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-rw-r--r--vendor/github.com/golang/snappy/encode.go285
1 files changed, 0 insertions, 285 deletions
diff --git a/vendor/github.com/golang/snappy/encode.go b/vendor/github.com/golang/snappy/encode.go
deleted file mode 100644
index 8d393e9..0000000
--- a/vendor/github.com/golang/snappy/encode.go
+++ /dev/null
@@ -1,285 +0,0 @@
-// 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
-}