diff options
Diffstat (limited to 'vendor/github.com/golang/snappy')
| -rw-r--r-- | vendor/github.com/golang/snappy/AUTHORS | 15 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/CONTRIBUTORS | 37 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/LICENSE | 27 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/README | 107 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/decode.go | 237 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/decode_amd64.go | 14 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/decode_amd64.s | 490 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/decode_other.go | 101 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/encode.go | 285 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/encode_amd64.go | 29 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/encode_amd64.s | 730 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/encode_other.go | 238 | ||||
| -rw-r--r-- | vendor/github.com/golang/snappy/snappy.go | 98 |
13 files changed, 0 insertions, 2408 deletions
diff --git a/vendor/github.com/golang/snappy/AUTHORS b/vendor/github.com/golang/snappy/AUTHORS deleted file mode 100644 index bcfa195..0000000 --- a/vendor/github.com/golang/snappy/AUTHORS +++ /dev/null @@ -1,15 +0,0 @@ -# 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> diff --git a/vendor/github.com/golang/snappy/CONTRIBUTORS b/vendor/github.com/golang/snappy/CONTRIBUTORS deleted file mode 100644 index 931ae31..0000000 --- a/vendor/github.com/golang/snappy/CONTRIBUTORS +++ /dev/null @@ -1,37 +0,0 @@ -# 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> -Nigel Tao <nigeltao@golang.org> -Rob Pike <r@golang.org> -Rodolfo Carvalho <rhcarvalho@gmail.com> -Russ Cox <rsc@golang.org> -Sebastien Binet <seb.binet@gmail.com> diff --git a/vendor/github.com/golang/snappy/LICENSE b/vendor/github.com/golang/snappy/LICENSE deleted file mode 100644 index 6050c10..0000000 --- a/vendor/github.com/golang/snappy/LICENSE +++ /dev/null @@ -1,27 +0,0 @@ -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. diff --git a/vendor/github.com/golang/snappy/README b/vendor/github.com/golang/snappy/README deleted file mode 100644 index cea1287..0000000 --- a/vendor/github.com/golang/snappy/README +++ /dev/null @@ -1,107 +0,0 @@ -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. - - - -Benchmarks. - -The golang/snappy benchmarks include compressing (Z) and decompressing (U) ten -or so files, the same set used by the C++ Snappy code (github.com/google/snappy -and note the "google", not "golang"). On an "Intel(R) Core(TM) i7-3770 CPU @ -3.40GHz", Go's GOARCH=amd64 numbers as of 2016-05-29: - -"go test -test.bench=." - -_UFlat0-8 2.19GB/s ± 0% html -_UFlat1-8 1.41GB/s ± 0% urls -_UFlat2-8 23.5GB/s ± 2% jpg -_UFlat3-8 1.91GB/s ± 0% jpg_200 -_UFlat4-8 14.0GB/s ± 1% pdf -_UFlat5-8 1.97GB/s ± 0% html4 -_UFlat6-8 814MB/s ± 0% txt1 -_UFlat7-8 785MB/s ± 0% txt2 -_UFlat8-8 857MB/s ± 0% txt3 -_UFlat9-8 719MB/s ± 1% txt4 -_UFlat10-8 2.84GB/s ± 0% pb -_UFlat11-8 1.05GB/s ± 0% gaviota - -_ZFlat0-8 1.04GB/s ± 0% html -_ZFlat1-8 534MB/s ± 0% urls -_ZFlat2-8 15.7GB/s ± 1% jpg -_ZFlat3-8 740MB/s ± 3% jpg_200 -_ZFlat4-8 9.20GB/s ± 1% pdf -_ZFlat5-8 991MB/s ± 0% html4 -_ZFlat6-8 379MB/s ± 0% txt1 -_ZFlat7-8 352MB/s ± 0% txt2 -_ZFlat8-8 396MB/s ± 1% txt3 -_ZFlat9-8 327MB/s ± 1% txt4 -_ZFlat10-8 1.33GB/s ± 1% pb -_ZFlat11-8 605MB/s ± 1% gaviota - - - -"go test -test.bench=. -tags=noasm" - -_UFlat0-8 621MB/s ± 2% html -_UFlat1-8 494MB/s ± 1% urls -_UFlat2-8 23.2GB/s ± 1% jpg -_UFlat3-8 1.12GB/s ± 1% jpg_200 -_UFlat4-8 4.35GB/s ± 1% pdf -_UFlat5-8 609MB/s ± 0% html4 -_UFlat6-8 296MB/s ± 0% txt1 -_UFlat7-8 288MB/s ± 0% txt2 -_UFlat8-8 309MB/s ± 1% txt3 -_UFlat9-8 280MB/s ± 1% txt4 -_UFlat10-8 753MB/s ± 0% pb -_UFlat11-8 400MB/s ± 0% gaviota - -_ZFlat0-8 409MB/s ± 1% html -_ZFlat1-8 250MB/s ± 1% urls -_ZFlat2-8 12.3GB/s ± 1% jpg -_ZFlat3-8 132MB/s ± 0% jpg_200 -_ZFlat4-8 2.92GB/s ± 0% pdf -_ZFlat5-8 405MB/s ± 1% html4 -_ZFlat6-8 179MB/s ± 1% txt1 -_ZFlat7-8 170MB/s ± 1% txt2 -_ZFlat8-8 189MB/s ± 1% txt3 -_ZFlat9-8 164MB/s ± 1% txt4 -_ZFlat10-8 479MB/s ± 1% pb -_ZFlat11-8 270MB/s ± 1% gaviota - - - -For comparison (Go's encoded output is byte-for-byte identical to C++'s), here -are the numbers from C++ Snappy's - -make CXXFLAGS="-O2 -DNDEBUG -g" clean snappy_unittest.log && cat snappy_unittest.log - -BM_UFlat/0 2.4GB/s html -BM_UFlat/1 1.4GB/s urls -BM_UFlat/2 21.8GB/s jpg -BM_UFlat/3 1.5GB/s jpg_200 -BM_UFlat/4 13.3GB/s pdf -BM_UFlat/5 2.1GB/s html4 -BM_UFlat/6 1.0GB/s txt1 -BM_UFlat/7 959.4MB/s txt2 -BM_UFlat/8 1.0GB/s txt3 -BM_UFlat/9 864.5MB/s txt4 -BM_UFlat/10 2.9GB/s pb -BM_UFlat/11 1.2GB/s gaviota - -BM_ZFlat/0 944.3MB/s html (22.31 %) -BM_ZFlat/1 501.6MB/s urls (47.78 %) -BM_ZFlat/2 14.3GB/s jpg (99.95 %) -BM_ZFlat/3 538.3MB/s jpg_200 (73.00 %) -BM_ZFlat/4 8.3GB/s pdf (83.30 %) -BM_ZFlat/5 903.5MB/s html4 (22.52 %) -BM_ZFlat/6 336.0MB/s txt1 (57.88 %) -BM_ZFlat/7 312.3MB/s txt2 (61.91 %) -BM_ZFlat/8 353.1MB/s txt3 (54.99 %) -BM_ZFlat/9 289.9MB/s txt4 (66.26 %) -BM_ZFlat/10 1.2GB/s pb (19.68 %) -BM_ZFlat/11 527.4MB/s gaviota (37.72 %) diff --git a/vendor/github.com/golang/snappy/decode.go b/vendor/github.com/golang/snappy/decode.go deleted file mode 100644 index 72efb03..0000000 --- a/vendor/github.com/golang/snappy/decode.go +++ /dev/null @@ -1,237 +0,0 @@ -// Copyright 2011 The Snappy-Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package snappy - -import ( - "encoding/binary" - "errors" - "io" -) - -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. -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. -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 -} - -// 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], true) { - 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, false) { - 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, false) { - 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 n > len(r.decoded) { - r.err = ErrCorrupt - return 0, r.err - } - if !r.readFull(r.decoded[:n], false) { - 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)], false) { - 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], false) { - return 0, r.err - } - } -} diff --git a/vendor/github.com/golang/snappy/decode_amd64.go b/vendor/github.com/golang/snappy/decode_amd64.go deleted file mode 100644 index fcd192b..0000000 --- a/vendor/github.com/golang/snappy/decode_amd64.go +++ /dev/null @@ -1,14 +0,0 @@ -// 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 !appengine -// +build gc -// +build !noasm - -package snappy - -// decode has the same semantics as in decode_other.go. -// -//go:noescape -func decode(dst, src []byte) int diff --git a/vendor/github.com/golang/snappy/decode_amd64.s b/vendor/github.com/golang/snappy/decode_amd64.s deleted file mode 100644 index e6179f6..0000000 --- a/vendor/github.com/golang/snappy/decode_amd64.s +++ /dev/null @@ -1,490 +0,0 @@ -// 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. - -// +build !appengine -// +build gc -// +build !noasm - -#include "textflag.h" - -// The asm code generally follows the pure Go code in decode_other.go, except -// where marked with a "!!!". - -// func decode(dst, src []byte) int -// -// 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. - -tagCopy4: - // case tagCopy4: - // s += 5 - ADDQ $5, SI - - // if uint(s) > uint(len(src)) { etc } - MOVQ SI, BX - SUBQ R11, BX - CMPQ BX, R12 - JA errCorrupt - - // length = 1 + int(src[s-5])>>2 - SHRQ $2, CX - INCQ CX - - // offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24) - MOVLQZX -4(SI), DX - JMP doCopy - -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(uint32(src[s-2]) | uint32(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 tagCopy4 - - // 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(uint32(src[s-2])&0xe0<<3 | uint32(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 diff --git a/vendor/github.com/golang/snappy/decode_other.go b/vendor/github.com/golang/snappy/decode_other.go deleted file mode 100644 index 8c9f204..0000000 --- a/vendor/github.com/golang/snappy/decode_other.go +++ /dev/null @@ -1,101 +0,0 @@ -// 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 appengine !gc noasm - -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(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. 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 -} diff --git a/vendor/github.com/golang/snappy/encode.go b/vendor/github.com/golang/snappy/encode.go deleted file mode 100644 index 8d393e9..0000000 --- a/vendor/github.com/golang/snappy/encode.go +++ /dev/null @@ -1,285 +0,0 @@ -// Copyright 2011 The Snappy-Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package snappy - -import ( - "encoding/binary" - "errors" - "io" -) - -// Encode returns the encoded form of src. The returned slice may be a sub- -// slice of dst if dst was large enough to hold the entire encoded block. -// Otherwise, a newly allocated slice will be returned. -// -// The dst and src must not overlap. It is valid to pass a nil dst. -func Encode(dst, src []byte) []byte { - if n := MaxEncodedLen(len(src)); n < 0 { - panic(ErrTooLarge) - } else if len(dst) < n { - dst = make([]byte, n) - } - - // The block starts with the varint-encoded length of the decompressed bytes. - d := binary.PutUvarint(dst, uint64(len(src))) - - for len(src) > 0 { - p := src - src = nil - if len(p) > maxBlockSize { - p, src = p[:maxBlockSize], p[maxBlockSize:] - } - if len(p) < minNonLiteralBlockSize { - d += emitLiteral(dst[d:], p) - } else { - d += encodeBlock(dst[d:], p) - } - } - return dst[:d] -} - -// inputMargin is the minimum number of extra input bytes to keep, inside -// encodeBlock's inner loop. On some architectures, this margin lets us -// implement a fast path for emitLiteral, where the copy of short (<= 16 byte) -// literals can be implemented as a single load to and store from a 16-byte -// register. That literal's actual length can be as short as 1 byte, so this -// can copy up to 15 bytes too much, but that's OK as subsequent iterations of -// the encoding loop will fix up the copy overrun, and this inputMargin ensures -// that we don't overrun the dst and src buffers. -const inputMargin = 16 - 1 - -// minNonLiteralBlockSize is the minimum size of the input to encodeBlock that -// could be encoded with a copy tag. This is the minimum with respect to the -// algorithm used by encodeBlock, not a minimum enforced by the file format. -// -// The encoded output must start with at least a 1 byte literal, as there are -// no previous bytes to copy. A minimal (1 byte) copy after that, generated -// from an emitCopy call in encodeBlock's main loop, would require at least -// another inputMargin bytes, for the reason above: we want any emitLiteral -// calls inside encodeBlock's main loop to use the fast path if possible, which -// requires being able to overrun by inputMargin bytes. Thus, -// minNonLiteralBlockSize equals 1 + 1 + inputMargin. -// -// The C++ code doesn't use this exact threshold, but it could, as discussed at -// https://groups.google.com/d/topic/snappy-compression/oGbhsdIJSJ8/discussion -// The difference between Go (2+inputMargin) and C++ (inputMargin) is purely an -// optimization. It should not affect the encoded form. This is tested by -// TestSameEncodingAsCppShortCopies. -const minNonLiteralBlockSize = 1 + 1 + inputMargin - -// MaxEncodedLen returns the maximum length of a snappy block, given its -// uncompressed length. -// -// It will return a negative value if srcLen is too large to encode. -func MaxEncodedLen(srcLen int) int { - n := uint64(srcLen) - if n > 0xffffffff { - return -1 - } - // Compressed data can be defined as: - // compressed := item* literal* - // item := literal* copy - // - // The trailing literal sequence has a space blowup of at most 62/60 - // since a literal of length 60 needs one tag byte + one extra byte - // for length information. - // - // Item blowup is trickier to measure. Suppose the "copy" op copies - // 4 bytes of data. Because of a special check in the encoding code, - // we produce a 4-byte copy only if the offset is < 65536. Therefore - // the copy op takes 3 bytes to encode, and this type of item leads - // to at most the 62/60 blowup for representing literals. - // - // Suppose the "copy" op copies 5 bytes of data. If the offset is big - // enough, it will take 5 bytes to encode the copy op. Therefore the - // worst case here is a one-byte literal followed by a five-byte copy. - // That is, 6 bytes of input turn into 7 bytes of "compressed" data. - // - // This last factor dominates the blowup, so the final estimate is: - n = 32 + n + n/6 - if n > 0xffffffff { - return -1 - } - return int(n) -} - -var errClosed = errors.New("snappy: Writer is closed") - -// NewWriter returns a new Writer that compresses to w. -// -// The Writer returned does not buffer writes. There is no need to Flush or -// Close such a Writer. -// -// Deprecated: the Writer returned is not suitable for many small writes, only -// for few large writes. Use NewBufferedWriter instead, which is efficient -// regardless of the frequency and shape of the writes, and remember to Close -// that Writer when done. -func NewWriter(w io.Writer) *Writer { - return &Writer{ - w: w, - obuf: make([]byte, obufLen), - } -} - -// NewBufferedWriter returns a new Writer that compresses to w, using the -// framing format described at -// https://github.com/google/snappy/blob/master/framing_format.txt -// -// The Writer returned buffers writes. Users must call Close to guarantee all -// data has been forwarded to the underlying io.Writer. They may also call -// Flush zero or more times before calling Close. -func NewBufferedWriter(w io.Writer) *Writer { - return &Writer{ - w: w, - ibuf: make([]byte, 0, maxBlockSize), - obuf: make([]byte, obufLen), - } -} - -// Writer is an io.Writer that can write Snappy-compressed bytes. -type Writer struct { - w io.Writer - err error - - // ibuf is a buffer for the incoming (uncompressed) bytes. - // - // Its use is optional. For backwards compatibility, Writers created by the - // NewWriter function have ibuf == nil, do not buffer incoming bytes, and - // therefore do not need to be Flush'ed or Close'd. - ibuf []byte - - // obuf is a buffer for the outgoing (compressed) bytes. - obuf []byte - - // wroteStreamHeader is whether we have written the stream header. - wroteStreamHeader bool -} - -// Reset discards the writer's state and switches the Snappy writer to write to -// w. This permits reusing a Writer rather than allocating a new one. -func (w *Writer) Reset(writer io.Writer) { - w.w = writer - w.err = nil - if w.ibuf != nil { - w.ibuf = w.ibuf[:0] - } - w.wroteStreamHeader = false -} - -// Write satisfies the io.Writer interface. -func (w *Writer) Write(p []byte) (nRet int, errRet error) { - if w.ibuf == nil { - // Do not buffer incoming bytes. This does not perform or compress well - // if the caller of Writer.Write writes many small slices. This - // behavior is therefore deprecated, but still supported for backwards - // compatibility with code that doesn't explicitly Flush or Close. - return w.write(p) - } - - // The remainder of this method is based on bufio.Writer.Write from the - // standard library. - - for len(p) > (cap(w.ibuf)-len(w.ibuf)) && w.err == nil { - var n int - if len(w.ibuf) == 0 { - // Large write, empty buffer. - // Write directly from p to avoid copy. - n, _ = w.write(p) - } else { - n = copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p) - w.ibuf = w.ibuf[:len(w.ibuf)+n] - w.Flush() - } - nRet += n - p = p[n:] - } - if w.err != nil { - return nRet, w.err - } - n := copy(w.ibuf[len(w.ibuf):cap(w.ibuf)], p) - w.ibuf = w.ibuf[:len(w.ibuf)+n] - nRet += n - return nRet, nil -} - -func (w *Writer) write(p []byte) (nRet int, errRet error) { - if w.err != nil { - return 0, w.err - } - for len(p) > 0 { - obufStart := len(magicChunk) - if !w.wroteStreamHeader { - w.wroteStreamHeader = true - copy(w.obuf, magicChunk) - obufStart = 0 - } - - var uncompressed []byte - if len(p) > maxBlockSize { - uncompressed, p = p[:maxBlockSize], p[maxBlockSize:] - } else { - uncompressed, p = p, nil - } - checksum := crc(uncompressed) - - // Compress the buffer, discarding the result if the improvement - // isn't at least 12.5%. - compressed := Encode(w.obuf[obufHeaderLen:], uncompressed) - chunkType := uint8(chunkTypeCompressedData) - chunkLen := 4 + len(compressed) - obufEnd := obufHeaderLen + len(compressed) - if len(compressed) >= len(uncompressed)-len(uncompressed)/8 { - chunkType = chunkTypeUncompressedData - chunkLen = 4 + len(uncompressed) - obufEnd = obufHeaderLen - } - - // Fill in the per-chunk header that comes before the body. - w.obuf[len(magicChunk)+0] = chunkType - w.obuf[len(magicChunk)+1] = uint8(chunkLen >> 0) - w.obuf[len(magicChunk)+2] = uint8(chunkLen >> 8) - w.obuf[len(magicChunk)+3] = uint8(chunkLen >> 16) - w.obuf[len(magicChunk)+4] = uint8(checksum >> 0) - w.obuf[len(magicChunk)+5] = uint8(checksum >> 8) - w.obuf[len(magicChunk)+6] = uint8(checksum >> 16) - w.obuf[len(magicChunk)+7] = uint8(checksum >> 24) - - if _, err := w.w.Write(w.obuf[obufStart:obufEnd]); err != nil { - w.err = err - return nRet, err - } - if chunkType == chunkTypeUncompressedData { - if _, err := w.w.Write(uncompressed); err != nil { - w.err = err - return nRet, err - } - } - nRet += len(uncompressed) - } - return nRet, nil -} - -// Flush flushes the Writer to its underlying io.Writer. -func (w *Writer) Flush() error { - if w.err != nil { - return w.err - } - if len(w.ibuf) == 0 { - return nil - } - w.write(w.ibuf) - w.ibuf = w.ibuf[:0] - return w.err -} - -// Close calls Flush and then closes the Writer. -func (w *Writer) Close() error { - w.Flush() - ret := w.err - if w.err == nil { - w.err = errClosed - } - return ret -} diff --git a/vendor/github.com/golang/snappy/encode_amd64.go b/vendor/github.com/golang/snappy/encode_amd64.go deleted file mode 100644 index 150d91b..0000000 --- a/vendor/github.com/golang/snappy/encode_amd64.go +++ /dev/null @@ -1,29 +0,0 @@ -// 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 !appengine -// +build gc -// +build !noasm - -package snappy - -// emitLiteral has the same semantics as in encode_other.go. -// -//go:noescape -func emitLiteral(dst, lit []byte) int - -// emitCopy has the same semantics as in encode_other.go. -// -//go:noescape -func emitCopy(dst []byte, offset, length int) int - -// extendMatch has the same semantics as in encode_other.go. -// -//go:noescape -func extendMatch(src []byte, i, j int) int - -// encodeBlock has the same semantics as in encode_other.go. -// -//go:noescape -func encodeBlock(dst, src []byte) (d int) diff --git a/vendor/github.com/golang/snappy/encode_amd64.s b/vendor/github.com/golang/snappy/encode_amd64.s deleted file mode 100644 index adfd979..0000000 --- a/vendor/github.com/golang/snappy/encode_amd64.s +++ /dev/null @@ -1,730 +0,0 @@ -// 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. - -// +build !appengine -// +build gc -// +build !noasm - -#include "textflag.h" - -// The XXX lines assemble on Go 1.4, 1.5 and 1.7, but not 1.6, due to a -// Go toolchain regression. See https://github.com/golang/go/issues/15426 and -// https://github.com/golang/snappy/issues/29 -// -// As a workaround, the package was built with a known good assembler, and -// those instructions were disassembled by "objdump -d" to yield the -// 4e 0f b7 7c 5c 78 movzwq 0x78(%rsp,%r11,2),%r15 -// style comments, in AT&T asm syntax. Note that rsp here is a physical -// register, not Go/asm's SP pseudo-register (see https://golang.org/doc/asm). -// The instructions were then encoded as "BYTE $0x.." sequences, which assemble -// fine on Go 1.6. - -// The asm code generally follows the pure Go code in encode_other.go, except -// where marked with a "!!!". - -// ---------------------------------------------------------------------------- - -// func emitLiteral(dst, lit []byte) int -// -// All local variables fit into registers. The register allocation: -// - AX len(lit) -// - BX n -// - DX return value -// - DI &dst[i] -// - R10 &lit[0] -// -// The 24 bytes of stack space is to call runtime·memmove. -// -// The unusual register allocation of local variables, such as R10 for the -// source pointer, matches the allocation used at the call site in encodeBlock, -// which makes it easier to manually inline this function. -TEXT ·emitLiteral(SB), NOSPLIT, $24-56 - MOVQ dst_base+0(FP), DI - MOVQ lit_base+24(FP), R10 - MOVQ lit_len+32(FP), AX - MOVQ AX, DX - MOVL AX, BX - SUBL $1, BX - - CMPL BX, $60 - JLT oneByte - CMPL BX, $256 - JLT twoBytes - -threeBytes: - MOVB $0xf4, 0(DI) - MOVW BX, 1(DI) - ADDQ $3, DI - ADDQ $3, DX - JMP memmove - -twoBytes: - MOVB $0xf0, 0(DI) - MOVB BX, 1(DI) - ADDQ $2, DI - ADDQ $2, DX - JMP memmove - -oneByte: - SHLB $2, BX - MOVB BX, 0(DI) - ADDQ $1, DI - ADDQ $1, DX - -memmove: - MOVQ DX, ret+48(FP) - - // copy(dst[i:], lit) - // - // This means calling runtime·memmove(&dst[i], &lit[0], len(lit)), so we push - // DI, R10 and AX as arguments. - MOVQ DI, 0(SP) - MOVQ R10, 8(SP) - MOVQ AX, 16(SP) - CALL runtime·memmove(SB) - RET - -// ---------------------------------------------------------------------------- - -// func emitCopy(dst []byte, offset, length int) int -// -// All local variables fit into registers. The register allocation: -// - AX length -// - SI &dst[0] -// - DI &dst[i] -// - R11 offset -// -// The unusual register allocation of local variables, such as R11 for the -// offset, matches the allocation used at the call site in encodeBlock, which -// makes it easier to manually inline this function. -TEXT ·emitCopy(SB), NOSPLIT, $0-48 - MOVQ dst_base+0(FP), DI - MOVQ DI, SI - MOVQ offset+24(FP), R11 - MOVQ length+32(FP), AX - -loop0: - // for length >= 68 { etc } - CMPL AX, $68 - JLT step1 - - // Emit a length 64 copy, encoded as 3 bytes. - MOVB $0xfe, 0(DI) - MOVW R11, 1(DI) - ADDQ $3, DI - SUBL $64, AX - JMP loop0 - -step1: - // if length > 64 { etc } - CMPL AX, $64 - JLE step2 - - // Emit a length 60 copy, encoded as 3 bytes. - MOVB $0xee, 0(DI) - MOVW R11, 1(DI) - ADDQ $3, DI - SUBL $60, AX - -step2: - // if length >= 12 || offset >= 2048 { goto step3 } - CMPL AX, $12 - JGE step3 - CMPL R11, $2048 - JGE step3 - - // Emit the remaining copy, encoded as 2 bytes. - MOVB R11, 1(DI) - SHRL $8, R11 - SHLB $5, R11 - SUBB $4, AX - SHLB $2, AX - ORB AX, R11 - ORB $1, R11 - MOVB R11, 0(DI) - ADDQ $2, DI - - // Return the number of bytes written. - SUBQ SI, DI - MOVQ DI, ret+40(FP) - RET - -step3: - // Emit the remaining copy, encoded as 3 bytes. - SUBL $1, AX - SHLB $2, AX - ORB $2, AX - MOVB AX, 0(DI) - MOVW R11, 1(DI) - ADDQ $3, DI - - // Return the number of bytes written. - SUBQ SI, DI - MOVQ DI, ret+40(FP) - RET - -// ---------------------------------------------------------------------------- - -// func extendMatch(src []byte, i, j int) int -// -// All local variables fit into registers. The register allocation: -// - DX &src[0] -// - SI &src[j] -// - R13 &src[len(src) - 8] -// - R14 &src[len(src)] -// - R15 &src[i] -// -// The unusual register allocation of local variables, such as R15 for a source -// pointer, matches the allocation used at the call site in encodeBlock, which -// makes it easier to manually inline this function. -TEXT ·extendMatch(SB), NOSPLIT, $0-48 - MOVQ src_base+0(FP), DX - MOVQ src_len+8(FP), R14 - MOVQ i+24(FP), R15 - MOVQ j+32(FP), SI - ADDQ DX, R14 - ADDQ DX, R15 - ADDQ DX, SI - MOVQ R14, R13 - SUBQ $8, R13 - -cmp8: - // As long as we are 8 or more bytes before the end of src, we can load and - // compare 8 bytes at a time. If those 8 bytes are equal, repeat. - CMPQ SI, R13 - JA cmp1 - MOVQ (R15), AX - MOVQ (SI), BX - CMPQ AX, BX - JNE bsf - ADDQ $8, R15 - ADDQ $8, SI - JMP cmp8 - -bsf: - // If those 8 bytes were not equal, XOR the two 8 byte values, and return - // the index of the first byte that differs. The BSF instruction finds the - // least significant 1 bit, the amd64 architecture is little-endian, and - // the shift by 3 converts a bit index to a byte index. - XORQ AX, BX - BSFQ BX, BX - SHRQ $3, BX - ADDQ BX, SI - - // Convert from &src[ret] to ret. - SUBQ DX, SI - MOVQ SI, ret+40(FP) - RET - -cmp1: - // In src's tail, compare 1 byte at a time. - CMPQ SI, R14 - JAE extendMatchEnd - MOVB (R15), AX - MOVB (SI), BX - CMPB AX, BX - JNE extendMatchEnd - ADDQ $1, R15 - ADDQ $1, SI - JMP cmp1 - -extendMatchEnd: - // Convert from &src[ret] to ret. - SUBQ DX, SI - MOVQ SI, ret+40(FP) - RET - -// ---------------------------------------------------------------------------- - -// func encodeBlock(dst, src []byte) (d int) -// -// All local variables fit into registers, other than "var table". The register -// allocation: -// - AX . . -// - BX . . -// - CX 56 shift (note that amd64 shifts by non-immediates must use CX). -// - DX 64 &src[0], tableSize -// - SI 72 &src[s] -// - DI 80 &dst[d] -// - R9 88 sLimit -// - R10 . &src[nextEmit] -// - R11 96 prevHash, currHash, nextHash, offset -// - R12 104 &src[base], skip -// - R13 . &src[nextS], &src[len(src) - 8] -// - R14 . len(src), bytesBetweenHashLookups, &src[len(src)], x -// - R15 112 candidate -// -// The second column (56, 64, etc) is the stack offset to spill the registers -// when calling other functions. We could pack this slightly tighter, but it's -// simpler to have a dedicated spill map independent of the function called. -// -// "var table [maxTableSize]uint16" takes up 32768 bytes of stack space. An -// extra 56 bytes, to call other functions, and an extra 64 bytes, to spill -// local variables (registers) during calls gives 32768 + 56 + 64 = 32888. -TEXT ·encodeBlock(SB), 0, $32888-56 - MOVQ dst_base+0(FP), DI - MOVQ src_base+24(FP), SI - MOVQ src_len+32(FP), R14 - - // shift, tableSize := uint32(32-8), 1<<8 - MOVQ $24, CX - MOVQ $256, DX - -calcShift: - // for ; tableSize < maxTableSize && tableSize < len(src); tableSize *= 2 { - // shift-- - // } - CMPQ DX, $16384 - JGE varTable - CMPQ DX, R14 - JGE varTable - SUBQ $1, CX - SHLQ $1, DX - JMP calcShift - -varTable: - // var table [maxTableSize]uint16 - // - // In the asm code, unlike the Go code, we can zero-initialize only the - // first tableSize elements. Each uint16 element is 2 bytes and each MOVOU - // writes 16 bytes, so we can do only tableSize/8 writes instead of the - // 2048 writes that would zero-initialize all of table's 32768 bytes. - SHRQ $3, DX - LEAQ table-32768(SP), BX - PXOR X0, X0 - -memclr: - MOVOU X0, 0(BX) - ADDQ $16, BX - SUBQ $1, DX - JNZ memclr - - // !!! DX = &src[0] - MOVQ SI, DX - - // sLimit := len(src) - inputMargin - MOVQ R14, R9 - SUBQ $15, R9 - - // !!! Pre-emptively spill CX, DX and R9 to the stack. Their values don't - // change for the rest of the function. - MOVQ CX, 56(SP) - MOVQ DX, 64(SP) - MOVQ R9, 88(SP) - - // nextEmit := 0 - MOVQ DX, R10 - - // s := 1 - ADDQ $1, SI - - // nextHash := hash(load32(src, s), shift) - MOVL 0(SI), R11 - IMULL $0x1e35a7bd, R11 - SHRL CX, R11 - -outer: - // for { etc } - - // skip := 32 - MOVQ $32, R12 - - // nextS := s - MOVQ SI, R13 - - // candidate := 0 - MOVQ $0, R15 - -inner0: - // for { etc } - - // s := nextS - MOVQ R13, SI - - // bytesBetweenHashLookups := skip >> 5 - MOVQ R12, R14 - SHRQ $5, R14 - - // nextS = s + bytesBetweenHashLookups - ADDQ R14, R13 - - // skip += bytesBetweenHashLookups - ADDQ R14, R12 - - // if nextS > sLimit { goto emitRemainder } - MOVQ R13, AX - SUBQ DX, AX - CMPQ AX, R9 - JA emitRemainder - - // candidate = int(table[nextHash]) - // XXX: MOVWQZX table-32768(SP)(R11*2), R15 - // XXX: 4e 0f b7 7c 5c 78 movzwq 0x78(%rsp,%r11,2),%r15 - BYTE $0x4e - BYTE $0x0f - BYTE $0xb7 - BYTE $0x7c - BYTE $0x5c - BYTE $0x78 - - // table[nextHash] = uint16(s) - MOVQ SI, AX - SUBQ DX, AX - - // XXX: MOVW AX, table-32768(SP)(R11*2) - // XXX: 66 42 89 44 5c 78 mov %ax,0x78(%rsp,%r11,2) - BYTE $0x66 - BYTE $0x42 - BYTE $0x89 - BYTE $0x44 - BYTE $0x5c - BYTE $0x78 - - // nextHash = hash(load32(src, nextS), shift) - MOVL 0(R13), R11 - IMULL $0x1e35a7bd, R11 - SHRL CX, R11 - - // if load32(src, s) != load32(src, candidate) { continue } break - MOVL 0(SI), AX - MOVL (DX)(R15*1), BX - CMPL AX, BX - JNE inner0 - -fourByteMatch: - // As per the encode_other.go code: - // - // A 4-byte match has been found. We'll later see etc. - - // !!! Jump to a fast path for short (<= 16 byte) literals. See the comment - // on inputMargin in encode.go. - MOVQ SI, AX - SUBQ R10, AX - CMPQ AX, $16 - JLE emitLiteralFastPath - - // ---------------------------------------- - // Begin inline of the emitLiteral call. - // - // d += emitLiteral(dst[d:], src[nextEmit:s]) - - MOVL AX, BX - SUBL $1, BX - - CMPL BX, $60 - JLT inlineEmitLiteralOneByte - CMPL BX, $256 - JLT inlineEmitLiteralTwoBytes - -inlineEmitLiteralThreeBytes: - MOVB $0xf4, 0(DI) - MOVW BX, 1(DI) - ADDQ $3, DI - JMP inlineEmitLiteralMemmove - -inlineEmitLiteralTwoBytes: - MOVB $0xf0, 0(DI) - MOVB BX, 1(DI) - ADDQ $2, DI - JMP inlineEmitLiteralMemmove - -inlineEmitLiteralOneByte: - SHLB $2, BX - MOVB BX, 0(DI) - ADDQ $1, DI - -inlineEmitLiteralMemmove: - // Spill local variables (registers) onto the stack; call; unspill. - // - // copy(dst[i:], lit) - // - // This means calling runtime·memmove(&dst[i], &lit[0], len(lit)), so we push - // DI, R10 and AX as arguments. - MOVQ DI, 0(SP) - MOVQ R10, 8(SP) - MOVQ AX, 16(SP) - ADDQ AX, DI // Finish the "d +=" part of "d += emitLiteral(etc)". - MOVQ SI, 72(SP) - MOVQ DI, 80(SP) - MOVQ R15, 112(SP) - CALL runtime·memmove(SB) - MOVQ 56(SP), CX - MOVQ 64(SP), DX - MOVQ 72(SP), SI - MOVQ 80(SP), DI - MOVQ 88(SP), R9 - MOVQ 112(SP), R15 - JMP inner1 - -inlineEmitLiteralEnd: - // End inline of the emitLiteral call. - // ---------------------------------------- - -emitLiteralFastPath: - // !!! Emit the 1-byte encoding "uint8(len(lit)-1)<<2". - MOVB AX, BX - SUBB $1, BX - SHLB $2, BX - MOVB BX, (DI) - ADDQ $1, DI - - // !!! Implement the copy from lit to dst as a 16-byte load and store. - // (Encode's documentation says that dst and src must not overlap.) - // - // This always copies 16 bytes, instead of only len(lit) bytes, but that's - // OK. Subsequent iterations will fix up the overrun. - // - // 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(R10), X0 - MOVOU X0, 0(DI) - ADDQ AX, DI - -inner1: - // for { etc } - - // base := s - MOVQ SI, R12 - - // !!! offset := base - candidate - MOVQ R12, R11 - SUBQ R15, R11 - SUBQ DX, R11 - - // ---------------------------------------- - // Begin inline of the extendMatch call. - // - // s = extendMatch(src, candidate+4, s+4) - - // !!! R14 = &src[len(src)] - MOVQ src_len+32(FP), R14 - ADDQ DX, R14 - - // !!! R13 = &src[len(src) - 8] - MOVQ R14, R13 - SUBQ $8, R13 - - // !!! R15 = &src[candidate + 4] - ADDQ $4, R15 - ADDQ DX, R15 - - // !!! s += 4 - ADDQ $4, SI - -inlineExtendMatchCmp8: - // As long as we are 8 or more bytes before the end of src, we can load and - // compare 8 bytes at a time. If those 8 bytes are equal, repeat. - CMPQ SI, R13 - JA inlineExtendMatchCmp1 - MOVQ (R15), AX - MOVQ (SI), BX - CMPQ AX, BX - JNE inlineExtendMatchBSF - ADDQ $8, R15 - ADDQ $8, SI - JMP inlineExtendMatchCmp8 - -inlineExtendMatchBSF: - // If those 8 bytes were not equal, XOR the two 8 byte values, and return - // the index of the first byte that differs. The BSF instruction finds the - // least significant 1 bit, the amd64 architecture is little-endian, and - // the shift by 3 converts a bit index to a byte index. - XORQ AX, BX - BSFQ BX, BX - SHRQ $3, BX - ADDQ BX, SI - JMP inlineExtendMatchEnd - -inlineExtendMatchCmp1: - // In src's tail, compare 1 byte at a time. - CMPQ SI, R14 - JAE inlineExtendMatchEnd - MOVB (R15), AX - MOVB (SI), BX - CMPB AX, BX - JNE inlineExtendMatchEnd - ADDQ $1, R15 - ADDQ $1, SI - JMP inlineExtendMatchCmp1 - -inlineExtendMatchEnd: - // End inline of the extendMatch call. - // ---------------------------------------- - - // ---------------------------------------- - // Begin inline of the emitCopy call. - // - // d += emitCopy(dst[d:], base-candidate, s-base) - - // !!! length := s - base - MOVQ SI, AX - SUBQ R12, AX - -inlineEmitCopyLoop0: - // for length >= 68 { etc } - CMPL AX, $68 - JLT inlineEmitCopyStep1 - - // Emit a length 64 copy, encoded as 3 bytes. - MOVB $0xfe, 0(DI) - MOVW R11, 1(DI) - ADDQ $3, DI - SUBL $64, AX - JMP inlineEmitCopyLoop0 - -inlineEmitCopyStep1: - // if length > 64 { etc } - CMPL AX, $64 - JLE inlineEmitCopyStep2 - - // Emit a length 60 copy, encoded as 3 bytes. - MOVB $0xee, 0(DI) - MOVW R11, 1(DI) - ADDQ $3, DI - SUBL $60, AX - -inlineEmitCopyStep2: - // if length >= 12 || offset >= 2048 { goto inlineEmitCopyStep3 } - CMPL AX, $12 - JGE inlineEmitCopyStep3 - CMPL R11, $2048 - JGE inlineEmitCopyStep3 - - // Emit the remaining copy, encoded as 2 bytes. - MOVB R11, 1(DI) - SHRL $8, R11 - SHLB $5, R11 - SUBB $4, AX - SHLB $2, AX - ORB AX, R11 - ORB $1, R11 - MOVB R11, 0(DI) - ADDQ $2, DI - JMP inlineEmitCopyEnd - -inlineEmitCopyStep3: - // Emit the remaining copy, encoded as 3 bytes. - SUBL $1, AX - SHLB $2, AX - ORB $2, AX - MOVB AX, 0(DI) - MOVW R11, 1(DI) - ADDQ $3, DI - -inlineEmitCopyEnd: - // End inline of the emitCopy call. - // ---------------------------------------- - - // nextEmit = s - MOVQ SI, R10 - - // if s >= sLimit { goto emitRemainder } - MOVQ SI, AX - SUBQ DX, AX - CMPQ AX, R9 - JAE emitRemainder - - // As per the encode_other.go code: - // - // We could immediately etc. - - // x := load64(src, s-1) - MOVQ -1(SI), R14 - - // prevHash := hash(uint32(x>>0), shift) - MOVL R14, R11 - IMULL $0x1e35a7bd, R11 - SHRL CX, R11 - - // table[prevHash] = uint16(s-1) - MOVQ SI, AX - SUBQ DX, AX - SUBQ $1, AX - - // XXX: MOVW AX, table-32768(SP)(R11*2) - // XXX: 66 42 89 44 5c 78 mov %ax,0x78(%rsp,%r11,2) - BYTE $0x66 - BYTE $0x42 - BYTE $0x89 - BYTE $0x44 - BYTE $0x5c - BYTE $0x78 - - // currHash := hash(uint32(x>>8), shift) - SHRQ $8, R14 - MOVL R14, R11 - IMULL $0x1e35a7bd, R11 - SHRL CX, R11 - - // candidate = int(table[currHash]) - // XXX: MOVWQZX table-32768(SP)(R11*2), R15 - // XXX: 4e 0f b7 7c 5c 78 movzwq 0x78(%rsp,%r11,2),%r15 - BYTE $0x4e - BYTE $0x0f - BYTE $0xb7 - BYTE $0x7c - BYTE $0x5c - BYTE $0x78 - - // table[currHash] = uint16(s) - ADDQ $1, AX - - // XXX: MOVW AX, table-32768(SP)(R11*2) - // XXX: 66 42 89 44 5c 78 mov %ax,0x78(%rsp,%r11,2) - BYTE $0x66 - BYTE $0x42 - BYTE $0x89 - BYTE $0x44 - BYTE $0x5c - BYTE $0x78 - - // if uint32(x>>8) == load32(src, candidate) { continue } - MOVL (DX)(R15*1), BX - CMPL R14, BX - JEQ inner1 - - // nextHash = hash(uint32(x>>16), shift) - SHRQ $8, R14 - MOVL R14, R11 - IMULL $0x1e35a7bd, R11 - SHRL CX, R11 - - // s++ - ADDQ $1, SI - - // break out of the inner1 for loop, i.e. continue the outer loop. - JMP outer - -emitRemainder: - // if nextEmit < len(src) { etc } - MOVQ src_len+32(FP), AX - ADDQ DX, AX - CMPQ R10, AX - JEQ encodeBlockEnd - - // d += emitLiteral(dst[d:], src[nextEmit:]) - // - // Push args. - MOVQ DI, 0(SP) - MOVQ $0, 8(SP) // Unnecessary, as the callee ignores it, but conservative. - MOVQ $0, 16(SP) // Unnecessary, as the callee ignores it, but conservative. - MOVQ R10, 24(SP) - SUBQ R10, AX - MOVQ AX, 32(SP) - MOVQ AX, 40(SP) // Unnecessary, as the callee ignores it, but conservative. - - // Spill local variables (registers) onto the stack; call; unspill. - MOVQ DI, 80(SP) - CALL ·emitLiteral(SB) - MOVQ 80(SP), DI - - // Finish the "d +=" part of "d += emitLiteral(etc)". - ADDQ 48(SP), DI - -encodeBlockEnd: - MOVQ dst_base+0(FP), AX - SUBQ AX, DI - MOVQ DI, d+48(FP) - RET diff --git a/vendor/github.com/golang/snappy/encode_other.go b/vendor/github.com/golang/snappy/encode_other.go deleted file mode 100644 index dbcae90..0000000 --- a/vendor/github.com/golang/snappy/encode_other.go +++ /dev/null @@ -1,238 +0,0 @@ -// 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 appengine !gc noasm - -package snappy - -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 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 -} - -// extendMatch returns the largest k such that k <= len(src) and that -// src[i:i+k-j] and src[j:k] have the same contents. -// -// It assumes that: -// 0 <= i && i < j && j <= len(src) -func extendMatch(src []byte, i, j int) int { - for ; j < len(src) && src[i] == src[j]; i, j = i+1, j+1 { - } - return j -} - -func hash(u, shift uint32) uint32 { - return (u * 0x1e35a7bd) >> shift -} - -// 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 -} diff --git a/vendor/github.com/golang/snappy/snappy.go b/vendor/github.com/golang/snappy/snappy.go deleted file mode 100644 index ece692e..0000000 --- a/vendor/github.com/golang/snappy/snappy.go +++ /dev/null @@ -1,98 +0,0 @@ -// Copyright 2011 The Snappy-Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// Package snappy 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 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 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 -} |