forked from forgejo/forgejo
Integrate public as bindata optionally (#293)
* Dropped unused codekit config * Integrated dynamic and static bindata for public * Ignore public bindata * Add a general generate make task * Integrated flexible public assets into web command * Updated vendoring, added all missiong govendor deps * Made the linter happy with the bindata and dynamic code * Moved public bindata definition to modules directory * Ignoring the new bindata path now * Updated to the new public modules import path * Updated public bindata command and drop the new prefix
This commit is contained in:
parent
4680c349dd
commit
b6a95a8cb3
691 changed files with 305318 additions and 1272 deletions
15
vendor/github.com/golang/snappy/AUTHORS
generated
vendored
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15
vendor/github.com/golang/snappy/AUTHORS
generated
vendored
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|
@ -0,0 +1,15 @@
|
|||
# This is the official list of Snappy-Go authors for copyright purposes.
|
||||
# This file is distinct from the CONTRIBUTORS files.
|
||||
# See the latter for an explanation.
|
||||
|
||||
# Names should be added to this file as
|
||||
# Name or Organization <email address>
|
||||
# The email address is not required for organizations.
|
||||
|
||||
# Please keep the list sorted.
|
||||
|
||||
Damian Gryski <dgryski@gmail.com>
|
||||
Google Inc.
|
||||
Jan Mercl <0xjnml@gmail.com>
|
||||
Rodolfo Carvalho <rhcarvalho@gmail.com>
|
||||
Sebastien Binet <seb.binet@gmail.com>
|
37
vendor/github.com/golang/snappy/CONTRIBUTORS
generated
vendored
Normal file
37
vendor/github.com/golang/snappy/CONTRIBUTORS
generated
vendored
Normal file
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@ -0,0 +1,37 @@
|
|||
# This is the official list of people who can contribute
|
||||
# (and typically have contributed) code to the Snappy-Go repository.
|
||||
# The AUTHORS file lists the copyright holders; this file
|
||||
# lists people. For example, Google employees are listed here
|
||||
# but not in AUTHORS, because Google holds the copyright.
|
||||
#
|
||||
# The submission process automatically checks to make sure
|
||||
# that people submitting code are listed in this file (by email address).
|
||||
#
|
||||
# Names should be added to this file only after verifying that
|
||||
# the individual or the individual's organization has agreed to
|
||||
# the appropriate Contributor License Agreement, found here:
|
||||
#
|
||||
# http://code.google.com/legal/individual-cla-v1.0.html
|
||||
# http://code.google.com/legal/corporate-cla-v1.0.html
|
||||
#
|
||||
# The agreement for individuals can be filled out on the web.
|
||||
#
|
||||
# When adding J Random Contributor's name to this file,
|
||||
# either J's name or J's organization's name should be
|
||||
# added to the AUTHORS file, depending on whether the
|
||||
# individual or corporate CLA was used.
|
||||
|
||||
# Names should be added to this file like so:
|
||||
# Name <email address>
|
||||
|
||||
# Please keep the list sorted.
|
||||
|
||||
Damian Gryski <dgryski@gmail.com>
|
||||
Jan Mercl <0xjnml@gmail.com>
|
||||
Kai Backman <kaib@golang.org>
|
||||
Marc-Antoine Ruel <maruel@chromium.org>
|
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Nigel Tao <nigeltao@golang.org>
|
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Rob Pike <r@golang.org>
|
||||
Rodolfo Carvalho <rhcarvalho@gmail.com>
|
||||
Russ Cox <rsc@golang.org>
|
||||
Sebastien Binet <seb.binet@gmail.com>
|
27
vendor/github.com/golang/snappy/LICENSE
generated
vendored
Normal file
27
vendor/github.com/golang/snappy/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.
|
7
vendor/github.com/golang/snappy/README
generated
vendored
Normal file
7
vendor/github.com/golang/snappy/README
generated
vendored
Normal file
|
@ -0,0 +1,7 @@
|
|||
The Snappy compression format in the Go programming language.
|
||||
|
||||
To download and install from source:
|
||||
$ go get github.com/golang/snappy
|
||||
|
||||
Unless otherwise noted, the Snappy-Go source files are distributed
|
||||
under the BSD-style license found in the LICENSE file.
|
237
vendor/github.com/golang/snappy/decode.go
generated
vendored
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237
vendor/github.com/golang/snappy/decode.go
generated
vendored
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|
@ -0,0 +1,237 @@
|
|||
// 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"
|
||||
)
|
||||
|
||||
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")
|
||||
|
||||
errUnsupportedCopy4Tag = errors.New("snappy: unsupported COPY_4 tag")
|
||||
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
|
||||
decodeErrCodeUnsupportedCopy4Tag = 3
|
||||
)
|
||||
|
||||
// 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.
|
||||
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
|
||||
case decodeErrCodeUnsupportedCopy4Tag:
|
||||
return nil, errUnsupportedCopy4Tag
|
||||
}
|
||||
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.
|
||||
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) (ok bool) {
|
||||
if _, r.err = io.ReadFull(r.r, p); r.err != nil {
|
||||
if r.err == io.ErrUnexpectedEOF {
|
||||
r.err = ErrCorrupt
|
||||
}
|
||||
return false
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
// Read satisfies the io.Reader interface.
|
||||
func (r *Reader) Read(p []byte) (int, error) {
|
||||
if r.err != nil {
|
||||
return 0, r.err
|
||||
}
|
||||
for {
|
||||
if r.i < r.j {
|
||||
n := copy(p, r.decoded[r.i:r.j])
|
||||
r.i += n
|
||||
return n, nil
|
||||
}
|
||||
if !r.readFull(r.buf[:4]) {
|
||||
return 0, r.err
|
||||
}
|
||||
chunkType := r.buf[0]
|
||||
if !r.readHeader {
|
||||
if chunkType != chunkTypeStreamIdentifier {
|
||||
r.err = ErrCorrupt
|
||||
return 0, 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 0, 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 0, r.err
|
||||
}
|
||||
buf := r.buf[:chunkLen]
|
||||
if !r.readFull(buf) {
|
||||
return 0, 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 0, r.err
|
||||
}
|
||||
if n > len(r.decoded) {
|
||||
r.err = ErrCorrupt
|
||||
return 0, r.err
|
||||
}
|
||||
if _, err := Decode(r.decoded, buf); err != nil {
|
||||
r.err = err
|
||||
return 0, r.err
|
||||
}
|
||||
if crc(r.decoded[:n]) != checksum {
|
||||
r.err = ErrCorrupt
|
||||
return 0, 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 0, r.err
|
||||
}
|
||||
buf := r.buf[:checksumSize]
|
||||
if !r.readFull(buf) {
|
||||
return 0, 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 !r.readFull(r.decoded[:n]) {
|
||||
return 0, r.err
|
||||
}
|
||||
if crc(r.decoded[:n]) != checksum {
|
||||
r.err = ErrCorrupt
|
||||
return 0, 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 0, r.err
|
||||
}
|
||||
if !r.readFull(r.buf[:len(magicBody)]) {
|
||||
return 0, r.err
|
||||
}
|
||||
for i := 0; i < len(magicBody); i++ {
|
||||
if r.buf[i] != magicBody[i] {
|
||||
r.err = ErrCorrupt
|
||||
return 0, r.err
|
||||
}
|
||||
}
|
||||
continue
|
||||
}
|
||||
|
||||
if chunkType <= 0x7f {
|
||||
// Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f).
|
||||
r.err = ErrUnsupported
|
||||
return 0, 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]) {
|
||||
return 0, r.err
|
||||
}
|
||||
}
|
||||
}
|
10
vendor/github.com/golang/snappy/decode_amd64.go
generated
vendored
Normal file
10
vendor/github.com/golang/snappy/decode_amd64.go
generated
vendored
Normal file
|
@ -0,0 +1,10 @@
|
|||
// 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 snappy
|
||||
|
||||
// decode has the same semantics as in decode_other.go.
|
||||
//
|
||||
//go:noescape
|
||||
func decode(dst, src []byte) int
|
472
vendor/github.com/golang/snappy/decode_amd64.s
generated
vendored
Normal file
472
vendor/github.com/golang/snappy/decode_amd64.s
generated
vendored
Normal file
|
@ -0,0 +1,472 @@
|
|||
// Copyright 2016 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.
|
||||
|
||||
#include "textflag.h"
|
||||
|
||||
// func decode(dst, src []byte) int
|
||||
//
|
||||
// The asm code generally follows the pure Go code in decode_other.go, except
|
||||
// where marked with a "!!!".
|
||||
//
|
||||
// All local variables fit into registers. The non-zero stack size is only to
|
||||
// spill registers and push args when issuing a CALL. The register allocation:
|
||||
// - AX scratch
|
||||
// - BX scratch
|
||||
// - CX length or x
|
||||
// - DX offset
|
||||
// - SI &src[s]
|
||||
// - DI &dst[d]
|
||||
// + R8 dst_base
|
||||
// + R9 dst_len
|
||||
// + R10 dst_base + dst_len
|
||||
// + R11 src_base
|
||||
// + R12 src_len
|
||||
// + R13 src_base + src_len
|
||||
// - R14 used by doCopy
|
||||
// - R15 used by doCopy
|
||||
//
|
||||
// The registers R8-R13 (marked with a "+") are set at the start of the
|
||||
// function, and after a CALL returns, and are not otherwise modified.
|
||||
//
|
||||
// The d variable is implicitly DI - R8, and len(dst)-d is R10 - DI.
|
||||
// The s variable is implicitly SI - R11, and len(src)-s is R13 - SI.
|
||||
TEXT ·decode(SB), NOSPLIT, $48-56
|
||||
// Initialize SI, DI and R8-R13.
|
||||
MOVQ dst_base+0(FP), R8
|
||||
MOVQ dst_len+8(FP), R9
|
||||
MOVQ R8, DI
|
||||
MOVQ R8, R10
|
||||
ADDQ R9, R10
|
||||
MOVQ src_base+24(FP), R11
|
||||
MOVQ src_len+32(FP), R12
|
||||
MOVQ R11, SI
|
||||
MOVQ R11, R13
|
||||
ADDQ R12, R13
|
||||
|
||||
loop:
|
||||
// for s < len(src)
|
||||
CMPQ SI, R13
|
||||
JEQ end
|
||||
|
||||
// CX = uint32(src[s])
|
||||
//
|
||||
// switch src[s] & 0x03
|
||||
MOVBLZX (SI), CX
|
||||
MOVL CX, BX
|
||||
ANDL $3, BX
|
||||
CMPL BX, $1
|
||||
JAE tagCopy
|
||||
|
||||
// ----------------------------------------
|
||||
// The code below handles literal tags.
|
||||
|
||||
// case tagLiteral:
|
||||
// x := uint32(src[s] >> 2)
|
||||
// switch
|
||||
SHRL $2, CX
|
||||
CMPL CX, $60
|
||||
JAE tagLit60Plus
|
||||
|
||||
// case x < 60:
|
||||
// s++
|
||||
INCQ SI
|
||||
|
||||
doLit:
|
||||
// This is the end of the inner "switch", when we have a literal tag.
|
||||
//
|
||||
// We assume that CX == x and x fits in a uint32, where x is the variable
|
||||
// used in the pure Go decode_other.go code.
|
||||
|
||||
// length = int(x) + 1
|
||||
//
|
||||
// Unlike the pure Go code, we don't need to check if length <= 0 because
|
||||
// CX can hold 64 bits, so the increment cannot overflow.
|
||||
INCQ CX
|
||||
|
||||
// Prepare to check if copying length bytes will run past the end of dst or
|
||||
// src.
|
||||
//
|
||||
// AX = len(dst) - d
|
||||
// BX = len(src) - s
|
||||
MOVQ R10, AX
|
||||
SUBQ DI, AX
|
||||
MOVQ R13, BX
|
||||
SUBQ SI, BX
|
||||
|
||||
// !!! Try a faster technique for short (16 or fewer bytes) copies.
|
||||
//
|
||||
// if length > 16 || len(dst)-d < 16 || len(src)-s < 16 {
|
||||
// goto callMemmove // Fall back on calling runtime·memmove.
|
||||
// }
|
||||
//
|
||||
// The C++ snappy code calls this TryFastAppend. It also checks len(src)-s
|
||||
// against 21 instead of 16, because it cannot assume that all of its input
|
||||
// is contiguous in memory and so it needs to leave enough source bytes to
|
||||
// read the next tag without refilling buffers, but Go's Decode assumes
|
||||
// contiguousness (the src argument is a []byte).
|
||||
CMPQ CX, $16
|
||||
JGT callMemmove
|
||||
CMPQ AX, $16
|
||||
JLT callMemmove
|
||||
CMPQ BX, $16
|
||||
JLT callMemmove
|
||||
|
||||
// !!! Implement the copy from src to dst as a 16-byte load and store.
|
||||
// (Decode's documentation says that dst and src must not overlap.)
|
||||
//
|
||||
// This always copies 16 bytes, instead of only length bytes, but that's
|
||||
// OK. If the input is a valid Snappy encoding then subsequent iterations
|
||||
// will fix up the overrun. Otherwise, Decode returns a nil []byte (and a
|
||||
// non-nil error), so the overrun will be ignored.
|
||||
//
|
||||
// Note that on amd64, it is legal and cheap to issue unaligned 8-byte or
|
||||
// 16-byte loads and stores. This technique probably wouldn't be as
|
||||
// effective on architectures that are fussier about alignment.
|
||||
MOVOU 0(SI), X0
|
||||
MOVOU X0, 0(DI)
|
||||
|
||||
// d += length
|
||||
// s += length
|
||||
ADDQ CX, DI
|
||||
ADDQ CX, SI
|
||||
JMP loop
|
||||
|
||||
callMemmove:
|
||||
// if length > len(dst)-d || length > len(src)-s { etc }
|
||||
CMPQ CX, AX
|
||||
JGT errCorrupt
|
||||
CMPQ CX, BX
|
||||
JGT errCorrupt
|
||||
|
||||
// copy(dst[d:], src[s:s+length])
|
||||
//
|
||||
// This means calling runtime·memmove(&dst[d], &src[s], length), so we push
|
||||
// DI, SI and CX as arguments. Coincidentally, we also need to spill those
|
||||
// three registers to the stack, to save local variables across the CALL.
|
||||
MOVQ DI, 0(SP)
|
||||
MOVQ SI, 8(SP)
|
||||
MOVQ CX, 16(SP)
|
||||
MOVQ DI, 24(SP)
|
||||
MOVQ SI, 32(SP)
|
||||
MOVQ CX, 40(SP)
|
||||
CALL runtime·memmove(SB)
|
||||
|
||||
// Restore local variables: unspill registers from the stack and
|
||||
// re-calculate R8-R13.
|
||||
MOVQ 24(SP), DI
|
||||
MOVQ 32(SP), SI
|
||||
MOVQ 40(SP), CX
|
||||
MOVQ dst_base+0(FP), R8
|
||||
MOVQ dst_len+8(FP), R9
|
||||
MOVQ R8, R10
|
||||
ADDQ R9, R10
|
||||
MOVQ src_base+24(FP), R11
|
||||
MOVQ src_len+32(FP), R12
|
||||
MOVQ R11, R13
|
||||
ADDQ R12, R13
|
||||
|
||||
// d += length
|
||||
// s += length
|
||||
ADDQ CX, DI
|
||||
ADDQ CX, SI
|
||||
JMP loop
|
||||
|
||||
tagLit60Plus:
|
||||
// !!! This fragment does the
|
||||
//
|
||||
// s += x - 58; if uint(s) > uint(len(src)) { etc }
|
||||
//
|
||||
// checks. In the asm version, we code it once instead of once per switch case.
|
||||
ADDQ CX, SI
|
||||
SUBQ $58, SI
|
||||
MOVQ SI, BX
|
||||
SUBQ R11, BX
|
||||
CMPQ BX, R12
|
||||
JA errCorrupt
|
||||
|
||||
// case x == 60:
|
||||
CMPL CX, $61
|
||||
JEQ tagLit61
|
||||
JA tagLit62Plus
|
||||
|
||||
// x = uint32(src[s-1])
|
||||
MOVBLZX -1(SI), CX
|
||||
JMP doLit
|
||||
|
||||
tagLit61:
|
||||
// case x == 61:
|
||||
// x = uint32(src[s-2]) | uint32(src[s-1])<<8
|
||||
MOVWLZX -2(SI), CX
|
||||
JMP doLit
|
||||
|
||||
tagLit62Plus:
|
||||
CMPL CX, $62
|
||||
JA tagLit63
|
||||
|
||||
// case x == 62:
|
||||
// x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
|
||||
MOVWLZX -3(SI), CX
|
||||
MOVBLZX -1(SI), BX
|
||||
SHLL $16, BX
|
||||
ORL BX, CX
|
||||
JMP doLit
|
||||
|
||||
tagLit63:
|
||||
// case x == 63:
|
||||
// x = uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24
|
||||
MOVL -4(SI), CX
|
||||
JMP doLit
|
||||
|
||||
// The code above handles literal tags.
|
||||
// ----------------------------------------
|
||||
// The code below handles copy tags.
|
||||
|
||||
tagCopy2:
|
||||
// case tagCopy2:
|
||||
// s += 3
|
||||
ADDQ $3, SI
|
||||
|
||||
// if uint(s) > uint(len(src)) { etc }
|
||||
MOVQ SI, BX
|
||||
SUBQ R11, BX
|
||||
CMPQ BX, R12
|
||||
JA errCorrupt
|
||||
|
||||
// length = 1 + int(src[s-3])>>2
|
||||
SHRQ $2, CX
|
||||
INCQ CX
|
||||
|
||||
// offset = int(src[s-2]) | int(src[s-1])<<8
|
||||
MOVWQZX -2(SI), DX
|
||||
JMP doCopy
|
||||
|
||||
tagCopy:
|
||||
// We have a copy tag. We assume that:
|
||||
// - BX == src[s] & 0x03
|
||||
// - CX == src[s]
|
||||
CMPQ BX, $2
|
||||
JEQ tagCopy2
|
||||
JA errUC4T
|
||||
|
||||
// case tagCopy1:
|
||||
// s += 2
|
||||
ADDQ $2, SI
|
||||
|
||||
// if uint(s) > uint(len(src)) { etc }
|
||||
MOVQ SI, BX
|
||||
SUBQ R11, BX
|
||||
CMPQ BX, R12
|
||||
JA errCorrupt
|
||||
|
||||
// offset = int(src[s-2])&0xe0<<3 | int(src[s-1])
|
||||
MOVQ CX, DX
|
||||
ANDQ $0xe0, DX
|
||||
SHLQ $3, DX
|
||||
MOVBQZX -1(SI), BX
|
||||
ORQ BX, DX
|
||||
|
||||
// length = 4 + int(src[s-2])>>2&0x7
|
||||
SHRQ $2, CX
|
||||
ANDQ $7, CX
|
||||
ADDQ $4, CX
|
||||
|
||||
doCopy:
|
||||
// This is the end of the outer "switch", when we have a copy tag.
|
||||
//
|
||||
// We assume that:
|
||||
// - CX == length && CX > 0
|
||||
// - DX == offset
|
||||
|
||||
// if offset <= 0 { etc }
|
||||
CMPQ DX, $0
|
||||
JLE errCorrupt
|
||||
|
||||
// if d < offset { etc }
|
||||
MOVQ DI, BX
|
||||
SUBQ R8, BX
|
||||
CMPQ BX, DX
|
||||
JLT errCorrupt
|
||||
|
||||
// if length > len(dst)-d { etc }
|
||||
MOVQ R10, BX
|
||||
SUBQ DI, BX
|
||||
CMPQ CX, BX
|
||||
JGT errCorrupt
|
||||
|
||||
// forwardCopy(dst[d:d+length], dst[d-offset:]); d += length
|
||||
//
|
||||
// Set:
|
||||
// - R14 = len(dst)-d
|
||||
// - R15 = &dst[d-offset]
|
||||
MOVQ R10, R14
|
||||
SUBQ DI, R14
|
||||
MOVQ DI, R15
|
||||
SUBQ DX, R15
|
||||
|
||||
// !!! Try a faster technique for short (16 or fewer bytes) forward copies.
|
||||
//
|
||||
// First, try using two 8-byte load/stores, similar to the doLit technique
|
||||
// above. Even if dst[d:d+length] and dst[d-offset:] can overlap, this is
|
||||
// still OK if offset >= 8. Note that this has to be two 8-byte load/stores
|
||||
// and not one 16-byte load/store, and the first store has to be before the
|
||||
// second load, due to the overlap if offset is in the range [8, 16).
|
||||
//
|
||||
// if length > 16 || offset < 8 || len(dst)-d < 16 {
|
||||
// goto slowForwardCopy
|
||||
// }
|
||||
// copy 16 bytes
|
||||
// d += length
|
||||
CMPQ CX, $16
|
||||
JGT slowForwardCopy
|
||||
CMPQ DX, $8
|
||||
JLT slowForwardCopy
|
||||
CMPQ R14, $16
|
||||
JLT slowForwardCopy
|
||||
MOVQ 0(R15), AX
|
||||
MOVQ AX, 0(DI)
|
||||
MOVQ 8(R15), BX
|
||||
MOVQ BX, 8(DI)
|
||||
ADDQ CX, DI
|
||||
JMP loop
|
||||
|
||||
slowForwardCopy:
|
||||
// !!! If the forward copy is longer than 16 bytes, or if offset < 8, we
|
||||
// can still try 8-byte load stores, provided we can overrun up to 10 extra
|
||||
// bytes. As above, the overrun will be fixed up by subsequent iterations
|
||||
// of the outermost loop.
|
||||
//
|
||||
// The C++ snappy code calls this technique IncrementalCopyFastPath. Its
|
||||
// commentary says:
|
||||
//
|
||||
// ----
|
||||
//
|
||||
// The main part of this loop is a simple copy of eight bytes at a time
|
||||
// until we've copied (at least) the requested amount of bytes. However,
|
||||
// if d and d-offset are less than eight bytes apart (indicating a
|
||||
// repeating pattern of length < 8), we first need to expand the pattern in
|
||||
// order to get the correct results. For instance, if the buffer looks like
|
||||
// this, with the eight-byte <d-offset> and <d> patterns marked as
|
||||
// intervals:
|
||||
//
|
||||
// abxxxxxxxxxxxx
|
||||
// [------] d-offset
|
||||
// [------] d
|
||||
//
|
||||
// a single eight-byte copy from <d-offset> to <d> will repeat the pattern
|
||||
// once, after which we can move <d> two bytes without moving <d-offset>:
|
||||
//
|
||||
// ababxxxxxxxxxx
|
||||
// [------] d-offset
|
||||
// [------] d
|
||||
//
|
||||
// and repeat the exercise until the two no longer overlap.
|
||||
//
|
||||
// This allows us to do very well in the special case of one single byte
|
||||
// repeated many times, without taking a big hit for more general cases.
|
||||
//
|
||||
// The worst case of extra writing past the end of the match occurs when
|
||||
// offset == 1 and length == 1; the last copy will read from byte positions
|
||||
// [0..7] and write to [4..11], whereas it was only supposed to write to
|
||||
// position 1. Thus, ten excess bytes.
|
||||
//
|
||||
// ----
|
||||
//
|
||||
// That "10 byte overrun" worst case is confirmed by Go's
|
||||
// TestSlowForwardCopyOverrun, which also tests the fixUpSlowForwardCopy
|
||||
// and finishSlowForwardCopy algorithm.
|
||||
//
|
||||
// if length > len(dst)-d-10 {
|
||||
// goto verySlowForwardCopy
|
||||
// }
|
||||
SUBQ $10, R14
|
||||
CMPQ CX, R14
|
||||
JGT verySlowForwardCopy
|
||||
|
||||
makeOffsetAtLeast8:
|
||||
// !!! As above, expand the pattern so that offset >= 8 and we can use
|
||||
// 8-byte load/stores.
|
||||
//
|
||||
// for offset < 8 {
|
||||
// copy 8 bytes from dst[d-offset:] to dst[d:]
|
||||
// length -= offset
|
||||
// d += offset
|
||||
// offset += offset
|
||||
// // The two previous lines together means that d-offset, and therefore
|
||||
// // R15, is unchanged.
|
||||
// }
|
||||
CMPQ DX, $8
|
||||
JGE fixUpSlowForwardCopy
|
||||
MOVQ (R15), BX
|
||||
MOVQ BX, (DI)
|
||||
SUBQ DX, CX
|
||||
ADDQ DX, DI
|
||||
ADDQ DX, DX
|
||||
JMP makeOffsetAtLeast8
|
||||
|
||||
fixUpSlowForwardCopy:
|
||||
// !!! Add length (which might be negative now) to d (implied by DI being
|
||||
// &dst[d]) so that d ends up at the right place when we jump back to the
|
||||
// top of the loop. Before we do that, though, we save DI to AX so that, if
|
||||
// length is positive, copying the remaining length bytes will write to the
|
||||
// right place.
|
||||
MOVQ DI, AX
|
||||
ADDQ CX, DI
|
||||
|
||||
finishSlowForwardCopy:
|
||||
// !!! Repeat 8-byte load/stores until length <= 0. Ending with a negative
|
||||
// length means that we overrun, but as above, that will be fixed up by
|
||||
// subsequent iterations of the outermost loop.
|
||||
CMPQ CX, $0
|
||||
JLE loop
|
||||
MOVQ (R15), BX
|
||||
MOVQ BX, (AX)
|
||||
ADDQ $8, R15
|
||||
ADDQ $8, AX
|
||||
SUBQ $8, CX
|
||||
JMP finishSlowForwardCopy
|
||||
|
||||
verySlowForwardCopy:
|
||||
// verySlowForwardCopy is a simple implementation of forward copy. In C
|
||||
// parlance, this is a do/while loop instead of a while loop, since we know
|
||||
// that length > 0. In Go syntax:
|
||||
//
|
||||
// for {
|
||||
// dst[d] = dst[d - offset]
|
||||
// d++
|
||||
// length--
|
||||
// if length == 0 {
|
||||
// break
|
||||
// }
|
||||
// }
|
||||
MOVB (R15), BX
|
||||
MOVB BX, (DI)
|
||||
INCQ R15
|
||||
INCQ DI
|
||||
DECQ CX
|
||||
JNZ verySlowForwardCopy
|
||||
JMP loop
|
||||
|
||||
// The code above handles copy tags.
|
||||
// ----------------------------------------
|
||||
|
||||
end:
|
||||
// This is the end of the "for s < len(src)".
|
||||
//
|
||||
// if d != len(dst) { etc }
|
||||
CMPQ DI, R10
|
||||
JNE errCorrupt
|
||||
|
||||
// return 0
|
||||
MOVQ $0, ret+48(FP)
|
||||
RET
|
||||
|
||||
errCorrupt:
|
||||
// return decodeErrCodeCorrupt
|
||||
MOVQ $1, ret+48(FP)
|
||||
RET
|
||||
|
||||
errUC4T:
|
||||
// return decodeErrCodeUnsupportedCopy4Tag
|
||||
MOVQ $3, ret+48(FP)
|
||||
RET
|
96
vendor/github.com/golang/snappy/decode_other.go
generated
vendored
Normal file
96
vendor/github.com/golang/snappy/decode_other.go
generated
vendored
Normal file
|
@ -0,0 +1,96 @@
|
|||
// 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.
|
||||
|
||||
// +build !amd64
|
||||
|
||||
package snappy
|
||||
|
||||
// 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(src[s-2])&0xe0<<3 | int(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(src[s-2]) | int(src[s-1])<<8
|
||||
|
||||
case tagCopy4:
|
||||
return decodeErrCodeUnsupportedCopy4Tag
|
||||
}
|
||||
|
||||
if offset <= 0 || d < offset || length > len(dst)-d {
|
||||
return decodeErrCodeCorrupt
|
||||
}
|
||||
// Copy from an earlier sub-slice of dst to a later sub-slice. 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:])
|
||||
for end := d + length; d != end; d++ {
|
||||
dst[d] = dst[d-offset]
|
||||
}
|
||||
}
|
||||
if d != len(dst) {
|
||||
return decodeErrCodeCorrupt
|
||||
}
|
||||
return 0
|
||||
}
|
403
vendor/github.com/golang/snappy/encode.go
generated
vendored
Normal file
403
vendor/github.com/golang/snappy/encode.go
generated
vendored
Normal file
|
@ -0,0 +1,403 @@
|
|||
// 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"
|
||||
)
|
||||
|
||||
// maxOffset limits how far copy back-references can go, the same as the C++
|
||||
// code.
|
||||
const maxOffset = 1 << 15
|
||||
|
||||
// emitLiteral writes a literal chunk and returns the number of bytes written.
|
||||
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
|
||||
case n < 1<<16:
|
||||
dst[0] = 61<<2 | tagLiteral
|
||||
dst[1] = uint8(n)
|
||||
dst[2] = uint8(n >> 8)
|
||||
i = 3
|
||||
case n < 1<<24:
|
||||
dst[0] = 62<<2 | tagLiteral
|
||||
dst[1] = uint8(n)
|
||||
dst[2] = uint8(n >> 8)
|
||||
dst[3] = uint8(n >> 16)
|
||||
i = 4
|
||||
case int64(n) < 1<<32:
|
||||
dst[0] = 63<<2 | tagLiteral
|
||||
dst[1] = uint8(n)
|
||||
dst[2] = uint8(n >> 8)
|
||||
dst[3] = uint8(n >> 16)
|
||||
dst[4] = uint8(n >> 24)
|
||||
i = 5
|
||||
default:
|
||||
panic("snappy: source buffer is too long")
|
||||
}
|
||||
if copy(dst[i:], lit) != len(lit) {
|
||||
panic("snappy: destination buffer is too short")
|
||||
}
|
||||
return i + len(lit)
|
||||
}
|
||||
|
||||
// emitCopy writes a copy chunk and returns the number of bytes written.
|
||||
func emitCopy(dst []byte, offset, length int32) int {
|
||||
i := 0
|
||||
for length > 0 {
|
||||
x := length - 4
|
||||
if 0 <= x && x < 1<<3 && offset < 1<<11 {
|
||||
dst[i+0] = uint8(offset>>8)&0x07<<5 | uint8(x)<<2 | tagCopy1
|
||||
dst[i+1] = uint8(offset)
|
||||
i += 2
|
||||
break
|
||||
}
|
||||
|
||||
x = length
|
||||
if x > 1<<6 {
|
||||
x = 1 << 6
|
||||
}
|
||||
dst[i+0] = uint8(x-1)<<2 | tagCopy2
|
||||
dst[i+1] = uint8(offset)
|
||||
dst[i+2] = uint8(offset >> 8)
|
||||
i += 3
|
||||
length -= x
|
||||
}
|
||||
return i
|
||||
}
|
||||
|
||||
// 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.
|
||||
//
|
||||
// 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:]
|
||||
}
|
||||
d += encodeBlock(dst[d:], p)
|
||||
}
|
||||
return dst[: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)) &&
|
||||
// 0 < len(src) && len(src) <= maxBlockSize
|
||||
func encodeBlock(dst, src []byte) (d int) {
|
||||
// Return early if src is short.
|
||||
if len(src) <= 4 {
|
||||
return emitLiteral(dst, src)
|
||||
}
|
||||
|
||||
// Initialize the hash table. Its size ranges from 1<<8 to 1<<14 inclusive.
|
||||
const maxTableSize = 1 << 14
|
||||
shift, tableSize := uint(32-8), 1<<8
|
||||
for tableSize < maxTableSize && tableSize < len(src) {
|
||||
shift--
|
||||
tableSize *= 2
|
||||
}
|
||||
var table [maxTableSize]int32
|
||||
|
||||
// Iterate over the source bytes.
|
||||
var (
|
||||
s int32 // The iterator position.
|
||||
t int32 // The last position with the same hash as s.
|
||||
lit int32 // The start position of any pending literal bytes.
|
||||
|
||||
// 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, 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 uint32 = 32
|
||||
)
|
||||
for uint32(s+3) < uint32(len(src)) { // The uint32 conversions catch overflow from the +3.
|
||||
// Update the hash table.
|
||||
b0, b1, b2, b3 := src[s], src[s+1], src[s+2], src[s+3]
|
||||
h := uint32(b0) | uint32(b1)<<8 | uint32(b2)<<16 | uint32(b3)<<24
|
||||
p := &table[(h*0x1e35a7bd)>>shift]
|
||||
// We need to to store values in [-1, inf) in table. To save
|
||||
// some initialization time, (re)use the table's zero value
|
||||
// and shift the values against this zero: add 1 on writes,
|
||||
// subtract 1 on reads.
|
||||
t, *p = *p-1, s+1
|
||||
// If t is invalid or src[s:s+4] differs from src[t:t+4], accumulate a literal byte.
|
||||
if t < 0 || s-t >= maxOffset || b0 != src[t] || b1 != src[t+1] || b2 != src[t+2] || b3 != src[t+3] {
|
||||
s += int32(skip >> 5)
|
||||
skip++
|
||||
continue
|
||||
}
|
||||
skip = 32
|
||||
// Otherwise, we have a match. First, emit any pending literal bytes.
|
||||
if lit != s {
|
||||
d += emitLiteral(dst[d:], src[lit:s])
|
||||
}
|
||||
// Extend the match to be as long as possible.
|
||||
s0 := s
|
||||
s, t = s+4, t+4
|
||||
for int(s) < len(src) && src[s] == src[t] {
|
||||
s++
|
||||
t++
|
||||
}
|
||||
// Emit the copied bytes.
|
||||
d += emitCopy(dst[d:], s-t, s-s0)
|
||||
lit = s
|
||||
}
|
||||
|
||||
// Emit any final pending literal bytes and return.
|
||||
if int(lit) != len(src) {
|
||||
d += emitLiteral(dst[d:], src[lit:])
|
||||
}
|
||||
return d
|
||||
}
|
||||
|
||||
// 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 than 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
|
||||
}
|
84
vendor/github.com/golang/snappy/snappy.go
generated
vendored
Normal file
84
vendor/github.com/golang/snappy/snappy.go
generated
vendored
Normal file
|
@ -0,0 +1,84 @@
|
|||
// 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 implements the snappy block-based compression format.
|
||||
// It aims for very high speeds and reasonable compression.
|
||||
//
|
||||
// The C++ snappy implementation is at https://github.com/google/snappy
|
||||
package snappy // import "github.com/golang/snappy"
|
||||
|
||||
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 supported.
|
||||
*/
|
||||
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
|
||||
}
|
Loading…
Add table
Add a link
Reference in a new issue