Merge pull request #2071 from baude/vendorcs

vendor in new containers/storage

1 files changed, 501 insertions, 0 deletions

diff --git a/vendor/github.com/klauspost/pgzip/gzip.go b/vendor/github.com/klauspost/pgzip/gzip.go
new file mode 100644
index 000000000..85d14e9cb
--- /dev/null
+++ b/vendor/github.com/klauspost/pgzip/gzip.go
@@ -0,0 +1,501 @@
+// Copyright 2010 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.
+
+package pgzip
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"hash"
+	"hash/crc32"
+	"io"
+	"sync"
+	"time"
+
+	"github.com/klauspost/compress/flate"
+)
+
+const (
+	defaultBlockSize = 256 << 10
+	tailSize         = 16384
+	defaultBlocks    = 16
+)
+
+// These constants are copied from the flate package, so that code that imports
+// "compress/gzip" does not also have to import "compress/flate".
+const (
+	NoCompression       = flate.NoCompression
+	BestSpeed           = flate.BestSpeed
+	BestCompression     = flate.BestCompression
+	DefaultCompression  = flate.DefaultCompression
+	ConstantCompression = flate.ConstantCompression
+	HuffmanOnly         = flate.HuffmanOnly
+)
+
+// A Writer is an io.WriteCloser.
+// Writes to a Writer are compressed and written to w.
+type Writer struct {
+	Header
+	w             io.Writer
+	level         int
+	wroteHeader   bool
+	blockSize     int
+	blocks        int
+	currentBuffer []byte
+	prevTail      []byte
+	digest        hash.Hash32
+	size          int
+	closed        bool
+	buf           [10]byte
+	errMu         sync.RWMutex
+	err           error
+	pushedErr     chan struct{}
+	results       chan result
+	dictFlatePool sync.Pool
+	dstPool       sync.Pool
+	wg            sync.WaitGroup
+}
+
+type result struct {
+	result        chan []byte
+	notifyWritten chan struct{}
+}
+
+// Use SetConcurrency to finetune the concurrency level if needed.
+//
+// With this you can control the approximate size of your blocks,
+// as well as how many you want to be processing in parallel.
+//
+// Default values for this is SetConcurrency(250000, 16),
+// meaning blocks are split at 250000 bytes and up to 16 blocks
+// can be processing at once before the writer blocks.
+func (z *Writer) SetConcurrency(blockSize, blocks int) error {
+	if blockSize <= tailSize {
+		return fmt.Errorf("gzip: block size cannot be less than or equal to %d", tailSize)
+	}
+	if blocks <= 0 {
+		return errors.New("gzip: blocks cannot be zero or less")
+	}
+	if blockSize == z.blockSize && blocks == z.blocks {
+		return nil
+	}
+	z.blockSize = blockSize
+	z.results = make(chan result, blocks)
+	z.blocks = blocks
+	z.dstPool = sync.Pool{New: func() interface{} { return make([]byte, 0, blockSize+(blockSize)>>4) }}
+	return nil
+}
+
+// NewWriter returns a new Writer.
+// Writes to the returned writer are compressed and written to w.
+//
+// It is the caller's responsibility to call Close on the WriteCloser when done.
+// Writes may be buffered and not flushed until Close.
+//
+// Callers that wish to set the fields in Writer.Header must do so before
+// the first call to Write or Close. The Comment and Name header fields are
+// UTF-8 strings in Go, but the underlying format requires NUL-terminated ISO
+// 8859-1 (Latin-1). NUL or non-Latin-1 runes in those strings will lead to an
+// error on Write.
+func NewWriter(w io.Writer) *Writer {
+	z, _ := NewWriterLevel(w, DefaultCompression)
+	return z
+}
+
+// NewWriterLevel is like NewWriter but specifies the compression level instead
+// of assuming DefaultCompression.
+//
+// The compression level can be DefaultCompression, NoCompression, or any
+// integer value between BestSpeed and BestCompression inclusive. The error
+// returned will be nil if the level is valid.
+func NewWriterLevel(w io.Writer, level int) (*Writer, error) {
+	if level < ConstantCompression || level > BestCompression {
+		return nil, fmt.Errorf("gzip: invalid compression level: %d", level)
+	}
+	z := new(Writer)
+	z.SetConcurrency(defaultBlockSize, defaultBlocks)
+	z.init(w, level)
+	return z, nil
+}
+
+// This function must be used by goroutines to set an
+// error condition, since z.err access is restricted
+// to the callers goruotine.
+func (z *Writer) pushError(err error) {
+	z.errMu.Lock()
+	if z.err != nil {
+		z.errMu.Unlock()
+		return
+	}
+	z.err = err
+	close(z.pushedErr)
+	z.errMu.Unlock()
+}
+
+func (z *Writer) init(w io.Writer, level int) {
+	z.wg.Wait()
+	digest := z.digest
+	if digest != nil {
+		digest.Reset()
+	} else {
+		digest = crc32.NewIEEE()
+	}
+	z.Header = Header{OS: 255}
+	z.w = w
+	z.level = level
+	z.digest = digest
+	z.pushedErr = make(chan struct{}, 0)
+	z.results = make(chan result, z.blocks)
+	z.err = nil
+	z.closed = false
+	z.Comment = ""
+	z.Extra = nil
+	z.ModTime = time.Time{}
+	z.wroteHeader = false
+	z.currentBuffer = nil
+	z.buf = [10]byte{}
+	z.prevTail = nil
+	z.size = 0
+	if z.dictFlatePool.New == nil {
+		z.dictFlatePool.New = func() interface{} {
+			f, _ := flate.NewWriterDict(w, level, nil)
+			return f
+		}
+	}
+}
+
+// Reset discards the Writer z's state and makes it equivalent to the
+// result of its original state from NewWriter or NewWriterLevel, but
+// writing to w instead. This permits reusing a Writer rather than
+// allocating a new one.
+func (z *Writer) Reset(w io.Writer) {
+	if z.results != nil && !z.closed {
+		close(z.results)
+	}
+	z.SetConcurrency(defaultBlockSize, defaultBlocks)
+	z.init(w, z.level)
+}
+
+// GZIP (RFC 1952) is little-endian, unlike ZLIB (RFC 1950).
+func put2(p []byte, v uint16) {
+	p[0] = uint8(v >> 0)
+	p[1] = uint8(v >> 8)
+}
+
+func put4(p []byte, v uint32) {
+	p[0] = uint8(v >> 0)
+	p[1] = uint8(v >> 8)
+	p[2] = uint8(v >> 16)
+	p[3] = uint8(v >> 24)
+}
+
+// writeBytes writes a length-prefixed byte slice to z.w.
+func (z *Writer) writeBytes(b []byte) error {
+	if len(b) > 0xffff {
+		return errors.New("gzip.Write: Extra data is too large")
+	}
+	put2(z.buf[0:2], uint16(len(b)))
+	_, err := z.w.Write(z.buf[0:2])
+	if err != nil {
+		return err
+	}
+	_, err = z.w.Write(b)
+	return err
+}
+
+// writeString writes a UTF-8 string s in GZIP's format to z.w.
+// GZIP (RFC 1952) specifies that strings are NUL-terminated ISO 8859-1 (Latin-1).
+func (z *Writer) writeString(s string) (err error) {
+	// GZIP stores Latin-1 strings; error if non-Latin-1; convert if non-ASCII.
+	needconv := false
+	for _, v := range s {
+		if v == 0 || v > 0xff {
+			return errors.New("gzip.Write: non-Latin-1 header string")
+		}
+		if v > 0x7f {
+			needconv = true
+		}
+	}
+	if needconv {
+		b := make([]byte, 0, len(s))
+		for _, v := range s {
+			b = append(b, byte(v))
+		}
+		_, err = z.w.Write(b)
+	} else {
+		_, err = io.WriteString(z.w, s)
+	}
+	if err != nil {
+		return err
+	}
+	// GZIP strings are NUL-terminated.
+	z.buf[0] = 0
+	_, err = z.w.Write(z.buf[0:1])
+	return err
+}
+
+// compressCurrent will compress the data currently buffered
+// This should only be called from the main writer/flush/closer
+func (z *Writer) compressCurrent(flush bool) {
+	r := result{}
+	r.result = make(chan []byte, 1)
+	r.notifyWritten = make(chan struct{}, 0)
+	select {
+	case z.results <- r:
+	case <-z.pushedErr:
+		return
+	}
+
+	// If block given is more than twice the block size, split it.
+	c := z.currentBuffer
+	if len(c) > z.blockSize*2 {
+		c = c[:z.blockSize]
+		z.wg.Add(1)
+		go z.compressBlock(c, z.prevTail, r, false)
+		z.prevTail = c[len(c)-tailSize:]
+		z.currentBuffer = z.currentBuffer[z.blockSize:]
+		z.compressCurrent(flush)
+		// Last one flushes if needed
+		return
+	}
+
+	z.wg.Add(1)
+	go z.compressBlock(c, z.prevTail, r, z.closed)
+	if len(c) > tailSize {
+		z.prevTail = c[len(c)-tailSize:]
+	} else {
+		z.prevTail = nil
+	}
+	z.currentBuffer = z.dstPool.Get().([]byte)
+	z.currentBuffer = z.currentBuffer[:0]
+
+	// Wait if flushing
+	if flush {
+		<-r.notifyWritten
+	}
+}
+
+// Returns an error if it has been set.
+// Cannot be used by functions that are from internal goroutines.
+func (z *Writer) checkError() error {
+	z.errMu.RLock()
+	err := z.err
+	z.errMu.RUnlock()
+	return err
+}
+
+// Write writes a compressed form of p to the underlying io.Writer. The
+// compressed bytes are not necessarily flushed to output until
+// the Writer is closed or Flush() is called.
+//
+// The function will return quickly, if there are unused buffers.
+// The sent slice (p) is copied, and the caller is free to re-use the buffer
+// when the function returns.
+//
+// Errors that occur during compression will be reported later, and a nil error
+// does not signify that the compression succeeded (since it is most likely still running)
+// That means that the call that returns an error may not be the call that caused it.
+// Only Flush and Close functions are guaranteed to return any errors up to that point.
+func (z *Writer) Write(p []byte) (int, error) {
+	if err := z.checkError(); err != nil {
+		return 0, err
+	}
+	// Write the GZIP header lazily.
+	if !z.wroteHeader {
+		z.wroteHeader = true
+		z.buf[0] = gzipID1
+		z.buf[1] = gzipID2
+		z.buf[2] = gzipDeflate
+		z.buf[3] = 0
+		if z.Extra != nil {
+			z.buf[3] |= 0x04
+		}
+		if z.Name != "" {
+			z.buf[3] |= 0x08
+		}
+		if z.Comment != "" {
+			z.buf[3] |= 0x10
+		}
+		put4(z.buf[4:8], uint32(z.ModTime.Unix()))
+		if z.level == BestCompression {
+			z.buf[8] = 2
+		} else if z.level == BestSpeed {
+			z.buf[8] = 4
+		} else {
+			z.buf[8] = 0
+		}
+		z.buf[9] = z.OS
+		var n int
+		var err error
+		n, err = z.w.Write(z.buf[0:10])
+		if err != nil {
+			z.pushError(err)
+			return n, err
+		}
+		if z.Extra != nil {
+			err = z.writeBytes(z.Extra)
+			if err != nil {
+				z.pushError(err)
+				return n, err
+			}
+		}
+		if z.Name != "" {
+			err = z.writeString(z.Name)
+			if err != nil {
+				z.pushError(err)
+				return n, err
+			}
+		}
+		if z.Comment != "" {
+			err = z.writeString(z.Comment)
+			if err != nil {
+				z.pushError(err)
+				return n, err
+			}
+		}
+		// Start receiving data from compressors
+		go func() {
+			listen := z.results
+			for {
+				r, ok := <-listen
+				// If closed, we are finished.
+				if !ok {
+					return
+				}
+				buf := <-r.result
+				n, err := z.w.Write(buf)
+				if err != nil {
+					z.pushError(err)
+					close(r.notifyWritten)
+					return
+				}
+				if n != len(buf) {
+					z.pushError(fmt.Errorf("gzip: short write %d should be %d", n, len(buf)))
+					close(r.notifyWritten)
+					return
+				}
+				z.dstPool.Put(buf)
+				close(r.notifyWritten)
+			}
+		}()
+		z.currentBuffer = make([]byte, 0, z.blockSize)
+	}
+	q := p
+	for len(q) > 0 {
+		length := len(q)
+		if length+len(z.currentBuffer) > z.blockSize {
+			length = z.blockSize - len(z.currentBuffer)
+		}
+		z.digest.Write(q[:length])
+		z.currentBuffer = append(z.currentBuffer, q[:length]...)
+		if len(z.currentBuffer) >= z.blockSize {
+			z.compressCurrent(false)
+			if err := z.checkError(); err != nil {
+				return len(p) - len(q) - length, err
+			}
+		}
+		z.size += length
+		q = q[length:]
+	}
+	return len(p), z.checkError()
+}
+
+// Step 1: compresses buffer to buffer
+// Step 2: send writer to channel
+// Step 3: Close result channel to indicate we are done
+func (z *Writer) compressBlock(p, prevTail []byte, r result, closed bool) {
+	defer func() {
+		close(r.result)
+		z.wg.Done()
+	}()
+	buf := z.dstPool.Get().([]byte)
+	dest := bytes.NewBuffer(buf[:0])
+
+	compressor := z.dictFlatePool.Get().(*flate.Writer)
+	compressor.ResetDict(dest, prevTail)
+	compressor.Write(p)
+
+	err := compressor.Flush()
+	if err != nil {
+		z.pushError(err)
+		return
+	}
+	if closed {
+		err = compressor.Close()
+		if err != nil {
+			z.pushError(err)
+			return
+		}
+	}
+	z.dictFlatePool.Put(compressor)
+	// Read back buffer
+	buf = dest.Bytes()
+	r.result <- buf
+}
+
+// Flush flushes any pending compressed data to the underlying writer.
+//
+// It is useful mainly in compressed network protocols, to ensure that
+// a remote reader has enough data to reconstruct a packet. Flush does
+// not return until the data has been written. If the underlying
+// writer returns an error, Flush returns that error.
+//
+// In the terminology of the zlib library, Flush is equivalent to Z_SYNC_FLUSH.
+func (z *Writer) Flush() error {
+	if err := z.checkError(); err != nil {
+		return err
+	}
+	if z.closed {
+		return nil
+	}
+	if !z.wroteHeader {
+		_, err := z.Write(nil)
+		if err != nil {
+			return err
+		}
+	}
+	// We send current block to compression
+	z.compressCurrent(true)
+
+	return z.checkError()
+}
+
+// UncompressedSize will return the number of bytes written.
+// pgzip only, not a function in the official gzip package.
+func (z *Writer) UncompressedSize() int {
+	return z.size
+}
+
+// Close closes the Writer, flushing any unwritten data to the underlying
+// io.Writer, but does not close the underlying io.Writer.
+func (z *Writer) Close() error {
+	if err := z.checkError(); err != nil {
+		return err
+	}
+	if z.closed {
+		return nil
+	}
+
+	z.closed = true
+	if !z.wroteHeader {
+		z.Write(nil)
+		if err := z.checkError(); err != nil {
+			return err
+		}
+	}
+	z.compressCurrent(true)
+	if err := z.checkError(); err != nil {
+		return err
+	}
+	close(z.results)
+	put4(z.buf[0:4], z.digest.Sum32())
+	put4(z.buf[4:8], uint32(z.size))
+	_, err := z.w.Write(z.buf[0:8])
+	if err != nil {
+		z.pushError(err)
+		return err
+	}
+	return nil
+}