mirror of
https://github.com/ceph/ceph-csi.git
synced 2025-06-13 10:33:35 +00:00
rebase: bump the github-dependencies group across 1 directory with 4 updates
Bumps the github-dependencies group with 4 updates in the / directory: [github.com/aws/aws-sdk-go-v2/service/sts](https://github.com/aws/aws-sdk-go-v2), [github.com/kubernetes-csi/csi-lib-utils](https://github.com/kubernetes-csi/csi-lib-utils), [github.com/onsi/ginkgo/v2](https://github.com/onsi/ginkgo) and [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang). Updates `github.com/aws/aws-sdk-go-v2/service/sts` from 1.30.3 to 1.30.4 - [Release notes](https://github.com/aws/aws-sdk-go-v2/releases) - [Commits](https://github.com/aws/aws-sdk-go-v2/compare/v1.30.3...v1.30.4) Updates `github.com/kubernetes-csi/csi-lib-utils` from 0.18.1 to 0.19.0 - [Release notes](https://github.com/kubernetes-csi/csi-lib-utils/releases) - [Commits](https://github.com/kubernetes-csi/csi-lib-utils/compare/v0.18.1...v0.19.0) Updates `github.com/onsi/ginkgo/v2` from 2.19.1 to 2.20.0 - [Release notes](https://github.com/onsi/ginkgo/releases) - [Changelog](https://github.com/onsi/ginkgo/blob/master/CHANGELOG.md) - [Commits](https://github.com/onsi/ginkgo/compare/v2.19.1...v2.20.0) Updates `github.com/prometheus/client_golang` from 1.19.1 to 1.20.1 - [Release notes](https://github.com/prometheus/client_golang/releases) - [Changelog](https://github.com/prometheus/client_golang/blob/v1.20.1/CHANGELOG.md) - [Commits](https://github.com/prometheus/client_golang/compare/v1.19.1...v1.20.1) --- updated-dependencies: - dependency-name: github.com/aws/aws-sdk-go-v2/service/sts dependency-type: direct:production update-type: version-update:semver-patch dependency-group: github-dependencies - dependency-name: github.com/kubernetes-csi/csi-lib-utils dependency-type: direct:production update-type: version-update:semver-minor dependency-group: github-dependencies - dependency-name: github.com/onsi/ginkgo/v2 dependency-type: direct:production update-type: version-update:semver-minor dependency-group: github-dependencies - dependency-name: github.com/prometheus/client_golang dependency-type: direct:production update-type: version-update:semver-minor dependency-group: github-dependencies ... Signed-off-by: dependabot[bot] <support@github.com>
This commit is contained in:
committed by
mergify[bot]
parent
4da71363b5
commit
b044363a31
27
vendor/github.com/klauspost/compress/internal/snapref/LICENSE
generated
vendored
Normal file
27
vendor/github.com/klauspost/compress/internal/snapref/LICENSE
generated
vendored
Normal file
@ -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.
|
264
vendor/github.com/klauspost/compress/internal/snapref/decode.go
generated
vendored
Normal file
264
vendor/github.com/klauspost/compress/internal/snapref/decode.go
generated
vendored
Normal file
@ -0,0 +1,264 @@
|
||||
// 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 snapref
|
||||
|
||||
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.
|
||||
//
|
||||
// Decode handles the Snappy block format, not the Snappy stream format.
|
||||
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.
|
||||
//
|
||||
// Reader handles the Snappy stream format, not the Snappy block format.
|
||||
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
|
||||
}
|
||||
|
||||
func (r *Reader) fill() error {
|
||||
for r.i >= r.j {
|
||||
if !r.readFull(r.buf[:4], true) {
|
||||
return r.err
|
||||
}
|
||||
chunkType := r.buf[0]
|
||||
if !r.readHeader {
|
||||
if chunkType != chunkTypeStreamIdentifier {
|
||||
r.err = ErrCorrupt
|
||||
return 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 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 r.err
|
||||
}
|
||||
buf := r.buf[:chunkLen]
|
||||
if !r.readFull(buf, false) {
|
||||
return 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 r.err
|
||||
}
|
||||
if n > len(r.decoded) {
|
||||
r.err = ErrCorrupt
|
||||
return r.err
|
||||
}
|
||||
if _, err := Decode(r.decoded, buf); err != nil {
|
||||
r.err = err
|
||||
return r.err
|
||||
}
|
||||
if crc(r.decoded[:n]) != checksum {
|
||||
r.err = ErrCorrupt
|
||||
return 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 r.err
|
||||
}
|
||||
buf := r.buf[:checksumSize]
|
||||
if !r.readFull(buf, false) {
|
||||
return 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 r.err
|
||||
}
|
||||
if !r.readFull(r.decoded[:n], false) {
|
||||
return r.err
|
||||
}
|
||||
if crc(r.decoded[:n]) != checksum {
|
||||
r.err = ErrCorrupt
|
||||
return 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 r.err
|
||||
}
|
||||
if !r.readFull(r.buf[:len(magicBody)], false) {
|
||||
return r.err
|
||||
}
|
||||
for i := 0; i < len(magicBody); i++ {
|
||||
if r.buf[i] != magicBody[i] {
|
||||
r.err = ErrCorrupt
|
||||
return r.err
|
||||
}
|
||||
}
|
||||
continue
|
||||
}
|
||||
|
||||
if chunkType <= 0x7f {
|
||||
// Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f).
|
||||
r.err = ErrUnsupported
|
||||
return 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 r.err
|
||||
}
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// Read satisfies the io.Reader interface.
|
||||
func (r *Reader) Read(p []byte) (int, error) {
|
||||
if r.err != nil {
|
||||
return 0, r.err
|
||||
}
|
||||
|
||||
if err := r.fill(); err != nil {
|
||||
return 0, err
|
||||
}
|
||||
|
||||
n := copy(p, r.decoded[r.i:r.j])
|
||||
r.i += n
|
||||
return n, nil
|
||||
}
|
||||
|
||||
// ReadByte satisfies the io.ByteReader interface.
|
||||
func (r *Reader) ReadByte() (byte, error) {
|
||||
if r.err != nil {
|
||||
return 0, r.err
|
||||
}
|
||||
|
||||
if err := r.fill(); err != nil {
|
||||
return 0, err
|
||||
}
|
||||
|
||||
c := r.decoded[r.i]
|
||||
r.i++
|
||||
return c, nil
|
||||
}
|
113
vendor/github.com/klauspost/compress/internal/snapref/decode_other.go
generated
vendored
Normal file
113
vendor/github.com/klauspost/compress/internal/snapref/decode_other.go
generated
vendored
Normal file
@ -0,0 +1,113 @@
|
||||
// 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.
|
||||
|
||||
package snapref
|
||||
|
||||
// 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.
|
||||
// If no overlap, use the built-in copy:
|
||||
if offset >= length {
|
||||
copy(dst[d:d+length], dst[d-offset:])
|
||||
d += length
|
||||
continue
|
||||
}
|
||||
|
||||
// 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:])
|
||||
//
|
||||
// We align the slices into a and b and show the compiler they are the same size.
|
||||
// This allows the loop to run without bounds checks.
|
||||
a := dst[d : d+length]
|
||||
b := dst[d-offset:]
|
||||
b = b[:len(a)]
|
||||
for i := range a {
|
||||
a[i] = b[i]
|
||||
}
|
||||
d += length
|
||||
}
|
||||
if d != len(dst) {
|
||||
return decodeErrCodeCorrupt
|
||||
}
|
||||
return 0
|
||||
}
|
289
vendor/github.com/klauspost/compress/internal/snapref/encode.go
generated
vendored
Normal file
289
vendor/github.com/klauspost/compress/internal/snapref/encode.go
generated
vendored
Normal file
@ -0,0 +1,289 @@
|
||||
// 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 snapref
|
||||
|
||||
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.
|
||||
//
|
||||
// Encode handles the Snappy block format, not the Snappy stream format.
|
||||
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.
|
||||
//
|
||||
// Writer handles the Snappy stream format, not the Snappy block format.
|
||||
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
|
||||
}
|
250
vendor/github.com/klauspost/compress/internal/snapref/encode_other.go
generated
vendored
Normal file
250
vendor/github.com/klauspost/compress/internal/snapref/encode_other.go
generated
vendored
Normal file
@ -0,0 +1,250 @@
|
||||
// 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.
|
||||
|
||||
package snapref
|
||||
|
||||
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 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
|
||||
}
|
||||
|
||||
func hash(u, shift uint32) uint32 {
|
||||
return (u * 0x1e35a7bd) >> shift
|
||||
}
|
||||
|
||||
// EncodeBlockInto exposes encodeBlock but checks dst size.
|
||||
func EncodeBlockInto(dst, src []byte) (d int) {
|
||||
if MaxEncodedLen(len(src)) > len(dst) {
|
||||
return 0
|
||||
}
|
||||
|
||||
// encodeBlock breaks on too big blocks, so split.
|
||||
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 d
|
||||
}
|
||||
|
||||
// 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
|
||||
}
|
98
vendor/github.com/klauspost/compress/internal/snapref/snappy.go
generated
vendored
Normal file
98
vendor/github.com/klauspost/compress/internal/snapref/snappy.go
generated
vendored
Normal file
@ -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 snapref 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 snapref
|
||||
|
||||
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
|
||||
}
|
Reference in New Issue
Block a user