where we need to intentionally +// avoid constant arithmetic (e.g., v1 := prime1 + prime2 fails because the +// result overflows a uint64). +var ( + prime1v = prime1 + prime2v = prime2 + prime3v = prime3 + prime4v = prime4 + prime5v = prime5 +) + +// Digest implements hash.Hash64. +type Digest struct { + v1 uint64 + v2 uint64 + v3 uint64 + v4 uint64 + total uint64 + mem [32]byte + n int // how much of mem is used +} + +// New creates a new Digest that computes the 64-bit xxHash algorithm. +func New() *Digest { + var d Digest + d.Reset() + return &d +} + +// Reset clears the Digest's state so that it can be reused. +func (d *Digest) Reset() { + d.v1 = prime1v + prime2 + d.v2 = prime2 + d.v3 = 0 + d.v4 = -prime1v + d.total = 0 + d.n = 0 +} + +// Size always returns 8 bytes. +func (d *Digest) Size() int { return 8 } + +// BlockSize always returns 32 bytes. +func (d *Digest) BlockSize() int { return 32 } + +// Write adds more data to d. It always returns len(b), nil. +func (d *Digest) Write(b []byte) (n int, err error) { + n = len(b) + d.total += uint64(n) + + if d.n+n < 32 { + // This new data doesn't even fill the current block. + copy(d.mem[d.n:], b) + d.n += n + return + } + + if d.n > 0 { + // Finish off the partial block. + copy(d.mem[d.n:], b) + d.v1 = round(d.v1, u64(d.mem[0:8])) + d.v2 = round(d.v2, u64(d.mem[8:16])) + d.v3 = round(d.v3, u64(d.mem[16:24])) + d.v4 = round(d.v4, u64(d.mem[24:32])) + b = b[32-d.n:] + d.n = 0 + } + + if len(b) >= 32 { + // One or more full blocks left. + nw := writeBlocks(d, b) + b = b[nw:] + } + + // Store any remaining partial block. + copy(d.mem[:], b) + d.n = len(b) + + return +} + +// Sum appends the current hash to b and returns the resulting slice. +func (d *Digest) Sum(b []byte) []byte { + s := d.Sum64() + return append( + b, + byte(s>>56), + byte(s>>48), + byte(s>>40), + byte(s>>32), + byte(s>>24), + byte(s>>16), + byte(s>>8), + byte(s), + ) +} + +// Sum64 returns the current hash. +func (d *Digest) Sum64() uint64 { + var h uint64 + + if d.total >= 32 { + v1, v2, v3, v4 := d.v1, d.v2, d.v3, d.v4 + h = rol1(v1) + rol7(v2) + rol12(v3) + rol18(v4) + h = mergeRound(h, v1) + h = mergeRound(h, v2) + h = mergeRound(h, v3) + h = mergeRound(h, v4) + } else { + h = d.v3 + prime5 + } + + h += d.total + + i, end := 0, d.n + for ; i+8 <= end; i += 8 { + k1 := round(0, u64(d.mem[i:i+8])) + h ^= k1 + h = rol27(h)*prime1 + prime4 + } + if i+4 <= end { + h ^= uint64(u32(d.mem[i:i+4])) * prime1 + h = rol23(h)*prime2 + prime3 + i += 4 + } + for i < end { + h ^= uint64(d.mem[i]) * prime5 + h = rol11(h) * prime1 + i++ + } + + h ^= h >> 33 + h *= prime2 + h ^= h >> 29 + h *= prime3 + h ^= h >> 32 + + return h +} + +const ( + magic = "xxh\x06" + marshaledSize = len(magic) + 8*5 + 32 +) + +// MarshalBinary implements the encoding.BinaryMarshaler interface. +func (d *Digest) MarshalBinary() ([]byte, error) { + b := make([]byte, 0, marshaledSize) + b = append(b, magic...) + b = appendUint64(b, d.v1) + b = appendUint64(b, d.v2) + b = appendUint64(b, d.v3) + b = appendUint64(b, d.v4) + b = appendUint64(b, d.total) + b = append(b, d.mem[:d.n]...) + b = b[:len(b)+len(d.mem)-d.n] + return b, nil +} + +// UnmarshalBinary implements the encoding.BinaryUnmarshaler interface. +func (d *Digest) UnmarshalBinary(b []byte) error { + if len(b) < len(magic) || string(b[:len(magic)]) != magic { + return errors.New("xxhash: invalid hash state identifier") + } + if len(b) != marshaledSize { + return errors.New("xxhash: invalid hash state size") + } + b = b[len(magic):] + b, d.v1 = consumeUint64(b) + b, d.v2 = consumeUint64(b) + b, d.v3 = consumeUint64(b) + b, d.v4 = consumeUint64(b) + b, d.total = consumeUint64(b) + copy(d.mem[:], b) + b = b[len(d.mem):] + d.n = int(d.total % uint64(len(d.mem))) + return nil +} + +func appendUint64(b []byte, x uint64) []byte { + var a [8]byte + binary.LittleEndian.PutUint64(a[:], x) + return append(b, a[:]...) +} + +func consumeUint64(b []byte) ([]byte, uint64) { + x := u64(b) + return b[8:], x +} + +func u64(b []byte) uint64 { return binary.LittleEndian.Uint64(b) } +func u32(b []byte) uint32 { return binary.LittleEndian.Uint32(b) } + +func round(acc, input uint64) uint64 { + acc += input * prime2 + acc = rol31(acc) + acc *= prime1 + return acc +} + +func mergeRound(acc, val uint64) uint64 { + val = round(0, val) + acc ^= val + acc = acc*prime1 + prime4 + return acc +} + +func rol1(x uint64) uint64 { return bits.RotateLeft64(x, 1) } +func rol7(x uint64) uint64 { return bits.RotateLeft64(x, 7) } +func rol11(x uint64) uint64 { return bits.RotateLeft64(x, 11) } +func rol12(x uint64) uint64 { return bits.RotateLeft64(x, 12) } +func rol18(x uint64) uint64 { return bits.RotateLeft64(x, 18) } +func rol23(x uint64) uint64 { return bits.RotateLeft64(x, 23) } +func rol27(x uint64) uint64 { return bits.RotateLeft64(x, 27) } +func rol31(x uint64) uint64 { return bits.RotateLeft64(x, 31) } diff --git a/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_amd64.go b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_amd64.go new file mode 100644 index 000000000..35318d7c4 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_amd64.go @@ -0,0 +1,13 @@ +// +build !appengine +// +build gc +// +build !purego + +package xxhash + +// Sum64 computes the 64-bit xxHash digest of b. +// +//go:noescape +func Sum64(b []byte) uint64 + +//go:noescape +func writeBlocks(*Digest, []byte) int diff --git a/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_amd64.s b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_amd64.s new file mode 100644 index 000000000..d580e32ae --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_amd64.s @@ -0,0 +1,215 @@ +// +build !appengine +// +build gc +// +build !purego + +#include "textflag.h" + +// Register allocation: +// AX h +// CX pointer to advance through b +// DX n +// BX loop end +// R8 v1, k1 +// R9 v2 +// R10 v3 +// R11 v4 +// R12 tmp +// R13 prime1v +// R14 prime2v +// R15 prime4v + +// round reads from and advances the buffer pointer in CX. +// It assumes that R13 has prime1v and R14 has prime2v. +#define round(r) \ + MOVQ (CX), R12 \ + ADDQ $8, CX \ + IMULQ R14, R12 \ + ADDQ R12, r \ + ROLQ $31, r \ + IMULQ R13, r + +// mergeRound applies a merge round on the two registers acc and val. +// It assumes that R13 has prime1v, R14 has prime2v, and R15 has prime4v. +#define mergeRound(acc, val) \ + IMULQ R14, val \ + ROLQ $31, val \ + IMULQ R13, val \ + XORQ val, acc \ + IMULQ R13, acc \ + ADDQ R15, acc + +// func Sum64(b []byte) uint64 +TEXT ·Sum64(SB), NOSPLIT, $0-32 + // Load fixed primes. + MOVQ ·prime1v(SB), R13 + MOVQ ·prime2v(SB), R14 + MOVQ ·prime4v(SB), R15 + + // Load slice. + MOVQ b_base+0(FP), CX + MOVQ b_len+8(FP), DX + LEAQ (CX)(DX*1), BX + + // The first loop limit will be len(b)-32. + SUBQ $32, BX + + // Check whether we have at least one block. + CMPQ DX, $32 + JLT noBlocks + + // Set up initial state (v1, v2, v3, v4). + MOVQ R13, R8 + ADDQ R14, R8 + MOVQ R14, R9 + XORQ R10, R10 + XORQ R11, R11 + SUBQ R13, R11 + + // Loop until CX > BX. +blockLoop: + round(R8) + round(R9) + round(R10) + round(R11) + + CMPQ CX, BX + JLE blockLoop + + MOVQ R8, AX + ROLQ $1, AX + MOVQ R9, R12 + ROLQ $7, R12 + ADDQ R12, AX + MOVQ R10, R12 + ROLQ $12, R12 + ADDQ R12, AX + MOVQ R11, R12 + ROLQ $18, R12 + ADDQ R12, AX + + mergeRound(AX, R8) + mergeRound(AX, R9) + mergeRound(AX, R10) + mergeRound(AX, R11) + + JMP afterBlocks + +noBlocks: + MOVQ ·prime5v(SB), AX + +afterBlocks: + ADDQ DX, AX + + // Right now BX has len(b)-32, and we want to loop until CX > len(b)-8. + ADDQ $24, BX + + CMPQ CX, BX + JG fourByte + +wordLoop: + // Calculate k1. + MOVQ (CX), R8 + ADDQ $8, CX + IMULQ R14, R8 + ROLQ $31, R8 + IMULQ R13, R8 + + XORQ R8, AX + ROLQ $27, AX + IMULQ R13, AX + ADDQ R15, AX + + CMPQ CX, BX + JLE wordLoop + +fourByte: + ADDQ $4, BX + CMPQ CX, BX + JG singles + + MOVL (CX), R8 + ADDQ $4, CX + IMULQ R13, R8 + XORQ R8, AX + + ROLQ $23, AX + IMULQ R14, AX + ADDQ ·prime3v(SB), AX + +singles: + ADDQ $4, BX + CMPQ CX, BX + JGE finalize + +singlesLoop: + MOVBQZX (CX), R12 + ADDQ $1, CX + IMULQ ·prime5v(SB), R12 + XORQ R12, AX + + ROLQ $11, AX + IMULQ R13, AX + + CMPQ CX, BX + JL singlesLoop + +finalize: + MOVQ AX, R12 + SHRQ $33, R12 + XORQ R12, AX + IMULQ R14, AX + MOVQ AX, R12 + SHRQ $29, R12 + XORQ R12, AX + IMULQ ·prime3v(SB), AX + MOVQ AX, R12 + SHRQ $32, R12 + XORQ R12, AX + + MOVQ AX, ret+24(FP) + RET + +// writeBlocks uses the same registers as above except that it uses AX to store +// the d pointer. + +// func writeBlocks(d *Digest, b []byte) int +TEXT ·writeBlocks(SB), NOSPLIT, $0-40 + // Load fixed primes needed for round. + MOVQ ·prime1v(SB), R13 + MOVQ ·prime2v(SB), R14 + + // Load slice. + MOVQ b_base+8(FP), CX + MOVQ b_len+16(FP), DX + LEAQ (CX)(DX*1), BX + SUBQ $32, BX + + // Load vN from d. + MOVQ d+0(FP), AX + MOVQ 0(AX), R8 // v1 + MOVQ 8(AX), R9 // v2 + MOVQ 16(AX), R10 // v3 + MOVQ 24(AX), R11 // v4 + + // We don't need to check the loop condition here; this function is + // always called with at least one block of data to process. +blockLoop: + round(R8) + round(R9) + round(R10) + round(R11) + + CMPQ CX, BX + JLE blockLoop + + // Copy vN back to d. + MOVQ R8, 0(AX) + MOVQ R9, 8(AX) + MOVQ R10, 16(AX) + MOVQ R11, 24(AX) + + // The number of bytes written is CX minus the old base pointer. + SUBQ b_base+8(FP), CX + MOVQ CX, ret+32(FP) + + RET diff --git a/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_other.go b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_other.go new file mode 100644 index 000000000..4a5a82160 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_other.go @@ -0,0 +1,76 @@ +// +build !amd64 appengine !gc purego + +package xxhash + +// Sum64 computes the 64-bit xxHash digest of b. +func Sum64(b []byte) uint64 { + // A simpler version would be + // d := New() + // d.Write(b) + // return d.Sum64() + // but this is faster, particularly for small inputs. + + n := len(b) + var h uint64 + + if n >= 32 { + v1 := prime1v + prime2 + v2 := prime2 + v3 := uint64(0) + v4 := -prime1v + for len(b) >= 32 { + v1 = round(v1, u64(b[0:8:len(b)])) + v2 = round(v2, u64(b[8:16:len(b)])) + v3 = round(v3, u64(b[16:24:len(b)])) + v4 = round(v4, u64(b[24:32:len(b)])) + b = b[32:len(b):len(b)] + } + h = rol1(v1) + rol7(v2) + rol12(v3) + rol18(v4) + h = mergeRound(h, v1) + h = mergeRound(h, v2) + h = mergeRound(h, v3) + h = mergeRound(h, v4) + } else { + h = prime5 + } + + h += uint64(n) + + i, end := 0, len(b) + for ; i+8 <= end; i += 8 { + k1 := round(0, u64(b[i:i+8:len(b)])) + h ^= k1 + h = rol27(h)*prime1 + prime4 + } + if i+4 <= end { + h ^= uint64(u32(b[i:i+4:len(b)])) * prime1 + h = rol23(h)*prime2 + prime3 + i += 4 + } + for ; i < end; i++ { + h ^= uint64(b[i]) * prime5 + h = rol11(h) * prime1 + } + + h ^= h >> 33 + h *= prime2 + h ^= h >> 29 + h *= prime3 + h ^= h >> 32 + + return h +} + +func writeBlocks(d *Digest, b []byte) int { + v1, v2, v3, v4 := d.v1, d.v2, d.v3, d.v4 + n := len(b) + for len(b) >= 32 { + v1 = round(v1, u64(b[0:8:len(b)])) + v2 = round(v2, u64(b[8:16:len(b)])) + v3 = round(v3, u64(b[16:24:len(b)])) + v4 = round(v4, u64(b[24:32:len(b)])) + b = b[32:len(b):len(b)] + } + d.v1, d.v2, d.v3, d.v4 = v1, v2, v3, v4 + return n - len(b) +} diff --git a/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_safe.go b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_safe.go new file mode 100644 index 000000000..6f3b0cb10 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/internal/xxhash/xxhash_safe.go @@ -0,0 +1,11 @@ +package xxhash + +// Sum64String computes the 64-bit xxHash digest of s. +func Sum64String(s string) uint64 { + return Sum64([]byte(s)) +} + +// WriteString adds more data to d. It always returns len(s), nil. +func (d *Digest) WriteString(s string) (n int, err error) { + return d.Write([]byte(s)) +} diff --git a/vendor/github.com/klauspost/compress/zstd/seqdec.go b/vendor/github.com/klauspost/compress/zstd/seqdec.go new file mode 100644 index 000000000..cef69e35b --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/seqdec.go @@ -0,0 +1,409 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "errors" + "fmt" + "io" +) + +type seq struct { + litLen uint32 + matchLen uint32 + offset uint32 + + // Codes are stored here for the encoder + // so they only have to be looked up once. + llCode, mlCode, ofCode uint8 +} + +func (s seq) String() string { + if s.offset <= 3 { + if s.offset == 0 { + return fmt.Sprint("litLen:", s.litLen, ", matchLen:", s.matchLen+zstdMinMatch, ", offset: INVALID (0)") + } + return fmt.Sprint("litLen:", s.litLen, ", matchLen:", s.matchLen+zstdMinMatch, ", offset:", s.offset, " (repeat)") + } + return fmt.Sprint("litLen:", s.litLen, ", matchLen:", s.matchLen+zstdMinMatch, ", offset:", s.offset-3, " (new)") +} + +type seqCompMode uint8 + +const ( + compModePredefined seqCompMode = iota + compModeRLE + compModeFSE + compModeRepeat +) + +type sequenceDec struct { + // decoder keeps track of the current state and updates it from the bitstream. + fse *fseDecoder + state fseState + repeat bool +} + +// init the state of the decoder with input from stream. +func (s *sequenceDec) init(br *bitReader) error { + if s.fse == nil { + return errors.New("sequence decoder not defined") + } + s.state.init(br, s.fse.actualTableLog, s.fse.dt[:1<<s.fse.actualTableLog]) + return nil +} + +// sequenceDecs contains all 3 sequence decoders and their state. +type sequenceDecs struct { + litLengths sequenceDec + offsets sequenceDec + matchLengths sequenceDec + prevOffset [3]int + hist []byte + literals []byte + out []byte + maxBits uint8 +} + +// initialize all 3 decoders from the stream input. +func (s *sequenceDecs) initialize(br *bitReader, hist *history, literals, out []byte) error { + if err := s.litLengths.init(br); err != nil { + return errors.New("litLengths:" + err.Error()) + } + if err := s.offsets.init(br); err != nil { + return errors.New("offsets:" + err.Error()) + } + if err := s.matchLengths.init(br); err != nil { + return errors.New("matchLengths:" + err.Error()) + } + s.literals = literals + s.hist = hist.b + s.prevOffset = hist.recentOffsets + s.maxBits = s.litLengths.fse.maxBits + s.offsets.fse.maxBits + s.matchLengths.fse.maxBits + s.out = out + return nil +} + +// decode sequences from the stream with the provided history. +func (s *sequenceDecs) decode(seqs int, br *bitReader, hist []byte) error { + startSize := len(s.out) + for i := seqs - 1; i >= 0; i-- { + if br.overread() { + printf("reading sequence %d, exceeded available data\n", seqs-i) + return io.ErrUnexpectedEOF + } + var litLen, matchOff, matchLen int + if br.off > 4+((maxOffsetBits+16+16)>>3) { + litLen, matchOff, matchLen = s.nextFast(br) + br.fillFast() + } else { + litLen, matchOff, matchLen = s.next(br) + br.fill() + } + + if debugSequences { + println("Seq", seqs-i-1, "Litlen:", litLen, "matchOff:", matchOff, "(abs) matchLen:", matchLen) + } + + if litLen > len(s.literals) { + return fmt.Errorf("unexpected literal count, want %d bytes, but only %d is available", litLen, len(s.literals)) + } + size := litLen + matchLen + len(s.out) + if size-startSize > maxBlockSize { + return fmt.Errorf("output (%d) bigger than max block size", size) + } + if size > cap(s.out) { + // Not enough size, will be extremely rarely triggered, + // but could be if destination slice is too small for sync operations. + // We add maxBlockSize to the capacity. + s.out = append(s.out, make([]byte, maxBlockSize)...) + s.out = s.out[:len(s.out)-maxBlockSize] + } + if matchLen > maxMatchLen { + return fmt.Errorf("match len (%d) bigger than max allowed length", matchLen) + } + if matchOff > len(s.out)+len(hist)+litLen { + return fmt.Errorf("match offset (%d) bigger than current history (%d)", matchOff, len(s.out)+len(hist)+litLen) + } + if matchOff == 0 && matchLen > 0 { + return fmt.Errorf("zero matchoff and matchlen > 0") + } + + s.out = append(s.out, s.literals[:litLen]...) + s.literals = s.literals[litLen:] + out := s.out + + // Copy from history. + // TODO: Blocks without history could be made to ignore this completely. + if v := matchOff - len(s.out); v > 0 { + // v is the start position in history from end. + start := len(s.hist) - v + if matchLen > v { + // Some goes into current block. + // Copy remainder of history + out = append(out, s.hist[start:]...) + matchOff -= v + matchLen -= v + } else { + out = append(out, s.hist[start:start+matchLen]...) + matchLen = 0 + } + } + // We must be in current buffer now + if matchLen > 0 { + start := len(s.out) - matchOff + if matchLen <= len(s.out)-start { + // No overlap + out = append(out, s.out[start:start+matchLen]...) + } else { + // Overlapping copy + // Extend destination slice and copy one byte at the time. + out = out[:len(out)+matchLen] + src := out[start : start+matchLen] + // Destination is the space we just added. + dst := out[len(out)-matchLen:] + dst = dst[:len(src)] + for i := range src { + dst[i] = src[i] + } + } + } + s.out = out + if i == 0 { + // This is the last sequence, so we shouldn't update state. + break + } + if true { + // Manually inlined, ~ 5-20% faster + // Update all 3 states at once. Approx 20% faster. + a, b, c := s.litLengths.state.state, s.matchLengths.state.state, s.offsets.state.state + + nBits := a.nbBits + b.nbBits + c.nbBits + if nBits == 0 { + s.litLengths.state.state = s.litLengths.state.dt[a.newState] + s.matchLengths.state.state = s.matchLengths.state.dt[b.newState] + s.offsets.state.state = s.offsets.state.dt[c.newState] + } else { + bits := br.getBitsFast(nBits) + lowBits := uint16(bits >> ((c.nbBits + b.nbBits) & 31)) + s.litLengths.state.state = s.litLengths.state.dt[a.newState+lowBits] + + lowBits = uint16(bits >> (c.nbBits & 31)) + lowBits &= bitMask[b.nbBits&15] + s.matchLengths.state.state = s.matchLengths.state.dt[b.newState+lowBits] + + lowBits = uint16(bits) & bitMask[c.nbBits&15] + s.offsets.state.state = s.offsets.state.dt[c.newState+lowBits] + } + } else { + s.updateAlt(br) + } + } + + // Add final literals + s.out = append(s.out, s.literals...) + return nil +} + +// update states, at least 27 bits must be available. +func (s *sequenceDecs) update(br *bitReader) { + // Max 8 bits + s.litLengths.state.next(br) + // Max 9 bits + s.matchLengths.state.next(br) + // Max 8 bits + s.offsets.state.next(br) +} + +var bitMask [16]uint16 + +func init() { + for i := range bitMask[:] { + bitMask[i] = uint16((1 << uint(i)) - 1) + } +} + +// update states, at least 27 bits must be available. +func (s *sequenceDecs) updateAlt(br *bitReader) { + // Update all 3 states at once. Approx 20% faster. + a, b, c := s.litLengths.state.state, s.matchLengths.state.state, s.offsets.state.state + + nBits := a.nbBits + b.nbBits + c.nbBits + if nBits == 0 { + s.litLengths.state.state = s.litLengths.state.dt[a.newState] + s.matchLengths.state.state = s.matchLengths.state.dt[b.newState] + s.offsets.state.state = s.offsets.state.dt[c.newState] + return + } + bits := br.getBitsFast(nBits) + lowBits := uint16(bits >> ((c.nbBits + b.nbBits) & 31)) + s.litLengths.state.state = s.litLengths.state.dt[a.newState+lowBits] + + lowBits = uint16(bits >> (c.nbBits & 31)) + lowBits &= bitMask[b.nbBits&15] + s.matchLengths.state.state = s.matchLengths.state.dt[b.newState+lowBits] + + lowBits = uint16(bits) & bitMask[c.nbBits&15] + s.offsets.state.state = s.offsets.state.dt[c.newState+lowBits] +} + +// nextFast will return new states when there are at least 4 unused bytes left on the stream when done. +func (s *sequenceDecs) nextFast(br *bitReader) (ll, mo, ml int) { + // Final will not read from stream. + ll, llB := s.litLengths.state.final() + ml, mlB := s.matchLengths.state.final() + mo, moB := s.offsets.state.final() + + // extra bits are stored in reverse order. + br.fillFast() + if s.maxBits <= 32 { + mo += br.getBits(moB) + ml += br.getBits(mlB) + ll += br.getBits(llB) + } else { + mo += br.getBits(moB) + br.fillFast() + // matchlength+literal length, max 32 bits + ml += br.getBits(mlB) + ll += br.getBits(llB) + } + + // mo = s.adjustOffset(mo, ll, moB) + // Inlined for rather big speedup + if moB > 1 { + s.prevOffset[2] = s.prevOffset[1] + s.prevOffset[1] = s.prevOffset[0] + s.prevOffset[0] = mo + return + } + + if ll == 0 { + // There is an exception though, when current sequence's literals_length = 0. + // In this case, repeated offsets are shifted by one, so an offset_value of 1 means Repeated_Offset2, + // an offset_value of 2 means Repeated_Offset3, and an offset_value of 3 means Repeated_Offset1 - 1_byte. + mo++ + } + + if mo == 0 { + mo = s.prevOffset[0] + return + } + var temp int + if mo == 3 { + temp = s.prevOffset[0] - 1 + } else { + temp = s.prevOffset[mo] + } + + if temp == 0 { + // 0 is not valid; input is corrupted; force offset to 1 + println("temp was 0") + temp = 1 + } + + if mo != 1 { + s.prevOffset[2] = s.prevOffset[1] + } + s.prevOffset[1] = s.prevOffset[0] + s.prevOffset[0] = temp + mo = temp + return +} + +func (s *sequenceDecs) next(br *bitReader) (ll, mo, ml int) { + // Final will not read from stream. + ll, llB := s.litLengths.state.final() + ml, mlB := s.matchLengths.state.final() + mo, moB := s.offsets.state.final() + + // extra bits are stored in reverse order. + br.fill() + if s.maxBits <= 32 { + mo += br.getBits(moB) + ml += br.getBits(mlB) + ll += br.getBits(llB) + } else { + mo += br.getBits(moB) + br.fill() + // matchlength+literal length, max 32 bits + ml += br.getBits(mlB) + ll += br.getBits(llB) + + } + mo = s.adjustOffset(mo, ll, moB) + return +} + +func (s *sequenceDecs) adjustOffset(offset, litLen int, offsetB uint8) int { + if offsetB > 1 { + s.prevOffset[2] = s.prevOffset[1] + s.prevOffset[1] = s.prevOffset[0] + s.prevOffset[0] = offset + return offset + } + + if litLen == 0 { + // There is an exception though, when current sequence's literals_length = 0. + // In this case, repeated offsets are shifted by one, so an offset_value of 1 means Repeated_Offset2, + // an offset_value of 2 means Repeated_Offset3, and an offset_value of 3 means Repeated_Offset1 - 1_byte. + offset++ + } + + if offset == 0 { + return s.prevOffset[0] + } + var temp int + if offset == 3 { + temp = s.prevOffset[0] - 1 + } else { + temp = s.prevOffset[offset] + } + + if temp == 0 { + // 0 is not valid; input is corrupted; force offset to 1 + println("temp was 0") + temp = 1 + } + + if offset != 1 { + s.prevOffset[2] = s.prevOffset[1] + } + s.prevOffset[1] = s.prevOffset[0] + s.prevOffset[0] = temp + return temp +} + +// mergeHistory will merge history. +func (s *sequenceDecs) mergeHistory(hist *sequenceDecs) (*sequenceDecs, error) { + for i := uint(0); i < 3; i++ { + var sNew, sHist *sequenceDec + switch i { + default: + // same as "case 0": + sNew = &s.litLengths + sHist = &hist.litLengths + case 1: + sNew = &s.offsets + sHist = &hist.offsets + case 2: + sNew = &s.matchLengths + sHist = &hist.matchLengths + } + if sNew.repeat { + if sHist.fse == nil { + return nil, fmt.Errorf("sequence stream %d, repeat requested, but no history", i) + } + continue + } + if sNew.fse == nil { + return nil, fmt.Errorf("sequence stream %d, no fse found", i) + } + if sHist.fse != nil && !sHist.fse.preDefined { + fseDecoderPool.Put(sHist.fse) + } + sHist.fse = sNew.fse + } + return hist, nil +} diff --git a/vendor/github.com/klauspost/compress/zstd/seqenc.go b/vendor/github.com/klauspost/compress/zstd/seqenc.go new file mode 100644 index 000000000..36bcc3cc0 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/seqenc.go @@ -0,0 +1,115 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import "math/bits" + +type seqCoders struct { + llEnc, ofEnc, mlEnc *fseEncoder + llPrev, ofPrev, mlPrev *fseEncoder +} + +// swap coders with another (block). +func (s *seqCoders) swap(other *seqCoders) { + *s, *other = *other, *s +} + +// setPrev will update the previous encoders to the actually used ones +// and make sure a fresh one is in the main slot. +func (s *seqCoders) setPrev(ll, ml, of *fseEncoder) { + compareSwap := func(used *fseEncoder, current, prev **fseEncoder) { + // We used the new one, more current to history and reuse the previous history + if *current == used { + *prev, *current = *current, *prev + c := *current + p := *prev + c.reUsed = false + p.reUsed = true + return + } + if used == *prev { + return + } + // Ensure we cannot reuse by accident + prevEnc := *prev + prevEnc.symbolLen = 0 + return + } + compareSwap(ll, &s.llEnc, &s.llPrev) + compareSwap(ml, &s.mlEnc, &s.mlPrev) + compareSwap(of, &s.ofEnc, &s.ofPrev) +} + +func highBit(val uint32) (n uint32) { + return uint32(bits.Len32(val) - 1) +} + +var llCodeTable = [64]byte{0, 1, 2, 3, 4, 5, 6, 7, + 8, 9, 10, 11, 12, 13, 14, 15, + 16, 16, 17, 17, 18, 18, 19, 19, + 20, 20, 20, 20, 21, 21, 21, 21, + 22, 22, 22, 22, 22, 22, 22, 22, + 23, 23, 23, 23, 23, 23, 23, 23, + 24, 24, 24, 24, 24, 24, 24, 24, + 24, 24, 24, 24, 24, 24, 24, 24} + +// Up to 6 bits +const maxLLCode = 35 + +// llBitsTable translates from ll code to number of bits. +var llBitsTable = [maxLLCode + 1]byte{ + 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, + 1, 1, 1, 1, 2, 2, 3, 3, + 4, 6, 7, 8, 9, 10, 11, 12, + 13, 14, 15, 16} + +// llCode returns the code that represents the literal length requested. +func llCode(litLength uint32) uint8 { + const llDeltaCode = 19 + if litLength <= 63 { + // Compiler insists on bounds check (Go 1.12) + return llCodeTable[litLength&63] + } + return uint8(highBit(litLength)) + llDeltaCode +} + +var mlCodeTable = [128]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, + 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, + 32, 32, 33, 33, 34, 34, 35, 35, 36, 36, 36, 36, 37, 37, 37, 37, + 38, 38, 38, 38, 38, 38, 38, 38, 39, 39, 39, 39, 39, 39, 39, 39, + 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, + 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, + 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, + 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42, 42} + +// Up to 6 bits +const maxMLCode = 52 + +// mlBitsTable translates from ml code to number of bits. +var mlBitsTable = [maxMLCode + 1]byte{ + 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, + 1, 1, 1, 1, 2, 2, 3, 3, + 4, 4, 5, 7, 8, 9, 10, 11, + 12, 13, 14, 15, 16} + +// note : mlBase = matchLength - MINMATCH; +// because it's the format it's stored in seqStore->sequences +func mlCode(mlBase uint32) uint8 { + const mlDeltaCode = 36 + if mlBase <= 127 { + // Compiler insists on bounds check (Go 1.12) + return mlCodeTable[mlBase&127] + } + return uint8(highBit(mlBase)) + mlDeltaCode +} + +func ofCode(offset uint32) uint8 { + // A valid offset will always be > 0. + return uint8(bits.Len32(offset) - 1) +} diff --git a/vendor/github.com/klauspost/compress/zstd/snappy.go b/vendor/github.com/klauspost/compress/zstd/snappy.go new file mode 100644 index 000000000..e9e518570 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/snappy.go @@ -0,0 +1,435 @@ +// Copyright 2019+ Klaus Post. All rights reserved. +// License information can be found in the LICENSE file. +// Based on work by Yann Collet, released under BSD License. + +package zstd + +import ( + "encoding/binary" + "errors" + "hash/crc32" + "io" + + "github.com/klauspost/compress/huff0" + "github.com/klauspost/compress/snappy" +) + +const ( + snappyTagLiteral = 0x00 + snappyTagCopy1 = 0x01 + snappyTagCopy2 = 0x02 + snappyTagCopy4 = 0x03 +) + +const ( + snappyChecksumSize = 4 + snappyMagicBody = "sNaPpY" + + // snappyMaxBlockSize is the maximum size of the input to encodeBlock. It is not + // part of the wire format per se, but some parts of the encoder assume + // that an offset fits into a uint16. + // + // Also, for the framing format (Writer type instead of Encode function), + // https://github.com/google/snappy/blob/master/framing_format.txt says + // that "the uncompressed data in a chunk must be no longer than 65536 + // bytes". + snappyMaxBlockSize = 65536 + + // snappyMaxEncodedLenOfMaxBlockSize equals MaxEncodedLen(snappyMaxBlockSize), but is + // hard coded to be a const instead of a variable, so that obufLen can also + // be a const. Their equivalence is confirmed by + // TestMaxEncodedLenOfMaxBlockSize. + snappyMaxEncodedLenOfMaxBlockSize = 76490 +) + +const ( + chunkTypeCompressedData = 0x00 + chunkTypeUncompressedData = 0x01 + chunkTypePadding = 0xfe + chunkTypeStreamIdentifier = 0xff +) + +var ( + // ErrSnappyCorrupt reports that the input is invalid. + ErrSnappyCorrupt = errors.New("snappy: corrupt input") + // ErrSnappyTooLarge reports that the uncompressed length is too large. + ErrSnappyTooLarge = errors.New("snappy: decoded block is too large") + // ErrSnappyUnsupported reports that the input isn't supported. + ErrSnappyUnsupported = errors.New("snappy: unsupported input") + + errUnsupportedLiteralLength = errors.New("snappy: unsupported literal length") +) + +// SnappyConverter can read SnappyConverter-compressed streams and convert them to zstd. +// Conversion is done by converting the stream directly from Snappy without intermediate +// full decoding. +// Therefore the compression ratio is much less than what can be done by a full decompression +// and compression, and a faulty Snappy stream may lead to a faulty Zstandard stream without +// any errors being generated. +// No CRC value is being generated and not all CRC values of the Snappy stream are checked. +// However, it provides really fast recompression of Snappy streams. +// The converter can be reused to avoid allocations, even after errors. +type SnappyConverter struct { + r io.Reader + err error + buf []byte + block *blockEnc +} + +// Convert the Snappy stream supplied in 'in' and write the zStandard stream to 'w'. +// If any error is detected on the Snappy stream it is returned. +// The number of bytes written is returned. +func (r *SnappyConverter) Convert(in io.Reader, w io.Writer) (int64, error) { + r.err = nil + r.r = in + if r.block == nil { + r.block = &blockEnc{} + r.block.init() + } + r.block.initNewEncode() + if len(r.buf) != snappyMaxEncodedLenOfMaxBlockSize+snappyChecksumSize { + r.buf = make([]byte, snappyMaxEncodedLenOfMaxBlockSize+snappyChecksumSize) + } + r.block.litEnc.Reuse = huff0.ReusePolicyNone + var written int64 + var readHeader bool + { + var header []byte + var n int + header, r.err = frameHeader{WindowSize: snappyMaxBlockSize}.appendTo(r.buf[:0]) + + n, r.err = w.Write(header) + if r.err != nil { + return written, r.err + } + written += int64(n) + } + + for { + if !r.readFull(r.buf[:4], true) { + // Add empty last block + r.block.reset(nil) + r.block.last = true + err := r.block.encodeLits() + if err != nil { + return written, err + } + n, err := w.Write(r.block.output) + if err != nil { + return written, err + } + written += int64(n) + + return written, r.err + } + chunkType := r.buf[0] + if !readHeader { + if chunkType != chunkTypeStreamIdentifier { + println("chunkType != chunkTypeStreamIdentifier", chunkType) + r.err = ErrSnappyCorrupt + return written, r.err + } + readHeader = true + } + chunkLen := int(r.buf[1]) | int(r.buf[2])<<8 | int(r.buf[3])<<16 + if chunkLen > len(r.buf) { + println("chunkLen > len(r.buf)", chunkType) + r.err = ErrSnappyUnsupported + return written, r.err + } + + // The chunk types are specified at + // https://github.com/google/snappy/blob/master/framing_format.txt + switch chunkType { + case chunkTypeCompressedData: + // Section 4.2. Compressed data (chunk type 0x00). + if chunkLen < snappyChecksumSize { + println("chunkLen < snappyChecksumSize", chunkLen, snappyChecksumSize) + r.err = ErrSnappyCorrupt + return written, r.err + } + buf := r.buf[:chunkLen] + if !r.readFull(buf, false) { + return written, r.err + } + //checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24 + buf = buf[snappyChecksumSize:] + + n, hdr, err := snappyDecodedLen(buf) + if err != nil { + r.err = err + return written, r.err + } + buf = buf[hdr:] + if n > snappyMaxBlockSize { + println("n > snappyMaxBlockSize", n, snappyMaxBlockSize) + r.err = ErrSnappyCorrupt + return written, r.err + } + r.block.reset(nil) + r.block.pushOffsets() + if err := decodeSnappy(r.block, buf); err != nil { + r.err = err + return written, r.err + } + if r.block.size+r.block.extraLits != n { + printf("invalid size, want %d, got %d\n", n, r.block.size+r.block.extraLits) + r.err = ErrSnappyCorrupt + return written, r.err + } + err = r.block.encode() + switch err { + case errIncompressible: + r.block.popOffsets() + r.block.reset(nil) + r.block.literals, err = snappy.Decode(r.block.literals[:n], r.buf[snappyChecksumSize:chunkLen]) + if err != nil { + println("snappy.Decode:", err) + return written, err + } + err = r.block.encodeLits() + if err != nil { + return written, err + } + case nil: + default: + return written, err + } + + n, r.err = w.Write(r.block.output) + if r.err != nil { + return written, err + } + written += int64(n) + continue + case chunkTypeUncompressedData: + if debug { + println("Uncompressed, chunklen", chunkLen) + } + // Section 4.3. Uncompressed data (chunk type 0x01). + if chunkLen < snappyChecksumSize { + println("chunkLen < snappyChecksumSize", chunkLen, snappyChecksumSize) + r.err = ErrSnappyCorrupt + return written, r.err + } + r.block.reset(nil) + buf := r.buf[:snappyChecksumSize] + if !r.readFull(buf, false) { + return written, r.err + } + checksum := uint32(buf[0]) | uint32(buf[1])<<8 | uint32(buf[2])<<16 | uint32(buf[3])<<24 + // Read directly into r.decoded instead of via r.buf. + n := chunkLen - snappyChecksumSize + if n > snappyMaxBlockSize { + println("n > snappyMaxBlockSize", n, snappyMaxBlockSize) + r.err = ErrSnappyCorrupt + return written, r.err + } + r.block.literals = r.block.literals[:n] + if !r.readFull(r.block.literals, false) { + return written, r.err + } + if snappyCRC(r.block.literals) != checksum { + println("literals crc mismatch") + r.err = ErrSnappyCorrupt + return written, r.err + } + err := r.block.encodeLits() + if err != nil { + return written, err + } + n, r.err = w.Write(r.block.output) + if r.err != nil { + return written, err + } + written += int64(n) + continue + + case chunkTypeStreamIdentifier: + if debug { + println("stream id", chunkLen, len(snappyMagicBody)) + } + // Section 4.1. Stream identifier (chunk type 0xff). + if chunkLen != len(snappyMagicBody) { + println("chunkLen != len(snappyMagicBody)", chunkLen, len(snappyMagicBody)) + r.err = ErrSnappyCorrupt + return written, r.err + } + if !r.readFull(r.buf[:len(snappyMagicBody)], false) { + return written, r.err + } + for i := 0; i < len(snappyMagicBody); i++ { + if r.buf[i] != snappyMagicBody[i] { + println("r.buf[i] != snappyMagicBody[i]", r.buf[i], snappyMagicBody[i], i) + r.err = ErrSnappyCorrupt + return written, r.err + } + } + continue + } + + if chunkType <= 0x7f { + // Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f). + println("chunkType <= 0x7f") + r.err = ErrSnappyUnsupported + return written, r.err + } + // Section 4.4 Padding (chunk type 0xfe). + // Section 4.6. Reserved skippable chunks (chunk types 0x80-0xfd). + if !r.readFull(r.buf[:chunkLen], false) { + return written, r.err + } + } +} + +// decodeSnappy writes the decoding of src to dst. It assumes that the varint-encoded +// length of the decompressed bytes has already been read. +func decodeSnappy(blk *blockEnc, src []byte) error { + //decodeRef(make([]byte, snappyMaxBlockSize), src) + var s, length int + lits := blk.extraLits + var offset uint32 + for s < len(src) { + switch src[s] & 0x03 { + case snappyTagLiteral: + x := uint32(src[s] >> 2) + switch { + case x < 60: + s++ + case x == 60: + s += 2 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + println("uint(s) > uint(len(src)", s, src) + return ErrSnappyCorrupt + } + x = uint32(src[s-1]) + case x == 61: + s += 3 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + println("uint(s) > uint(len(src)", s, src) + return ErrSnappyCorrupt + } + x = uint32(src[s-2]) | uint32(src[s-1])<<8 + case x == 62: + s += 4 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + println("uint(s) > uint(len(src)", s, src) + return ErrSnappyCorrupt + } + x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16 + case x == 63: + s += 5 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + println("uint(s) > uint(len(src)", s, src) + return ErrSnappyCorrupt + } + x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24 + } + if x > snappyMaxBlockSize { + println("x > snappyMaxBlockSize", x, snappyMaxBlockSize) + return ErrSnappyCorrupt + } + length = int(x) + 1 + if length <= 0 { + println("length <= 0 ", length) + + return errUnsupportedLiteralLength + } + //if length > snappyMaxBlockSize-d || uint32(length) > len(src)-s { + // return ErrSnappyCorrupt + //} + + blk.literals = append(blk.literals, src[s:s+length]...) + //println(length, "litLen") + lits += length + s += length + continue + + case snappyTagCopy1: + s += 2 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + println("uint(s) > uint(len(src)", s, len(src)) + return ErrSnappyCorrupt + } + length = 4 + int(src[s-2])>>2&0x7 + offset = uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]) + + case snappyTagCopy2: + s += 3 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + println("uint(s) > uint(len(src)", s, len(src)) + return ErrSnappyCorrupt + } + length = 1 + int(src[s-3])>>2 + offset = uint32(src[s-2]) | uint32(src[s-1])<<8 + + case snappyTagCopy4: + s += 5 + if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line. + println("uint(s) > uint(len(src)", s, len(src)) + return ErrSnappyCorrupt + } + length = 1 + int(src[s-5])>>2 + offset = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24 + } + + if offset <= 0 || blk.size+lits < int(offset) /*|| length > len(blk)-d */ { + println("offset <= 0 || blk.size+lits < int(offset)", offset, blk.size+lits, int(offset), blk.size, lits) + + return ErrSnappyCorrupt + } + + // Check if offset is one of the recent offsets. + // Adjusts the output offset accordingly. + // Gives a tiny bit of compression, typically around 1%. + if false { + offset = blk.matchOffset(offset, uint32(lits)) + } else { + offset += 3 + } + + blk.sequences = append(blk.sequences, seq{ + litLen: uint32(lits), + offset: offset, + matchLen: uint32(length) - zstdMinMatch, + }) + blk.size += length + lits + lits = 0 + } + blk.extraLits = lits + return nil +} + +func (r *SnappyConverter) readFull(p []byte, allowEOF bool) (ok bool) { + if _, r.err = io.ReadFull(r.r, p); r.err != nil { + if r.err == io.ErrUnexpectedEOF || (r.err == io.EOF && !allowEOF) { + r.err = ErrSnappyCorrupt + } + return false + } + return true +} + +var crcTable = crc32.MakeTable(crc32.Castagnoli) + +// crc implements the checksum specified in section 3 of +// https://github.com/google/snappy/blob/master/framing_format.txt +func snappyCRC(b []byte) uint32 { + c := crc32.Update(0, crcTable, b) + return uint32(c>>15|c<<17) + 0xa282ead8 +} + +// snappyDecodedLen returns the length of the decoded block and the number of bytes +// that the length header occupied. +func snappyDecodedLen(src []byte) (blockLen, headerLen int, err error) { + v, n := binary.Uvarint(src) + if n <= 0 || v > 0xffffffff { + return 0, 0, ErrSnappyCorrupt + } + + const wordSize = 32 << (^uint(0) >> 32 & 1) + if wordSize == 32 && v > 0x7fffffff { + return 0, 0, ErrSnappyTooLarge + } + return int(v), n, nil +} diff --git a/vendor/github.com/klauspost/compress/zstd/zstd.go b/vendor/github.com/klauspost/compress/zstd/zstd.go new file mode 100644 index 000000000..b975954c1 --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/zstd.go @@ -0,0 +1,135 @@ +// Package zstd provides decompression of zstandard files. +// +// For advanced usage and examples, go to the README: https://github.com/klauspost/compress/tree/master/zstd#zstd +package zstd + +import ( + "errors" + "log" + "math/bits" +) + +const debug = false +const debugSequences = false + +// force encoder to use predefined tables. +const forcePreDef = false + +// zstdMinMatch is the minimum zstd match length. +const zstdMinMatch = 3 + +var ( + // ErrReservedBlockType is returned when a reserved block type is found. + // Typically this indicates wrong or corrupted input. + ErrReservedBlockType = errors.New("invalid input: reserved block type encountered") + + // ErrCompressedSizeTooBig is returned when a block is bigger than allowed. + // Typically this indicates wrong or corrupted input. + ErrCompressedSizeTooBig = errors.New("invalid input: compressed size too big") + + // ErrBlockTooSmall is returned when a block is too small to be decoded. + // Typically returned on invalid input. + ErrBlockTooSmall = errors.New("block too small") + + // ErrMagicMismatch is returned when a "magic" number isn't what is expected. + // Typically this indicates wrong or corrupted input. + ErrMagicMismatch = errors.New("invalid input: magic number mismatch") + + // ErrWindowSizeExceeded is returned when a reference exceeds the valid window size. + // Typically this indicates wrong or corrupted input. + ErrWindowSizeExceeded = errors.New("window size exceeded") + + // ErrWindowSizeTooSmall is returned when no window size is specified. + // Typically this indicates wrong or corrupted input. + ErrWindowSizeTooSmall = errors.New("invalid input: window size was too small") + + // ErrDecoderSizeExceeded is returned if decompressed size exceeds the configured limit. + ErrDecoderSizeExceeded = errors.New("decompressed size exceeds configured limit") + + // ErrUnknownDictionary is returned if the dictionary ID is unknown. + // For the time being dictionaries are not supported. + ErrUnknownDictionary = errors.New("unknown dictionary") + + // ErrFrameSizeExceeded is returned if the stated frame size is exceeded. + // This is only returned if SingleSegment is specified on the frame. + ErrFrameSizeExceeded = errors.New("frame size exceeded") + + // ErrCRCMismatch is returned if CRC mismatches. + ErrCRCMismatch = errors.New("CRC check failed") + + // ErrDecoderClosed will be returned if the Decoder was used after + // Close has been called. + ErrDecoderClosed = errors.New("decoder used after Close") +) + +func println(a ...interface{}) { + if debug { + log.Println(a...) + } +} + +func printf(format string, a ...interface{}) { + if debug { + log.Printf(format, a...) + } +} + +// matchLen returns the maximum length. +// a must be the shortest of the two. +// The function also returns whether all bytes matched. +func matchLen(a, b []byte) int { + b = b[:len(a)] + for i := 0; i < len(a)-7; i += 8 { + if diff := load64(a, i) ^ load64(b, i); diff != 0 { + return i + (bits.TrailingZeros64(diff) >> 3) + } + } + checked := (len(a) >> 3) << 3 + a = a[checked:] + b = b[checked:] + // TODO: We could do a 4 check. + for i := range a { + if a[i] != b[i] { + return int(i) + checked + } + } + return len(a) + checked +} + +// matchLen returns a match length in src between index s and t +func matchLenIn(src []byte, s, t int32) int32 { + s1 := len(src) + b := src[t:] + a := src[s:s1] + b = b[:len(a)] + // Extend the match to be as long as possible. + for i := range a { + if a[i] != b[i] { + return int32(i) + } + } + return int32(len(a)) +} + +func load3232(b []byte, i int32) uint32 { + // Help the compiler eliminate bounds checks on the read so it can be done in a single read. + b = b[i:] + b = b[:4] + return uint32(b[0]) | uint32(b[1])<<8 | uint32(b[2])<<16 | uint32(b[3])<<24 +} + +func load6432(b []byte, i int32) uint64 { + // Help the compiler eliminate bounds checks on the read so it can be done in a single read. + b = b[i:] + b = b[:8] + return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | + uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 +} + +func load64(b []byte, i int) uint64 { + // Help the compiler eliminate bounds checks on the read so it can be done in a single read. + b = b[i:] + b = b[:8] + return uint64(b[0]) | uint64(b[1])<<8 | uint64(b[2])<<16 | uint64(b[3])<<24 | + uint64(b[4])<<32 | uint64(b[5])<<40 | uint64(b[6])<<48 | uint64(b[7])<<56 +} |