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author | baude <bbaude@redhat.com> | 2019-01-03 08:55:35 -0600 |
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committer | baude <bbaude@redhat.com> | 2019-01-03 12:49:30 -0600 |
commit | 561e65969f89c6f60193cf1755752b571a1149f5 (patch) | |
tree | 8f2f784c27546f061a38cf5fe68a9ee672be950f /vendor/github.com/klauspost/pgzip/gunzip.go | |
parent | 098c13418abf3985f20689bdda0361904a40ef98 (diff) | |
download | podman-561e65969f89c6f60193cf1755752b571a1149f5.tar.gz podman-561e65969f89c6f60193cf1755752b571a1149f5.tar.bz2 podman-561e65969f89c6f60193cf1755752b571a1149f5.zip |
vendor in new containers/storage
vendor in latest containers/storage which contains a fix for when
a filesystem that overlayfs is on is ENOSPC.
adding pgzip/compress as a new dep for c/s
Signed-off-by: baude <bbaude@redhat.com>
Diffstat (limited to 'vendor/github.com/klauspost/pgzip/gunzip.go')
-rw-r--r-- | vendor/github.com/klauspost/pgzip/gunzip.go | 573 |
1 files changed, 573 insertions, 0 deletions
diff --git a/vendor/github.com/klauspost/pgzip/gunzip.go b/vendor/github.com/klauspost/pgzip/gunzip.go new file mode 100644 index 000000000..93efec714 --- /dev/null +++ b/vendor/github.com/klauspost/pgzip/gunzip.go @@ -0,0 +1,573 @@ +// Copyright 2009 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 implements reading and writing of gzip format compressed files, +// as specified in RFC 1952. +// +// This is a drop in replacement for "compress/gzip". +// This will split compression into blocks that are compressed in parallel. +// This can be useful for compressing big amounts of data. +// The gzip decompression has not been modified, but remains in the package, +// so you can use it as a complete replacement for "compress/gzip". +// +// See more at https://github.com/klauspost/pgzip +package pgzip + +import ( + "bufio" + "errors" + "hash" + "hash/crc32" + "io" + "sync" + "time" + + "github.com/klauspost/compress/flate" +) + +const ( + gzipID1 = 0x1f + gzipID2 = 0x8b + gzipDeflate = 8 + flagText = 1 << 0 + flagHdrCrc = 1 << 1 + flagExtra = 1 << 2 + flagName = 1 << 3 + flagComment = 1 << 4 +) + +func makeReader(r io.Reader) flate.Reader { + if rr, ok := r.(flate.Reader); ok { + return rr + } + return bufio.NewReader(r) +} + +var ( + // ErrChecksum is returned when reading GZIP data that has an invalid checksum. + ErrChecksum = errors.New("gzip: invalid checksum") + // ErrHeader is returned when reading GZIP data that has an invalid header. + ErrHeader = errors.New("gzip: invalid header") +) + +// The gzip file stores a header giving metadata about the compressed file. +// That header is exposed as the fields of the Writer and Reader structs. +type Header struct { + Comment string // comment + Extra []byte // "extra data" + ModTime time.Time // modification time + Name string // file name + OS byte // operating system type +} + +// A Reader is an io.Reader that can be read to retrieve +// uncompressed data from a gzip-format compressed file. +// +// In general, a gzip file can be a concatenation of gzip files, +// each with its own header. Reads from the Reader +// return the concatenation of the uncompressed data of each. +// Only the first header is recorded in the Reader fields. +// +// Gzip files store a length and checksum of the uncompressed data. +// The Reader will return a ErrChecksum when Read +// reaches the end of the uncompressed data if it does not +// have the expected length or checksum. Clients should treat data +// returned by Read as tentative until they receive the io.EOF +// marking the end of the data. +type Reader struct { + Header + r flate.Reader + decompressor io.ReadCloser + digest hash.Hash32 + size uint32 + flg byte + buf [512]byte + err error + closeErr chan error + multistream bool + + readAhead chan read + roff int // read offset + current []byte + closeReader chan struct{} + lastBlock bool + blockSize int + blocks int + + activeRA bool // Indication if readahead is active + mu sync.Mutex // Lock for above + + blockPool chan []byte +} + +type read struct { + b []byte + err error +} + +// NewReader creates a new Reader reading the given reader. +// The implementation buffers input and may read more data than necessary from r. +// It is the caller's responsibility to call Close on the Reader when done. +func NewReader(r io.Reader) (*Reader, error) { + z := new(Reader) + z.blocks = defaultBlocks + z.blockSize = defaultBlockSize + z.r = makeReader(r) + z.digest = crc32.NewIEEE() + z.multistream = true + z.blockPool = make(chan []byte, z.blocks) + for i := 0; i < z.blocks; i++ { + z.blockPool <- make([]byte, z.blockSize) + } + if err := z.readHeader(true); err != nil { + return nil, err + } + return z, nil +} + +// NewReaderN creates a new Reader reading the given reader. +// The implementation buffers input and may read more data than necessary from r. +// It is the caller's responsibility to call Close on the Reader when done. +// +// With this you can control the approximate size of your blocks, +// as well as how many blocks you want to have prefetched. +// +// Default values for this is blockSize = 250000, blocks = 16, +// meaning up to 16 blocks of maximum 250000 bytes will be +// prefetched. +func NewReaderN(r io.Reader, blockSize, blocks int) (*Reader, error) { + z := new(Reader) + z.blocks = blocks + z.blockSize = blockSize + z.r = makeReader(r) + z.digest = crc32.NewIEEE() + z.multistream = true + + // Account for too small values + if z.blocks <= 0 { + z.blocks = defaultBlocks + } + if z.blockSize <= 512 { + z.blockSize = defaultBlockSize + } + z.blockPool = make(chan []byte, z.blocks) + for i := 0; i < z.blocks; i++ { + z.blockPool <- make([]byte, z.blockSize) + } + if err := z.readHeader(true); err != nil { + return nil, err + } + return z, nil +} + +// Reset discards the Reader z's state and makes it equivalent to the +// result of its original state from NewReader, but reading from r instead. +// This permits reusing a Reader rather than allocating a new one. +func (z *Reader) Reset(r io.Reader) error { + z.killReadAhead() + z.r = makeReader(r) + z.digest = crc32.NewIEEE() + z.size = 0 + z.err = nil + z.multistream = true + + // Account for uninitialized values + if z.blocks <= 0 { + z.blocks = defaultBlocks + } + if z.blockSize <= 512 { + z.blockSize = defaultBlockSize + } + + if z.blockPool == nil { + z.blockPool = make(chan []byte, z.blocks) + for i := 0; i < z.blocks; i++ { + z.blockPool <- make([]byte, z.blockSize) + } + } + + return z.readHeader(true) +} + +// Multistream controls whether the reader supports multistream files. +// +// If enabled (the default), the Reader expects the input to be a sequence +// of individually gzipped data streams, each with its own header and +// trailer, ending at EOF. The effect is that the concatenation of a sequence +// of gzipped files is treated as equivalent to the gzip of the concatenation +// of the sequence. This is standard behavior for gzip readers. +// +// Calling Multistream(false) disables this behavior; disabling the behavior +// can be useful when reading file formats that distinguish individual gzip +// data streams or mix gzip data streams with other data streams. +// In this mode, when the Reader reaches the end of the data stream, +// Read returns io.EOF. If the underlying reader implements io.ByteReader, +// it will be left positioned just after the gzip stream. +// To start the next stream, call z.Reset(r) followed by z.Multistream(false). +// If there is no next stream, z.Reset(r) will return io.EOF. +func (z *Reader) Multistream(ok bool) { + z.multistream = ok +} + +// GZIP (RFC 1952) is little-endian, unlike ZLIB (RFC 1950). +func get4(p []byte) uint32 { + return uint32(p[0]) | uint32(p[1])<<8 | uint32(p[2])<<16 | uint32(p[3])<<24 +} + +func (z *Reader) readString() (string, error) { + var err error + needconv := false + for i := 0; ; i++ { + if i >= len(z.buf) { + return "", ErrHeader + } + z.buf[i], err = z.r.ReadByte() + if err != nil { + return "", err + } + if z.buf[i] > 0x7f { + needconv = true + } + if z.buf[i] == 0 { + // GZIP (RFC 1952) specifies that strings are NUL-terminated ISO 8859-1 (Latin-1). + if needconv { + s := make([]rune, 0, i) + for _, v := range z.buf[0:i] { + s = append(s, rune(v)) + } + return string(s), nil + } + return string(z.buf[0:i]), nil + } + } +} + +func (z *Reader) read2() (uint32, error) { + _, err := io.ReadFull(z.r, z.buf[0:2]) + if err != nil { + return 0, err + } + return uint32(z.buf[0]) | uint32(z.buf[1])<<8, nil +} + +func (z *Reader) readHeader(save bool) error { + z.killReadAhead() + + _, err := io.ReadFull(z.r, z.buf[0:10]) + if err != nil { + return err + } + if z.buf[0] != gzipID1 || z.buf[1] != gzipID2 || z.buf[2] != gzipDeflate { + return ErrHeader + } + z.flg = z.buf[3] + if save { + z.ModTime = time.Unix(int64(get4(z.buf[4:8])), 0) + // z.buf[8] is xfl, ignored + z.OS = z.buf[9] + } + z.digest.Reset() + z.digest.Write(z.buf[0:10]) + + if z.flg&flagExtra != 0 { + n, err := z.read2() + if err != nil { + return err + } + data := make([]byte, n) + if _, err = io.ReadFull(z.r, data); err != nil { + return err + } + if save { + z.Extra = data + } + } + + var s string + if z.flg&flagName != 0 { + if s, err = z.readString(); err != nil { + return err + } + if save { + z.Name = s + } + } + + if z.flg&flagComment != 0 { + if s, err = z.readString(); err != nil { + return err + } + if save { + z.Comment = s + } + } + + if z.flg&flagHdrCrc != 0 { + n, err := z.read2() + if err != nil { + return err + } + sum := z.digest.Sum32() & 0xFFFF + if n != sum { + return ErrHeader + } + } + + z.digest.Reset() + z.decompressor = flate.NewReader(z.r) + z.doReadAhead() + return nil +} + +func (z *Reader) killReadAhead() error { + z.mu.Lock() + defer z.mu.Unlock() + if z.activeRA { + if z.closeReader != nil { + close(z.closeReader) + } + + // Wait for decompressor to be closed and return error, if any. + e, ok := <-z.closeErr + z.activeRA = false + if !ok { + // Channel is closed, so if there was any error it has already been returned. + return nil + } + return e + } + return nil +} + +// Starts readahead. +// Will return on error (including io.EOF) +// or when z.closeReader is closed. +func (z *Reader) doReadAhead() { + z.mu.Lock() + defer z.mu.Unlock() + z.activeRA = true + + if z.blocks <= 0 { + z.blocks = defaultBlocks + } + if z.blockSize <= 512 { + z.blockSize = defaultBlockSize + } + ra := make(chan read, z.blocks) + z.readAhead = ra + closeReader := make(chan struct{}, 0) + z.closeReader = closeReader + z.lastBlock = false + closeErr := make(chan error, 1) + z.closeErr = closeErr + z.size = 0 + z.roff = 0 + z.current = nil + decomp := z.decompressor + + go func() { + defer func() { + closeErr <- decomp.Close() + close(closeErr) + close(ra) + }() + + // We hold a local reference to digest, since + // it way be changed by reset. + digest := z.digest + var wg sync.WaitGroup + for { + var buf []byte + select { + case buf = <-z.blockPool: + case <-closeReader: + return + } + buf = buf[0:z.blockSize] + // Try to fill the buffer + n, err := io.ReadFull(decomp, buf) + if err == io.ErrUnexpectedEOF { + if n > 0 { + err = nil + } else { + // If we got zero bytes, we need to establish if + // we reached end of stream or truncated stream. + _, err = decomp.Read([]byte{}) + if err == io.EOF { + err = nil + } + } + } + if n < len(buf) { + buf = buf[0:n] + } + wg.Wait() + wg.Add(1) + go func() { + digest.Write(buf) + wg.Done() + }() + z.size += uint32(n) + + // If we return any error, out digest must be ready + if err != nil { + wg.Wait() + } + select { + case z.readAhead <- read{b: buf, err: err}: + case <-closeReader: + // Sent on close, we don't care about the next results + return + } + if err != nil { + return + } + } + }() +} + +func (z *Reader) Read(p []byte) (n int, err error) { + if z.err != nil { + return 0, z.err + } + if len(p) == 0 { + return 0, nil + } + + for { + if len(z.current) == 0 && !z.lastBlock { + read := <-z.readAhead + + if read.err != nil { + // If not nil, the reader will have exited + z.closeReader = nil + + if read.err != io.EOF { + z.err = read.err + return + } + if read.err == io.EOF { + z.lastBlock = true + err = nil + } + } + z.current = read.b + z.roff = 0 + } + avail := z.current[z.roff:] + if len(p) >= len(avail) { + // If len(p) >= len(current), return all content of current + n = copy(p, avail) + z.blockPool <- z.current + z.current = nil + if z.lastBlock { + err = io.EOF + break + } + } else { + // We copy as much as there is space for + n = copy(p, avail) + z.roff += n + } + return + } + + // Finished file; check checksum + size. + if _, err := io.ReadFull(z.r, z.buf[0:8]); err != nil { + z.err = err + return 0, err + } + crc32, isize := get4(z.buf[0:4]), get4(z.buf[4:8]) + sum := z.digest.Sum32() + if sum != crc32 || isize != z.size { + z.err = ErrChecksum + return 0, z.err + } + + // File is ok; should we attempt reading one more? + if !z.multistream { + return 0, io.EOF + } + + // Is there another? + if err = z.readHeader(false); err != nil { + z.err = err + return + } + + // Yes. Reset and read from it. + return z.Read(p) +} + +func (z *Reader) WriteTo(w io.Writer) (n int64, err error) { + total := int64(0) + for { + if z.err != nil { + return total, z.err + } + // We write both to output and digest. + for { + // Read from input + read := <-z.readAhead + if read.err != nil { + // If not nil, the reader will have exited + z.closeReader = nil + + if read.err != io.EOF { + z.err = read.err + return total, z.err + } + if read.err == io.EOF { + z.lastBlock = true + err = nil + } + } + // Write what we got + n, err := w.Write(read.b) + if n != len(read.b) { + return total, io.ErrShortWrite + } + total += int64(n) + if err != nil { + return total, err + } + // Put block back + z.blockPool <- read.b + if z.lastBlock { + break + } + } + + // Finished file; check checksum + size. + if _, err := io.ReadFull(z.r, z.buf[0:8]); err != nil { + z.err = err + return total, err + } + crc32, isize := get4(z.buf[0:4]), get4(z.buf[4:8]) + sum := z.digest.Sum32() + if sum != crc32 || isize != z.size { + z.err = ErrChecksum + return total, z.err + } + // File is ok; should we attempt reading one more? + if !z.multistream { + return total, nil + } + + // Is there another? + err = z.readHeader(false) + if err == io.EOF { + return total, nil + } + if err != nil { + z.err = err + return total, err + } + } +} + +// Close closes the Reader. It does not close the underlying io.Reader. +func (z *Reader) Close() error { + return z.killReadAhead() +} |