diff options
Diffstat (limited to 'vendor/github.com/klauspost/compress/gzip/gzip.go')
| -rw-r--r-- | vendor/github.com/klauspost/compress/gzip/gzip.go | 290 |
1 files changed, 0 insertions, 290 deletions
diff --git a/vendor/github.com/klauspost/compress/gzip/gzip.go b/vendor/github.com/klauspost/compress/gzip/gzip.go deleted file mode 100644 index 5bc720593..000000000 --- a/vendor/github.com/klauspost/compress/gzip/gzip.go +++ /dev/null @@ -1,290 +0,0 @@ -// 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 gzip - -import ( - "errors" - "fmt" - "hash/crc32" - "io" - - "github.com/klauspost/compress/flate" -) - -// 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 - - // StatelessCompression will do compression but without maintaining any state - // between Write calls. - // There will be no memory kept between Write calls, - // but compression and speed will be suboptimal. - // Because of this, the size of actual Write calls will affect output size. - StatelessCompression = -3 -) - -// A Writer is an io.WriteCloser. -// Writes to a Writer are compressed and written to w. -type Writer struct { - Header // written at first call to Write, Flush, or Close - w io.Writer - level int - err error - compressor *flate.Writer - digest uint32 // CRC-32, IEEE polynomial (section 8) - size uint32 // Uncompressed size (section 2.3.1) - wroteHeader bool - closed bool - buf [10]byte -} - -// 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, Flush, or Close. -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 < StatelessCompression || level > BestCompression { - return nil, fmt.Errorf("gzip: invalid compression level: %d", level) - } - z := new(Writer) - z.init(w, level) - return z, nil -} - -// MinCustomWindowSize is the minimum window size that can be sent to NewWriterWindow. -const MinCustomWindowSize = flate.MinCustomWindowSize - -// MaxCustomWindowSize is the maximum custom window that can be sent to NewWriterWindow. -const MaxCustomWindowSize = flate.MaxCustomWindowSize - -// NewWriterWindow returns a new Writer compressing data with a custom window size. -// windowSize must be from MinCustomWindowSize to MaxCustomWindowSize. -func NewWriterWindow(w io.Writer, windowSize int) (*Writer, error) { - if windowSize < MinCustomWindowSize { - return nil, errors.New("gzip: requested window size less than MinWindowSize") - } - if windowSize > MaxCustomWindowSize { - return nil, errors.New("gzip: requested window size bigger than MaxCustomWindowSize") - } - - z := new(Writer) - z.init(w, -windowSize) - return z, nil -} - -func (z *Writer) init(w io.Writer, level int) { - compressor := z.compressor - if level != StatelessCompression { - if compressor != nil { - compressor.Reset(w) - } - } - - *z = Writer{ - Header: Header{ - OS: 255, // unknown - }, - w: w, - level: level, - compressor: compressor, - } -} - -// 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) { - z.init(w, z.level) -} - -// 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") - } - le.PutUint16(z.buf[:2], uint16(len(b))) - _, err := z.w.Write(z.buf[: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[:1]) - return err -} - -// Write writes a compressed form of p to the underlying io.Writer. The -// compressed bytes are not necessarily flushed until the Writer is closed. -func (z *Writer) Write(p []byte) (int, error) { - if z.err != nil { - return 0, z.err - } - var n int - // 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 - } - le.PutUint32(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 - n, z.err = z.w.Write(z.buf[:10]) - if z.err != nil { - return n, z.err - } - if z.Extra != nil { - z.err = z.writeBytes(z.Extra) - if z.err != nil { - return n, z.err - } - } - if z.Name != "" { - z.err = z.writeString(z.Name) - if z.err != nil { - return n, z.err - } - } - if z.Comment != "" { - z.err = z.writeString(z.Comment) - if z.err != nil { - return n, z.err - } - } - - if z.compressor == nil && z.level != StatelessCompression { - z.compressor, _ = flate.NewWriter(z.w, z.level) - } - } - z.size += uint32(len(p)) - z.digest = crc32.Update(z.digest, crc32.IEEETable, p) - if z.level == StatelessCompression { - return len(p), flate.StatelessDeflate(z.w, p, false, nil) - } - n, z.err = z.compressor.Write(p) - return n, z.err -} - -// 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 z.err != nil { - return z.err - } - if z.closed || z.level == StatelessCompression { - return nil - } - if !z.wroteHeader { - z.Write(nil) - if z.err != nil { - return z.err - } - } - z.err = z.compressor.Flush() - return z.err -} - -// 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 z.err != nil { - return z.err - } - if z.closed { - return nil - } - z.closed = true - if !z.wroteHeader { - z.Write(nil) - if z.err != nil { - return z.err - } - } - if z.level == StatelessCompression { - z.err = flate.StatelessDeflate(z.w, nil, true, nil) - } else { - z.err = z.compressor.Close() - } - if z.err != nil { - return z.err - } - le.PutUint32(z.buf[:4], z.digest) - le.PutUint32(z.buf[4:8], z.size) - _, z.err = z.w.Write(z.buf[:8]) - return z.err -} |