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Add the teller module that waits for the gate's asks and writes nothing in release 3c (issue 1240)

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jschoubben
2026-10-19 15:07:12 +02:00
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modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/LICENSE
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Copyright (c) 2012 The Go Authors. All rights reserved.
Copyright (c) 2019 Klaus Post. All rights reserved.
Redistribution and use in source and binary forms, with or without
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met:
* Redistributions of source code must retain the above copyright
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------------------
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------------------
Files: s2/cmd/internal/readahead/*
The MIT License (MIT)
Copyright (c) 2015 Klaus Post
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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SOFTWARE.
---------------------
Files: snappy/*
Files: internal/snapref/*
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-----------------
Files: s2/cmd/internal/filepathx/*
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modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/deflate.go
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// Copyright 2009 The Go Authors. All rights reserved.
// Copyright (c) 2015 Klaus Post
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"errors"
"fmt"
"io"
"math"
"github.com/klauspost/compress/internal/le"
)
const (
NoCompression = 0
BestSpeed = 1
BestCompression = 9
DefaultCompression = -1
// HuffmanOnly disables Lempel-Ziv match searching and only performs Huffman
// entropy encoding. This mode is useful in compressing data that has
// already been compressed with an LZ style algorithm (e.g. Snappy or LZ4)
// that lacks an entropy encoder. Compression gains are achieved when
// certain bytes in the input stream occur more frequently than others.
//
// Note that HuffmanOnly produces a compressed output that is
// RFC 1951 compliant. That is, any valid DEFLATE decompressor will
// continue to be able to decompress this output.
HuffmanOnly = -2
ConstantCompression = HuffmanOnly // compatibility alias.
logWindowSize = 15
windowSize = 1 << logWindowSize
windowMask = windowSize - 1
logMaxOffsetSize = 15 // Standard DEFLATE
minMatchLength = 4 // The smallest match that the compressor looks for
maxMatchLength = 258 // The longest match for the compressor
minOffsetSize = 1 // The shortest offset that makes any sense
// The maximum number of tokens we will encode at the time.
// Smaller sizes usually creates less optimal blocks.
// Bigger can make context switching slow.
// We use this for levels 7-9, so we make it big.
maxFlateBlockTokens = 1 << 15
maxStoreBlockSize = 65535
hashBits = 17 // After 17 performance degrades
hashSize = 1 << hashBits
hashMask = (1 << hashBits) - 1
hashShift = (hashBits + minMatchLength - 1) / minMatchLength
maxHashOffset = 1 << 28
skipNever = math.MaxInt32
debugDeflate = false
)
type compressionLevel struct {
good, lazy, nice, chain, fastSkipHashing, level int
}
// Compression levels have been rebalanced from zlib deflate defaults
// to give a bigger spread in speed and compression.
// See https://blog.klauspost.com/rebalancing-deflate-compression-levels/
var levels = []compressionLevel{
{}, // 0
// Level 1-6 uses specialized algorithm - values not used
{0, 0, 0, 0, 0, 1},
{0, 0, 0, 0, 0, 2},
{0, 0, 0, 0, 0, 3},
{0, 0, 0, 0, 0, 4},
{0, 0, 0, 0, 0, 5},
{0, 0, 0, 0, 0, 6},
// Levels 7-9 use increasingly more lazy matching
// and increasingly stringent conditions for "good enough".
{8, 12, 16, 24, skipNever, 7},
{16, 30, 40, 64, skipNever, 8},
{32, 258, 258, 1024, skipNever, 9},
}
// advancedState contains state for the advanced levels, with bigger hash tables, etc.
type advancedState struct {
// deflate state
length int
offset int
maxInsertIndex int
chainHead int
hashOffset int
ii uint16 // position of last match, intended to overflow to reset.
// input window: unprocessed data is window[index:windowEnd]
index int
hashMatch [maxMatchLength + minMatchLength]uint32
// Input hash chains
// hashHead[hashValue] contains the largest inputIndex with the specified hash value
// If hashHead[hashValue] is within the current window, then
// hashPrev[hashHead[hashValue] & windowMask] contains the previous index
// with the same hash value.
hashHead [hashSize]uint32
hashPrev [windowSize]uint32
}
type compressor struct {
compressionLevel
h *huffmanEncoder
w *huffmanBitWriter
// compression algorithm
fill func(*compressor, []byte) int // copy data to window
step func(*compressor) // process window
window []byte
windowEnd int
blockStart int // window index where current tokens start
err error
// queued output tokens
tokens tokens
fast fastEnc
state *advancedState
sync bool // requesting flush
byteAvailable bool // if true, still need to process window[index-1].
}
func (d *compressor) fillDeflate(b []byte) int {
s := d.state
if s.index >= 2*windowSize-(minMatchLength+maxMatchLength) {
// shift the window by windowSize
//copy(d.window[:], d.window[windowSize:2*windowSize])
*(*[windowSize]byte)(d.window) = *(*[windowSize]byte)(d.window[windowSize:])
s.index -= windowSize
d.windowEnd -= windowSize
if d.blockStart >= windowSize {
d.blockStart -= windowSize
} else {
d.blockStart = math.MaxInt32
}
s.hashOffset += windowSize
if s.hashOffset > maxHashOffset {
delta := s.hashOffset - 1
s.hashOffset -= delta
s.chainHead -= delta
// Iterate over slices instead of arrays to avoid copying
// the entire table onto the stack (Issue #18625).
for i, v := range s.hashPrev[:] {
if int(v) > delta {
s.hashPrev[i] = uint32(int(v) - delta)
} else {
s.hashPrev[i] = 0
}
}
for i, v := range s.hashHead[:] {
if int(v) > delta {
s.hashHead[i] = uint32(int(v) - delta)
} else {
s.hashHead[i] = 0
}
}
}
}
n := copy(d.window[d.windowEnd:], b)
d.windowEnd += n
return n
}
func (d *compressor) writeBlock(tok *tokens, index int, eof bool) error {
if index > 0 || eof {
var window []byte
if d.blockStart <= index {
window = d.window[d.blockStart:index]
}
d.blockStart = index
//d.w.writeBlock(tok, eof, window)
d.w.writeBlockDynamic(tok, eof, window, d.sync)
return d.w.err
}
return nil
}
// writeBlockSkip writes the current block and uses the number of tokens
// to determine if the block should be stored on no matches, or
// only huffman encoded.
func (d *compressor) writeBlockSkip(tok *tokens, index int, eof bool) error {
if index > 0 || eof {
if d.blockStart <= index {
window := d.window[d.blockStart:index]
// If we removed less than a 64th of all literals
// we huffman compress the block.
if int(tok.n) > len(window)-int(tok.n>>6) {
d.w.writeBlockHuff(eof, window, d.sync)
} else {
// Write a dynamic huffman block.
d.w.writeBlockDynamic(tok, eof, window, d.sync)
}
} else {
d.w.writeBlock(tok, eof, nil)
}
d.blockStart = index
return d.w.err
}
return nil
}
// fillWindow will fill the current window with the supplied
// dictionary and calculate all hashes.
// This is much faster than doing a full encode.
// Should only be used after a start/reset.
func (d *compressor) fillWindow(b []byte) {
// Do not fill window if we are in store-only or huffman mode.
if d.level <= 0 && d.level > -MinCustomWindowSize {
return
}
if d.fast != nil {
// encode the last data, but discard the result
if len(b) > maxMatchOffset {
b = b[len(b)-maxMatchOffset:]
}
d.fast.Encode(&d.tokens, b)
d.tokens.Reset()
return
}
s := d.state
// If we are given too much, cut it.
if len(b) > windowSize {
b = b[len(b)-windowSize:]
}
// Add all to window.
n := copy(d.window[d.windowEnd:], b)
// Calculate 256 hashes at the time (more L1 cache hits)
loops := (n + 256 - minMatchLength) / 256
for j := range loops {
startindex := j * 256
end := min(startindex+256+minMatchLength-1, n)
tocheck := d.window[startindex:end]
dstSize := len(tocheck) - minMatchLength + 1
if dstSize <= 0 {
continue
}
dst := s.hashMatch[:dstSize]
bulkHash4(tocheck, dst)
var newH uint32
for i, val := range dst {
di := i + startindex
newH = val & hashMask
// Get previous value with the same hash.
// Our chain should point to the previous value.
s.hashPrev[di&windowMask] = s.hashHead[newH]
// Set the head of the hash chain to us.
s.hashHead[newH] = uint32(di + s.hashOffset)
}
}
// Update window information.
d.windowEnd += n
d.blockStart = d.windowEnd
s.index = n
}
// Try to find a match starting at index whose length is greater than prevSize.
// We only look at chainCount possibilities before giving up.
// pos = s.index, prevHead = s.chainHead-s.hashOffset, prevLength=minMatchLength-1, lookahead
func (d *compressor) findMatch(pos int, prevHead int, lookahead int) (length, offset int, ok bool) {
minMatchLook := min(lookahead, maxMatchLength)
win := d.window[0 : pos+minMatchLook]
// We quit when we get a match that's at least nice long
nice := min(d.nice, len(win)-pos)
// If we've got a match that's good enough, only look in 1/4 the chain.
tries := d.chain
length = minMatchLength - 1
wEnd := win[pos+length]
wPos := win[pos:]
minIndex := max(pos-windowSize, 0)
offset = 0
if d.chain < 100 {
for i := prevHead; tries > 0; tries-- {
if wEnd == win[i+length] {
n := matchLen(win[i:i+minMatchLook], wPos)
if n > length {
length = n
offset = pos - i
ok = true
if n >= nice {
// The match is good enough that we don't try to find a better one.
break
}
wEnd = win[pos+n]
}
}
if i <= minIndex {
// hashPrev[i & windowMask] has already been overwritten, so stop now.
break
}
i = int(d.state.hashPrev[i&windowMask]) - d.state.hashOffset
if i < minIndex {
break
}
}
return
}
// Minimum gain to accept a match.
cGain := 4
// Some like it higher (CSV), some like it lower (JSON)
const baseCost = 3
// Base is 4 bytes at with an additional cost.
// Matches must be better than this.
for i := prevHead; tries > 0; tries-- {
if wEnd == win[i+length] {
n := matchLen(win[i:i+minMatchLook], wPos)
if n > length {
// Calculate gain. Estimate
newGain := d.h.bitLengthRaw(wPos[:n]) - int(offsetExtraBits[offsetCode(uint32(pos-i))]) - baseCost - int(lengthExtraBits[lengthCodes[(n-3)&255]])
//fmt.Println("gain:", newGain, "prev:", cGain, "raw:", d.h.bitLengthRaw(wPos[:n]), "this-len:", n, "prev-len:", length)
if newGain > cGain {
length = n
offset = pos - i
cGain = newGain
ok = true
if n >= nice {
// The match is good enough that we don't try to find a better one.
break
}
wEnd = win[pos+n]
}
}
}
if i <= minIndex {
// hashPrev[i & windowMask] has already been overwritten, so stop now.
break
}
i = int(d.state.hashPrev[i&windowMask]) - d.state.hashOffset
if i < minIndex {
break
}
}
return
}
func (d *compressor) writeStoredBlock(buf []byte) error {
if d.w.writeStoredHeader(len(buf), false); d.w.err != nil {
return d.w.err
}
d.w.writeBytes(buf)
return d.w.err
}
// hash4 returns a hash representation of the first 4 bytes
// of the supplied slice.
// The caller must ensure that len(b) >= 4.
func hash4(b []byte) uint32 {
return hash4u(le.Load32(b, 0), hashBits)
}
// hash4 returns the hash of u to fit in a hash table with h bits.
// Preferably h should be a constant and should always be <32.
func hash4u(u uint32, h uint8) uint32 {
return (u * prime4bytes) >> (32 - h)
}
// bulkHash4 will compute hashes using the same
// algorithm as hash4
func bulkHash4(b []byte, dst []uint32) {
if len(b) < 4 {
return
}
hb := le.Load32(b, 0)
dst[0] = hash4u(hb, hashBits)
end := len(b) - 4 + 1
for i := 1; i < end; i++ {
hb = (hb >> 8) | uint32(b[i+3])<<24
dst[i] = hash4u(hb, hashBits)
}
}
func (d *compressor) initDeflate() {
d.window = make([]byte, 2*windowSize)
d.byteAvailable = false
d.err = nil
if d.state == nil {
return
}
s := d.state
s.index = 0
s.hashOffset = 1
s.length = minMatchLength - 1
s.offset = 0
s.chainHead = -1
}
// deflateLazy is the same as deflate, but with d.fastSkipHashing == skipNever,
// meaning it always has lazy matching on.
func (d *compressor) deflateLazy() {
s := d.state
// Sanity enables additional runtime tests.
// It's intended to be used during development
// to supplement the currently ad-hoc unit tests.
const sanity = debugDeflate
if d.windowEnd-s.index < minMatchLength+maxMatchLength && !d.sync {
return
}
if d.windowEnd != s.index && d.chain > 100 {
// Get literal huffman coder.
if d.h == nil {
d.h = newHuffmanEncoder(maxFlateBlockTokens)
}
var tmp [256]uint16
toIndex := d.window[s.index:d.windowEnd]
toIndex = toIndex[:min(len(toIndex), maxFlateBlockTokens)]
for _, v := range toIndex {
tmp[v]++
}
d.h.generate(tmp[:], 15)
}
s.maxInsertIndex = d.windowEnd - (minMatchLength - 1)
for {
if sanity && s.index > d.windowEnd {
panic("index > windowEnd")
}
lookahead := d.windowEnd - s.index
if lookahead < minMatchLength+maxMatchLength {
if !d.sync {
return
}
if sanity && s.index > d.windowEnd {
panic("index > windowEnd")
}
if lookahead == 0 {
// Flush current output block if any.
if d.byteAvailable {
// There is still one pending token that needs to be flushed
d.tokens.AddLiteral(d.window[s.index-1])
d.byteAvailable = false
}
if d.tokens.n > 0 {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
return
}
}
if s.index < s.maxInsertIndex {
// Update the hash
hash := hash4(d.window[s.index:])
ch := s.hashHead[hash]
s.chainHead = int(ch)
s.hashPrev[s.index&windowMask] = ch
s.hashHead[hash] = uint32(s.index + s.hashOffset)
}
prevLength := s.length
prevOffset := s.offset
s.length = minMatchLength - 1
s.offset = 0
minIndex := max(s.index-windowSize, 0)
if s.chainHead-s.hashOffset >= minIndex && lookahead > prevLength && prevLength < d.lazy {
if newLength, newOffset, ok := d.findMatch(s.index, s.chainHead-s.hashOffset, lookahead); ok {
s.length = newLength
s.offset = newOffset
}
}
if prevLength >= minMatchLength && s.length <= prevLength {
// No better match, but check for better match at end...
//
// Skip forward a number of bytes.
// Offset of 2 seems to yield best results. 3 is sometimes better.
const checkOff = 2
// Check all, except full length
if prevLength < maxMatchLength-checkOff {
prevIndex := s.index - 1
if prevIndex+prevLength < s.maxInsertIndex {
end := min(lookahead, maxMatchLength+checkOff)
end += prevIndex
// Hash at match end.
h := hash4(d.window[prevIndex+prevLength:])
ch2 := int(s.hashHead[h]) - s.hashOffset - prevLength
if prevIndex-ch2 != prevOffset && ch2 > minIndex+checkOff {
length := matchLen(d.window[prevIndex+checkOff:end], d.window[ch2+checkOff:])
// It seems like a pure length metric is best.
if length > prevLength {
prevLength = length
prevOffset = prevIndex - ch2
// Extend back...
for i := checkOff - 1; i >= 0; i-- {
if prevLength >= maxMatchLength || d.window[prevIndex+i] != d.window[ch2+i] {
// Emit tokens we "owe"
for j := 0; j <= i; j++ {
d.tokens.AddLiteral(d.window[prevIndex+j])
if d.tokens.n == maxFlateBlockTokens {
// The block includes the current character
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
s.index++
if s.index < s.maxInsertIndex {
h := hash4(d.window[s.index:])
ch := s.hashHead[h]
s.chainHead = int(ch)
s.hashPrev[s.index&windowMask] = ch
s.hashHead[h] = uint32(s.index + s.hashOffset)
}
}
break
} else {
prevLength++
}
}
} else if false {
// Check one further ahead.
// Only rarely better, disabled for now.
prevIndex++
h := hash4(d.window[prevIndex+prevLength:])
ch2 := int(s.hashHead[h]) - s.hashOffset - prevLength
if prevIndex-ch2 != prevOffset && ch2 > minIndex+checkOff {
length := matchLen(d.window[prevIndex+checkOff:end], d.window[ch2+checkOff:])
// It seems like a pure length metric is best.
if length > prevLength+checkOff {
prevLength = length
prevOffset = prevIndex - ch2
prevIndex--
// Extend back...
for i := checkOff; i >= 0; i-- {
if prevLength >= maxMatchLength || d.window[prevIndex+i] != d.window[ch2+i-1] {
// Emit tokens we "owe"
for j := 0; j <= i; j++ {
d.tokens.AddLiteral(d.window[prevIndex+j])
if d.tokens.n == maxFlateBlockTokens {
// The block includes the current character
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
s.index++
if s.index < s.maxInsertIndex {
h := hash4(d.window[s.index:])
ch := s.hashHead[h]
s.chainHead = int(ch)
s.hashPrev[s.index&windowMask] = ch
s.hashHead[h] = uint32(s.index + s.hashOffset)
}
}
break
} else {
prevLength++
}
}
}
}
}
}
}
}
// There was a match at the previous step, and the current match is
// not better. Output the previous match.
d.tokens.AddMatch(uint32(prevLength-3), uint32(prevOffset-minOffsetSize))
// Insert in the hash table all strings up to the end of the match.
// index and index-1 are already inserted. If there is not enough
// lookahead, the last two strings are not inserted into the hash
// table.
newIndex := s.index + prevLength - 1
// Calculate missing hashes
end := min(newIndex, s.maxInsertIndex)
end += minMatchLength - 1
startindex := min(s.index+1, s.maxInsertIndex)
tocheck := d.window[startindex:end]
dstSize := len(tocheck) - minMatchLength + 1
if dstSize > 0 {
dst := s.hashMatch[:dstSize]
bulkHash4(tocheck, dst)
var newH uint32
for i, val := range dst {
di := i + startindex
newH = val & hashMask
// Get previous value with the same hash.
// Our chain should point to the previous value.
s.hashPrev[di&windowMask] = s.hashHead[newH]
// Set the head of the hash chain to us.
s.hashHead[newH] = uint32(di + s.hashOffset)
}
}
s.index = newIndex
d.byteAvailable = false
s.length = minMatchLength - 1
if d.tokens.n == maxFlateBlockTokens {
// The block includes the current character
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
s.ii = 0
} else {
// Reset, if we got a match this run.
if s.length >= minMatchLength {
s.ii = 0
}
// We have a byte waiting. Emit it.
if d.byteAvailable {
s.ii++
d.tokens.AddLiteral(d.window[s.index-1])
if d.tokens.n == maxFlateBlockTokens {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
s.index++
// If we have a long run of no matches, skip additional bytes
// Resets when s.ii overflows after 64KB.
if n := int(s.ii) - d.chain; n > 0 {
n = 1 + int(n>>6)
for j := 0; j < n; j++ {
if s.index >= d.windowEnd-1 {
break
}
d.tokens.AddLiteral(d.window[s.index-1])
if d.tokens.n == maxFlateBlockTokens {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
// Index...
if s.index < s.maxInsertIndex {
h := hash4(d.window[s.index:])
ch := s.hashHead[h]
s.chainHead = int(ch)
s.hashPrev[s.index&windowMask] = ch
s.hashHead[h] = uint32(s.index + s.hashOffset)
}
s.index++
}
// Flush last byte
d.tokens.AddLiteral(d.window[s.index-1])
d.byteAvailable = false
// s.length = minMatchLength - 1 // not needed, since s.ii is reset above, so it should never be > minMatchLength
if d.tokens.n == maxFlateBlockTokens {
if d.err = d.writeBlock(&d.tokens, s.index, false); d.err != nil {
return
}
d.tokens.Reset()
}
}
} else {
s.index++
d.byteAvailable = true
}
}
}
}
func (d *compressor) store() {
if d.windowEnd > 0 && (d.windowEnd == maxStoreBlockSize || d.sync) {
d.err = d.writeStoredBlock(d.window[:d.windowEnd])
d.windowEnd = 0
}
}
// fillWindow will fill the buffer with data for huffman-only compression.
// The number of bytes copied is returned.
func (d *compressor) fillBlock(b []byte) int {
n := copy(d.window[d.windowEnd:], b)
d.windowEnd += n
return n
}
// storeHuff will compress and store the currently added data,
// if enough has been accumulated or we at the end of the stream.
// Any error that occurred will be in d.err
func (d *compressor) storeHuff() {
if d.windowEnd < len(d.window) && !d.sync || d.windowEnd == 0 {
return
}
d.w.writeBlockHuff(false, d.window[:d.windowEnd], d.sync)
d.err = d.w.err
d.windowEnd = 0
}
// storeFast will compress and store the currently added data,
// if enough has been accumulated or we at the end of the stream.
// Any error that occurred will be in d.err
func (d *compressor) storeFast() {
// We only compress if we have maxStoreBlockSize.
if d.windowEnd < len(d.window) {
if !d.sync {
return
}
// Handle extremely small sizes.
if d.windowEnd < 128 {
if d.windowEnd == 0 {
return
}
if d.windowEnd <= 32 {
d.err = d.writeStoredBlock(d.window[:d.windowEnd])
} else {
d.w.writeBlockHuff(false, d.window[:d.windowEnd], true)
d.err = d.w.err
}
d.tokens.Reset()
d.windowEnd = 0
d.fast.Reset()
return
}
}
d.fast.Encode(&d.tokens, d.window[:d.windowEnd])
// If we made zero matches, store the block as is.
if d.tokens.n == 0 {
d.err = d.writeStoredBlock(d.window[:d.windowEnd])
// If we removed less than 1/16th, huffman compress the block.
} else if int(d.tokens.n) > d.windowEnd-(d.windowEnd>>4) {
d.w.writeBlockHuff(false, d.window[:d.windowEnd], d.sync)
d.err = d.w.err
} else {
d.w.writeBlockDynamic(&d.tokens, false, d.window[:d.windowEnd], d.sync)
d.err = d.w.err
}
d.tokens.Reset()
d.windowEnd = 0
}
// write will add input byte to the stream.
// Unless an error occurs all bytes will be consumed.
func (d *compressor) write(b []byte) (n int, err error) {
if d.err != nil {
return 0, d.err
}
n = len(b)
for len(b) > 0 {
if d.windowEnd == len(d.window) || d.sync {
d.step(d)
}
b = b[d.fill(d, b):]
if d.err != nil {
return 0, d.err
}
}
return n, d.err
}
func (d *compressor) syncFlush() error {
d.sync = true
if d.err != nil {
return d.err
}
d.step(d)
if d.err == nil {
d.w.writeStoredHeader(0, false)
d.w.flush()
d.err = d.w.err
}
d.sync = false
return d.err
}
func (d *compressor) init(w io.Writer, level int) (err error) {
d.w = newHuffmanBitWriter(w)
switch {
case level == NoCompression:
d.window = make([]byte, maxStoreBlockSize)
d.fill = (*compressor).fillBlock
d.step = (*compressor).store
case level == ConstantCompression:
d.w.logNewTablePenalty = 10
d.window = make([]byte, 32<<10)
d.fill = (*compressor).fillBlock
d.step = (*compressor).storeHuff
case level == DefaultCompression:
level = 5
fallthrough
case level >= 1 && level <= 6:
d.w.logNewTablePenalty = 7
d.fast = newFastEnc(level)
d.window = make([]byte, maxStoreBlockSize)
d.fill = (*compressor).fillBlock
d.step = (*compressor).storeFast
case 7 <= level && level <= 9:
d.w.logNewTablePenalty = 8
d.state = &advancedState{}
d.compressionLevel = levels[level]
d.initDeflate()
d.fill = (*compressor).fillDeflate
d.step = (*compressor).deflateLazy
case -level >= MinCustomWindowSize && -level <= MaxCustomWindowSize:
d.w.logNewTablePenalty = 7
d.fast = &fastEncL5Window{maxOffset: int32(-level), cur: maxStoreBlockSize}
d.window = make([]byte, maxStoreBlockSize)
d.fill = (*compressor).fillBlock
d.step = (*compressor).storeFast
default:
return fmt.Errorf("flate: invalid compression level %d: want value in range [-2, 9]", level)
}
d.level = level
return nil
}
// reset the state of the compressor.
func (d *compressor) reset(w io.Writer) {
d.w.reset(w)
d.sync = false
d.err = nil
// We only need to reset a few things for Snappy.
if d.fast != nil {
d.fast.Reset()
d.windowEnd = 0
d.tokens.Reset()
return
}
switch d.compressionLevel.chain {
case 0:
// level was NoCompression or ConstantCompression.
d.windowEnd = 0
default:
s := d.state
s.chainHead = -1
for i := range s.hashHead {
s.hashHead[i] = 0
}
for i := range s.hashPrev {
s.hashPrev[i] = 0
}
s.hashOffset = 1
s.index, d.windowEnd = 0, 0
d.blockStart, d.byteAvailable = 0, false
d.tokens.Reset()
s.length = minMatchLength - 1
s.offset = 0
s.ii = 0
s.maxInsertIndex = 0
}
}
func (d *compressor) close() error {
if d.err != nil {
return d.err
}
d.sync = true
d.step(d)
if d.err != nil {
return d.err
}
if d.w.writeStoredHeader(0, true); d.w.err != nil {
return d.w.err
}
d.w.flush()
d.w.reset(nil)
return d.w.err
}
// NewWriter returns a new Writer compressing data at the given level.
// Following zlib, levels range from 1 (BestSpeed) to 9 (BestCompression);
// higher levels typically run slower but compress more.
// Level 0 (NoCompression) does not attempt any compression; it only adds the
// necessary DEFLATE framing.
// Level -1 (DefaultCompression) uses the default compression level.
// Level -2 (ConstantCompression) will use Huffman compression only, giving
// a very fast compression for all types of input, but sacrificing considerable
// compression efficiency.
//
// If level is in the range [-2, 9] then the error returned will be nil.
// Otherwise the error returned will be non-nil.
func NewWriter(w io.Writer, level int) (*Writer, error) {
var dw Writer
if err := dw.d.init(w, level); err != nil {
return nil, err
}
return &dw, nil
}
// NewWriterDict is like NewWriter but initializes the new
// Writer with a preset dictionary. The returned Writer behaves
// as if the dictionary had been written to it without producing
// any compressed output. The compressed data written to w
// can only be decompressed by a Reader initialized with the
// same dictionary.
func NewWriterDict(w io.Writer, level int, dict []byte) (*Writer, error) {
zw, err := NewWriter(w, level)
if err != nil {
return nil, err
}
zw.d.fillWindow(dict)
zw.dict = append(zw.dict, dict...) // duplicate dictionary for Reset method.
return zw, err
}
// MinCustomWindowSize is the minimum window size that can be sent to NewWriterWindow.
const MinCustomWindowSize = 32
// MaxCustomWindowSize is the maximum custom window that can be sent to NewWriterWindow.
const MaxCustomWindowSize = windowSize
// NewWriterWindow returns a new Writer compressing data with a custom window size.
// windowSize must be from MinCustomWindowSize to MaxCustomWindowSize.
func NewWriterWindow(w io.Writer, windowSize int) (*Writer, error) {
if windowSize < MinCustomWindowSize {
return nil, errors.New("flate: requested window size less than MinWindowSize")
}
if windowSize > MaxCustomWindowSize {
return nil, errors.New("flate: requested window size bigger than MaxCustomWindowSize")
}
var dw Writer
if err := dw.d.init(w, -windowSize); err != nil {
return nil, err
}
return &dw, nil
}
// A Writer takes data written to it and writes the compressed
// form of that data to an underlying writer (see NewWriter).
type Writer struct {
d compressor
dict []byte
}
// Write writes data to w, which will eventually write the
// compressed form of data to its underlying writer.
func (w *Writer) Write(data []byte) (n int, err error) {
return w.d.write(data)
}
// Flush flushes any pending data to the underlying writer.
// It is useful mainly in compressed network protocols, to ensure that
// a remote reader has enough data to reconstruct a packet.
// Flush does not return until the data has been written.
// Calling Flush when there is no pending data still causes the Writer
// to emit a sync marker of at least 4 bytes.
// If the underlying writer returns an error, Flush returns that error.
//
// In the terminology of the zlib library, Flush is equivalent to Z_SYNC_FLUSH.
func (w *Writer) Flush() error {
// For more about flushing:
// http://www.bolet.org/~pornin/deflate-flush.html
return w.d.syncFlush()
}
// Close flushes and closes the writer.
func (w *Writer) Close() error {
return w.d.close()
}
// Reset discards the writer's state and makes it equivalent to
// the result of NewWriter or NewWriterDict called with dst
// and w's level and dictionary.
func (w *Writer) Reset(dst io.Writer) {
if len(w.dict) > 0 {
// w was created with NewWriterDict
w.d.reset(dst)
if dst != nil {
w.d.fillWindow(w.dict)
}
} else {
// w was created with NewWriter
w.d.reset(dst)
}
}
// ResetDict discards the writer's state and makes it equivalent to
// the result of NewWriter or NewWriterDict called with dst
// and w's level, but sets a specific dictionary.
func (w *Writer) ResetDict(dst io.Writer, dict []byte) {
w.dict = dict
w.d.reset(dst)
w.d.fillWindow(w.dict)
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/dict_decoder.go
Generated Vendored
+199
View File
@@ -0,0 +1,199 @@
// 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.
package flate
// dictDecoder implements the LZ77 sliding dictionary as used in decompression.
// LZ77 decompresses data through sequences of two forms of commands:
//
// - Literal insertions: Runs of one or more symbols are inserted into the data
// stream as is. This is accomplished through the writeByte method for a
// single symbol, or combinations of writeSlice/writeMark for multiple symbols.
// Any valid stream must start with a literal insertion if no preset dictionary
// is used.
//
// - Backward copies: Runs of one or more symbols are copied from previously
// emitted data. Backward copies come as the tuple (dist, length) where dist
// determines how far back in the stream to copy from and length determines how
// many bytes to copy. Note that it is valid for the length to be greater than
// the distance. Since LZ77 uses forward copies, that situation is used to
// perform a form of run-length encoding on repeated runs of symbols.
// The writeCopy and tryWriteCopy are used to implement this command.
//
// For performance reasons, this implementation performs little to no sanity
// checks about the arguments. As such, the invariants documented for each
// method call must be respected.
type dictDecoder struct {
hist []byte // Sliding window history
// Invariant: 0 <= rdPos <= wrPos <= len(hist)
wrPos int // Current output position in buffer
rdPos int // Have emitted hist[:rdPos] already
flushed int64 // Total bytes returned by readFlush since init
full bool // Has a full window length been written yet?
}
// init initializes dictDecoder to have a sliding window dictionary of the given
// size. If a preset dict is provided, it will initialize the dictionary with
// the contents of dict.
func (dd *dictDecoder) init(size int, dict []byte) {
*dd = dictDecoder{hist: dd.hist}
if cap(dd.hist) < size {
dd.hist = make([]byte, size)
}
dd.hist = dd.hist[:size]
if len(dict) > len(dd.hist) {
dict = dict[len(dict)-len(dd.hist):]
}
dd.wrPos = copy(dd.hist, dict)
if dd.wrPos == len(dd.hist) {
dd.wrPos = 0
dd.full = true
}
dd.rdPos = dd.wrPos
}
// histSize reports the total amount of historical data in the dictionary.
func (dd *dictDecoder) histSize() int {
if dd.full {
return len(dd.hist)
}
return dd.wrPos
}
// availRead reports the number of bytes that can be flushed by readFlush.
func (dd *dictDecoder) availRead() int {
return dd.wrPos - dd.rdPos
}
// availWrite reports the available amount of output buffer space.
func (dd *dictDecoder) availWrite() int {
return len(dd.hist) - dd.wrPos
}
// writeSlice returns a slice of the available buffer to write data to.
//
// This invariant will be kept: len(s) <= availWrite()
func (dd *dictDecoder) writeSlice() []byte {
return dd.hist[dd.wrPos:]
}
// writeMark advances the writer pointer by cnt.
//
// This invariant must be kept: 0 <= cnt <= availWrite()
func (dd *dictDecoder) writeMark(cnt int) {
dd.wrPos += cnt
}
// writeByte writes a single byte to the dictionary.
//
// This invariant must be kept: 0 < availWrite()
func (dd *dictDecoder) writeByte(c byte) {
dd.hist[dd.wrPos] = c
dd.wrPos++
}
// writeCopy copies a string at a given (dist, length) to the output.
// This returns the number of bytes copied and may be less than the requested
// length if the available space in the output buffer is too small.
//
// This invariant must be kept: 0 < dist <= histSize()
func (dd *dictDecoder) writeCopy(dist, length int) int {
dstBase := dd.wrPos
dstPos := dstBase
srcPos := dstPos - dist
endPos := min(dstPos+length, len(dd.hist))
// Copy non-overlapping section after destination position.
//
// This section is non-overlapping in that the copy length for this section
// is always less than or equal to the backwards distance. This can occur
// if a distance refers to data that wraps-around in the buffer.
// Thus, a backwards copy is performed here; that is, the exact bytes in
// the source prior to the copy is placed in the destination.
if srcPos < 0 {
srcPos += len(dd.hist)
dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:])
srcPos = 0
}
// Copy possibly overlapping section before destination position.
//
// This section can overlap if the copy length for this section is larger
// than the backwards distance. This is allowed by LZ77 so that repeated
// strings can be succinctly represented using (dist, length) pairs.
// Thus, a forwards copy is performed here; that is, the bytes copied is
// possibly dependent on the resulting bytes in the destination as the copy
// progresses along. This is functionally equivalent to the following:
//
// for i := 0; i < endPos-dstPos; i++ {
// dd.hist[dstPos+i] = dd.hist[srcPos+i]
// }
// dstPos = endPos
//
for dstPos < endPos {
dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:dstPos])
}
dd.wrPos = dstPos
return dstPos - dstBase
}
// tryWriteCopy tries to copy a string at a given (distance, length) to the
// output. This specialized version is optimized for short distances.
//
// This method is designed to be inlined for performance reasons.
//
// This invariant must be kept: 0 < dist <= histSize()
func (dd *dictDecoder) tryWriteCopy(dist, length int) int {
dstPos := dd.wrPos
endPos := dstPos + length
if dstPos < dist || endPos > len(dd.hist) {
return 0
}
dstBase := dstPos
srcPos := dstPos - dist
// Copy possibly overlapping section before destination position.
loop:
dstPos += copy(dd.hist[dstPos:endPos], dd.hist[srcPos:dstPos])
if dstPos < endPos {
goto loop // Avoid for-loop so that this function can be inlined
}
dd.wrPos = dstPos
return dstPos - dstBase
}
// appendWindow appends the current sliding window (up to len(hist) most recent
// bytes, oldest first) to dst.
func (dd *dictDecoder) appendWindow(dst []byte) []byte {
if dd.full {
dst = append(dst, dd.hist[dd.wrPos:]...)
return append(dst, dd.hist[:dd.wrPos]...)
}
return append(dst, dd.hist[:dd.wrPos]...)
}
// readFlush returns a slice of the historical buffer that is ready to be
// emitted to the user. The data returned by readFlush must be fully consumed
// before calling any other dictDecoder methods.
func (dd *dictDecoder) readFlush() []byte {
toRead := dd.hist[dd.rdPos:dd.wrPos]
dd.flushed += int64(len(toRead))
dd.rdPos = dd.wrPos
if dd.wrPos == len(dd.hist) {
dd.wrPos, dd.rdPos = 0, 0
dd.full = true
}
return toRead
}
// decoded reports the total number of bytes written into the dictionary since
// init (i.e. excluding any preset dict bytes).
func (dd *dictDecoder) decoded() int64 {
return dd.flushed + int64(dd.wrPos-dd.rdPos)
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/fast_encoder.go
Generated Vendored
+190
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@@ -0,0 +1,190 @@
// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Modified for deflate by Klaus Post (c) 2015.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"fmt"
"github.com/klauspost/compress/internal/le"
"github.com/klauspost/compress/internal/regmask"
)
type fastEnc interface {
Encode(dst *tokens, src []byte)
Reset()
}
func newFastEnc(level int) fastEnc {
switch level {
case 1:
return &fastEncL1{fastGen: fastGen{cur: maxStoreBlockSize}}
case 2:
return &fastEncL2{fastGen: fastGen{cur: maxStoreBlockSize}}
case 3:
return &fastEncL3{fastGen: fastGen{cur: maxStoreBlockSize}}
case 4:
return &fastEncL4{fastGen: fastGen{cur: maxStoreBlockSize}}
case 5:
return &fastEncL5{fastGen: fastGen{cur: maxStoreBlockSize}}
case 6:
return &fastEncL6{fastGen: fastGen{cur: maxStoreBlockSize}}
default:
panic("invalid level specified")
}
}
const (
tableBits = 15 // Bits used in the table
tableSize = 1 << tableBits // Size of the table
tableShift = 32 - tableBits // Right-shift to get the tableBits most significant bits of a uint32.
baseMatchOffset = 1 // The smallest match offset
baseMatchLength = 3 // The smallest match length per the RFC section 3.2.5
maxMatchOffset = 1 << 15 // The largest match offset
bTableBits = 17 // Bits used in the big tables
bTableSize = 1 << bTableBits // Size of the table
allocHistory = maxStoreBlockSize * 5 // Size to preallocate for history.
bufferReset = (1 << 31) - allocHistory - maxStoreBlockSize - 1 // Reset the buffer offset when reaching this.
)
const (
prime3bytes = 506832829
prime4bytes = 2654435761
prime5bytes = 889523592379
prime6bytes = 227718039650203
prime7bytes = 58295818150454627
prime8bytes = 0xcf1bbcdcb7a56463
)
func load3232(b []byte, i int32) uint32 {
return le.Load32(b, i)
}
func load6432(b []byte, i int32) uint64 {
return le.Load64(b, i)
}
type tableEntry struct {
offset int32
}
// fastGen maintains the table for matches,
// and the previous byte block for level 2.
// This is the generic implementation.
type fastGen struct {
hist []byte
cur int32
}
func (e *fastGen) addBlock(src []byte) int32 {
// check if we have space already
if len(e.hist)+len(src) > cap(e.hist) {
if cap(e.hist) == 0 {
e.hist = make([]byte, 0, allocHistory)
} else {
if cap(e.hist) < maxMatchOffset*2 {
panic("unexpected buffer size")
}
// Move down
offset := int32(len(e.hist)) - maxMatchOffset
// copy(e.hist[0:maxMatchOffset], e.hist[offset:])
*(*[maxMatchOffset]byte)(e.hist) = *(*[maxMatchOffset]byte)(e.hist[offset:])
e.cur += offset
e.hist = e.hist[:maxMatchOffset]
}
}
s := int32(len(e.hist))
e.hist = append(e.hist, src...)
return s
}
type tableEntryPrev struct {
Cur tableEntry
Prev tableEntry
}
// hash7 returns the hash of the lowest 7 bytes of u to fit in a hash table with h bits.
// Preferably h should be a constant and should always be <64.
func hash7(u uint64, h uint8) uint32 {
return uint32(((u << (64 - 56)) * prime7bytes) >> ((64 - h) & regmask.Shift64ByUint8))
}
// hashLen returns a hash of the lowest mls bytes of with length output bits.
// mls must be >=3 and <=8. Any other value will return hash for 4 bytes.
// length should always be < 32.
// Preferably length and mls should be a constant for inlining.
func hashLen(u uint64, length, mls uint8) uint32 {
switch mls {
case 3:
return (uint32(u<<8) * prime3bytes) >> (32 - length)
case 5:
return uint32(((u << (64 - 40)) * prime5bytes) >> (64 - length))
case 6:
return uint32(((u << (64 - 48)) * prime6bytes) >> (64 - length))
case 7:
return uint32(((u << (64 - 56)) * prime7bytes) >> (64 - length))
case 8:
return uint32((u * prime8bytes) >> (64 - length))
default:
return (uint32(u) * prime4bytes) >> (32 - length)
}
}
// matchlen will return the match length between offsets and t in src.
// The maximum length returned is maxMatchLength - 4.
// It is assumed that s > t, that t >=0 and s < len(src).
func (e *fastGen) matchlen(s, t int, src []byte) int32 {
if debugDeflate {
if t >= s {
panic(fmt.Sprint("t >=s:", t, s))
}
if int(s) >= len(src) {
panic(fmt.Sprint("s >= len(src):", s, len(src)))
}
if t < 0 {
panic(fmt.Sprint("t < 0:", t))
}
if s-t > maxMatchOffset {
panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")"))
}
}
a := src[s:min(s+maxMatchLength-4, len(src))]
b := src[t:]
return int32(matchLen(a, b))
}
// matchlenLong will return the match length between offsets and t in src.
// It is assumed that s > t, that t >=0 and s < len(src).
func (e *fastGen) matchlenLong(s, t int, src []byte) int32 {
if debugDeflate {
if t >= s {
panic(fmt.Sprint("t >=s:", t, s))
}
if int(s) >= len(src) {
panic(fmt.Sprint("s >= len(src):", s, len(src)))
}
if t < 0 {
panic(fmt.Sprint("t < 0:", t))
}
if s-t > maxMatchOffset {
panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")"))
}
}
return int32(matchLen(src[s:], src[t:]))
}
// Reset the encoding table.
func (e *fastGen) Reset() {
if cap(e.hist) < allocHistory {
e.hist = make([]byte, 0, allocHistory)
}
// We offset current position so everything will be out of reach.
// If we are above the buffer reset it will be cleared anyway since len(hist) == 0.
if e.cur <= bufferReset {
e.cur += maxMatchOffset + int32(len(e.hist))
}
e.hist = e.hist[:0]
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/huffman_bit_writer.go
Generated Vendored
+1174
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modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/huffman_code.go
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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"math"
"math/bits"
)
const (
maxBitsLimit = 16
// number of valid literals
literalCount = 286
)
// hcode is a huffman code with a bit code and bit length.
type hcode uint32
func (h hcode) len() uint8 {
return uint8(h)
}
func (h hcode) code64() uint64 {
return uint64(h >> 8)
}
func (h hcode) zero() bool {
return h == 0
}
type huffmanEncoder struct {
codes []hcode
bitCount [17]int32
// Allocate a reusable buffer with the longest possible frequency table.
// Possible lengths are codegenCodeCount, offsetCodeCount and literalCount.
// The largest of these is literalCount, so we allocate for that case.
freqcache [literalCount + 1]literalNode
}
type literalNode struct {
literal uint16
freq uint16
}
// A levelInfo describes the state of the constructed tree for a given depth.
type levelInfo struct {
// Our level. for better printing
level int32
// The frequency of the last node at this level
lastFreq int32
// The frequency of the next character to add to this level
nextCharFreq int32
// The frequency of the next pair (from level below) to add to this level.
// Only valid if the "needed" value of the next lower level is 0.
nextPairFreq int32
// The number of chains remaining to generate for this level before moving
// up to the next level
needed int32
}
// set sets the code and length of an hcode.
func (h *hcode) set(code uint16, length uint8) {
*h = hcode(length) | (hcode(code) << 8)
}
func newhcode(code uint16, length uint8) hcode {
return hcode(length) | (hcode(code) << 8)
}
func reverseBits(number uint16, bitLength byte) uint16 {
return bits.Reverse16(number << ((16 - bitLength) & 15))
}
func maxNode() literalNode { return literalNode{math.MaxUint16, math.MaxUint16} }
func newHuffmanEncoder(size int) *huffmanEncoder {
// Make capacity to next power of two.
c := uint(bits.Len32(uint32(size - 1)))
return &huffmanEncoder{codes: make([]hcode, size, 1<<c)}
}
// Generates a HuffmanCode corresponding to the fixed literal table
func generateFixedLiteralEncoding() *huffmanEncoder {
h := newHuffmanEncoder(literalCount)
codes := h.codes
var ch uint16
for ch = range uint16(literalCount) {
var bits uint16
var size uint8
switch {
case ch < 144:
// size 8, 000110000 .. 10111111
bits = ch + 48
size = 8
case ch < 256:
// size 9, 110010000 .. 111111111
bits = ch + 400 - 144
size = 9
case ch < 280:
// size 7, 0000000 .. 0010111
bits = ch - 256
size = 7
default:
// size 8, 11000000 .. 11000111
bits = ch + 192 - 280
size = 8
}
codes[ch] = newhcode(reverseBits(bits, size), size)
}
return h
}
func generateFixedOffsetEncoding() *huffmanEncoder {
h := newHuffmanEncoder(30)
codes := h.codes
for ch := range codes {
codes[ch] = newhcode(reverseBits(uint16(ch), 5), 5)
}
return h
}
var fixedLiteralEncoding = generateFixedLiteralEncoding()
var fixedOffsetEncoding = generateFixedOffsetEncoding()
func (h *huffmanEncoder) bitLength(freq []uint16) int {
var total int
for i, f := range freq {
if f != 0 {
total += int(f) * int(h.codes[i].len())
}
}
return total
}
func (h *huffmanEncoder) bitLengthRaw(b []byte) int {
var total int
for _, f := range b {
total += int(h.codes[f].len())
}
return total
}
// canReuseBits returns the number of bits or math.MaxInt32 if the encoder cannot be reused.
func (h *huffmanEncoder) canReuseBits(freq []uint16) int {
var total int
for i, f := range freq {
if f != 0 {
code := h.codes[i]
if code.zero() {
return math.MaxInt32
}
total += int(f) * int(code.len())
}
}
return total
}
// Return the number of literals assigned to each bit size in the Huffman encoding
//
// This method is only called when list.length >= 3
// The cases of 0, 1, and 2 literals are handled by special case code.
//
// list An array of the literals with non-zero frequencies
//
// and their associated frequencies. The array is in order of increasing
// frequency, and has as its last element a special element with frequency
// MaxInt32
//
// maxBits The maximum number of bits that should be used to encode any literal.
//
// Must be less than 16.
//
// return An integer array in which array[i] indicates the number of literals
//
// that should be encoded in i bits.
func (h *huffmanEncoder) bitCounts(list []literalNode, maxBits int32) []int32 {
if maxBits >= maxBitsLimit {
panic("flate: maxBits too large")
}
n := int32(len(list))
list = list[0 : n+1]
list[n] = maxNode()
// The tree can't have greater depth than n - 1, no matter what. This
// saves a little bit of work in some small cases
if maxBits > n-1 {
maxBits = n - 1
}
// Create information about each of the levels.
// A bogus "Level 0" whose sole purpose is so that
// level1.prev.needed==0. This makes level1.nextPairFreq
// be a legitimate value that never gets chosen.
var levels [maxBitsLimit]levelInfo
// leafCounts[i] counts the number of literals at the left
// of ancestors of the rightmost node at level i.
// leafCounts[i][j] is the number of literals at the left
// of the level j ancestor.
var leafCounts [maxBitsLimit][maxBitsLimit]int32
// Descending to only have 1 bounds check.
l2f := int32(list[2].freq)
l1f := int32(list[1].freq)
l0f := int32(list[0].freq) + int32(list[1].freq)
for level := int32(1); level <= maxBits; level++ {
// For every level, the first two items are the first two characters.
// We initialize the levels as if we had already figured this out.
levels[level] = levelInfo{
level: level,
lastFreq: l1f,
nextCharFreq: l2f,
nextPairFreq: l0f,
}
leafCounts[level][level] = 2
if level == 1 {
levels[level].nextPairFreq = math.MaxInt32
}
}
// We need a total of 2*n - 2 items at top level and have already generated 2.
levels[maxBits].needed = 2*n - 4
level := uint32(maxBits)
for level < 16 {
l := &levels[level]
if l.nextPairFreq == math.MaxInt32 && l.nextCharFreq == math.MaxInt32 {
// We've run out of both leafs and pairs.
// End all calculations for this level.
// To make sure we never come back to this level or any lower level,
// set nextPairFreq impossibly large.
l.needed = 0
levels[level+1].nextPairFreq = math.MaxInt32
level++
continue
}
prevFreq := l.lastFreq
if l.nextCharFreq < l.nextPairFreq {
// The next item on this row is a leaf node.
n := leafCounts[level][level] + 1
l.lastFreq = l.nextCharFreq
// Lower leafCounts are the same of the previous node.
leafCounts[level][level] = n
e := list[n]
if e.literal < math.MaxUint16 {
l.nextCharFreq = int32(e.freq)
} else {
l.nextCharFreq = math.MaxInt32
}
} else {
// The next item on this row is a pair from the previous row.
// nextPairFreq isn't valid until we generate two
// more values in the level below
l.lastFreq = l.nextPairFreq
// Take leaf counts from the lower level, except counts[level] remains the same.
if true {
save := leafCounts[level][level]
leafCounts[level] = leafCounts[level-1]
leafCounts[level][level] = save
} else {
copy(leafCounts[level][:level], leafCounts[level-1][:level])
}
levels[l.level-1].needed = 2
}
if l.needed--; l.needed == 0 {
// We've done everything we need to do for this level.
// Continue calculating one level up. Fill in nextPairFreq
// of that level with the sum of the two nodes we've just calculated on
// this level.
if l.level == maxBits {
// All done!
break
}
levels[l.level+1].nextPairFreq = prevFreq + l.lastFreq
level++
} else {
// If we stole from below, move down temporarily to replenish it.
for levels[level-1].needed > 0 {
level--
}
}
}
// Somethings is wrong if at the end, the top level is null or hasn't used
// all of the leaves.
if leafCounts[maxBits][maxBits] != n {
panic("leafCounts[maxBits][maxBits] != n")
}
bitCount := h.bitCount[:maxBits+1]
bits := 1
counts := &leafCounts[maxBits]
for level := maxBits; level > 0; level-- {
// chain.leafCount gives the number of literals requiring at least "bits"
// bits to encode.
bitCount[bits] = counts[level] - counts[level-1]
bits++
}
return bitCount
}
// Look at the leaves and assign them a bit count and an encoding as specified
// in RFC 1951 3.2.2
func (h *huffmanEncoder) assignEncodingAndSize(bitCount []int32, list []literalNode) {
code := uint16(0)
for n, bits := range bitCount {
code <<= 1
if n == 0 || bits == 0 {
continue
}
// The literals list[len(list)-bits] .. list[len(list)-bits]
// are encoded using "bits" bits, and get the values
// code, code + 1, .... The code values are
// assigned in literal order (not frequency order).
chunk := list[len(list)-int(bits):]
sortByLiteral(chunk)
for _, node := range chunk {
h.codes[node.literal] = newhcode(reverseBits(code, uint8(n)), uint8(n))
code++
}
list = list[0 : len(list)-int(bits)]
}
}
// Update this Huffman Code object to be the minimum code for the specified frequency count.
//
// freq An array of frequencies, in which frequency[i] gives the frequency of literal i.
// maxBits The maximum number of bits to use for any literal.
func (h *huffmanEncoder) generate(freq []uint16, maxBits int32) {
list := h.freqcache[:len(freq)+1]
codes := h.codes[:len(freq)]
// Number of non-zero literals
count := 0
// Set list to be the set of all non-zero literals and their frequencies
for i, f := range freq {
if f != 0 {
list[count] = literalNode{uint16(i), f}
count++
} else {
codes[i] = 0
}
}
list[count] = literalNode{}
list = list[:count]
if count <= 2 {
// Handle the small cases here, because they are awkward for the general case code. With
// two or fewer literals, everything has bit length 1.
for i, node := range list {
// "list" is in order of increasing literal value.
h.codes[node.literal].set(uint16(i), 1)
}
return
}
sortByFreq(list)
// Get the number of literals for each bit count
bitCount := h.bitCounts(list, maxBits)
// And do the assignment
h.assignEncodingAndSize(bitCount, list)
}
// atLeastOne clamps the result between 1 and 15.
func atLeastOne(v float32) float32 {
if v < 1 {
return 1
}
if v > 15 {
return 15
}
return v
}
func histogram(b []byte, h []uint16) {
if true && len(b) >= 8<<10 {
// Split for bigger inputs
histogramSplit(b, h)
} else {
h = h[:256]
for _, t := range b {
h[t]++
}
}
}
func histogramSplit(b []byte, h []uint16) {
// Tested, and slightly faster than 2-way.
// Writing to separate arrays and combining is also slightly slower.
h = h[:256]
for len(b)&3 != 0 {
h[b[0]]++
b = b[1:]
}
n := len(b) / 4
x, y, z, w := b[:n], b[n:], b[n+n:], b[n+n+n:]
y, z, w = y[:len(x)], z[:len(x)], w[:len(x)]
for i, t := range x {
v0 := &h[t]
v1 := &h[y[i]]
v2 := &h[z[i]]
v3 := &h[w[i]]
*v0++
*v1++
*v2++
*v3++
}
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/huffman_sortByFreq.go
Generated Vendored
+159
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@@ -0,0 +1,159 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
// Sort sorts data.
// It makes one call to data.Len to determine n, and O(n*log(n)) calls to
// data.Less and data.Swap. The sort is not guaranteed to be stable.
func sortByFreq(data []literalNode) {
n := len(data)
quickSortByFreq(data, 0, n, maxDepth(n))
}
func quickSortByFreq(data []literalNode, a, b, maxDepth int) {
for b-a > 12 { // Use ShellSort for slices <= 12 elements
if maxDepth == 0 {
heapSort(data, a, b)
return
}
maxDepth--
mlo, mhi := doPivotByFreq(data, a, b)
// Avoiding recursion on the larger subproblem guarantees
// a stack depth of at most lg(b-a).
if mlo-a < b-mhi {
quickSortByFreq(data, a, mlo, maxDepth)
a = mhi // i.e., quickSortByFreq(data, mhi, b)
} else {
quickSortByFreq(data, mhi, b, maxDepth)
b = mlo // i.e., quickSortByFreq(data, a, mlo)
}
}
if b-a > 1 {
// Do ShellSort pass with gap 6
// It could be written in this simplified form cause b-a <= 12
for i := a + 6; i < b; i++ {
if data[i].freq == data[i-6].freq && data[i].literal < data[i-6].literal || data[i].freq < data[i-6].freq {
data[i], data[i-6] = data[i-6], data[i]
}
}
insertionSortByFreq(data, a, b)
}
}
func doPivotByFreq(data []literalNode, lo, hi int) (midlo, midhi int) {
m := int(uint(lo+hi) >> 1) // Written like this to avoid integer overflow.
if hi-lo > 40 {
// Tukey's ``Ninther,'' median of three medians of three.
s := (hi - lo) / 8
medianOfThreeSortByFreq(data, lo, lo+s, lo+2*s)
medianOfThreeSortByFreq(data, m, m-s, m+s)
medianOfThreeSortByFreq(data, hi-1, hi-1-s, hi-1-2*s)
}
medianOfThreeSortByFreq(data, lo, m, hi-1)
// Invariants are:
// data[lo] = pivot (set up by ChoosePivot)
// data[lo < i < a] < pivot
// data[a <= i < b] <= pivot
// data[b <= i < c] unexamined
// data[c <= i < hi-1] > pivot
// data[hi-1] >= pivot
pivot := lo
a, c := lo+1, hi-1
for ; a < c && (data[a].freq == data[pivot].freq && data[a].literal < data[pivot].literal || data[a].freq < data[pivot].freq); a++ {
}
b := a
for {
for ; b < c && (data[pivot].freq == data[b].freq && data[pivot].literal > data[b].literal || data[pivot].freq > data[b].freq); b++ { // data[b] <= pivot
}
for ; b < c && (data[pivot].freq == data[c-1].freq && data[pivot].literal < data[c-1].literal || data[pivot].freq < data[c-1].freq); c-- { // data[c-1] > pivot
}
if b >= c {
break
}
// data[b] > pivot; data[c-1] <= pivot
data[b], data[c-1] = data[c-1], data[b]
b++
c--
}
// If hi-c<3 then there are duplicates (by property of median of nine).
// Let's be a bit more conservative, and set border to 5.
protect := hi-c < 5
if !protect && hi-c < (hi-lo)/4 {
// Lets test some points for equality to pivot
dups := 0
if data[pivot].freq == data[hi-1].freq && data[pivot].literal > data[hi-1].literal || data[pivot].freq > data[hi-1].freq { // data[hi-1] = pivot
data[c], data[hi-1] = data[hi-1], data[c]
c++
dups++
}
if data[b-1].freq == data[pivot].freq && data[b-1].literal > data[pivot].literal || data[b-1].freq > data[pivot].freq { // data[b-1] = pivot
b--
dups++
}
// m-lo = (hi-lo)/2 > 6
// b-lo > (hi-lo)*3/4-1 > 8
// ==> m < b ==> data[m] <= pivot
if data[m].freq == data[pivot].freq && data[m].literal > data[pivot].literal || data[m].freq > data[pivot].freq { // data[m] = pivot
data[m], data[b-1] = data[b-1], data[m]
b--
dups++
}
// if at least 2 points are equal to pivot, assume skewed distribution
protect = dups > 1
}
if protect {
// Protect against a lot of duplicates
// Add invariant:
// data[a <= i < b] unexamined
// data[b <= i < c] = pivot
for {
for ; a < b && (data[b-1].freq == data[pivot].freq && data[b-1].literal > data[pivot].literal || data[b-1].freq > data[pivot].freq); b-- { // data[b] == pivot
}
for ; a < b && (data[a].freq == data[pivot].freq && data[a].literal < data[pivot].literal || data[a].freq < data[pivot].freq); a++ { // data[a] < pivot
}
if a >= b {
break
}
// data[a] == pivot; data[b-1] < pivot
data[a], data[b-1] = data[b-1], data[a]
a++
b--
}
}
// Swap pivot into middle
data[pivot], data[b-1] = data[b-1], data[pivot]
return b - 1, c
}
// Insertion sort
func insertionSortByFreq(data []literalNode, a, b int) {
for i := a + 1; i < b; i++ {
for j := i; j > a && (data[j].freq == data[j-1].freq && data[j].literal < data[j-1].literal || data[j].freq < data[j-1].freq); j-- {
data[j], data[j-1] = data[j-1], data[j]
}
}
}
// quickSortByFreq, loosely following Bentley and McIlroy,
// ``Engineering a Sort Function,'' SP&E November 1993.
// medianOfThreeSortByFreq moves the median of the three values data[m0], data[m1], data[m2] into data[m1].
func medianOfThreeSortByFreq(data []literalNode, m1, m0, m2 int) {
// sort 3 elements
if data[m1].freq == data[m0].freq && data[m1].literal < data[m0].literal || data[m1].freq < data[m0].freq {
data[m1], data[m0] = data[m0], data[m1]
}
// data[m0] <= data[m1]
if data[m2].freq == data[m1].freq && data[m2].literal < data[m1].literal || data[m2].freq < data[m1].freq {
data[m2], data[m1] = data[m1], data[m2]
// data[m0] <= data[m2] && data[m1] < data[m2]
if data[m1].freq == data[m0].freq && data[m1].literal < data[m0].literal || data[m1].freq < data[m0].freq {
data[m1], data[m0] = data[m0], data[m1]
}
}
// now data[m0] <= data[m1] <= data[m2]
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/huffman_sortByLiteral.go
Generated Vendored
+201
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@@ -0,0 +1,201 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
// Sort sorts data.
// It makes one call to data.Len to determine n, and O(n*log(n)) calls to
// data.Less and data.Swap. The sort is not guaranteed to be stable.
func sortByLiteral(data []literalNode) {
n := len(data)
quickSort(data, 0, n, maxDepth(n))
}
func quickSort(data []literalNode, a, b, maxDepth int) {
for b-a > 12 { // Use ShellSort for slices <= 12 elements
if maxDepth == 0 {
heapSort(data, a, b)
return
}
maxDepth--
mlo, mhi := doPivot(data, a, b)
// Avoiding recursion on the larger subproblem guarantees
// a stack depth of at most lg(b-a).
if mlo-a < b-mhi {
quickSort(data, a, mlo, maxDepth)
a = mhi // i.e., quickSort(data, mhi, b)
} else {
quickSort(data, mhi, b, maxDepth)
b = mlo // i.e., quickSort(data, a, mlo)
}
}
if b-a > 1 {
// Do ShellSort pass with gap 6
// It could be written in this simplified form cause b-a <= 12
for i := a + 6; i < b; i++ {
if data[i].literal < data[i-6].literal {
data[i], data[i-6] = data[i-6], data[i]
}
}
insertionSort(data, a, b)
}
}
func heapSort(data []literalNode, a, b int) {
first := a
lo := 0
hi := b - a
// Build heap with greatest element at top.
for i := (hi - 1) / 2; i >= 0; i-- {
siftDown(data, i, hi, first)
}
// Pop elements, largest first, into end of data.
for i := hi - 1; i >= 0; i-- {
data[first], data[first+i] = data[first+i], data[first]
siftDown(data, lo, i, first)
}
}
// siftDown implements the heap property on data[lo, hi).
// first is an offset into the array where the root of the heap lies.
func siftDown(data []literalNode, lo, hi, first int) {
root := lo
for {
child := 2*root + 1
if child >= hi {
break
}
if child+1 < hi && data[first+child].literal < data[first+child+1].literal {
child++
}
if data[first+root].literal > data[first+child].literal {
return
}
data[first+root], data[first+child] = data[first+child], data[first+root]
root = child
}
}
func doPivot(data []literalNode, lo, hi int) (midlo, midhi int) {
m := int(uint(lo+hi) >> 1) // Written like this to avoid integer overflow.
if hi-lo > 40 {
// Tukey's ``Ninther,'' median of three medians of three.
s := (hi - lo) / 8
medianOfThree(data, lo, lo+s, lo+2*s)
medianOfThree(data, m, m-s, m+s)
medianOfThree(data, hi-1, hi-1-s, hi-1-2*s)
}
medianOfThree(data, lo, m, hi-1)
// Invariants are:
// data[lo] = pivot (set up by ChoosePivot)
// data[lo < i < a] < pivot
// data[a <= i < b] <= pivot
// data[b <= i < c] unexamined
// data[c <= i < hi-1] > pivot
// data[hi-1] >= pivot
pivot := lo
a, c := lo+1, hi-1
for ; a < c && data[a].literal < data[pivot].literal; a++ {
}
b := a
for {
for ; b < c && data[pivot].literal > data[b].literal; b++ { // data[b] <= pivot
}
for ; b < c && data[pivot].literal < data[c-1].literal; c-- { // data[c-1] > pivot
}
if b >= c {
break
}
// data[b] > pivot; data[c-1] <= pivot
data[b], data[c-1] = data[c-1], data[b]
b++
c--
}
// If hi-c<3 then there are duplicates (by property of median of nine).
// Let's be a bit more conservative, and set border to 5.
protect := hi-c < 5
if !protect && hi-c < (hi-lo)/4 {
// Lets test some points for equality to pivot
dups := 0
if data[pivot].literal > data[hi-1].literal { // data[hi-1] = pivot
data[c], data[hi-1] = data[hi-1], data[c]
c++
dups++
}
if data[b-1].literal > data[pivot].literal { // data[b-1] = pivot
b--
dups++
}
// m-lo = (hi-lo)/2 > 6
// b-lo > (hi-lo)*3/4-1 > 8
// ==> m < b ==> data[m] <= pivot
if data[m].literal > data[pivot].literal { // data[m] = pivot
data[m], data[b-1] = data[b-1], data[m]
b--
dups++
}
// if at least 2 points are equal to pivot, assume skewed distribution
protect = dups > 1
}
if protect {
// Protect against a lot of duplicates
// Add invariant:
// data[a <= i < b] unexamined
// data[b <= i < c] = pivot
for {
for ; a < b && data[b-1].literal > data[pivot].literal; b-- { // data[b] == pivot
}
for ; a < b && data[a].literal < data[pivot].literal; a++ { // data[a] < pivot
}
if a >= b {
break
}
// data[a] == pivot; data[b-1] < pivot
data[a], data[b-1] = data[b-1], data[a]
a++
b--
}
}
// Swap pivot into middle
data[pivot], data[b-1] = data[b-1], data[pivot]
return b - 1, c
}
// Insertion sort
func insertionSort(data []literalNode, a, b int) {
for i := a + 1; i < b; i++ {
for j := i; j > a && data[j].literal < data[j-1].literal; j-- {
data[j], data[j-1] = data[j-1], data[j]
}
}
}
// maxDepth returns a threshold at which quicksort should switch
// to heapsort. It returns 2*ceil(lg(n+1)).
func maxDepth(n int) int {
var depth int
for i := n; i > 0; i >>= 1 {
depth++
}
return depth * 2
}
// medianOfThree moves the median of the three values data[m0], data[m1], data[m2] into data[m1].
func medianOfThree(data []literalNode, m1, m0, m2 int) {
// sort 3 elements
if data[m1].literal < data[m0].literal {
data[m1], data[m0] = data[m0], data[m1]
}
// data[m0] <= data[m1]
if data[m2].literal < data[m1].literal {
data[m2], data[m1] = data[m1], data[m2]
// data[m0] <= data[m2] && data[m1] < data[m2]
if data[m1].literal < data[m0].literal {
data[m1], data[m0] = data[m0], data[m1]
}
}
// now data[m0] <= data[m1] <= data[m2]
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/inflate.go
Generated Vendored
+959
View File
@@ -0,0 +1,959 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package flate implements the DEFLATE compressed data format, described in
// RFC 1951. The gzip and zlib packages implement access to DEFLATE-based file
// formats.
package flate
import (
"bufio"
"compress/flate"
"fmt"
"io"
"math/bits"
"sync"
"github.com/klauspost/compress/internal/regmask"
)
const (
maxCodeLen = 16 // max length of Huffman code
maxCodeLenMask = 15 // mask for max length of Huffman code
// The next three numbers come from the RFC section 3.2.7, with the
// additional proviso in section 3.2.5 which implies that distance codes
// 30 and 31 should never occur in compressed data.
maxNumLit = 286
maxNumDist = 30
numCodes = 19 // number of codes in Huffman meta-code
debugDecode = false
)
// Value of length - 3 and extra bits.
type lengthExtra struct {
length, extra uint8
}
var decCodeToLen = [32]lengthExtra{{length: 0x0, extra: 0x0}, {length: 0x1, extra: 0x0}, {length: 0x2, extra: 0x0}, {length: 0x3, extra: 0x0}, {length: 0x4, extra: 0x0}, {length: 0x5, extra: 0x0}, {length: 0x6, extra: 0x0}, {length: 0x7, extra: 0x0}, {length: 0x8, extra: 0x1}, {length: 0xa, extra: 0x1}, {length: 0xc, extra: 0x1}, {length: 0xe, extra: 0x1}, {length: 0x10, extra: 0x2}, {length: 0x14, extra: 0x2}, {length: 0x18, extra: 0x2}, {length: 0x1c, extra: 0x2}, {length: 0x20, extra: 0x3}, {length: 0x28, extra: 0x3}, {length: 0x30, extra: 0x3}, {length: 0x38, extra: 0x3}, {length: 0x40, extra: 0x4}, {length: 0x50, extra: 0x4}, {length: 0x60, extra: 0x4}, {length: 0x70, extra: 0x4}, {length: 0x80, extra: 0x5}, {length: 0xa0, extra: 0x5}, {length: 0xc0, extra: 0x5}, {length: 0xe0, extra: 0x5}, {length: 0xff, extra: 0x0}, {length: 0x0, extra: 0x0}, {length: 0x0, extra: 0x0}, {length: 0x0, extra: 0x0}}
var bitMask32 = [32]uint32{
0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F, 0xFF,
0x1FF, 0x3FF, 0x7FF, 0xFFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF,
0x1ffff, 0x3ffff, 0x7FFFF, 0xfFFFF, 0x1fFFFF, 0x3fFFFF, 0x7fFFFF, 0xffFFFF,
0x1ffFFFF, 0x3ffFFFF, 0x7ffFFFF, 0xfffFFFF, 0x1fffFFFF, 0x3fffFFFF, 0x7fffFFFF,
} // up to 32 bits
// Initialize the fixedHuffmanDecoder only once upon first use.
var fixedOnce sync.Once
var fixedHuffmanDecoder huffmanDecoder
// A CorruptInputError reports the presence of corrupt input at a given offset.
type CorruptInputError = flate.CorruptInputError
// An InternalError reports an error in the flate code itself.
type InternalError string
func (e InternalError) Error() string { return "flate: internal error: " + string(e) }
// A ReadError reports an error encountered while reading input.
//
// Deprecated: No longer returned.
type ReadError = flate.ReadError
// A WriteError reports an error encountered while writing output.
//
// Deprecated: No longer returned.
type WriteError = flate.WriteError
// Resetter resets a ReadCloser returned by NewReader or NewReaderDict to
// to switch to a new underlying Reader. This permits reusing a ReadCloser
// instead of allocating a new one.
type Resetter interface {
// Reset discards any buffered data and resets the Resetter as if it was
// newly initialized with the given reader.
Reset(r io.Reader, dict []byte) error
}
// The data structure for decoding Huffman tables is based on that of
// zlib. There is a lookup table of a fixed bit width (huffmanChunkBits),
// For codes smaller than the table width, there are multiple entries
// (each combination of trailing bits has the same value). For codes
// larger than the table width, the table contains a link to an overflow
// table. The width of each entry in the link table is the maximum code
// size minus the chunk width.
//
// Note that you can do a lookup in the table even without all bits
// filled. Since the extra bits are zero, and the DEFLATE Huffman codes
// have the property that shorter codes come before longer ones, the
// bit length estimate in the result is a lower bound on the actual
// number of bits.
//
// See the following:
// http://www.gzip.org/algorithm.txt
// chunk & 15 is number of bits
// chunk >> 4 is value, including table link
const (
huffmanChunkBits = 9
huffmanNumChunks = 1 << huffmanChunkBits
huffmanCountMask = 15
huffmanValueShift = 4
)
type huffmanDecoder struct {
maxRead int // the maximum number of bits we can read and not overread
chunks *[huffmanNumChunks]uint16 // chunks as described above
links [][]uint16 // overflow links
linkMask uint32 // mask the width of the link table
}
// Initialize Huffman decoding tables from array of code lengths.
// Following this function, h is guaranteed to be initialized into a complete
// tree (i.e., neither over-subscribed nor under-subscribed). The exception is a
// degenerate case where the tree has only a single symbol with length 1. Empty
// trees are permitted.
func (h *huffmanDecoder) init(lengths []int) bool {
// Sanity enables additional runtime tests during Huffman
// table construction. It's intended to be used during
// development to supplement the currently ad-hoc unit tests.
const sanity = false
if h.chunks == nil {
h.chunks = new([huffmanNumChunks]uint16)
}
if h.maxRead != 0 {
*h = huffmanDecoder{chunks: h.chunks, links: h.links}
}
// Count number of codes of each length,
// compute maxRead and max length.
var count [maxCodeLen]int
var min, max int
for _, n := range lengths {
if n == 0 {
continue
}
if min == 0 || n < min {
min = n
}
if n > max {
max = n
}
count[n&maxCodeLenMask]++
}
// Empty tree. The decompressor.huffSym function will fail later if the tree
// is used. Technically, an empty tree is only valid for the HDIST tree and
// not the HCLEN and HLIT tree. However, a stream with an empty HCLEN tree
// is guaranteed to fail since it will attempt to use the tree to decode the
// codes for the HLIT and HDIST trees. Similarly, an empty HLIT tree is
// guaranteed to fail later since the compressed data section must be
// composed of at least one symbol (the end-of-block marker).
if max == 0 {
return true
}
code := 0
var nextcode [maxCodeLen]int
for i := min; i <= max; i++ {
code <<= 1
nextcode[i&maxCodeLenMask] = code
code += count[i&maxCodeLenMask]
}
// Check that the coding is complete (i.e., that we've
// assigned all 2-to-the-max possible bit sequences).
// Exception: To be compatible with zlib, we also need to
// accept degenerate single-code codings. See also
// TestDegenerateHuffmanCoding.
if code != 1<<uint(max) && !(code == 1 && max == 1) {
if debugDecode {
fmt.Println("coding failed, code, max:", code, max, code == 1<<uint(max), code == 1 && max == 1, "(one should be true)")
}
return false
}
h.maxRead = min
chunks := h.chunks[:]
for i := range chunks {
chunks[i] = 0
}
if max > huffmanChunkBits {
numLinks := 1 << (uint(max) - huffmanChunkBits)
h.linkMask = uint32(numLinks - 1)
// create link tables
link := nextcode[huffmanChunkBits+1] >> 1
if cap(h.links) < huffmanNumChunks-link {
h.links = make([][]uint16, huffmanNumChunks-link)
} else {
h.links = h.links[:huffmanNumChunks-link]
}
for j := uint(link); j < huffmanNumChunks; j++ {
reverse := int(bits.Reverse16(uint16(j)))
reverse >>= uint(16 - huffmanChunkBits)
off := j - uint(link)
if sanity && h.chunks[reverse] != 0 {
panic("impossible: overwriting existing chunk")
}
h.chunks[reverse] = uint16(off<<huffmanValueShift | (huffmanChunkBits + 1))
if cap(h.links[off]) < numLinks {
h.links[off] = make([]uint16, numLinks)
} else {
h.links[off] = h.links[off][:numLinks]
}
}
} else {
h.links = h.links[:0]
}
for i, n := range lengths {
if n == 0 {
continue
}
code := nextcode[n]
nextcode[n]++
chunk := uint16(i<<huffmanValueShift | n)
reverse := int(bits.Reverse16(uint16(code)))
reverse >>= uint(16 - n)
if n <= huffmanChunkBits {
for off := reverse; off < len(h.chunks); off += 1 << uint(n) {
// We should never need to overwrite
// an existing chunk. Also, 0 is
// never a valid chunk, because the
// lower 4 "count" bits should be
// between 1 and 15.
if sanity && h.chunks[off] != 0 {
panic("impossible: overwriting existing chunk")
}
h.chunks[off] = chunk
}
} else {
j := reverse & (huffmanNumChunks - 1)
if sanity && h.chunks[j]&huffmanCountMask != huffmanChunkBits+1 {
// Longer codes should have been
// associated with a link table above.
panic("impossible: not an indirect chunk")
}
value := h.chunks[j] >> huffmanValueShift
linktab := h.links[value]
reverse >>= huffmanChunkBits
for off := reverse; off < len(linktab); off += 1 << uint(n-huffmanChunkBits) {
if sanity && linktab[off] != 0 {
panic("impossible: overwriting existing chunk")
}
linktab[off] = chunk
}
}
}
if sanity {
// Above we've sanity checked that we never overwrote
// an existing entry. Here we additionally check that
// we filled the tables completely.
for i, chunk := range h.chunks {
if chunk == 0 {
// As an exception, in the degenerate
// single-code case, we allow odd
// chunks to be missing.
if code == 1 && i%2 == 1 {
continue
}
panic("impossible: missing chunk")
}
}
for _, linktab := range h.links {
for _, chunk := range linktab {
if chunk == 0 {
panic("impossible: missing chunk")
}
}
}
}
return true
}
// Reader is the actual read interface needed by NewReader.
// If the passed in io.Reader does not also have ReadByte,
// the NewReader will introduce its own buffering.
type Reader interface {
io.Reader
io.ByteReader
}
type step uint8
const (
copyData step = iota + 1
nextBlock
huffmanBytesBuffer
huffmanBytesReader
huffmanBufioReader
huffmanStringsReader
huffmanGenericReader
)
// flushMode tells decompressor when to return data
type flushMode uint8
const (
syncFlush flushMode = iota // return data after sync flush block
partialFlush // return data after each block
)
// Decompress state.
type decompressor struct {
// Input source.
r Reader
roffset int64
// Huffman decoders for literal/length, distance.
h1, h2 huffmanDecoder
// Length arrays used to define Huffman codes.
bits *[maxNumLit + maxNumDist]int
codebits *[numCodes]int
// Output history, buffer.
dict dictDecoder
// Next step in the decompression,
// and decompression state.
step step
stepState int
err error
toRead []byte
hl, hd *huffmanDecoder
copyLen int
copyDist int
// Temporary buffer (avoids repeated allocation).
buf [4]byte
// Input bits, in top of b.
b uint32
nb uint
final bool
flushMode flushMode
cb func(InflateCheckpoint)
cp InflateCheckpoint
hasCP bool // WithResumeFrom was supplied
uncOffset int64 // baseline uncompressed offset (from a resume checkpoint)
cpBuf []byte
}
func (f *decompressor) nextBlock() {
for f.nb < 1+2 {
if f.err = f.moreBits(); f.err != nil {
return
}
}
f.final = f.b&1 == 1
f.b >>= 1
typ := f.b & 3
f.b >>= 2
f.nb -= 1 + 2
switch typ {
case 0:
f.dataBlock()
if debugDecode {
fmt.Println("stored block")
}
case 1:
// compressed, fixed Huffman tables
f.hl = &fixedHuffmanDecoder
f.hd = nil
f.huffmanBlockDecoder()
if debugDecode {
fmt.Println("predefinied huffman block")
}
case 2:
// compressed, dynamic Huffman tables
if f.err = f.readHuffman(); f.err != nil {
break
}
f.hl = &f.h1
f.hd = &f.h2
f.huffmanBlockDecoder()
if debugDecode {
fmt.Println("dynamic huffman block")
}
default:
// 3 is reserved.
if debugDecode {
fmt.Println("reserved data block encountered")
}
f.err = CorruptInputError(f.roffset)
}
}
func (f *decompressor) Read(b []byte) (int, error) {
for {
if len(f.toRead) > 0 {
n := copy(b, f.toRead)
f.toRead = f.toRead[n:]
if len(f.toRead) == 0 {
return n, f.err
}
return n, nil
}
if f.err != nil {
return 0, f.err
}
f.doStep()
if f.err != nil && len(f.toRead) == 0 {
f.toRead = f.dict.readFlush() // Flush what's left in case of error
}
}
}
// WriteTo implements the io.WriteTo interface for io.Copy and friends.
func (f *decompressor) WriteTo(w io.Writer) (int64, error) {
total := int64(0)
flushed := false
for {
if len(f.toRead) > 0 {
n, err := w.Write(f.toRead)
total += int64(n)
if err != nil {
f.err = err
return total, err
}
if n != len(f.toRead) {
return total, io.ErrShortWrite
}
f.toRead = f.toRead[:0]
}
if f.err != nil && flushed {
if f.err == io.EOF {
return total, nil
}
return total, f.err
}
if f.err == nil {
f.doStep()
}
if len(f.toRead) == 0 && f.err != nil && !flushed {
f.toRead = f.dict.readFlush() // Flush what's left in case of error
flushed = true
}
}
}
func (f *decompressor) Close() error {
if f.err == io.EOF {
return nil
}
return f.err
}
// RFC 1951 section 3.2.7.
// Compression with dynamic Huffman codes
var codeOrder = [...]int{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}
func (f *decompressor) readHuffman() error {
// HLIT[5], HDIST[5], HCLEN[4].
for f.nb < 5+5+4 {
if err := f.moreBits(); err != nil {
return err
}
}
nlit := int(f.b&0x1F) + 257
if nlit > maxNumLit {
if debugDecode {
fmt.Println("nlit > maxNumLit", nlit)
}
return CorruptInputError(f.roffset)
}
f.b >>= 5
ndist := int(f.b&0x1F) + 1
if ndist > maxNumDist {
if debugDecode {
fmt.Println("ndist > maxNumDist", ndist)
}
return CorruptInputError(f.roffset)
}
f.b >>= 5
nclen := int(f.b&0xF) + 4
// numCodes is 19, so nclen is always valid.
f.b >>= 4
f.nb -= 5 + 5 + 4
// (HCLEN+4)*3 bits: code lengths in the magic codeOrder order.
for i := range nclen {
for f.nb < 3 {
if err := f.moreBits(); err != nil {
return err
}
}
f.codebits[codeOrder[i]] = int(f.b & 0x7)
f.b >>= 3
f.nb -= 3
}
for i := nclen; i < len(codeOrder); i++ {
f.codebits[codeOrder[i]] = 0
}
if !f.h1.init(f.codebits[0:]) {
if debugDecode {
fmt.Println("init codebits failed")
}
return CorruptInputError(f.roffset)
}
// HLIT + 257 code lengths, HDIST + 1 code lengths,
// using the code length Huffman code.
for i, n := 0, nlit+ndist; i < n; {
x, err := f.huffSym(&f.h1)
if err != nil {
return err
}
if x < 16 {
// Actual length.
f.bits[i] = x
i++
continue
}
// Repeat previous length or zero.
var rep int
var nb uint
var b int
switch x {
default:
return InternalError("unexpected length code")
case 16:
rep = 3
nb = 2
if i == 0 {
if debugDecode {
fmt.Println("i==0")
}
return CorruptInputError(f.roffset)
}
b = f.bits[i-1]
case 17:
rep = 3
nb = 3
b = 0
case 18:
rep = 11
nb = 7
b = 0
}
for f.nb < nb {
if err := f.moreBits(); err != nil {
if debugDecode {
fmt.Println("morebits:", err)
}
return err
}
}
rep += int(f.b & uint32(1<<(nb&regmask.Shift32ByUint)-1))
f.b >>= nb & regmask.Shift32ByUint
f.nb -= nb
if i+rep > n {
if debugDecode {
fmt.Println("i+rep > n", i, rep, n)
}
return CorruptInputError(f.roffset)
}
for j := 0; j < rep; j++ {
f.bits[i] = b
i++
}
}
if !f.h1.init(f.bits[0:nlit]) || !f.h2.init(f.bits[nlit:nlit+ndist]) {
if debugDecode {
fmt.Println("init2 failed")
}
return CorruptInputError(f.roffset)
}
// As an optimization, we can initialize the maxRead bits to read at a time
// for the HLIT tree to the length of the EOB marker since we know that
// every block must terminate with one. This preserves the property that
// we never read any extra bytes after the end of the DEFLATE stream.
if f.h1.maxRead < f.bits[endBlockMarker] {
f.h1.maxRead = f.bits[endBlockMarker]
}
if !f.final {
// If not the final block, the smallest block possible is
// a predefined table, BTYPE=01, with a single EOB marker.
// This will take up 3 + 7 bits.
f.h1.maxRead += 10
}
return nil
}
// Copy a single uncompressed data block from input to output.
func (f *decompressor) dataBlock() {
// Uncompressed.
// Discard current half-byte.
left := (f.nb) & 7
f.nb -= left
f.b >>= left
offBytes := f.nb >> 3
// Unfilled values will be overwritten.
f.buf[0] = uint8(f.b)
f.buf[1] = uint8(f.b >> 8)
f.buf[2] = uint8(f.b >> 16)
f.buf[3] = uint8(f.b >> 24)
f.roffset += int64(offBytes)
f.nb, f.b = 0, 0
// Length then ones-complement of length.
nr, err := io.ReadFull(f.r, f.buf[offBytes:4])
f.roffset += int64(nr)
if err != nil {
f.err = noEOF(err)
return
}
n := uint16(f.buf[0]) | uint16(f.buf[1])<<8
nn := uint16(f.buf[2]) | uint16(f.buf[3])<<8
if nn != ^n {
if debugDecode {
ncomp := ^n
fmt.Println("uint16(nn) != uint16(^n)", nn, ncomp)
}
f.err = CorruptInputError(f.roffset)
return
}
if n == 0 {
if f.flushMode == syncFlush {
f.toRead = f.dict.readFlush()
}
f.finishBlock()
return
}
f.copyLen = int(n)
f.copyData()
}
// copyData copies f.copyLen bytes from the underlying reader into f.hist.
// It pauses for reads when f.hist is full.
func (f *decompressor) copyData() {
buf := f.dict.writeSlice()
if len(buf) > f.copyLen {
buf = buf[:f.copyLen]
}
cnt, err := io.ReadFull(f.r, buf)
f.roffset += int64(cnt)
f.copyLen -= cnt
f.dict.writeMark(cnt)
if err != nil {
f.err = noEOF(err)
return
}
if f.dict.availWrite() == 0 || f.copyLen > 0 {
f.toRead = f.dict.readFlush()
f.step = copyData
return
}
f.finishBlock()
}
func (f *decompressor) finishBlock() {
if f.final {
if f.dict.availRead() > 0 {
f.toRead = f.dict.readFlush()
}
f.err = io.EOF
} else if f.flushMode == partialFlush && f.dict.availRead() > 0 {
f.toRead = f.dict.readFlush()
}
if f.cb != nil {
bitPos := f.roffset*8 - int64(f.nb)
f.cpBuf = f.dict.appendWindow(f.cpBuf[:0])
f.cb(InflateCheckpoint{
UncompressedOffset: f.uncOffset + f.dict.decoded(),
CompressedOffset: bitPos / 8,
Final: f.final,
BitOffset: uint8(bitPos & 7),
Window: f.cpBuf,
})
}
f.step = nextBlock
}
func (f *decompressor) doStep() {
switch f.step {
case copyData:
f.copyData()
case nextBlock:
f.nextBlock()
case huffmanBytesBuffer:
f.huffmanBytesBuffer()
case huffmanBytesReader:
f.huffmanBytesReader()
case huffmanBufioReader:
f.huffmanBufioReader()
case huffmanStringsReader:
f.huffmanStringsReader()
case huffmanGenericReader:
f.huffmanGenericReader()
default:
panic("BUG: unexpected step state")
}
}
// noEOF returns err, unless err == io.EOF, in which case it returns io.ErrUnexpectedEOF.
func noEOF(e error) error {
if e == io.EOF {
return io.ErrUnexpectedEOF
}
return e
}
func (f *decompressor) moreBits() error {
c, err := f.r.ReadByte()
if err != nil {
return noEOF(err)
}
f.roffset++
f.b |= uint32(c) << (f.nb & regmask.Shift32ByUint)
f.nb += 8
return nil
}
// Read the next Huffman-encoded symbol from f according to h.
func (f *decompressor) huffSym(h *huffmanDecoder) (int, error) {
// Since a huffmanDecoder can be empty or be composed of a degenerate tree
// with single element, huffSym must error on these two edge cases. In both
// cases, the chunks slice will be 0 for the invalid sequence, leading it
// satisfy the n == 0 check below.
n := uint(h.maxRead)
// Optimization. Compiler isn't smart enough to keep f.b,f.nb in registers,
// but is smart enough to keep local variables in registers, so use nb and b,
// inline call to moreBits and reassign b,nb back to f on return.
nb, b := f.nb, f.b
for {
for nb < n {
c, err := f.r.ReadByte()
if err != nil {
f.b = b
f.nb = nb
return 0, noEOF(err)
}
f.roffset++
b |= uint32(c) << (nb & regmask.Shift32ByUint)
nb += 8
}
chunk := h.chunks[b&(huffmanNumChunks-1)]
n = uint(chunk & huffmanCountMask)
if n > huffmanChunkBits {
chunk = h.links[chunk>>huffmanValueShift][(b>>huffmanChunkBits)&h.linkMask]
n = uint(chunk & huffmanCountMask)
}
if n <= nb {
if n == 0 {
f.b = b
f.nb = nb
if debugDecode {
fmt.Println("huffsym: n==0")
}
f.err = CorruptInputError(f.roffset)
return 0, f.err
}
f.b = b >> (n & regmask.Shift32ByUint)
f.nb = nb - n
return int(chunk >> huffmanValueShift), nil
}
}
}
func makeReader(r io.Reader) Reader {
if rr, ok := r.(Reader); ok {
return rr
}
return bufio.NewReader(r)
}
func fixedHuffmanDecoderInit() {
fixedOnce.Do(func() {
// These come from the RFC section 3.2.6.
var bits [288]int
for i := range 144 {
bits[i] = 8
}
for i := 144; i < 256; i++ {
bits[i] = 9
}
for i := 256; i < 280; i++ {
bits[i] = 7
}
for i := 280; i < 288; i++ {
bits[i] = 8
}
fixedHuffmanDecoder.init(bits[:])
})
}
func (f *decompressor) Reset(r io.Reader, dict []byte) error {
*f = decompressor{
r: makeReader(r),
bits: f.bits,
codebits: f.codebits,
h1: f.h1,
h2: f.h2,
dict: f.dict,
step: nextBlock,
}
f.dict.init(maxMatchOffset, dict)
return nil
}
// ResetCP will adjust the input to the provided checkpoint.
// It is assumed the input stream is forwarded to cp.CompressedOffset.
func (f *decompressor) ResetCP(r io.Reader, cp InflateCheckpoint) error {
*f = decompressor{
r: makeReader(r),
bits: f.bits,
codebits: f.codebits,
h1: f.h1,
h2: f.h2,
dict: f.dict,
step: nextBlock,
cpBuf: f.cpBuf,
}
return f.applyCP(cp)
}
// applyCP seeds the decompressor state from a resume checkpoint:
// loads the sliding window, sets the absolute compressed/uncompressed
// offsets, and skips cp.BitOffset bits into the first input byte so
// the next decode aligns with the start of a deflate block.
func (f *decompressor) applyCP(cp InflateCheckpoint) error {
f.dict.init(maxMatchOffset, cp.Window)
f.roffset = cp.CompressedOffset
f.uncOffset = cp.UncompressedOffset
f.final = cp.Final
f.b = 0
f.nb = 0
if cp.BitOffset > 0 {
c, err := f.r.ReadByte()
if err != nil {
return noEOF(err)
}
f.roffset++
f.b = uint32(c) >> cp.BitOffset
f.nb = 8 - uint(cp.BitOffset)
}
return nil
}
type ReaderOpt func(*decompressor)
// WithPartialBlock tells decompressor to return after each block,
// so it can read data written with partial flush
func WithPartialBlock() ReaderOpt {
return func(f *decompressor) {
f.flushMode = partialFlush
}
}
// WithDict initializes the reader with a preset dictionary
func WithDict(dict []byte) ReaderOpt {
return func(f *decompressor) {
f.dict.init(maxMatchOffset, dict)
}
}
// InflateCheckpoint provides a resumable checkpoint for inflate.
type InflateCheckpoint struct {
UncompressedOffset int64 // Byte offset in the decompressed stream
CompressedOffset int64 // Byte offset in the compressed stream
Final bool // True if this is the final block
BitOffset uint8 // 0-7 bits
Window []byte // 32KB sliding window dictionary
}
// WithEobCallback will call the provided function after each block
// with the current gzip checkpoint.
// After returning the provided window can no longer be referenced.
// The callback will not be triggered after a block is marked "final".
// The callback is not retained after Reset.
func WithEobCallback(cb func(InflateCheckpoint)) ReaderOpt {
return func(f *decompressor) {
f.cb = cb
}
}
// WithResumeFrom will adjust the input to the provided checkpoint.
// It is assumed the input stream is forwarded to the provided offset.
// The checkpoint is removed when Reset is called.
func WithResumeFrom(cp InflateCheckpoint) ReaderOpt {
return func(f *decompressor) {
f.cp = cp
f.hasCP = true
}
}
// NewReaderOpts returns new reader with provided options
func NewReaderOpts(r io.Reader, opts ...ReaderOpt) io.ReadCloser {
fixedHuffmanDecoderInit()
var f decompressor
f.r = makeReader(r)
f.bits = new([maxNumLit + maxNumDist]int)
f.codebits = new([numCodes]int)
f.step = nextBlock
f.dict.init(maxMatchOffset, nil)
for _, opt := range opts {
opt(&f)
}
if f.hasCP {
if err := f.applyCP(f.cp); err != nil {
f.err = err
}
}
return &f
}
// NewReader returns a new ReadCloser that can be used
// to read the uncompressed version of r.
// If r does not also implement io.ByteReader,
// the decompressor may read more data than necessary from r.
// It is the caller's responsibility to call Close on the ReadCloser
// when finished reading.
//
// The ReadCloser returned by NewReader also implements Resetter.
func NewReader(r io.Reader) io.ReadCloser {
return NewReaderOpts(r)
}
// NewReaderDict is like NewReader but initializes the reader
// with a preset dictionary. The returned Reader behaves as if
// the uncompressed data stream started with the given dictionary,
// which has already been read. NewReaderDict is typically used
// to read data compressed by NewWriterDict.
//
// The ReadCloser returned by NewReader also implements Resetter.
func NewReaderDict(r io.Reader, dict []byte) io.ReadCloser {
return NewReaderOpts(r, WithDict(dict))
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/inflate_gen.go
Generated Vendored
+1339
View File
File diff suppressed because it is too large Load Diff
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/level1.go
Generated Vendored
+215
View File
@@ -0,0 +1,215 @@
package flate
import (
"fmt"
"github.com/klauspost/compress/internal/le"
)
// fastGen maintains the table for matches,
// and the previous byte block for level 2.
// This is the generic implementation.
type fastEncL1 struct {
fastGen
table [tableSize]tableEntry
}
// EncodeL1 uses a similar algorithm to level 1
func (e *fastEncL1) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashBytes = 5
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// 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 := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 5
const doEvery = 2
nextS := s
var candidate tableEntry
var t int32
for {
nextHash := hashLen(cv, tableBits, hashBytes)
candidate = e.table[nextHash]
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
now := load6432(src, nextS)
e.table[nextHash] = tableEntry{offset: s + e.cur}
nextHash = hashLen(now, tableBits, hashBytes)
t = candidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
e.table[nextHash] = tableEntry{offset: nextS + e.cur}
break
}
// Do one right away...
cv = now
s = nextS
nextS++
candidate = e.table[nextHash]
now >>= 8
e.table[nextHash] = tableEntry{offset: s + e.cur}
t = candidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
e.table[nextHash] = tableEntry{offset: nextS + e.cur}
break
}
cv = now
s = nextS
}
// 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.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
// Extend the 4-byte match as long as possible.
l := e.matchlenLong(int(s+4), int(t+4), src) + 4
// Extend backwards
for t > 0 && s > nextEmit && le.Load8(src, t-1) == le.Load8(src, s-1) {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
// Save the match found
if false {
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
} else {
// Inlined...
xoffset := uint32(s - t - baseMatchOffset)
xlength := l
oc := offsetCode(xoffset)
xoffset |= oc << 16
for xlength > 0 {
xl := xlength
if xl > 258 {
if xl > 258+baseMatchLength {
xl = 258
} else {
xl = 258 - baseMatchLength
}
}
xlength -= xl
xl -= baseMatchLength
dst.extraHist[lengthCodes1[uint8(xl)]]++
dst.offHist[oc]++
dst.tokens[dst.n] = token(matchType | uint32(xl)<<lengthShift | xoffset)
dst.n++
}
}
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index first pair after match end.
if int(s+l+8) < len(src) {
cv := load6432(src, s)
e.table[hashLen(cv, tableBits, hashBytes)] = tableEntry{offset: s + e.cur}
}
goto emitRemainder
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-2 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 := load6432(src, s-2)
o := e.cur + s - 2
prevHash := hashLen(x, tableBits, hashBytes)
e.table[prevHash] = tableEntry{offset: o}
x >>= 16
currHash := hashLen(x, tableBits, hashBytes)
candidate = e.table[currHash]
e.table[currHash] = tableEntry{offset: o + 2}
t = candidate.offset - e.cur
if s-t > maxMatchOffset || uint32(x) != load3232(src, t) {
cv = x >> 8
s++
break
}
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/level2.go
Generated Vendored
+214
View File
@@ -0,0 +1,214 @@
package flate
import "fmt"
// fastGen maintains the table for matches,
// and the previous byte block for level 2.
// This is the generic implementation.
type fastEncL2 struct {
fastGen
table [bTableSize]tableEntry
}
// EncodeL2 uses a similar algorithm to level 1, but is capable
// of matching across blocks giving better compression at a small slowdown.
func (e *fastEncL2) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashBytes = 5
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// 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 := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
// When should we start skipping if we haven't found matches in a long while.
const skipLog = 5
const doEvery = 2
nextS := s
var candidate tableEntry
for {
nextHash := hashLen(cv, bTableBits, hashBytes)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
candidate = e.table[nextHash]
now := load6432(src, nextS)
e.table[nextHash] = tableEntry{offset: s + e.cur}
nextHash = hashLen(now, bTableBits, hashBytes)
offset := s - (candidate.offset - e.cur)
if offset < maxMatchOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) {
e.table[nextHash] = tableEntry{offset: nextS + e.cur}
break
}
// Do one right away...
cv = now
s = nextS
nextS++
candidate = e.table[nextHash]
now >>= 8
e.table[nextHash] = tableEntry{offset: s + e.cur}
offset = s - (candidate.offset - e.cur)
if offset < maxMatchOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) {
break
}
cv = now
}
// 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.
// 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.
// Extend the 4-byte match as long as possible.
t := candidate.offset - e.cur
l := e.matchlenLong(int(s+4), int(t+4), src) + 4
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index first pair after match end.
if int(s+l+8) < len(src) {
cv := load6432(src, s)
e.table[hashLen(cv, bTableBits, hashBytes)] = tableEntry{offset: s + e.cur}
}
goto emitRemainder
}
// Store every second hash in-between, but offset by 1.
for i := s - l + 2; i < s-5; i += 7 {
x := load6432(src, i)
nextHash := hashLen(x, bTableBits, hashBytes)
e.table[nextHash] = tableEntry{offset: e.cur + i}
// Skip one
x >>= 16
nextHash = hashLen(x, bTableBits, hashBytes)
e.table[nextHash] = tableEntry{offset: e.cur + i + 2}
// Skip one
x >>= 16
nextHash = hashLen(x, bTableBits, hashBytes)
e.table[nextHash] = tableEntry{offset: e.cur + i + 4}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-2 to 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 := load6432(src, s-2)
o := e.cur + s - 2
prevHash := hashLen(x, bTableBits, hashBytes)
prevHash2 := hashLen(x>>8, bTableBits, hashBytes)
e.table[prevHash] = tableEntry{offset: o}
e.table[prevHash2] = tableEntry{offset: o + 1}
currHash := hashLen(x>>16, bTableBits, hashBytes)
candidate = e.table[currHash]
e.table[currHash] = tableEntry{offset: o + 2}
offset := s - (candidate.offset - e.cur)
if offset > maxMatchOffset || uint32(x>>16) != load3232(src, candidate.offset-e.cur) {
cv = x >> 24
s++
break
}
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/level3.go
Generated Vendored
+241
View File
@@ -0,0 +1,241 @@
package flate
import "fmt"
// fastEncL3
type fastEncL3 struct {
fastGen
table [1 << 16]tableEntryPrev
}
// Encode uses a similar algorithm to level 2, will check up to two candidates.
func (e *fastEncL3) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
tableBits = 16
tableSize = 1 << tableBits
hashBytes = 5
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntryPrev{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i]
if v.Cur.offset <= minOff {
v.Cur.offset = 0
} else {
v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
}
if v.Prev.offset <= minOff {
v.Prev.offset = 0
} else {
v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
}
e.table[i] = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// Skip if too small.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// 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 := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 7
nextS := s
var candidate tableEntry
for {
nextHash := hashLen(cv, tableBits, hashBytes)
s = nextS
nextS = s + 1 + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
candidates := e.table[nextHash]
now := load6432(src, nextS)
// Safe offset distance until s + 4...
minOffset := e.cur + s - (maxMatchOffset - 4)
e.table[nextHash] = tableEntryPrev{Prev: candidates.Cur, Cur: tableEntry{offset: s + e.cur}}
// Check both candidates
candidate = candidates.Cur
if candidate.offset < minOffset {
cv = now
// Previous will also be invalid, we have nothing.
continue
}
if uint32(cv) == load3232(src, candidate.offset-e.cur) {
if candidates.Prev.offset < minOffset || uint32(cv) != load3232(src, candidates.Prev.offset-e.cur) {
break
}
// Both match and are valid, pick longest.
offset := s - (candidate.offset - e.cur)
o2 := s - (candidates.Prev.offset - e.cur)
l1, l2 := matchLen(src[s+4:], src[s-offset+4:]), matchLen(src[s+4:], src[s-o2+4:])
if l2 > l1 {
candidate = candidates.Prev
}
break
} else {
// We only check if value mismatches.
// Offset will always be invalid in other cases.
candidate = candidates.Prev
if candidate.offset > minOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) {
break
}
}
cv = now
}
// 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.
// Extend the 4-byte match as long as possible.
//
t := candidate.offset - e.cur
l := e.matchlenLong(int(s+4), int(t+4), src) + 4
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
t += l
// Index first pair after match end.
if int(t+8) < len(src) && t > 0 {
cv = load6432(src, t)
nextHash := hashLen(cv, tableBits, hashBytes)
e.table[nextHash] = tableEntryPrev{
Prev: e.table[nextHash].Cur,
Cur: tableEntry{offset: e.cur + t},
}
}
goto emitRemainder
}
// Store every 5th hash in-between.
for i := s - l + 2; i < s-5; i += 6 {
nextHash := hashLen(load6432(src, i), tableBits, hashBytes)
e.table[nextHash] = tableEntryPrev{
Prev: e.table[nextHash].Cur,
Cur: tableEntry{offset: e.cur + i}}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-2 to s.
x := load6432(src, s-2)
prevHash := hashLen(x, tableBits, hashBytes)
e.table[prevHash] = tableEntryPrev{
Prev: e.table[prevHash].Cur,
Cur: tableEntry{offset: e.cur + s - 2},
}
x >>= 8
prevHash = hashLen(x, tableBits, hashBytes)
e.table[prevHash] = tableEntryPrev{
Prev: e.table[prevHash].Cur,
Cur: tableEntry{offset: e.cur + s - 1},
}
x >>= 8
currHash := hashLen(x, tableBits, hashBytes)
candidates := e.table[currHash]
cv = x
e.table[currHash] = tableEntryPrev{
Prev: candidates.Cur,
Cur: tableEntry{offset: s + e.cur},
}
// Check both candidates
candidate = candidates.Cur
minOffset := e.cur + s - (maxMatchOffset - 4)
if candidate.offset > minOffset {
if uint32(cv) == load3232(src, candidate.offset-e.cur) {
// Found a match...
continue
}
candidate = candidates.Prev
if candidate.offset > minOffset && uint32(cv) == load3232(src, candidate.offset-e.cur) {
// Match at prev...
continue
}
}
cv = x >> 8
s++
break
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/level4.go
Generated Vendored
+221
View File
@@ -0,0 +1,221 @@
package flate
import "fmt"
type fastEncL4 struct {
fastGen
table [tableSize]tableEntry
bTable [tableSize]tableEntry
}
func (e *fastEncL4) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashShortBytes = 4
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
for i := range e.bTable[:] {
e.bTable[i] = tableEntry{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
for i := range e.bTable[:] {
v := e.bTable[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.bTable[i].offset = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// 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 := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 6
const doEvery = 1
nextS := s
var t int32
for {
nextHashS := hashLen(cv, tableBits, hashShortBytes)
nextHashL := hash7(cv, tableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
// Fetch a short+long candidate
sCandidate := e.table[nextHashS]
lCandidate := e.bTable[nextHashL]
next := load6432(src, nextS)
entry := tableEntry{offset: s + e.cur}
e.table[nextHashS] = entry
e.bTable[nextHashL] = entry
t = lCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// We got a long match. Use that.
break
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
lCandidate = e.bTable[hash7(next, tableBits)]
// If the next long is a candidate, check if we should use that instead...
lOff := lCandidate.offset - e.cur
if nextS-lOff < maxMatchOffset && load3232(src, lOff) == uint32(next) {
l1, l2 := matchLen(src[s+4:], src[t+4:]), matchLen(src[nextS+4:], src[nextS-lOff+4:])
if l2 > l1 {
s = nextS
t = lCandidate.offset - e.cur
}
}
break
}
cv = next
}
// 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.
// Extend the 4-byte match as long as possible.
l := e.matchlenLong(int(s+4), int(t+4), src) + 4
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
if debugDeflate {
if t >= s {
panic("s-t")
}
if (s - t) > maxMatchOffset {
panic(fmt.Sprintln("mmo", t))
}
if l < baseMatchLength {
panic("bml")
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index first pair after match end.
if int(s+8) < len(src) {
cv := load6432(src, s)
e.table[hashLen(cv, tableBits, hashShortBytes)] = tableEntry{offset: s + e.cur}
e.bTable[hash7(cv, tableBits)] = tableEntry{offset: s + e.cur}
}
goto emitRemainder
}
// Store every 3rd hash in-between
if true {
i := nextS
if i < s-1 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
e.bTable[hash7(cv, tableBits)] = t
e.bTable[hash7(cv>>8, tableBits)] = t2
e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = t2
i += 3
for ; i < s-1; i += 3 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
e.bTable[hash7(cv, tableBits)] = t
e.bTable[hash7(cv>>8, tableBits)] = t2
e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = t2
}
}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s.
x := load6432(src, s-1)
o := e.cur + s - 1
prevHashS := hashLen(x, tableBits, hashShortBytes)
prevHashL := hash7(x, tableBits)
e.table[prevHashS] = tableEntry{offset: o}
e.bTable[prevHashL] = tableEntry{offset: o}
cv = x >> 8
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/level5.go
Generated Vendored
+705
View File
@@ -0,0 +1,705 @@
package flate
import "fmt"
type fastEncL5 struct {
fastGen
table [tableSize]tableEntry
bTable [tableSize]tableEntryPrev
}
func (e *fastEncL5) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashShortBytes = 4
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
for i := range e.bTable[:] {
e.bTable[i] = tableEntryPrev{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
for i := range e.bTable[:] {
v := e.bTable[i]
if v.Cur.offset <= minOff {
v.Cur.offset = 0
v.Prev.offset = 0
} else {
v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
if v.Prev.offset <= minOff {
v.Prev.offset = 0
} else {
v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
}
}
e.bTable[i] = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// 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 := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 6
const doEvery = 1
nextS := s
var l int32
var t int32
for {
nextHashS := hashLen(cv, tableBits, hashShortBytes)
nextHashL := hash7(cv, tableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
// Fetch a short+long candidate
sCandidate := e.table[nextHashS]
lCandidate := e.bTable[nextHashL]
next := load6432(src, nextS)
entry := tableEntry{offset: s + e.cur}
e.table[nextHashS] = entry
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = entry, eLong.Cur
nextHashS = hashLen(next, tableBits, hashShortBytes)
nextHashL = hash7(next, tableBits)
t = lCandidate.Cur.offset - e.cur
if s-t < maxMatchOffset {
if uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, t2) {
l = e.matchlen(int(s+4), int(t+4), src) + 4
ml1 := e.matchlen(int(s+4), int(t2+4), src) + 4
if ml1 > l {
t = t2
l = ml1
break
}
}
break
}
t = lCandidate.Prev.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
break
}
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
l = e.matchlen(int(s+4), int(t+4), src) + 4
lCandidate = e.bTable[nextHashL]
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
// If the next long is a candidate, use that...
t2 := lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if load3232(src, t2) == uint32(next) {
ml := e.matchlen(int(nextS+4), int(t2+4), src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
// If the previous long is a candidate, use that...
t2 = lCandidate.Prev.offset - e.cur
if nextS-t2 < maxMatchOffset && load3232(src, t2) == uint32(next) {
ml := e.matchlen(int(nextS+4), int(t2+4), src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
}
break
}
cv = next
}
// 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.
if l == 0 {
// Extend the 4-byte match as long as possible.
l = e.matchlenLong(int(s+4), int(t+4), src) + 4
} else if l == maxMatchLength {
l += e.matchlenLong(int(s+l), int(t+l), src)
}
// Try to locate a better match by checking the end of best match...
if sAt := s + l; l < 30 && sAt < sLimit {
// Allow some bytes at the beginning to mismatch.
// Sweet spot is 2/3 bytes depending on input.
// 3 is only a little better when it is but sometimes a lot worse.
// The skipped bytes are tested in Extend backwards,
// and still picked up as part of the match if they do.
const skipBeginning = 2
eLong := e.bTable[hash7(load6432(src, sAt), tableBits)].Cur.offset
t2 := eLong - e.cur - l + skipBeginning
s2 := s + skipBeginning
off := s2 - t2
if t2 >= 0 && off < maxMatchOffset && off > 0 {
if l2 := e.matchlenLong(int(s2), int(t2), src); l2 > l {
t = t2
l = l2
s = s2
}
}
}
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
if debugDeflate {
if t >= s {
panic(fmt.Sprintln("s-t", s, t))
}
if (s - t) > maxMatchOffset {
panic(fmt.Sprintln("mmo", s-t))
}
if l < baseMatchLength {
panic("bml")
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
goto emitRemainder
}
// Store every 3rd hash in-between.
if true {
const hashEvery = 3
i := s - l + 1
if i < s-1 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
e.table[hashLen(cv, tableBits, hashShortBytes)] = t
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
// Do an long at i+1
cv >>= 8
t = tableEntry{offset: t.offset + 1}
eLong = &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
// We only have enough bits for a short entry at i+2
cv >>= 8
t = tableEntry{offset: t.offset + 1}
e.table[hashLen(cv, tableBits, hashShortBytes)] = t
// Skip one - otherwise we risk hitting 's'
i += 4
for ; i < s-1; i += hashEvery {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = t2
}
}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s.
x := load6432(src, s-1)
o := e.cur + s - 1
prevHashS := hashLen(x, tableBits, hashShortBytes)
prevHashL := hash7(x, tableBits)
e.table[prevHashS] = tableEntry{offset: o}
eLong := &e.bTable[prevHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: o}, eLong.Cur
cv = x >> 8
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
// fastEncL5Window is a level 5 encoder,
// but with a custom window size.
type fastEncL5Window struct {
hist []byte
cur int32
maxOffset int32
table [tableSize]tableEntry
bTable [tableSize]tableEntryPrev
}
func (e *fastEncL5Window) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashShortBytes = 4
)
maxMatchOffset := e.maxOffset
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
for i := range e.bTable[:] {
e.bTable[i] = tableEntryPrev{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
for i := range e.bTable[:] {
v := e.bTable[i]
if v.Cur.offset <= minOff {
v.Cur.offset = 0
v.Prev.offset = 0
} else {
v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
if v.Prev.offset <= minOff {
v.Prev.offset = 0
} else {
v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
}
}
e.bTable[i] = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// 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 := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
for {
const skipLog = 6
const doEvery = 1
nextS := s
var l int32
var t int32
for {
nextHashS := hashLen(cv, tableBits, hashShortBytes)
nextHashL := hash7(cv, tableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
// Fetch a short+long candidate
sCandidate := e.table[nextHashS]
lCandidate := e.bTable[nextHashL]
next := load6432(src, nextS)
entry := tableEntry{offset: s + e.cur}
e.table[nextHashS] = entry
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = entry, eLong.Cur
nextHashS = hashLen(next, tableBits, hashShortBytes)
nextHashL = hash7(next, tableBits)
t = lCandidate.Cur.offset - e.cur
if s-t < maxMatchOffset {
if uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, t2) {
l = e.matchlen(s+4, t+4, src) + 4
ml1 := e.matchlen(s+4, t2+4, src) + 4
if ml1 > l {
t = t2
l = ml1
break
}
}
break
}
t = lCandidate.Prev.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
break
}
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
l = e.matchlen(s+4, t+4, src) + 4
lCandidate = e.bTable[nextHashL]
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
// If the next long is a candidate, use that...
t2 := lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if load3232(src, t2) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
// If the previous long is a candidate, use that...
t2 = lCandidate.Prev.offset - e.cur
if nextS-t2 < maxMatchOffset && load3232(src, t2) == uint32(next) {
ml := e.matchlen(nextS+4, t2+4, src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
}
break
}
cv = next
}
// 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.
if l == 0 {
// Extend the 4-byte match as long as possible.
l = e.matchlenLong(s+4, t+4, src) + 4
} else if l == maxMatchLength {
l += e.matchlenLong(s+l, t+l, src)
}
// Try to locate a better match by checking the end of best match...
if sAt := s + l; l < 30 && sAt < sLimit {
// Allow some bytes at the beginning to mismatch.
// Sweet spot is 2/3 bytes depending on input.
// 3 is only a little better when it is but sometimes a lot worse.
// The skipped bytes are tested in Extend backwards,
// and still picked up as part of the match if they do.
const skipBeginning = 2
eLong := e.bTable[hash7(load6432(src, sAt), tableBits)].Cur.offset
t2 := eLong - e.cur - l + skipBeginning
s2 := s + skipBeginning
off := s2 - t2
if t2 >= 0 && off < maxMatchOffset && off > 0 {
if l2 := e.matchlenLong(s2, t2, src); l2 > l {
t = t2
l = l2
s = s2
}
}
}
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
if debugDeflate {
if t >= s {
panic(fmt.Sprintln("s-t", s, t))
}
if (s - t) > maxMatchOffset {
panic(fmt.Sprintln("mmo", s-t))
}
if l < baseMatchLength {
panic("bml")
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
goto emitRemainder
}
// Store every 3rd hash in-between.
if true {
const hashEvery = 3
i := s - l + 1
if i < s-1 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
e.table[hashLen(cv, tableBits, hashShortBytes)] = t
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
// Do an long at i+1
cv >>= 8
t = tableEntry{offset: t.offset + 1}
eLong = &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
// We only have enough bits for a short entry at i+2
cv >>= 8
t = tableEntry{offset: t.offset + 1}
e.table[hashLen(cv, tableBits, hashShortBytes)] = t
// Skip one - otherwise we risk hitting 's'
i += 4
for ; i < s-1; i += hashEvery {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = t, eLong.Cur
e.table[hashLen(cv>>8, tableBits, hashShortBytes)] = t2
}
}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s.
x := load6432(src, s-1)
o := e.cur + s - 1
prevHashS := hashLen(x, tableBits, hashShortBytes)
prevHashL := hash7(x, tableBits)
e.table[prevHashS] = tableEntry{offset: o}
eLong := &e.bTable[prevHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: o}, eLong.Cur
cv = x >> 8
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
// Reset the encoding table.
func (e *fastEncL5Window) Reset() {
// We keep the same allocs, since we are compressing the same block sizes.
if cap(e.hist) < allocHistory {
e.hist = make([]byte, 0, allocHistory)
}
// We offset current position so everything will be out of reach.
// If we are above the buffer reset it will be cleared anyway since len(hist) == 0.
if e.cur <= int32(bufferReset) {
e.cur += e.maxOffset + int32(len(e.hist))
}
e.hist = e.hist[:0]
}
func (e *fastEncL5Window) addBlock(src []byte) int32 {
// check if we have space already
maxMatchOffset := e.maxOffset
if len(e.hist)+len(src) > cap(e.hist) {
if cap(e.hist) == 0 {
e.hist = make([]byte, 0, allocHistory)
} else {
if cap(e.hist) < int(maxMatchOffset*2) {
panic("unexpected buffer size")
}
// Move down
offset := int32(len(e.hist)) - maxMatchOffset
copy(e.hist[0:maxMatchOffset], e.hist[offset:])
e.cur += offset
e.hist = e.hist[:maxMatchOffset]
}
}
s := int32(len(e.hist))
e.hist = append(e.hist, src...)
return s
}
// matchlen will return the match length between offsets and t in src.
// The maximum length returned is maxMatchLength - 4.
// It is assumed that s > t, that t >=0 and s < len(src).
func (e *fastEncL5Window) matchlen(s, t int32, src []byte) int32 {
if debugDecode {
if t >= s {
panic(fmt.Sprint("t >=s:", t, s))
}
if int(s) >= len(src) {
panic(fmt.Sprint("s >= len(src):", s, len(src)))
}
if t < 0 {
panic(fmt.Sprint("t < 0:", t))
}
if s-t > e.maxOffset {
panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")"))
}
}
s1 := min(int(s)+maxMatchLength-4, len(src))
// Extend the match to be as long as possible.
return int32(matchLen(src[s:s1], src[t:]))
}
// matchlenLong will return the match length between offsets and t in src.
// It is assumed that s > t, that t >=0 and s < len(src).
func (e *fastEncL5Window) matchlenLong(s, t int32, src []byte) int32 {
if debugDeflate {
if t >= s {
panic(fmt.Sprint("t >=s:", t, s))
}
if int(s) >= len(src) {
panic(fmt.Sprint("s >= len(src):", s, len(src)))
}
if t < 0 {
panic(fmt.Sprint("t < 0:", t))
}
if s-t > e.maxOffset {
panic(fmt.Sprint(s, "-", t, "(", s-t, ") > maxMatchLength (", maxMatchOffset, ")"))
}
}
// Extend the match to be as long as possible.
return int32(matchLen(src[s:], src[t:]))
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/level6.go
Generated Vendored
+325
View File
@@ -0,0 +1,325 @@
package flate
import "fmt"
type fastEncL6 struct {
fastGen
table [tableSize]tableEntry
bTable [tableSize]tableEntryPrev
}
func (e *fastEncL6) Encode(dst *tokens, src []byte) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
hashShortBytes = 4
)
if debugDeflate && e.cur < 0 {
panic(fmt.Sprint("e.cur < 0: ", e.cur))
}
// Protect against e.cur wraparound.
for e.cur >= bufferReset {
if len(e.hist) == 0 {
for i := range e.table[:] {
e.table[i] = tableEntry{}
}
for i := range e.bTable[:] {
e.bTable[i] = tableEntryPrev{}
}
e.cur = maxMatchOffset
break
}
// Shift down everything in the table that isn't already too far away.
minOff := e.cur + int32(len(e.hist)) - maxMatchOffset
for i := range e.table[:] {
v := e.table[i].offset
if v <= minOff {
v = 0
} else {
v = v - e.cur + maxMatchOffset
}
e.table[i].offset = v
}
for i := range e.bTable[:] {
v := e.bTable[i]
if v.Cur.offset <= minOff {
v.Cur.offset = 0
v.Prev.offset = 0
} else {
v.Cur.offset = v.Cur.offset - e.cur + maxMatchOffset
if v.Prev.offset <= minOff {
v.Prev.offset = 0
} else {
v.Prev.offset = v.Prev.offset - e.cur + maxMatchOffset
}
}
e.bTable[i] = v
}
e.cur = maxMatchOffset
}
s := e.addBlock(src)
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = uint16(len(src))
return
}
// Override src
src = e.hist
nextEmit := s
// 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 := int32(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load6432(src, s)
// Repeat MUST be > 1 and within range
repeat := int32(1)
for {
const skipLog = 7
const doEvery = 1
nextS := s
var l int32
var t int32
for {
nextHashS := hashLen(cv, tableBits, hashShortBytes)
nextHashL := hash7(cv, tableBits)
s = nextS
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit {
goto emitRemainder
}
// Fetch a short+long candidate
sCandidate := e.table[nextHashS]
lCandidate := e.bTable[nextHashL]
next := load6432(src, nextS)
entry := tableEntry{offset: s + e.cur}
e.table[nextHashS] = entry
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = entry, eLong.Cur
// Calculate hashes of 'next'
nextHashS = hashLen(next, tableBits, hashShortBytes)
nextHashL = hash7(next, tableBits)
t = lCandidate.Cur.offset - e.cur
if s-t < maxMatchOffset {
if uint32(cv) == load3232(src, t) {
// Long candidate matches at least 4 bytes.
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
// Check the previous long candidate as well.
t2 := lCandidate.Prev.offset - e.cur
if s-t2 < maxMatchOffset && uint32(cv) == load3232(src, t2) {
l = e.matchlen(int(s+4), int(t+4), src) + 4
ml1 := e.matchlen(int(s+4), int(t2+4), src) + 4
if ml1 > l {
t = t2
l = ml1
break
}
}
break
}
// Current value did not match, but check if previous long value does.
t = lCandidate.Prev.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
break
}
}
t = sCandidate.offset - e.cur
if s-t < maxMatchOffset && uint32(cv) == load3232(src, t) {
// Found a 4 match...
l = e.matchlen(int(s+4), int(t+4), src) + 4
// Look up next long candidate (at nextS)
lCandidate = e.bTable[nextHashL]
// Store the next match
e.table[nextHashS] = tableEntry{offset: nextS + e.cur}
eLong := &e.bTable[nextHashL]
eLong.Cur, eLong.Prev = tableEntry{offset: nextS + e.cur}, eLong.Cur
// Check repeat at s + repOff
const repOff = 1
t2 := s - repeat + repOff
if load3232(src, t2) == uint32(cv>>(8*repOff)) {
ml := e.matchlen(int(s+4+repOff), int(t2+4), src) + 4
if ml > l {
t = t2
l = ml
s += repOff
// Not worth checking more.
break
}
}
// If the next long is a candidate, use that...
t2 = lCandidate.Cur.offset - e.cur
if nextS-t2 < maxMatchOffset {
if load3232(src, t2) == uint32(next) {
ml := e.matchlen(int(nextS+4), int(t2+4), src) + 4
if ml > l {
t = t2
s = nextS
l = ml
// This is ok, but check previous as well.
}
}
// If the previous long is a candidate, use that...
t2 = lCandidate.Prev.offset - e.cur
if nextS-t2 < maxMatchOffset && load3232(src, t2) == uint32(next) {
ml := e.matchlen(int(nextS+4), int(t2+4), src) + 4
if ml > l {
t = t2
s = nextS
l = ml
break
}
}
}
break
}
cv = next
}
// 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.
// Extend the 4-byte match as long as possible.
if l == 0 {
l = e.matchlenLong(int(s+4), int(t+4), src) + 4
} else if l == maxMatchLength {
l += e.matchlenLong(int(s+l), int(t+l), src)
}
// Try to locate a better match by checking the end-of-match...
if sAt := s + l; sAt < sLimit {
// Allow some bytes at the beginning to mismatch.
// Sweet spot is 2/3 bytes depending on input.
// 3 is only a little better when it is but sometimes a lot worse.
// The skipped bytes are tested in Extend backwards,
// and still picked up as part of the match if they do.
const skipBeginning = 2
eLong := &e.bTable[hash7(load6432(src, sAt), tableBits)]
// Test current
t2 := eLong.Cur.offset - e.cur - l + skipBeginning
s2 := s + skipBeginning
off := s2 - t2
if off < maxMatchOffset {
if off > 0 && t2 >= 0 {
if l2 := e.matchlenLong(int(s2), int(t2), src); l2 > l {
t = t2
l = l2
s = s2
}
}
// Test next:
t2 = eLong.Prev.offset - e.cur - l + skipBeginning
off := s2 - t2
if off > 0 && off < maxMatchOffset && t2 >= 0 {
if l2 := e.matchlenLong(int(s2), int(t2), src); l2 > l {
t = t2
l = l2
s = s2
}
}
}
}
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
if false {
if t >= s {
panic(fmt.Sprintln("s-t", s, t))
}
if (s - t) > maxMatchOffset {
panic(fmt.Sprintln("mmo", s-t))
}
if l < baseMatchLength {
panic("bml")
}
}
dst.AddMatchLong(l, uint32(s-t-baseMatchOffset))
repeat = s - t
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
if s >= sLimit {
// Index after match end.
for i := nextS + 1; i < int32(len(src))-8; i += 2 {
cv := load6432(src, i)
e.table[hashLen(cv, tableBits, hashShortBytes)] = tableEntry{offset: i + e.cur}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong.Cur, eLong.Prev = tableEntry{offset: i + e.cur}, eLong.Cur
}
goto emitRemainder
}
// Store every long hash in-between and every second short.
if true {
for i := nextS + 1; i < s-1; i += 2 {
cv := load6432(src, i)
t := tableEntry{offset: i + e.cur}
t2 := tableEntry{offset: t.offset + 1}
eLong := &e.bTable[hash7(cv, tableBits)]
eLong2 := &e.bTable[hash7(cv>>8, tableBits)]
e.table[hashLen(cv, tableBits, hashShortBytes)] = t
eLong.Cur, eLong.Prev = t, eLong.Cur
eLong2.Cur, eLong2.Prev = t2, eLong2.Cur
}
}
// We could immediately start working at s now, but to improve
// compression we first update the hash table at s-1 and at s.
cv = load6432(src, s)
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/matchlen_generic.go
Generated Vendored
+34
View File
@@ -0,0 +1,34 @@
// Copyright 2019+ Klaus Post. All rights reserved.
// License information can be found in the LICENSE file.
package flate
import (
"math/bits"
"github.com/klauspost/compress/internal/le"
)
// matchLen returns the maximum common prefix length of a and b.
// a must be the shortest of the two.
func matchLen(a, b []byte) (n int) {
left := len(a)
for left >= 8 {
diff := le.Load64(a, n) ^ le.Load64(b, n)
if diff != 0 {
return n + bits.TrailingZeros64(diff)>>3
}
n += 8
left -= 8
}
a = a[n:]
b = b[n:]
for i := range a {
if a[i] != b[i] {
break
}
n++
}
return n
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/stateless.go
Generated Vendored
+325
View File
@@ -0,0 +1,325 @@
package flate
import (
"io"
"math"
"sync"
"github.com/klauspost/compress/internal/le"
)
const (
maxStatelessBlock = math.MaxInt16
// dictionary will be taken from maxStatelessBlock, so limit it.
maxStatelessDict = 8 << 10
slTableBits = 13
slTableSize = 1 << slTableBits
slTableShift = 32 - slTableBits
)
type statelessWriter struct {
dst io.Writer
closed bool
}
func (s *statelessWriter) Close() error {
if s.closed {
return nil
}
s.closed = true
// Emit EOF block
return StatelessDeflate(s.dst, nil, true, nil)
}
func (s *statelessWriter) Write(p []byte) (n int, err error) {
err = StatelessDeflate(s.dst, p, false, nil)
if err != nil {
return 0, err
}
return len(p), nil
}
func (s *statelessWriter) Reset(w io.Writer) {
s.dst = w
s.closed = false
}
// NewStatelessWriter will do compression but without maintaining any state
// between Write calls.
// There will be no memory kept between Write calls,
// but compression and speed will be suboptimal.
// Because of this, the size of actual Write calls will affect output size.
func NewStatelessWriter(dst io.Writer) io.WriteCloser {
return &statelessWriter{dst: dst}
}
// bitWriterPool contains bit writers that can be reused.
var bitWriterPool = sync.Pool{
New: func() any {
return newHuffmanBitWriter(nil)
},
}
// tokensPool contains tokens struct objects that can be reused
var tokensPool = sync.Pool{
New: func() any {
return &tokens{}
},
}
// StatelessDeflate allows compressing directly to a Writer without retaining state.
// When returning everything will be flushed.
// Up to 8KB of an optional dictionary can be given which is presumed to precede the block.
// Longer dictionaries will be truncated and will still produce valid output.
// Sending nil dictionary is perfectly fine.
func StatelessDeflate(out io.Writer, in []byte, eof bool, dict []byte) error {
bw := bitWriterPool.Get().(*huffmanBitWriter)
bw.reset(out)
defer func() {
// don't keep a reference to our output
bw.reset(nil)
bitWriterPool.Put(bw)
}()
if eof && len(in) == 0 {
// Just write an EOF block.
// Could be faster...
bw.writeStoredHeader(0, true)
bw.flush()
return bw.err
}
// Truncate dict
if len(dict) > maxStatelessDict {
dict = dict[len(dict)-maxStatelessDict:]
}
// For subsequent loops, keep shallow dict reference to avoid alloc+copy.
var inDict []byte
dst := tokensPool.Get().(*tokens)
dst.Reset()
defer func() {
tokensPool.Put(dst)
}()
for len(in) > 0 {
todo := in
if len(inDict) > 0 {
if len(todo) > maxStatelessBlock-maxStatelessDict {
todo = todo[:maxStatelessBlock-maxStatelessDict]
}
} else if len(todo) > maxStatelessBlock-len(dict) {
todo = todo[:maxStatelessBlock-len(dict)]
}
inOrg := in
in = in[len(todo):]
uncompressed := todo
if len(dict) > 0 {
// combine dict and source
bufLen := len(todo) + len(dict)
combined := make([]byte, bufLen)
copy(combined, dict)
copy(combined[len(dict):], todo)
todo = combined
}
// Compress
if len(inDict) == 0 {
statelessEnc(dst, todo, int16(len(dict)))
} else {
statelessEnc(dst, inDict[:maxStatelessDict+len(todo)], maxStatelessDict)
}
isEof := eof && len(in) == 0
if dst.n == 0 {
bw.writeStoredHeader(len(uncompressed), isEof)
if bw.err != nil {
return bw.err
}
bw.writeBytes(uncompressed)
} else if int(dst.n) > len(uncompressed)-len(uncompressed)>>4 {
// If we removed less than 1/16th, huffman compress the block.
bw.writeBlockHuff(isEof, uncompressed, len(in) == 0)
} else {
bw.writeBlockDynamic(dst, isEof, uncompressed, len(in) == 0)
}
if len(in) > 0 {
// Retain a dict if we have more
inDict = inOrg[len(uncompressed)-maxStatelessDict:]
dict = nil
dst.Reset()
}
if bw.err != nil {
return bw.err
}
}
if !eof {
// Align, only a stored block can do that.
bw.writeStoredHeader(0, false)
}
bw.flush()
return bw.err
}
func hashSL(u uint32) uint32 {
return (u * 0x1e35a7bd) >> slTableShift
}
func load3216(b []byte, i int16) uint32 {
return le.Load32(b, i)
}
func load6416(b []byte, i int16) uint64 {
return le.Load64(b, i)
}
func statelessEnc(dst *tokens, src []byte, startAt int16) {
const (
inputMargin = 12 - 1
minNonLiteralBlockSize = 1 + 1 + inputMargin
)
type tableEntry struct {
offset int16
}
var table [slTableSize]tableEntry
// This check isn't in the Snappy implementation, but there, the caller
// instead of the callee handles this case.
if len(src)-int(startAt) < minNonLiteralBlockSize {
// We do not fill the token table.
// This will be picked up by caller.
dst.n = 0
return
}
// Index until startAt
if startAt > 0 {
cv := load3232(src, 0)
for i := range startAt {
table[hashSL(cv)] = tableEntry{offset: i}
cv = (cv >> 8) | (uint32(src[i+4]) << 24)
}
}
s := startAt + 1
nextEmit := startAt
// 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 := int16(len(src) - inputMargin)
// nextEmit is where in src the next emitLiteral should start from.
cv := load3216(src, s)
for {
const skipLog = 5
const doEvery = 2
nextS := s
var candidate tableEntry
for {
nextHash := hashSL(cv)
candidate = table[nextHash]
nextS = s + doEvery + (s-nextEmit)>>skipLog
if nextS > sLimit || nextS <= 0 {
goto emitRemainder
}
now := load6416(src, nextS)
table[nextHash] = tableEntry{offset: s}
nextHash = hashSL(uint32(now))
if cv == load3216(src, candidate.offset) {
table[nextHash] = tableEntry{offset: nextS}
break
}
// Do one right away...
cv = uint32(now)
s = nextS
nextS++
candidate = table[nextHash]
now >>= 8
table[nextHash] = tableEntry{offset: s}
if cv == load3216(src, candidate.offset) {
table[nextHash] = tableEntry{offset: nextS}
break
}
cv = uint32(now)
s = nextS
}
// 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.
for {
// Invariant: we have a 4-byte match at s, and no need to emit any
// literal bytes prior to s.
// Extend the 4-byte match as long as possible.
t := candidate.offset
l := int16(matchLen(src[s+4:], src[t+4:]) + 4)
// Extend backwards
for t > 0 && s > nextEmit && src[t-1] == src[s-1] {
s--
t--
l++
}
if nextEmit < s {
if false {
emitLiteral(dst, src[nextEmit:s])
} else {
for _, v := range src[nextEmit:s] {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
}
// Save the match found
dst.AddMatchLong(int32(l), uint32(s-t-baseMatchOffset))
s += l
nextEmit = s
if nextS >= s {
s = nextS + 1
}
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-2 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 := load6416(src, s-2)
o := s - 2
prevHash := hashSL(uint32(x))
table[prevHash] = tableEntry{offset: o}
x >>= 16
currHash := hashSL(uint32(x))
candidate = table[currHash]
table[currHash] = tableEntry{offset: o + 2}
if uint32(x) != load3216(src, candidate.offset) {
cv = uint32(x >> 8)
s++
break
}
}
}
emitRemainder:
if int(nextEmit) < len(src) {
// If nothing was added, don't encode literals.
if dst.n == 0 {
return
}
emitLiteral(dst, src[nextEmit:])
}
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/flate/token.go
Generated Vendored
+379
View File
@@ -0,0 +1,379 @@
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flate
import (
"bytes"
"encoding/binary"
"fmt"
"io"
"math"
)
const (
// bits 0-16 xoffset = offset - MIN_OFFSET_SIZE, or literal - 16 bits
// bits 16-22 offsetcode - 5 bits
// bits 22-30 xlength = length - MIN_MATCH_LENGTH - 8 bits
// bits 30-32 type 0 = literal 1=EOF 2=Match 3=Unused - 2 bits
lengthShift = 22
offsetMask = 1<<lengthShift - 1
typeMask = 3 << 30
literalType = 0 << 30
matchType = 1 << 30
matchOffsetOnlyMask = 0xffff
)
// The length code for length X (MIN_MATCH_LENGTH <= X <= MAX_MATCH_LENGTH)
// is lengthCodes[length - MIN_MATCH_LENGTH]
var lengthCodes = [256]uint8{
0, 1, 2, 3, 4, 5, 6, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 12, 12,
13, 13, 13, 13, 14, 14, 14, 14, 15, 15,
15, 15, 16, 16, 16, 16, 16, 16, 16, 16,
17, 17, 17, 17, 17, 17, 17, 17, 18, 18,
18, 18, 18, 18, 18, 18, 19, 19, 19, 19,
19, 19, 19, 19, 20, 20, 20, 20, 20, 20,
20, 20, 20, 20, 20, 20, 20, 20, 20, 20,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
21, 21, 21, 21, 21, 21, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 28,
}
// lengthCodes1 is length codes, but starting at 1.
var lengthCodes1 = [256]uint8{
1, 2, 3, 4, 5, 6, 7, 8, 9, 9,
10, 10, 11, 11, 12, 12, 13, 13, 13, 13,
14, 14, 14, 14, 15, 15, 15, 15, 16, 16,
16, 16, 17, 17, 17, 17, 17, 17, 17, 17,
18, 18, 18, 18, 18, 18, 18, 18, 19, 19,
19, 19, 19, 19, 19, 19, 20, 20, 20, 20,
20, 20, 20, 20, 21, 21, 21, 21, 21, 21,
21, 21, 21, 21, 21, 21, 21, 21, 21, 21,
22, 22, 22, 22, 22, 22, 22, 22, 22, 22,
22, 22, 22, 22, 22, 22, 23, 23, 23, 23,
23, 23, 23, 23, 23, 23, 23, 23, 23, 23,
23, 23, 24, 24, 24, 24, 24, 24, 24, 24,
24, 24, 24, 24, 24, 24, 24, 24, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 29,
}
var offsetCodes = [256]uint32{
0, 1, 2, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7,
8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9,
10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
}
// offsetCodes14 are offsetCodes, but with 14 added.
var offsetCodes14 = [256]uint32{
14, 15, 16, 17, 18, 18, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21,
22, 22, 22, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 23, 23, 23,
24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24, 24,
25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26, 26,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27, 27,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28, 28,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29, 29,
}
type token uint32
type tokens struct {
extraHist [32]uint16 // codes 256->maxnumlit
offHist [32]uint16 // offset codes
litHist [256]uint16 // codes 0->255
nFilled int
n uint16 // Must be able to contain maxStoreBlockSize
tokens [maxStoreBlockSize + 1]token
}
func (t *tokens) Reset() {
if t.n == 0 {
return
}
t.n = 0
t.nFilled = 0
for i := range t.litHist[:] {
t.litHist[i] = 0
}
for i := range t.extraHist[:] {
t.extraHist[i] = 0
}
for i := range t.offHist[:] {
t.offHist[i] = 0
}
}
func (t *tokens) Fill() {
if t.n == 0 {
return
}
for i, v := range t.litHist[:] {
if v == 0 {
t.litHist[i] = 1
t.nFilled++
}
}
for i, v := range t.extraHist[:literalCount-256] {
if v == 0 {
t.nFilled++
t.extraHist[i] = 1
}
}
for i, v := range t.offHist[:offsetCodeCount] {
if v == 0 {
t.offHist[i] = 1
}
}
}
func indexTokens(in []token) tokens {
var t tokens
t.indexTokens(in)
return t
}
func (t *tokens) indexTokens(in []token) {
t.Reset()
for _, tok := range in {
if tok < matchType {
t.AddLiteral(tok.literal())
continue
}
t.AddMatch(uint32(tok.length()), tok.offset()&matchOffsetOnlyMask)
}
}
// emitLiteral writes a literal chunk and returns the number of bytes written.
func emitLiteral(dst *tokens, lit []byte) {
for _, v := range lit {
dst.tokens[dst.n] = token(v)
dst.litHist[v]++
dst.n++
}
}
func (t *tokens) AddLiteral(lit byte) {
t.tokens[t.n] = token(lit)
t.litHist[lit]++
t.n++
}
// from https://stackoverflow.com/a/28730362
func mFastLog2(val float32) float32 {
ux := int32(math.Float32bits(val))
log2 := (float32)(((ux >> 23) & 255) - 128)
ux &= -0x7f800001
ux += 127 << 23
uval := math.Float32frombits(uint32(ux))
log2 += ((-0.34484843)*uval+2.02466578)*uval - 0.67487759
return log2
}
// EstimatedBits will return an minimum size estimated by an *optimal*
// compression of the block.
// The size of the block
func (t *tokens) EstimatedBits() int {
shannon := float32(0)
bits := int(0)
nMatches := 0
total := int(t.n) + t.nFilled
if total > 0 {
invTotal := 1.0 / float32(total)
for _, v := range t.litHist[:] {
if v > 0 {
n := float32(v)
shannon += atLeastOne(-mFastLog2(n*invTotal)) * n
}
}
// Just add 15 for EOB
shannon += 15
for i, v := range t.extraHist[1 : literalCount-256] {
if v > 0 {
n := float32(v)
shannon += atLeastOne(-mFastLog2(n*invTotal)) * n
bits += int(lengthExtraBits[i&31]) * int(v)
nMatches += int(v)
}
}
}
if nMatches > 0 {
invTotal := 1.0 / float32(nMatches)
for i, v := range t.offHist[:offsetCodeCount] {
if v > 0 {
n := float32(v)
shannon += atLeastOne(-mFastLog2(n*invTotal)) * n
bits += int(offsetExtraBits[i&31]) * int(v)
}
}
}
return int(shannon) + bits
}
// AddMatch adds a match to the tokens.
// This function is very sensitive to inlining and right on the border.
func (t *tokens) AddMatch(xlength uint32, xoffset uint32) {
if debugDeflate {
if xlength >= maxMatchLength+baseMatchLength {
panic(fmt.Errorf("invalid length: %v", xlength))
}
if xoffset >= maxMatchOffset+baseMatchOffset {
panic(fmt.Errorf("invalid offset: %v", xoffset))
}
}
oCode := offsetCode(xoffset)
xoffset |= oCode << 16
t.extraHist[lengthCodes1[uint8(xlength)]]++
t.offHist[oCode&31]++
t.tokens[t.n] = token(matchType | xlength<<lengthShift | xoffset)
t.n++
}
// AddMatchLong adds a match to the tokens, potentially longer than max match length.
// Length should NOT have the base subtracted, only offset should.
func (t *tokens) AddMatchLong(xlength int32, xoffset uint32) {
if debugDeflate {
if xoffset >= maxMatchOffset+baseMatchOffset {
panic(fmt.Errorf("invalid offset: %v", xoffset))
}
}
oc := offsetCode(xoffset)
xoffset |= oc << 16
for xlength > 0 {
xl := xlength
if xl > 258 {
// We need to have at least baseMatchLength left over for next loop.
if xl > 258+baseMatchLength {
xl = 258
} else {
xl = 258 - baseMatchLength
}
}
xlength -= xl
xl -= baseMatchLength
t.extraHist[lengthCodes1[uint8(xl)]]++
t.offHist[oc&31]++
t.tokens[t.n] = token(matchType | uint32(xl)<<lengthShift | xoffset)
t.n++
}
}
func (t *tokens) AddEOB() {
t.tokens[t.n] = token(endBlockMarker)
t.extraHist[0]++
t.n++
}
func (t *tokens) Slice() []token {
return t.tokens[:t.n]
}
// VarInt returns the tokens as varint encoded bytes.
func (t *tokens) VarInt() []byte {
var b = make([]byte, binary.MaxVarintLen32*int(t.n))
var off int
for _, v := range t.tokens[:t.n] {
off += binary.PutUvarint(b[off:], uint64(v))
}
return b[:off]
}
// FromVarInt restores t to the varint encoded tokens provided.
// Any data in t is removed.
func (t *tokens) FromVarInt(b []byte) error {
var buf = bytes.NewReader(b)
var toks []token
for {
r, err := binary.ReadUvarint(buf)
if err == io.EOF {
break
}
if err != nil {
return err
}
toks = append(toks, token(r))
}
t.indexTokens(toks)
return nil
}
// Returns the type of a token
func (t token) typ() uint32 { return uint32(t) & typeMask }
// Returns the literal of a literal token
func (t token) literal() uint8 { return uint8(t) }
// Returns the extra offset of a match token
func (t token) offset() uint32 { return uint32(t) & offsetMask }
func (t token) length() uint8 { return uint8(t >> lengthShift) }
// Convert length to code.
func lengthCode(len uint8) uint8 { return lengthCodes[len] }
// Returns the offset code corresponding to a specific offset
func offsetCode(off uint32) uint32 {
if false {
if off < uint32(len(offsetCodes)) {
return offsetCodes[off&255]
} else if off>>7 < uint32(len(offsetCodes)) {
return offsetCodes[(off>>7)&255] + 14
} else {
return offsetCodes[(off>>14)&255] + 28
}
}
if off < uint32(len(offsetCodes)) {
return offsetCodes[uint8(off)]
}
return offsetCodes14[uint8(off>>7)]
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/internal/le/le.go
Generated Vendored
+5
View File
@@ -0,0 +1,5 @@
package le
type Indexer interface {
int | int8 | int16 | int32 | int64 | uint | uint8 | uint16 | uint32 | uint64
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/internal/le/unsafe_disabled.go
Generated Vendored
+42
View File
@@ -0,0 +1,42 @@
//go:build !(amd64 || arm64 || ppc64le || riscv64) || nounsafe || purego || appengine
package le
import (
"encoding/binary"
)
// Load8 will load from b at index i.
func Load8[I Indexer](b []byte, i I) byte {
return b[i]
}
// Load16 will load from b at index i.
func Load16[I Indexer](b []byte, i I) uint16 {
return binary.LittleEndian.Uint16(b[i:])
}
// Load32 will load from b at index i.
func Load32[I Indexer](b []byte, i I) uint32 {
return binary.LittleEndian.Uint32(b[i:])
}
// Load64 will load from b at index i.
func Load64[I Indexer](b []byte, i I) uint64 {
return binary.LittleEndian.Uint64(b[i:])
}
// Store16 will store v at b.
func Store16(b []byte, v uint16) {
binary.LittleEndian.PutUint16(b, v)
}
// Store32 will store v at b.
func Store32(b []byte, v uint32) {
binary.LittleEndian.PutUint32(b, v)
}
// Store64 will store v at b.
func Store64[I Indexer](b []byte, i I, v uint64) {
binary.LittleEndian.PutUint64(b[i:], v)
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/internal/le/unsafe_enabled.go
Generated Vendored
+52
View File
@@ -0,0 +1,52 @@
// We enable 64 bit LE platforms:
//go:build (amd64 || arm64 || ppc64le || riscv64) && !nounsafe && !purego && !appengine
package le
import (
"unsafe"
)
// Load8 will load from b at index i.
func Load8[I Indexer](b []byte, i I) byte {
//return binary.LittleEndian.Uint16(b[i:])
//return *(*uint16)(unsafe.Pointer(&b[i]))
return *(*byte)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(b)), i))
}
// Load16 will load from b at index i.
func Load16[I Indexer](b []byte, i I) uint16 {
//return binary.LittleEndian.Uint16(b[i:])
//return *(*uint16)(unsafe.Pointer(&b[i]))
return *(*uint16)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(b)), i))
}
// Load32 will load from b at index i.
func Load32[I Indexer](b []byte, i I) uint32 {
//return binary.LittleEndian.Uint32(b[i:])
//return *(*uint32)(unsafe.Pointer(&b[i]))
return *(*uint32)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(b)), i))
}
// Load64 will load from b at index i.
func Load64[I Indexer](b []byte, i I) uint64 {
//return binary.LittleEndian.Uint64(b[i:])
//return *(*uint64)(unsafe.Pointer(&b[i]))
return *(*uint64)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(b)), i))
}
// Store16 will store v at b.
func Store16(b []byte, v uint16) {
*(*uint16)(unsafe.Pointer(unsafe.SliceData(b))) = v
}
// Store32 will store v at b.
func Store32(b []byte, v uint32) {
*(*uint32)(unsafe.Pointer(unsafe.SliceData(b))) = v
}
// Store64 will store v at b[i:].
func Store64[I Indexer](b []byte, i I, v uint64) {
*(*uint64)(unsafe.Add(unsafe.Pointer(unsafe.SliceData(b)), i)) = v
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/internal/race/norace.go
Generated Vendored
+13
View File
@@ -0,0 +1,13 @@
// Copyright 2015 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.
//go:build !race
package race
func ReadSlice[T any](s []T) {
}
func WriteSlice[T any](s []T) {
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/internal/race/race.go
Generated Vendored
+26
View File
@@ -0,0 +1,26 @@
// Copyright 2015 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.
//go:build race
package race
import (
"runtime"
"unsafe"
)
func ReadSlice[T any](s []T) {
if len(s) == 0 {
return
}
runtime.RaceReadRange(unsafe.Pointer(&s[0]), len(s)*int(unsafe.Sizeof(s[0])))
}
func WriteSlice[T any](s []T) {
if len(s) == 0 {
return
}
runtime.RaceWriteRange(unsafe.Pointer(&s[0]), len(s)*int(unsafe.Sizeof(s[0])))
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/internal/regmask/regmask.go
Generated Vendored
+50
View File
@@ -0,0 +1,50 @@
//go:build !386
// Package regmask provides masks for variable shift counts.
//
// Go defines a shift by more than the width of the shifted value as producing
// zero, so the compiler has to guard every variable shift against that: on
// amd64 with a CMP and an SBB, on arm64 with a CMP and a CSEL, and so on. When
// the count is known to be smaller than the width anyway, masking it with the
// width minus one lets the compiler drop the guard. The mask itself costs
// nothing on the architectures whose shift instructions already use only the
// low bits of the count, which the compiler knows about.
//
// Each constant is named for the width of the value being shifted and the type
// of the shift count, and may only be used where the count is always smaller
// than that width:
//
// x := y >> (n & regmask.Shift64ByUint) // y is 64 bits, n is a uint below 64
package regmask
const (
// ShiftNByUint8 - shifting an N bit value by a uint8
Shift8ByUint8 = 7
Shift16ByUint8 = 15
Shift32ByUint8 = 31
Shift64ByUint8 = 63
// ShiftNByUint16 - shifting an N bit value by a uint16
Shift8ByUint16 = Shift8ByUint8
Shift16ByUint16 = Shift16ByUint8
Shift32ByUint16 = Shift32ByUint8
Shift64ByUint16 = Shift64ByUint8
// ShiftNByUint32 - shifting an N bit value by a uint32
Shift8ByUint32 = Shift8ByUint8
Shift16ByUint32 = Shift16ByUint8
Shift32ByUint32 = Shift32ByUint8
Shift64ByUint32 = Shift64ByUint8
// ShiftNByUint64 - shifting an N bit value by a uint64
Shift8ByUint64 = Shift8ByUint8
Shift16ByUint64 = Shift16ByUint8
Shift32ByUint64 = Shift32ByUint8
Shift64ByUint64 = Shift64ByUint8
// ShiftNByUint - shifting an N bit value by a uint
Shift8ByUint = Shift8ByUint8
Shift16ByUint = Shift16ByUint8
Shift32ByUint = Shift32ByUint8
Shift64ByUint = Shift64ByUint8
)
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/internal/regmask/regmask_386.go
Generated Vendored
+39
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@@ -0,0 +1,39 @@
//go:build 386
package regmask
// A 64 bit shift on 386 is synthesized from 32 bit instructions, and masking its
// count makes the compiler emit more code rather than less, so those masks are
// no-ops here: each is the largest value its count type can hold, which the
// compiler folds away. Shifts of narrower values behave as elsewhere.
const (
// ShiftNByUint8 - shifting an N bit value by a uint8
Shift8ByUint8 = 7
Shift16ByUint8 = 15
Shift32ByUint8 = 31
Shift64ByUint8 = 0xff
// ShiftNByUint16 - shifting an N bit value by a uint16
Shift8ByUint16 = Shift8ByUint8
Shift16ByUint16 = Shift16ByUint8
Shift32ByUint16 = Shift32ByUint8
Shift64ByUint16 = 0xffff
// ShiftNByUint32 - shifting an N bit value by a uint32
Shift8ByUint32 = Shift8ByUint8
Shift16ByUint32 = Shift16ByUint8
Shift32ByUint32 = Shift32ByUint8
Shift64ByUint32 = 0xffffffff
// ShiftNByUint64 - shifting an N bit value by a uint64
Shift8ByUint64 = Shift8ByUint8
Shift16ByUint64 = Shift16ByUint8
Shift32ByUint64 = Shift32ByUint8
Shift64ByUint64 = 0xffffffffffffffff
// ShiftNByUint - shifting an N bit value by a uint
Shift8ByUint = Shift8ByUint8
Shift16ByUint = Shift16ByUint8
Shift32ByUint = Shift32ByUint8
Shift64ByUint = ^uint(0)
)
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/.gitignore
Generated
+15
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@@ -0,0 +1,15 @@
testdata/bench
# These explicitly listed benchmark data files are for an obsolete version of
# snappy_test.go.
testdata/alice29.txt
testdata/asyoulik.txt
testdata/fireworks.jpeg
testdata/geo.protodata
testdata/html
testdata/html_x_4
testdata/kppkn.gtb
testdata/lcet10.txt
testdata/paper-100k.pdf
testdata/plrabn12.txt
testdata/urls.10K
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/LICENSE
Generated Vendored
+28
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@@ -0,0 +1,28 @@
Copyright (c) 2011 The Snappy-Go Authors. All rights reserved.
Copyright (c) 2019 Klaus Post. 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.
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/README.md
Generated Vendored
+1134
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File diff suppressed because it is too large Load Diff
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/decode.go
Generated Vendored
+443
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// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"encoding/binary"
"errors"
"fmt"
"strconv"
"github.com/klauspost/compress/internal/race"
)
var (
// ErrCorrupt reports that the input is invalid.
ErrCorrupt = errors.New("s2: corrupt input")
// ErrCRC reports that the input failed CRC validation (streams only)
ErrCRC = errors.New("s2: corrupt input, crc mismatch")
// ErrTooLarge reports that the uncompressed length is too large.
ErrTooLarge = errors.New("s2: decoded block is too large")
// ErrUnsupported reports that the input isn't supported.
ErrUnsupported = errors.New("s2: unsupported input")
)
// 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 || n > 5 || 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
)
// 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 <= cap(dst) {
dst = dst[:dLen]
} else {
dst = make([]byte, dLen)
}
race.WriteSlice(dst)
race.ReadSlice(src[s:])
if s2Decode(dst, src[s:]) != 0 {
return nil, ErrCorrupt
}
return dst, nil
}
// s2DecodeDict 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 s2DecodeDict(dst, src []byte, dict *Dict) int {
if dict == nil {
return s2Decode(dst, src)
}
const debug = false
const debugErrs = debug
if debug {
fmt.Println("Starting decode, dst len:", len(dst))
}
var d, s, length int
offset := len(dict.dict) - dict.repeat
// As long as we can read at least 5 bytes...
for s < len(src)-5 {
// Removing bounds checks is SLOWER, when if doing
// in := src[s:s+5]
// Checked on Go 1.18
switch src[s] & 0x03 {
case tagLiteral:
x := uint32(src[s] >> 2)
switch {
case x < 60:
s++
case x == 60:
s += 2
x = uint32(src[s-1])
case x == 61:
in := src[s : s+3]
x = uint32(in[1]) | uint32(in[2])<<8
s += 3
case x == 62:
in := src[s : s+4]
// Load as 32 bit and shift down.
x = uint32(in[0]) | uint32(in[1])<<8 | uint32(in[2])<<16 | uint32(in[3])<<24
x >>= 8
s += 4
case x == 63:
in := src[s : s+5]
x = uint32(in[1]) | uint32(in[2])<<8 | uint32(in[3])<<16 | uint32(in[4])<<24
s += 5
}
length = int(x) + 1
if debug {
fmt.Println("literals, length:", length, "d-after:", d+length)
}
if length > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
if debugErrs {
fmt.Println("corrupt literal: length:", length, "d-left:", len(dst)-d, "src-left:", len(src)-s)
}
return decodeErrCodeCorrupt
}
copy(dst[d:], src[s:s+length])
d += length
s += length
continue
case tagCopy1:
s += 2
toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
length = int(src[s-2]) >> 2 & 0x7
if toffset == 0 {
if debug {
fmt.Print("(repeat) ")
}
// keep last offset
switch length {
case 5:
length = int(src[s]) + 4
s += 1
case 6:
in := src[s : s+2]
length = int(uint32(in[0])|(uint32(in[1])<<8)) + (1 << 8)
s += 2
case 7:
in := src[s : s+3]
length = int((uint32(in[2])<<16)|(uint32(in[1])<<8)|uint32(in[0])) + (1 << 16)
s += 3
default: // 0-> 4
}
} else {
offset = toffset
}
length += 4
case tagCopy2:
in := src[s : s+3]
offset = int(uint32(in[1]) | uint32(in[2])<<8)
length = 1 + int(in[0])>>2
s += 3
case tagCopy4:
in := src[s : s+5]
offset = int(uint32(in[1]) | uint32(in[2])<<8 | uint32(in[3])<<16 | uint32(in[4])<<24)
length = 1 + int(in[0])>>2
s += 5
}
if offset <= 0 || length > len(dst)-d {
if debugErrs {
fmt.Println("match error; offset:", offset, "length:", length, "dst-left:", len(dst)-d)
}
return decodeErrCodeCorrupt
}
// copy from dict
if d < offset {
if d > MaxDictSrcOffset {
if debugErrs {
fmt.Println("dict after", MaxDictSrcOffset, "d:", d, "offset:", offset, "length:", length)
}
return decodeErrCodeCorrupt
}
startOff := len(dict.dict) - offset + d
if startOff < 0 || startOff+length > len(dict.dict) {
if debugErrs {
fmt.Printf("offset (%d) + length (%d) bigger than dict (%d)\n", offset, length, len(dict.dict))
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("dict copy, length:", length, "offset:", offset, "d-after:", d+length, "dict start offset:", startOff)
}
copy(dst[d:d+length], dict.dict[startOff:])
d += length
continue
}
if debug {
fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset > length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
// Remaining with extra checks...
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.
if debugErrs {
fmt.Println("src went oob")
}
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.
if debugErrs {
fmt.Println("src went oob")
}
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.
if debugErrs {
fmt.Println("src went oob")
}
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.
if debugErrs {
fmt.Println("src went oob")
}
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 > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
if debugErrs {
fmt.Println("corrupt literal: length:", length, "d-left:", len(dst)-d, "src-left:", len(src)-s)
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("literals, length:", length, "d-after:", d+length)
}
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.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
length = int(src[s-2]) >> 2 & 0x7
toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
if toffset == 0 {
if debug {
fmt.Print("(repeat) ")
}
// keep last offset
switch length {
case 5:
s += 1
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-1])) + 4
case 6:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-2])|(uint32(src[s-1])<<8)) + (1 << 8)
case 7:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-3])|(uint32(src[s-2])<<8)|(uint32(src[s-1])<<16)) + (1 << 16)
default: // 0-> 4
}
} else {
offset = toffset
}
length += 4
case tagCopy2:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
if debugErrs {
fmt.Println("src went oob")
}
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.
if debugErrs {
fmt.Println("src went oob")
}
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 || length > len(dst)-d {
if debugErrs {
fmt.Println("match error; offset:", offset, "length:", length, "dst-left:", len(dst)-d)
}
return decodeErrCodeCorrupt
}
// copy from dict
if d < offset {
if d > MaxDictSrcOffset {
if debugErrs {
fmt.Println("dict after", MaxDictSrcOffset, "d:", d, "offset:", offset, "length:", length)
}
return decodeErrCodeCorrupt
}
rOff := len(dict.dict) - (offset - d)
if debug {
fmt.Println("starting dict entry from dict offset", len(dict.dict)-rOff)
}
if rOff+length > len(dict.dict) {
if debugErrs {
fmt.Println("err: END offset", rOff+length, "bigger than dict", len(dict.dict), "dict offset:", rOff, "length:", length)
}
return decodeErrCodeCorrupt
}
if rOff < 0 {
if debugErrs {
fmt.Println("err: START offset", rOff, "less than 0", len(dict.dict), "dict offset:", rOff, "length:", length)
}
return decodeErrCodeCorrupt
}
copy(dst[d:d+length], dict.dict[rOff:])
d += length
continue
}
if debug {
fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset > length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
if d != len(dst) {
if debugErrs {
fmt.Println("wanted length", len(dst), "got", d)
}
return decodeErrCodeCorrupt
}
return 0
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/decode_amd64.s
Generated Vendored
+568
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@@ -0,0 +1,568 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. 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"
#define R_TMP0 AX
#define R_TMP1 BX
#define R_LEN CX
#define R_OFF DX
#define R_SRC SI
#define R_DST DI
#define R_DBASE R8
#define R_DLEN R9
#define R_DEND R10
#define R_SBASE R11
#define R_SLEN R12
#define R_SEND R13
#define R_TMP2 R14
#define R_TMP3 R15
// 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:
// - R_TMP0 scratch
// - R_TMP1 scratch
// - R_LEN length or x (shared)
// - R_OFF offset
// - R_SRC &src[s]
// - R_DST &dst[d]
// + R_DBASE dst_base
// + R_DLEN dst_len
// + R_DEND dst_base + dst_len
// + R_SBASE src_base
// + R_SLEN src_len
// + R_SEND src_base + src_len
// - R_TMP2 used by doCopy
// - R_TMP3 used by doCopy
//
// The registers R_DBASE-R_SEND (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 R_DST - R_DBASE, and len(dst)-d is R_DEND - R_DST.
// The s variable is implicitly R_SRC - R_SBASE, and len(src)-s is R_SEND - R_SRC.
TEXT ·s2Decode(SB), NOSPLIT, $56-56
// Initialize R_SRC, R_DST and R_DBASE-R_SEND.
MOVQ dst_base+0(FP), R_DBASE
MOVQ dst_len+8(FP), R_DLEN
MOVQ R_DBASE, R_DST
MOVQ R_DBASE, R_DEND
ADDQ R_DLEN, R_DEND
MOVQ src_base+24(FP), R_SBASE
MOVQ src_len+32(FP), R_SLEN
MOVQ R_SBASE, R_SRC
MOVQ R_SBASE, R_SEND
ADDQ R_SLEN, R_SEND
XORQ R_OFF, R_OFF
loop:
// for s < len(src)
CMPQ R_SRC, R_SEND
JEQ end
// R_LEN = uint32(src[s])
//
// switch src[s] & 0x03
MOVBLZX (R_SRC), R_LEN
MOVL R_LEN, R_TMP1
ANDL $3, R_TMP1
CMPL R_TMP1, $1
JAE tagCopy
// ----------------------------------------
// The code below handles literal tags.
// case tagLiteral:
// x := uint32(src[s] >> 2)
// switch
SHRL $2, R_LEN
CMPL R_LEN, $60
JAE tagLit60Plus
// case x < 60:
// s++
INCQ R_SRC
doLit:
// This is the end of the inner "switch", when we have a literal tag.
//
// We assume that R_LEN == 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
// R_LEN can hold 64 bits, so the increment cannot overflow.
INCQ R_LEN
// Prepare to check if copying length bytes will run past the end of dst or
// src.
//
// R_TMP0 = len(dst) - d
// R_TMP1 = len(src) - s
MOVQ R_DEND, R_TMP0
SUBQ R_DST, R_TMP0
MOVQ R_SEND, R_TMP1
SUBQ R_SRC, R_TMP1
// !!! 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 R_LEN, $16
JGT callMemmove
CMPQ R_TMP0, $16
JLT callMemmove
CMPQ R_TMP1, $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(R_SRC), X0
MOVOU X0, 0(R_DST)
// d += length
// s += length
ADDQ R_LEN, R_DST
ADDQ R_LEN, R_SRC
JMP loop
callMemmove:
// if length > len(dst)-d || length > len(src)-s { etc }
CMPQ R_LEN, R_TMP0
JGT errCorrupt
CMPQ R_LEN, R_TMP1
JGT errCorrupt
// copy(dst[d:], src[s:s+length])
//
// This means calling runtime·memmove(&dst[d], &src[s], length), so we push
// R_DST, R_SRC and R_LEN as arguments. Coincidentally, we also need to spill those
// three registers to the stack, to save local variables across the CALL.
MOVQ R_DST, 0(SP)
MOVQ R_SRC, 8(SP)
MOVQ R_LEN, 16(SP)
MOVQ R_DST, 24(SP)
MOVQ R_SRC, 32(SP)
MOVQ R_LEN, 40(SP)
MOVQ R_OFF, 48(SP)
CALL runtime·memmove(SB)
// Restore local variables: unspill registers from the stack and
// re-calculate R_DBASE-R_SEND.
MOVQ 24(SP), R_DST
MOVQ 32(SP), R_SRC
MOVQ 40(SP), R_LEN
MOVQ 48(SP), R_OFF
MOVQ dst_base+0(FP), R_DBASE
MOVQ dst_len+8(FP), R_DLEN
MOVQ R_DBASE, R_DEND
ADDQ R_DLEN, R_DEND
MOVQ src_base+24(FP), R_SBASE
MOVQ src_len+32(FP), R_SLEN
MOVQ R_SBASE, R_SEND
ADDQ R_SLEN, R_SEND
// d += length
// s += length
ADDQ R_LEN, R_DST
ADDQ R_LEN, R_SRC
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 R_LEN, R_SRC
SUBQ $58, R_SRC
CMPQ R_SRC, R_SEND
JA errCorrupt
// case x == 60:
CMPL R_LEN, $61
JEQ tagLit61
JA tagLit62Plus
// x = uint32(src[s-1])
MOVBLZX -1(R_SRC), R_LEN
JMP doLit
tagLit61:
// case x == 61:
// x = uint32(src[s-2]) | uint32(src[s-1])<<8
MOVWLZX -2(R_SRC), R_LEN
JMP doLit
tagLit62Plus:
CMPL R_LEN, $62
JA tagLit63
// case x == 62:
// x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
// We read one byte, safe to read one back, since we are just reading tag.
// x = binary.LittleEndian.Uint32(src[s-1:]) >> 8
MOVL -4(R_SRC), R_LEN
SHRL $8, R_LEN
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(R_SRC), R_LEN
JMP doLit
// The code above handles literal tags.
// ----------------------------------------
// The code below handles copy tags.
tagCopy4:
// case tagCopy4:
// s += 5
ADDQ $5, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = 1 + int(src[s-5])>>2
SHRQ $2, R_LEN
INCQ R_LEN
// offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
MOVLQZX -4(R_SRC), R_OFF
JMP doCopy
tagCopy2:
// case tagCopy2:
// s += 3
ADDQ $3, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = 1 + int(src[s-3])>>2
SHRQ $2, R_LEN
INCQ R_LEN
// offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
MOVWQZX -2(R_SRC), R_OFF
JMP doCopy
tagCopy:
// We have a copy tag. We assume that:
// - R_TMP1 == src[s] & 0x03
// - R_LEN == src[s]
CMPQ R_TMP1, $2
JEQ tagCopy2
JA tagCopy4
// case tagCopy1:
// s += 2
ADDQ $2, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
// length = 4 + int(src[s-2])>>2&0x7
MOVBQZX -1(R_SRC), R_TMP1
MOVQ R_LEN, R_TMP0
SHRQ $2, R_LEN
ANDQ $0xe0, R_TMP0
ANDQ $7, R_LEN
SHLQ $3, R_TMP0
ADDQ $4, R_LEN
ORQ R_TMP1, R_TMP0
// check if repeat code, ZF set by ORQ.
JZ repeatCode
// This is a regular copy, transfer our temporary value to R_OFF (length)
MOVQ R_TMP0, R_OFF
JMP doCopy
// This is a repeat code.
repeatCode:
// If length < 9, reuse last offset, with the length already calculated.
CMPQ R_LEN, $9
JL doCopyRepeat
// Read additional bytes for length.
JE repeatLen1
// Rare, so the extra branch shouldn't hurt too much.
CMPQ R_LEN, $10
JE repeatLen2
JMP repeatLen3
// Read repeat lengths.
repeatLen1:
// s ++
ADDQ $1, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = src[s-1] + 8
MOVBQZX -1(R_SRC), R_LEN
ADDL $8, R_LEN
JMP doCopyRepeat
repeatLen2:
// s +=2
ADDQ $2, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = uint32(src[s-2]) | (uint32(src[s-1])<<8) + (1 << 8)
MOVWQZX -2(R_SRC), R_LEN
ADDL $260, R_LEN
JMP doCopyRepeat
repeatLen3:
// s +=3
ADDQ $3, R_SRC
// if uint(s) > uint(len(src)) { etc }
CMPQ R_SRC, R_SEND
JA errCorrupt
// length = uint32(src[s-3]) | (uint32(src[s-2])<<8) | (uint32(src[s-1])<<16) + (1 << 16)
// Read one byte further back (just part of the tag, shifted out)
MOVL -4(R_SRC), R_LEN
SHRL $8, R_LEN
ADDL $65540, R_LEN
JMP doCopyRepeat
doCopy:
// This is the end of the outer "switch", when we have a copy tag.
//
// We assume that:
// - R_LEN == length && R_LEN > 0
// - R_OFF == offset
// if d < offset { etc }
MOVQ R_DST, R_TMP1
SUBQ R_DBASE, R_TMP1
CMPQ R_TMP1, R_OFF
JLT errCorrupt
// Repeat values can skip the test above, since any offset > 0 will be in dst.
doCopyRepeat:
// if offset <= 0 { etc }
CMPQ R_OFF, $0
JLE errCorrupt
// if length > len(dst)-d { etc }
MOVQ R_DEND, R_TMP1
SUBQ R_DST, R_TMP1
CMPQ R_LEN, R_TMP1
JGT errCorrupt
// forwardCopy(dst[d:d+length], dst[d-offset:]); d += length
//
// Set:
// - R_TMP2 = len(dst)-d
// - R_TMP3 = &dst[d-offset]
MOVQ R_DEND, R_TMP2
SUBQ R_DST, R_TMP2
MOVQ R_DST, R_TMP3
SUBQ R_OFF, R_TMP3
// !!! 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 R_LEN, $16
JGT slowForwardCopy
CMPQ R_OFF, $8
JLT slowForwardCopy
CMPQ R_TMP2, $16
JLT slowForwardCopy
MOVQ 0(R_TMP3), R_TMP0
MOVQ R_TMP0, 0(R_DST)
MOVQ 8(R_TMP3), R_TMP1
MOVQ R_TMP1, 8(R_DST)
ADDQ R_LEN, R_DST
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, R_TMP2
CMPQ R_LEN, R_TMP2
JGT verySlowForwardCopy
// We want to keep the offset, so we use R_TMP2 from here.
MOVQ R_OFF, R_TMP2
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
// // R_TMP3, is unchanged.
// }
CMPQ R_TMP2, $8
JGE fixUpSlowForwardCopy
MOVQ (R_TMP3), R_TMP1
MOVQ R_TMP1, (R_DST)
SUBQ R_TMP2, R_LEN
ADDQ R_TMP2, R_DST
ADDQ R_TMP2, R_TMP2
JMP makeOffsetAtLeast8
fixUpSlowForwardCopy:
// !!! Add length (which might be negative now) to d (implied by R_DST 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 R_DST to R_TMP0 so that, if
// length is positive, copying the remaining length bytes will write to the
// right place.
MOVQ R_DST, R_TMP0
ADDQ R_LEN, R_DST
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 R_LEN, $0
JLE loop
MOVQ (R_TMP3), R_TMP1
MOVQ R_TMP1, (R_TMP0)
ADDQ $8, R_TMP3
ADDQ $8, R_TMP0
SUBQ $8, R_LEN
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 (R_TMP3), R_TMP1
MOVB R_TMP1, (R_DST)
INCQ R_TMP3
INCQ R_DST
DECQ R_LEN
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 R_DST, R_DEND
JNE errCorrupt
// return 0
MOVQ $0, ret+48(FP)
RET
errCorrupt:
// return decodeErrCodeCorrupt
MOVQ $1, ret+48(FP)
RET
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/decode_arm64.s
Generated Vendored
+574
View File
@@ -0,0 +1,574 @@
// Copyright 2020 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"
#define R_TMP0 R2
#define R_TMP1 R3
#define R_LEN R4
#define R_OFF R5
#define R_SRC R6
#define R_DST R7
#define R_DBASE R8
#define R_DLEN R9
#define R_DEND R10
#define R_SBASE R11
#define R_SLEN R12
#define R_SEND R13
#define R_TMP2 R14
#define R_TMP3 R15
// TEST_SRC will check if R_SRC is <= SRC_END
#define TEST_SRC() \
CMP R_SEND, R_SRC \
BGT errCorrupt
// MOVD R_SRC, R_TMP1
// SUB R_SBASE, R_TMP1, R_TMP1
// CMP R_SLEN, R_TMP1
// BGT errCorrupt
// 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:
// - R_TMP0 scratch
// - R_TMP1 scratch
// - R_LEN length or x
// - R_OFF offset
// - R_SRC &src[s]
// - R_DST &dst[d]
// + R_DBASE dst_base
// + R_DLEN dst_len
// + R_DEND dst_base + dst_len
// + R_SBASE src_base
// + R_SLEN src_len
// + R_SEND src_base + src_len
// - R_TMP2 used by doCopy
// - R_TMP3 used by doCopy
//
// The registers R_DBASE-R_SEND (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 R_DST - R_DBASE, and len(dst)-d is R_DEND - R_DST.
// The s variable is implicitly R_SRC - R_SBASE, and len(src)-s is R_SEND - R_SRC.
TEXT ·s2Decode(SB), NOSPLIT, $56-56
// Initialize R_SRC, R_DST and R_DBASE-R_SEND.
MOVD dst_base+0(FP), R_DBASE
MOVD dst_len+8(FP), R_DLEN
MOVD R_DBASE, R_DST
MOVD R_DBASE, R_DEND
ADD R_DLEN, R_DEND, R_DEND
MOVD src_base+24(FP), R_SBASE
MOVD src_len+32(FP), R_SLEN
MOVD R_SBASE, R_SRC
MOVD R_SBASE, R_SEND
ADD R_SLEN, R_SEND, R_SEND
MOVD $0, R_OFF
loop:
// for s < len(src)
CMP R_SEND, R_SRC
BEQ end
// R_LEN = uint32(src[s])
//
// switch src[s] & 0x03
MOVBU (R_SRC), R_LEN
MOVW R_LEN, R_TMP1
ANDW $3, R_TMP1
MOVW $1, R1
CMPW R1, R_TMP1
BGE tagCopy
// ----------------------------------------
// The code below handles literal tags.
// case tagLiteral:
// x := uint32(src[s] >> 2)
// switch
MOVW $60, R1
LSRW $2, R_LEN, R_LEN
CMPW R_LEN, R1
BLS tagLit60Plus
// case x < 60:
// s++
ADD $1, R_SRC, R_SRC
doLit:
// This is the end of the inner "switch", when we have a literal tag.
//
// We assume that R_LEN == 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
// R_LEN can hold 64 bits, so the increment cannot overflow.
ADD $1, R_LEN, R_LEN
// Prepare to check if copying length bytes will run past the end of dst or
// src.
//
// R_TMP0 = len(dst) - d
// R_TMP1 = len(src) - s
MOVD R_DEND, R_TMP0
SUB R_DST, R_TMP0, R_TMP0
MOVD R_SEND, R_TMP1
SUB R_SRC, R_TMP1, R_TMP1
// !!! 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).
CMP $16, R_LEN
BGT callMemmove
CMP $16, R_TMP0
BLT callMemmove
CMP $16, R_TMP1
BLT 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 arm64, 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.
LDP 0(R_SRC), (R_TMP2, R_TMP3)
STP (R_TMP2, R_TMP3), 0(R_DST)
// d += length
// s += length
ADD R_LEN, R_DST, R_DST
ADD R_LEN, R_SRC, R_SRC
B loop
callMemmove:
// if length > len(dst)-d || length > len(src)-s { etc }
CMP R_TMP0, R_LEN
BGT errCorrupt
CMP R_TMP1, R_LEN
BGT errCorrupt
// copy(dst[d:], src[s:s+length])
//
// This means calling runtime·memmove(&dst[d], &src[s], length), so we push
// R_DST, R_SRC and R_LEN as arguments. Coincidentally, we also need to spill those
// three registers to the stack, to save local variables across the CALL.
MOVD R_DST, 8(RSP)
MOVD R_SRC, 16(RSP)
MOVD R_LEN, 24(RSP)
MOVD R_DST, 32(RSP)
MOVD R_SRC, 40(RSP)
MOVD R_LEN, 48(RSP)
MOVD R_OFF, 56(RSP)
CALL runtime·memmove(SB)
// Restore local variables: unspill registers from the stack and
// re-calculate R_DBASE-R_SEND.
MOVD 32(RSP), R_DST
MOVD 40(RSP), R_SRC
MOVD 48(RSP), R_LEN
MOVD 56(RSP), R_OFF
MOVD dst_base+0(FP), R_DBASE
MOVD dst_len+8(FP), R_DLEN
MOVD R_DBASE, R_DEND
ADD R_DLEN, R_DEND, R_DEND
MOVD src_base+24(FP), R_SBASE
MOVD src_len+32(FP), R_SLEN
MOVD R_SBASE, R_SEND
ADD R_SLEN, R_SEND, R_SEND
// d += length
// s += length
ADD R_LEN, R_DST, R_DST
ADD R_LEN, R_SRC, R_SRC
B 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.
ADD R_LEN, R_SRC, R_SRC
SUB $58, R_SRC, R_SRC
TEST_SRC()
// case x == 60:
MOVW $61, R1
CMPW R1, R_LEN
BEQ tagLit61
BGT tagLit62Plus
// x = uint32(src[s-1])
MOVBU -1(R_SRC), R_LEN
B doLit
tagLit61:
// case x == 61:
// x = uint32(src[s-2]) | uint32(src[s-1])<<8
MOVHU -2(R_SRC), R_LEN
B doLit
tagLit62Plus:
CMPW $62, R_LEN
BHI tagLit63
// case x == 62:
// x = uint32(src[s-3]) | uint32(src[s-2])<<8 | uint32(src[s-1])<<16
MOVHU -3(R_SRC), R_LEN
MOVBU -1(R_SRC), R_TMP1
ORR R_TMP1<<16, R_LEN
B 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
MOVWU -4(R_SRC), R_LEN
B doLit
// The code above handles literal tags.
// ----------------------------------------
// The code below handles copy tags.
tagCopy4:
// case tagCopy4:
// s += 5
ADD $5, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
MOVD R_SRC, R_TMP1
SUB R_SBASE, R_TMP1, R_TMP1
CMP R_SLEN, R_TMP1
BGT errCorrupt
// length = 1 + int(src[s-5])>>2
MOVD $1, R1
ADD R_LEN>>2, R1, R_LEN
// offset = int(uint32(src[s-4]) | uint32(src[s-3])<<8 | uint32(src[s-2])<<16 | uint32(src[s-1])<<24)
MOVWU -4(R_SRC), R_OFF
B doCopy
tagCopy2:
// case tagCopy2:
// s += 3
ADD $3, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = 1 + int(src[s-3])>>2
MOVD $1, R1
ADD R_LEN>>2, R1, R_LEN
// offset = int(uint32(src[s-2]) | uint32(src[s-1])<<8)
MOVHU -2(R_SRC), R_OFF
B doCopy
tagCopy:
// We have a copy tag. We assume that:
// - R_TMP1 == src[s] & 0x03
// - R_LEN == src[s]
CMP $2, R_TMP1
BEQ tagCopy2
BGT tagCopy4
// case tagCopy1:
// s += 2
ADD $2, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// offset = int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
// Calculate offset in R_TMP0 in case it is a repeat.
MOVD R_LEN, R_TMP0
AND $0xe0, R_TMP0
MOVBU -1(R_SRC), R_TMP1
ORR R_TMP0<<3, R_TMP1, R_TMP0
// length = 4 + int(src[s-2])>>2&0x7
MOVD $7, R1
AND R_LEN>>2, R1, R_LEN
ADD $4, R_LEN, R_LEN
// check if repeat code with offset 0.
CMP $0, R_TMP0
BEQ repeatCode
// This is a regular copy, transfer our temporary value to R_OFF (offset)
MOVD R_TMP0, R_OFF
B doCopy
// This is a repeat code.
repeatCode:
// If length < 9, reuse last offset, with the length already calculated.
CMP $9, R_LEN
BLT doCopyRepeat
BEQ repeatLen1
CMP $10, R_LEN
BEQ repeatLen2
repeatLen3:
// s +=3
ADD $3, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = uint32(src[s-3]) | (uint32(src[s-2])<<8) | (uint32(src[s-1])<<16) + 65540
MOVBU -1(R_SRC), R_TMP0
MOVHU -3(R_SRC), R_LEN
ORR R_TMP0<<16, R_LEN, R_LEN
ADD $65540, R_LEN, R_LEN
B doCopyRepeat
repeatLen2:
// s +=2
ADD $2, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = uint32(src[s-2]) | (uint32(src[s-1])<<8) + 260
MOVHU -2(R_SRC), R_LEN
ADD $260, R_LEN, R_LEN
B doCopyRepeat
repeatLen1:
// s +=1
ADD $1, R_SRC, R_SRC
// if uint(s) > uint(len(src)) { etc }
TEST_SRC()
// length = src[s-1] + 8
MOVBU -1(R_SRC), R_LEN
ADD $8, R_LEN, R_LEN
B doCopyRepeat
doCopy:
// This is the end of the outer "switch", when we have a copy tag.
//
// We assume that:
// - R_LEN == length && R_LEN > 0
// - R_OFF == offset
// if d < offset { etc }
MOVD R_DST, R_TMP1
SUB R_DBASE, R_TMP1, R_TMP1
CMP R_OFF, R_TMP1
BLT errCorrupt
// Repeat values can skip the test above, since any offset > 0 will be in dst.
doCopyRepeat:
// if offset <= 0 { etc }
CMP $0, R_OFF
BLE errCorrupt
// if length > len(dst)-d { etc }
MOVD R_DEND, R_TMP1
SUB R_DST, R_TMP1, R_TMP1
CMP R_TMP1, R_LEN
BGT errCorrupt
// forwardCopy(dst[d:d+length], dst[d-offset:]); d += length
//
// Set:
// - R_TMP2 = len(dst)-d
// - R_TMP3 = &dst[d-offset]
MOVD R_DEND, R_TMP2
SUB R_DST, R_TMP2, R_TMP2
MOVD R_DST, R_TMP3
SUB R_OFF, R_TMP3, R_TMP3
// !!! 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
CMP $16, R_LEN
BGT slowForwardCopy
CMP $8, R_OFF
BLT slowForwardCopy
CMP $16, R_TMP2
BLT slowForwardCopy
MOVD 0(R_TMP3), R_TMP0
MOVD R_TMP0, 0(R_DST)
MOVD 8(R_TMP3), R_TMP1
MOVD R_TMP1, 8(R_DST)
ADD R_LEN, R_DST, R_DST
B 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
// }
SUB $10, R_TMP2, R_TMP2
CMP R_TMP2, R_LEN
BGT verySlowForwardCopy
// We want to keep the offset, so we use R_TMP2 from here.
MOVD R_OFF, R_TMP2
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
// // R_TMP3, is unchanged.
// }
CMP $8, R_TMP2
BGE fixUpSlowForwardCopy
MOVD (R_TMP3), R_TMP1
MOVD R_TMP1, (R_DST)
SUB R_TMP2, R_LEN, R_LEN
ADD R_TMP2, R_DST, R_DST
ADD R_TMP2, R_TMP2, R_TMP2
B makeOffsetAtLeast8
fixUpSlowForwardCopy:
// !!! Add length (which might be negative now) to d (implied by R_DST 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 R_DST to R_TMP0 so that, if
// length is positive, copying the remaining length bytes will write to the
// right place.
MOVD R_DST, R_TMP0
ADD R_LEN, R_DST, R_DST
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.
MOVD $0, R1
CMP R1, R_LEN
BLE loop
MOVD (R_TMP3), R_TMP1
MOVD R_TMP1, (R_TMP0)
ADD $8, R_TMP3, R_TMP3
ADD $8, R_TMP0, R_TMP0
SUB $8, R_LEN, R_LEN
B 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 (R_TMP3), R_TMP1
MOVB R_TMP1, (R_DST)
ADD $1, R_TMP3, R_TMP3
ADD $1, R_DST, R_DST
SUB $1, R_LEN, R_LEN
CBNZ R_LEN, verySlowForwardCopy
B loop
// The code above handles copy tags.
// ----------------------------------------
end:
// This is the end of the "for s < len(src)".
//
// if d != len(dst) { etc }
CMP R_DEND, R_DST
BNE errCorrupt
// return 0
MOVD $0, ret+48(FP)
RET
errCorrupt:
// return decodeErrCodeCorrupt
MOVD $1, R_TMP0
MOVD R_TMP0, ret+48(FP)
RET
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/decode_asm.go
Generated Vendored
+17
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// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build (amd64 || arm64) && !appengine && gc && !noasm
// +build amd64 arm64
// +build !appengine
// +build gc
// +build !noasm
package s2
// decode has the same semantics as in decode_other.go.
//
//go:noescape
func s2Decode(dst, src []byte) int
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/decode_other.go
Generated Vendored
+287
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@@ -0,0 +1,287 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build (!amd64 && !arm64) || appengine || !gc || noasm
package s2
import (
"fmt"
"strconv"
"github.com/klauspost/compress/internal/le"
)
// 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 s2Decode(dst, src []byte) int {
const debug = false
if debug {
fmt.Println("Starting decode, dst len:", len(dst))
}
var d, s, length int
offset := 0
// As long as we can read at least 5 bytes...
for s < len(src)-5 {
// Removing bounds checks is SLOWER, when if doing
// in := src[s:s+5]
// Checked on Go 1.18
switch src[s] & 0x03 {
case tagLiteral:
x := uint32(src[s] >> 2)
switch {
case x < 60:
s++
case x == 60:
x = uint32(src[s+1])
s += 2
case x == 61:
x = uint32(le.Load16(src, s+1))
s += 3
case x == 62:
// Load as 32 bit and shift down.
x = le.Load32(src, s)
x >>= 8
s += 4
case x == 63:
x = le.Load32(src, s+1)
s += 5
}
length = int(x) + 1
if length > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
if debug {
fmt.Println("corrupt: lit size", length)
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("literals, length:", length, "d-after:", d+length)
}
copy(dst[d:], src[s:s+length])
d += length
s += length
continue
case tagCopy1:
s += 2
toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
length = int(src[s-2]) >> 2 & 0x7
if toffset == 0 {
if debug {
fmt.Print("(repeat) ")
}
// keep last offset
switch length {
case 5:
length = int(src[s]) + 4
s += 1
case 6:
length = int(le.Load16(src, s)) + 1<<8
s += 2
case 7:
in := src[s : s+3]
length = int((uint32(in[2])<<16)|(uint32(in[1])<<8)|uint32(in[0])) + (1 << 16)
s += 3
default: // 0-> 4
}
} else {
offset = toffset
}
length += 4
case tagCopy2:
offset = int(le.Load16(src, s+1))
length = 1 + int(src[s])>>2
s += 3
case tagCopy4:
offset = int(le.Load32(src, s+1))
length = 1 + int(src[s])>>2
s += 5
}
if offset <= 0 || d < offset || length > len(dst)-d {
if debug {
fmt.Println("corrupt: match, length", length, "offset:", offset, "dst avail:", len(dst)-d, "dst pos:", d)
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset > length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
// Remaining with extra checks...
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 > len(dst)-d || length > len(src)-s || (strconv.IntSize == 32 && length <= 0) {
if debug {
fmt.Println("corrupt: lit size", length)
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("literals, length:", length, "d-after:", d+length)
}
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 = int(src[s-2]) >> 2 & 0x7
toffset := int(uint32(src[s-2])&0xe0<<3 | uint32(src[s-1]))
if toffset == 0 {
if debug {
fmt.Print("(repeat) ")
}
// keep last offset
switch length {
case 5:
s += 1
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-1])) + 4
case 6:
s += 2
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-2])|(uint32(src[s-1])<<8)) + (1 << 8)
case 7:
s += 3
if uint(s) > uint(len(src)) { // The uint conversions catch overflow from the previous line.
return decodeErrCodeCorrupt
}
length = int(uint32(src[s-3])|(uint32(src[s-2])<<8)|(uint32(src[s-1])<<16)) + (1 << 16)
default: // 0-> 4
}
} else {
offset = toffset
}
length += 4
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 {
if debug {
fmt.Println("corrupt: match, length", length, "offset:", offset, "dst avail:", len(dst)-d, "dst pos:", d)
}
return decodeErrCodeCorrupt
}
if debug {
fmt.Println("copy, length:", length, "offset:", offset, "d-after:", d+length)
}
// Copy from an earlier sub-slice of dst to a later sub-slice.
// If no overlap, use the built-in copy:
if offset > length {
copy(dst[d:d+length], dst[d-offset:])
d += length
continue
}
// Unlike the built-in copy function, this byte-by-byte copy always runs
// forwards, even if the slices overlap. Conceptually, this is:
//
// d += forwardCopy(dst[d:d+length], dst[d-offset:])
//
// We align the slices into a and b and show the compiler they are the same size.
// This allows the loop to run without bounds checks.
a := dst[d : d+length]
b := dst[d-offset:]
b = b[:len(a)]
for i := range a {
a[i] = b[i]
}
d += length
}
if d != len(dst) {
return decodeErrCodeCorrupt
}
return 0
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/dict.go
Generated Vendored
+352
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@@ -0,0 +1,352 @@
// Copyright (c) 2022+ Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"bytes"
"encoding/binary"
"sync"
)
const (
// MinDictSize is the minimum dictionary size when repeat has been read.
MinDictSize = 16
// MaxDictSize is the maximum dictionary size when repeat has been read.
MaxDictSize = 65536
// MaxDictSrcOffset is the maximum offset where a dictionary entry can start.
MaxDictSrcOffset = 65535
)
// Dict contains a dictionary that can be used for encoding and decoding s2
type Dict struct {
dict []byte
repeat int // Repeat as index of dict
fast, better, best sync.Once
fastTable *[1 << 14]uint16
betterTableShort *[1 << 14]uint16
betterTableLong *[1 << 17]uint16
bestTableShort *[1 << 16]uint32
bestTableLong *[1 << 19]uint32
}
// NewDict will read a dictionary.
// It will return nil if the dictionary is invalid.
func NewDict(dict []byte) *Dict {
if len(dict) == 0 {
return nil
}
var d Dict
// Repeat is the first value of the dict
r, n := binary.Uvarint(dict)
if n <= 0 {
return nil
}
dict = dict[n:]
d.dict = dict
if cap(d.dict) < len(d.dict)+16 {
d.dict = append(make([]byte, 0, len(d.dict)+16), d.dict...)
}
if len(dict) < MinDictSize || len(dict) > MaxDictSize {
return nil
}
// Compare as uint64: int(r) would wrap negative for r > MaxInt64,
// slipping past the bounds check and causing an OOB read in encode.
if r > uint64(len(dict)) {
return nil
}
d.repeat = int(r)
return &d
}
// Bytes will return a serialized version of the dictionary.
// The output can be sent to NewDict.
func (d *Dict) Bytes() []byte {
dst := make([]byte, binary.MaxVarintLen16+len(d.dict))
return append(dst[:binary.PutUvarint(dst, uint64(d.repeat))], d.dict...)
}
// MakeDict will create a dictionary.
// 'data' must be at least MinDictSize.
// If data is longer than MaxDictSize only the last MaxDictSize bytes will be used.
// If searchStart is set the start repeat value will be set to the last
// match of this content.
// If no matches are found, it will attempt to find shorter matches.
// This content should match the typical start of a block.
// If at least 4 bytes cannot be matched, repeat is set to start of block.
func MakeDict(data []byte, searchStart []byte) *Dict {
if len(data) == 0 {
return nil
}
if len(data) > MaxDictSize {
data = data[len(data)-MaxDictSize:]
}
var d Dict
dict := data
d.dict = dict
if cap(d.dict) < len(d.dict)+16 {
d.dict = append(make([]byte, 0, len(d.dict)+16), d.dict...)
}
if len(dict) < MinDictSize {
return nil
}
// Find the longest match possible, last entry if multiple.
for s := len(searchStart); s > 4; s-- {
if idx := bytes.LastIndex(data, searchStart[:s]); idx >= 0 && idx <= len(data)-8 {
d.repeat = idx
break
}
}
return &d
}
// MakeDictManual will create a dictionary.
// 'data' must be at least MinDictSize and less than or equal to MaxDictSize.
// A manual first repeat index into data must be provided.
// It must be less than len(data)-8.
func MakeDictManual(data []byte, firstIdx uint16) *Dict {
if len(data) < MinDictSize || int(firstIdx) >= len(data)-8 || len(data) > MaxDictSize {
return nil
}
var d Dict
dict := data
d.dict = dict
if cap(d.dict) < len(d.dict)+16 {
d.dict = append(make([]byte, 0, len(d.dict)+16), d.dict...)
}
d.repeat = int(firstIdx)
return &d
}
// 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.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func (d *Dict) Encode(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
dstP := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:dstP]
}
if len(src) < minNonLiteralBlockSize {
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
n := encodeBlockDictGo(dst[dstP:], src, d)
if n > 0 {
dstP += n
return dst[:dstP]
}
// Not compressible
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
// EncodeBetter 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.
//
// EncodeBetter compresses better than Encode but typically with a
// 10-40% speed decrease on both compression and decompression.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func (d *Dict) EncodeBetter(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.
dstP := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:dstP]
}
if len(src) < minNonLiteralBlockSize {
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
n := encodeBlockBetterDict(dst[dstP:], src, d)
if n > 0 {
dstP += n
return dst[:dstP]
}
// Not compressible
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
// EncodeBest 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.
//
// EncodeBest compresses as good as reasonably possible but with a
// big speed decrease.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func (d *Dict) EncodeBest(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.
dstP := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:dstP]
}
if len(src) < minNonLiteralBlockSize {
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
n := encodeBlockBest(dst[dstP:], src, d)
if n > 0 {
dstP += n
return dst[:dstP]
}
// Not compressible
dstP += emitLiteral(dst[dstP:], src)
return dst[:dstP]
}
// 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 (d *Dict) Decode(dst, src []byte) ([]byte, error) {
dLen, s, err := decodedLen(src)
if err != nil {
return nil, err
}
if dLen <= cap(dst) {
dst = dst[:dLen]
} else {
dst = make([]byte, dLen)
}
if s2DecodeDict(dst, src[s:], d) != 0 {
return nil, ErrCorrupt
}
return dst, nil
}
func (d *Dict) initFast() {
d.fast.Do(func() {
const (
tableBits = 14
maxTableSize = 1 << tableBits
)
var table [maxTableSize]uint16
// We stop so any entry of length 8 can always be read.
for i := 0; i < len(d.dict)-8-2; i += 3 {
x0 := load64(d.dict, i)
h0 := hash6(x0, tableBits)
h1 := hash6(x0>>8, tableBits)
h2 := hash6(x0>>16, tableBits)
table[h0] = uint16(i)
table[h1] = uint16(i + 1)
table[h2] = uint16(i + 2)
}
d.fastTable = &table
})
}
func (d *Dict) initBetter() {
d.better.Do(func() {
const (
// Long hash matches.
lTableBits = 17
maxLTableSize = 1 << lTableBits
// Short hash matches.
sTableBits = 14
maxSTableSize = 1 << sTableBits
)
var lTable [maxLTableSize]uint16
var sTable [maxSTableSize]uint16
// We stop so any entry of length 8 can always be read.
for i := 0; i < len(d.dict)-8; i++ {
cv := load64(d.dict, i)
lTable[hash7(cv, lTableBits)] = uint16(i)
sTable[hash4(cv, sTableBits)] = uint16(i)
}
d.betterTableShort = &sTable
d.betterTableLong = &lTable
})
}
func (d *Dict) initBest() {
d.best.Do(func() {
const (
// Long hash matches.
lTableBits = 19
maxLTableSize = 1 << lTableBits
// Short hash matches.
sTableBits = 16
maxSTableSize = 1 << sTableBits
)
var lTable [maxLTableSize]uint32
var sTable [maxSTableSize]uint32
// We stop so any entry of length 8 can always be read.
for i := 0; i < len(d.dict)-8; i++ {
cv := load64(d.dict, i)
hashL := hash8(cv, lTableBits)
hashS := hash4(cv, sTableBits)
candidateL := lTable[hashL]
candidateS := sTable[hashS]
lTable[hashL] = uint32(i) | candidateL<<16
sTable[hashS] = uint32(i) | candidateS<<16
}
d.bestTableShort = &sTable
d.bestTableLong = &lTable
})
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/encode.go
Generated Vendored
+418
View File
@@ -0,0 +1,418 @@
// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"encoding/binary"
"math"
"math/bits"
"sync"
"github.com/klauspost/compress/internal/race"
)
// 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.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func Encode(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlock(dst[d:], src)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
var estblockPool [2]sync.Pool
// EstimateBlockSize will perform a very fast compression
// without outputting the result and return the compressed output size.
// The function returns -1 if no improvement could be achieved.
// Using actual compression will most often produce better compression than the estimate.
func EstimateBlockSize(src []byte) (d int) {
if len(src) <= inputMargin || int64(len(src)) > 0xffffffff {
return -1
}
if len(src) <= 1024 {
const sz, pool = 2048, 0
tmp, ok := estblockPool[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer estblockPool[pool].Put(tmp)
d = calcBlockSizeSmall(src, tmp)
} else {
const sz, pool = 32768, 1
tmp, ok := estblockPool[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer estblockPool[pool].Put(tmp)
d = calcBlockSize(src, tmp)
}
if d == 0 {
return -1
}
// Size of the varint encoded block size.
d += (bits.Len64(uint64(len(src))) + 7) / 7
if d >= len(src) {
return -1
}
return d
}
// EncodeBetter 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.
//
// EncodeBetter compresses better than Encode but typically with a
// 10-40% speed decrease on both compression and decompression.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func EncodeBetter(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlockBetter(dst[d:], src)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
// EncodeBest 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.
//
// EncodeBest compresses as good as reasonably possible but with a
// big speed decrease.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func EncodeBest(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlockBest(dst[d:], src, nil)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
// EncodeSnappy 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 output is Snappy compatible and will likely decompress faster.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func EncodeSnappy(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlockSnappy(dst[d:], src)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
// EncodeSnappyBetter 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 output is Snappy compatible and will likely decompress faster.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func EncodeSnappyBetter(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlockBetterSnappy(dst[d:], src)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
// EncodeSnappyBest 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 output is Snappy compatible and will likely decompress faster.
//
// The dst and src must not overlap. It is valid to pass a nil dst.
//
// The blocks will require the same amount of memory to decode as encoding,
// and does not make for concurrent decoding.
// Also note that blocks do not contain CRC information, so corruption may be undetected.
//
// If you need to encode larger amounts of data, consider using
// the streaming interface which gives all of these features.
func EncodeSnappyBest(dst, src []byte) []byte {
if n := MaxEncodedLen(len(src)); n < 0 {
panic(ErrTooLarge)
} else if cap(dst) < n {
dst = make([]byte, n)
} else {
dst = dst[:n]
}
// The block starts with the varint-encoded length of the decompressed bytes.
d := binary.PutUvarint(dst, uint64(len(src)))
if len(src) == 0 {
return dst[:d]
}
if len(src) < minNonLiteralBlockSize {
d += emitLiteral(dst[d:], src)
return dst[:d]
}
n := encodeBlockBestSnappy(dst[d:], src)
if n > 0 {
d += n
return dst[:d]
}
// Not compressible
d += emitLiteral(dst[d:], src)
return dst[:d]
}
// ConcatBlocks will concatenate the supplied blocks and append them to the supplied destination.
// If the destination is nil or too small, a new will be allocated.
// The blocks are not validated, so garbage in = garbage out.
// dst may not overlap block data.
// Any data in dst is preserved as is, so it will not be considered a block.
func ConcatBlocks(dst []byte, blocks ...[]byte) ([]byte, error) {
totalSize := uint64(0)
compSize := 0
for _, b := range blocks {
l, hdr, err := decodedLen(b)
if err != nil {
return nil, err
}
totalSize += uint64(l)
compSize += len(b) - hdr
}
if totalSize == 0 {
dst = append(dst, 0)
return dst, nil
}
if totalSize > math.MaxUint32 {
return nil, ErrTooLarge
}
var tmp [binary.MaxVarintLen32]byte
hdrSize := binary.PutUvarint(tmp[:], totalSize)
wantSize := hdrSize + compSize
if cap(dst)-len(dst) < wantSize {
dst = append(make([]byte, 0, wantSize+len(dst)), dst...)
}
dst = append(dst, tmp[:hdrSize]...)
for _, b := range blocks {
_, hdr, err := decodedLen(b)
if err != nil {
return nil, err
}
dst = append(dst, b[hdr:]...)
}
return dst, nil
}
// 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 = 8
// minNonLiteralBlockSize is the minimum size of the input to encodeBlock that
// will be accepted by the encoder.
const minNonLiteralBlockSize = 32
const intReduction = 2 - (1 << (^uint(0) >> 63)) // 1 (32 bits) or 0 (64 bits)
// MaxBlockSize is the maximum value where MaxEncodedLen will return a valid block size.
// Blocks this big are highly discouraged, though.
// Half the size on 32 bit systems.
const MaxBlockSize = (1<<(32-intReduction) - 1) - binary.MaxVarintLen32 - 5
// 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.
// 32 bit platforms will have lower thresholds for rejecting big content.
func MaxEncodedLen(srcLen int) int {
n := uint64(srcLen)
if intReduction == 1 {
// 32 bits
if n > math.MaxInt32 {
// Also includes negative.
return -1
}
} else if n > 0xffffffff {
// 64 bits
// Also includes negative.
return -1
}
// Size of the varint encoded block size.
n = n + uint64((bits.Len64(n)+7)/7)
// Add maximum size of encoding block as literals.
n += uint64(literalExtraSize(int64(srcLen)))
if intReduction == 1 {
// 32 bits
if n > math.MaxInt32 {
return -1
}
} else if n > 0xffffffff {
// 64 bits
// Also includes negative.
return -1
}
return int(n)
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/encode_all.go
Generated Vendored
+1477
View File
File diff suppressed because it is too large Load Diff
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/encode_asm.go
Generated Vendored
+316
View File
@@ -0,0 +1,316 @@
//go:build (amd64 || arm64) && !appengine && !noasm && gc
package s2
import (
"sync"
"github.com/klauspost/compress/internal/race"
)
const hasAsm = true
var encPools [4]sync.Pool
// 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) {
race.ReadSlice(src)
race.WriteSlice(dst)
const (
// Use 12 bit table when less than...
limit12B = 16 << 10
// Use 10 bit table when less than...
limit10B = 4 << 10
// Use 8 bit table when less than...
limit8B = 512
)
if len(src) >= 4<<20 {
const sz, pool = 65536, 0
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeBlockAsm(dst, src, tmp)
}
if len(src) >= limit12B {
const sz, pool = 65536, 0
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeBlockAsm4MB(dst, src, tmp)
}
if len(src) >= limit10B {
const sz, pool = 16384, 1
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeBlockAsm12B(dst, src, tmp)
}
if len(src) >= limit8B {
const sz, pool = 4096, 2
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeBlockAsm10B(dst, src, tmp)
}
if len(src) < minNonLiteralBlockSize {
return 0
}
const sz, pool = 1024, 3
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeBlockAsm8B(dst, src, tmp)
}
var encBetterPools [5]sync.Pool
// encodeBlockBetter 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 encodeBlockBetter(dst, src []byte) (d int) {
race.ReadSlice(src)
race.WriteSlice(dst)
const (
// Use 12 bit table when less than...
limit12B = 16 << 10
// Use 10 bit table when less than...
limit10B = 4 << 10
// Use 8 bit table when less than...
limit8B = 512
)
if len(src) > 4<<20 {
const sz, pool = 589824, 0
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeBetterBlockAsm(dst, src, tmp)
}
if len(src) >= limit12B {
const sz, pool = 589824, 0
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeBetterBlockAsm4MB(dst, src, tmp)
}
if len(src) >= limit10B {
const sz, pool = 81920, 0
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeBetterBlockAsm12B(dst, src, tmp)
}
if len(src) >= limit8B {
const sz, pool = 20480, 1
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeBetterBlockAsm10B(dst, src, tmp)
}
if len(src) < minNonLiteralBlockSize {
return 0
}
const sz, pool = 5120, 2
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeBetterBlockAsm8B(dst, src, tmp)
}
// encodeBlockSnappy 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 encodeBlockSnappy(dst, src []byte) (d int) {
race.ReadSlice(src)
race.WriteSlice(dst)
const (
// Use 12 bit table when less than...
limit12B = 16 << 10
// Use 10 bit table when less than...
limit10B = 4 << 10
// Use 8 bit table when less than...
limit8B = 512
)
if len(src) > 65536 {
const sz, pool = 65536, 0
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeSnappyBlockAsm(dst, src, tmp)
}
if len(src) >= limit12B {
const sz, pool = 65536, 0
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeSnappyBlockAsm64K(dst, src, tmp)
}
if len(src) >= limit10B {
const sz, pool = 16384, 1
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeSnappyBlockAsm12B(dst, src, tmp)
}
if len(src) >= limit8B {
const sz, pool = 4096, 2
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeSnappyBlockAsm10B(dst, src, tmp)
}
if len(src) < minNonLiteralBlockSize {
return 0
}
const sz, pool = 1024, 3
tmp, ok := encPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encPools[pool].Put(tmp)
return encodeSnappyBlockAsm8B(dst, src, tmp)
}
// encodeBlockSnappy 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 encodeBlockBetterSnappy(dst, src []byte) (d int) {
race.ReadSlice(src)
race.WriteSlice(dst)
const (
// Use 12 bit table when less than...
limit12B = 16 << 10
// Use 10 bit table when less than...
limit10B = 4 << 10
// Use 8 bit table when less than...
limit8B = 512
)
if len(src) > 65536 {
const sz, pool = 589824, 0
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeSnappyBetterBlockAsm(dst, src, tmp)
}
if len(src) >= limit12B {
const sz, pool = 294912, 4
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeSnappyBetterBlockAsm64K(dst, src, tmp)
}
if len(src) >= limit10B {
const sz, pool = 81920, 0
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeSnappyBetterBlockAsm12B(dst, src, tmp)
}
if len(src) >= limit8B {
const sz, pool = 20480, 1
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeSnappyBetterBlockAsm10B(dst, src, tmp)
}
if len(src) < minNonLiteralBlockSize {
return 0
}
const sz, pool = 5120, 2
tmp, ok := encBetterPools[pool].Get().(*[sz]byte)
if !ok {
tmp = &[sz]byte{}
}
race.WriteSlice(tmp[:])
defer encBetterPools[pool].Put(tmp)
return encodeSnappyBetterBlockAsm8B(dst, src, tmp)
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/encode_best.go
Generated Vendored
+797
View File
@@ -0,0 +1,797 @@
// Copyright 2016 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"fmt"
"math"
"math/bits"
)
// encodeBlockBest 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 encodeBlockBest(dst, src []byte, dict *Dict) (d int) {
// Initialize the hash tables.
const (
// Long hash matches.
lTableBits = bestLongTableBits
maxLTableSize = bestLongTableSize
// Short hash matches.
sTableBits = bestShortTableBits
maxSTableSize = bestShortTableSize
inputMargin = 8 + 2
debug = false
)
// 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
if len(src) < minNonLiteralBlockSize {
return 0
}
sLimitDict := min(len(src)-inputMargin, MaxDictSrcOffset-inputMargin)
tbl := getBestTables()
lTable := &tbl.lTable
sTable := &tbl.sTable
defer bestTablePool.Put(tbl)
// Bail if we can't compress to at least this.
dstLimit := len(src) - 5
// 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
repeat := 1
if dict != nil {
dict.initBest()
s = 0
repeat = len(dict.dict) - dict.repeat
}
cv := load64(src, s)
// We search for a repeat at -1, but don't output repeats when nextEmit == 0
const lowbitMask = 0xffffffff
getCur := func(x uint64) int {
return int(x & lowbitMask)
}
getPrev := func(x uint64) int {
return int(x >> 32)
}
const maxSkip = 64
for {
type match struct {
offset int
s int
length int
score int
rep, dict bool
}
var best match
for {
// Next src position to check
nextS := (s-nextEmit)>>8 + 1
if nextS > maxSkip {
nextS = s + maxSkip
} else {
nextS += s
}
if nextS > sLimit {
goto emitRemainder
}
if dict != nil && s >= MaxDictSrcOffset {
dict = nil
if repeat > s {
repeat = math.MinInt32
}
}
hashL := hash8(cv, lTableBits)
hashS := hash4(cv, sTableBits)
candidateL := lTable[hashL]
candidateS := sTable[hashS]
score := func(m match) int {
// Matches that are longer forward are penalized since we must emit it as a literal.
score := m.length - m.s
if nextEmit == m.s {
// If we do not have to emit literals, we save 1 byte
score++
}
offset := m.s - m.offset
if m.rep {
return score - emitRepeatSize(offset, m.length)
}
return score - emitCopySize(offset, m.length)
}
matchAt := func(offset, s int, first uint32, rep bool) match {
if best.length != 0 && best.s-best.offset == s-offset {
// Don't retest if we have the same offset.
return match{offset: offset, s: s}
}
if load32(src, offset) != first {
return match{offset: offset, s: s}
}
m := match{offset: offset, s: s, length: 4 + offset, rep: rep}
s += 4
for s < len(src) {
if len(src)-s < 8 {
if src[s] == src[m.length] {
m.length++
s++
continue
}
break
}
if diff := load64(src, s) ^ load64(src, m.length); diff != 0 {
m.length += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
m.length += 8
}
m.length -= offset
m.score = score(m)
if m.score <= -m.s {
// Eliminate if no savings, we might find a better one.
m.length = 0
}
return m
}
matchDict := func(candidate, s int, first uint32, rep bool) match {
if s >= MaxDictSrcOffset {
return match{offset: candidate, s: s}
}
// Calculate offset as if in continuous array with s
offset := -len(dict.dict) + candidate
if best.length != 0 && best.s-best.offset == s-offset && !rep {
// Don't retest if we have the same offset.
return match{offset: offset, s: s}
}
if load32(dict.dict, candidate) != first {
return match{offset: offset, s: s}
}
m := match{offset: offset, s: s, length: 4 + candidate, rep: rep, dict: true}
s += 4
if !rep {
for s < sLimitDict && m.length < len(dict.dict) {
if len(src)-s < 8 || len(dict.dict)-m.length < 8 {
if src[s] == dict.dict[m.length] {
m.length++
s++
continue
}
break
}
if diff := load64(src, s) ^ load64(dict.dict, m.length); diff != 0 {
m.length += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
m.length += 8
}
} else {
for s < len(src) && m.length < len(dict.dict) {
if len(src)-s < 8 || len(dict.dict)-m.length < 8 {
if src[s] == dict.dict[m.length] {
m.length++
s++
continue
}
break
}
if diff := load64(src, s) ^ load64(dict.dict, m.length); diff != 0 {
m.length += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
m.length += 8
}
}
m.length -= candidate
m.score = score(m)
if m.score <= -m.s {
// Eliminate if no savings, we might find a better one.
m.length = 0
}
return m
}
bestOf := func(a, b match) match {
if b.length == 0 {
return a
}
if a.length == 0 {
return b
}
as := a.score + b.s
bs := b.score + a.s
if as >= bs {
return a
}
return b
}
if s > 0 {
best = bestOf(matchAt(getCur(candidateL), s, uint32(cv), false), matchAt(getPrev(candidateL), s, uint32(cv), false))
best = bestOf(best, matchAt(getCur(candidateS), s, uint32(cv), false))
best = bestOf(best, matchAt(getPrev(candidateS), s, uint32(cv), false))
}
if dict != nil {
candidateL := dict.bestTableLong[hashL]
candidateS := dict.bestTableShort[hashS]
best = bestOf(best, matchDict(int(candidateL&0xffff), s, uint32(cv), false))
best = bestOf(best, matchDict(int(candidateL>>16), s, uint32(cv), false))
best = bestOf(best, matchDict(int(candidateS&0xffff), s, uint32(cv), false))
best = bestOf(best, matchDict(int(candidateS>>16), s, uint32(cv), false))
}
{
if (dict == nil || repeat <= s) && repeat > 0 {
best = bestOf(best, matchAt(s-repeat+1, s+1, uint32(cv>>8), true))
} else if s-repeat < -4 && dict != nil {
candidate := len(dict.dict) - (repeat - s)
best = bestOf(best, matchDict(candidate, s, uint32(cv), true))
candidate++
best = bestOf(best, matchDict(candidate, s+1, uint32(cv>>8), true))
}
if best.length > 0 {
hashS := hash4(cv>>8, sTableBits)
// s+1
nextShort := sTable[hashS]
s := s + 1
cv := load64(src, s)
hashL := hash8(cv, lTableBits)
nextLong := lTable[hashL]
best = bestOf(best, matchAt(getCur(nextShort), s, uint32(cv), false))
best = bestOf(best, matchAt(getPrev(nextShort), s, uint32(cv), false))
best = bestOf(best, matchAt(getCur(nextLong), s, uint32(cv), false))
best = bestOf(best, matchAt(getPrev(nextLong), s, uint32(cv), false))
// Dict at + 1
if dict != nil {
candidateL := dict.bestTableLong[hashL]
candidateS := dict.bestTableShort[hashS]
best = bestOf(best, matchDict(int(candidateL&0xffff), s, uint32(cv), false))
best = bestOf(best, matchDict(int(candidateS&0xffff), s, uint32(cv), false))
}
// s+2
if true {
hashS := hash4(cv>>8, sTableBits)
nextShort = sTable[hashS]
s++
cv = load64(src, s)
hashL := hash8(cv, lTableBits)
nextLong = lTable[hashL]
if (dict == nil || repeat <= s) && repeat > 0 {
// Repeat at + 2
best = bestOf(best, matchAt(s-repeat, s, uint32(cv), true))
} else if repeat-s > 4 && dict != nil {
candidate := len(dict.dict) - (repeat - s)
best = bestOf(best, matchDict(candidate, s, uint32(cv), true))
}
best = bestOf(best, matchAt(getCur(nextShort), s, uint32(cv), false))
best = bestOf(best, matchAt(getPrev(nextShort), s, uint32(cv), false))
best = bestOf(best, matchAt(getCur(nextLong), s, uint32(cv), false))
best = bestOf(best, matchAt(getPrev(nextLong), s, uint32(cv), false))
// Dict at +2
// Very small gain
if dict != nil {
candidateL := dict.bestTableLong[hashL]
candidateS := dict.bestTableShort[hashS]
best = bestOf(best, matchDict(int(candidateL&0xffff), s, uint32(cv), false))
best = bestOf(best, matchDict(int(candidateS&0xffff), s, uint32(cv), false))
}
}
// Search for a match at best match end, see if that is better.
// Allow some bytes at the beginning to mismatch.
// Sweet spot is around 1-2 bytes, but depends on input.
// The skipped bytes are tested in Extend backwards,
// and still picked up as part of the match if they do.
const skipBeginning = 2
const skipEnd = 1
if sAt := best.s + best.length - skipEnd; sAt < sLimit {
sBack := best.s + skipBeginning - skipEnd
backL := best.length - skipBeginning
// Load initial values
cv = load64(src, sBack)
// Grab candidates...
next := lTable[hash8(load64(src, sAt), lTableBits)]
if checkAt := getCur(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv), false))
}
if checkAt := getPrev(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv), false))
}
// Disabled: Extremely small gain
if false {
next = sTable[hash4(load64(src, sAt), sTableBits)]
if checkAt := getCur(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv), false))
}
if checkAt := getPrev(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv), false))
}
}
}
}
}
// Update table
lTable[hashL] = uint64(s) | candidateL<<32
sTable[hashS] = uint64(s) | candidateS<<32
if best.length > 0 {
break
}
cv = load64(src, nextS)
s = nextS
}
// Extend backwards, not needed for repeats...
s = best.s
if !best.rep && !best.dict {
for best.offset > 0 && s > nextEmit && src[best.offset-1] == src[s-1] {
best.offset--
best.length++
s--
}
}
if false && best.offset >= s {
panic(fmt.Errorf("t %d >= s %d", best.offset, s))
}
// Bail if we exceed the maximum size.
if d+(s-nextEmit) > dstLimit {
return 0
}
base := s
offset := s - best.offset
s += best.length
if offset > 65535 && s-base <= 5 && !best.rep {
// Bail if the match is equal or worse to the encoding.
s = best.s + 1
if s >= sLimit {
goto emitRemainder
}
cv = load64(src, s)
continue
}
if debug && nextEmit != base {
fmt.Println("EMIT", base-nextEmit, "literals. base-after:", base)
}
d += emitLiteral(dst[d:], src[nextEmit:base])
if best.rep {
if nextEmit > 0 || best.dict {
if debug {
fmt.Println("REPEAT, length", best.length, "offset:", offset, "s-after:", s, "dict:", best.dict, "best:", best)
}
// same as `add := emitCopy(dst[d:], repeat, s-base)` but skips storing offset.
d += emitRepeat(dst[d:], offset, best.length)
} else {
// First match without dict cannot be a repeat.
if debug {
fmt.Println("COPY, length", best.length, "offset:", offset, "s-after:", s, "dict:", best.dict, "best:", best)
}
d += emitCopy(dst[d:], offset, best.length)
}
} else {
if debug {
fmt.Println("COPY, length", best.length, "offset:", offset, "s-after:", s, "dict:", best.dict, "best:", best)
}
d += emitCopy(dst[d:], offset, best.length)
}
repeat = offset
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
if d > dstLimit {
// Do we have space for more, if not bail.
return 0
}
// Fill tables...
for i := best.s + 1; i < s; i++ {
cv0 := load64(src, i)
long0 := hash8(cv0, lTableBits)
short0 := hash4(cv0, sTableBits)
lTable[long0] = uint64(i) | lTable[long0]<<32
sTable[short0] = uint64(i) | sTable[short0]<<32
}
cv = load64(src, s)
}
emitRemainder:
if nextEmit < len(src) {
// Bail if we exceed the maximum size.
if d+len(src)-nextEmit > dstLimit {
return 0
}
if debug && nextEmit != s {
fmt.Println("emitted ", len(src)-nextEmit, "literals")
}
d += emitLiteral(dst[d:], src[nextEmit:])
}
return d
}
// encodeBlockBestSnappy 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 encodeBlockBestSnappy(dst, src []byte) (d int) {
// Initialize the hash tables.
const (
// Long hash matches.
lTableBits = bestLongTableBits
maxLTableSize = bestLongTableSize
// Short hash matches.
sTableBits = bestShortTableBits
maxSTableSize = bestShortTableSize
inputMargin = 8 + 2
)
// 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
if len(src) < minNonLiteralBlockSize {
return 0
}
tbl := getBestTables()
lTable := &tbl.lTable
sTable := &tbl.sTable
defer bestTablePool.Put(tbl)
// Bail if we can't compress to at least this.
dstLimit := len(src) - 5
// 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
cv := load64(src, s)
// We search for a repeat at -1, but don't output repeats when nextEmit == 0
repeat := 1
const lowbitMask = 0xffffffff
getCur := func(x uint64) int {
return int(x & lowbitMask)
}
getPrev := func(x uint64) int {
return int(x >> 32)
}
const maxSkip = 64
for {
type match struct {
offset int
s int
length int
score int
}
var best match
for {
// Next src position to check
nextS := (s-nextEmit)>>8 + 1
if nextS > maxSkip {
nextS = s + maxSkip
} else {
nextS += s
}
if nextS > sLimit {
goto emitRemainder
}
hashL := hash8(cv, lTableBits)
hashS := hash4(cv, sTableBits)
candidateL := lTable[hashL]
candidateS := sTable[hashS]
score := func(m match) int {
// Matches that are longer forward are penalized since we must emit it as a literal.
score := m.length - m.s
if nextEmit == m.s {
// If we do not have to emit literals, we save 1 byte
score++
}
offset := m.s - m.offset
return score - emitCopyNoRepeatSize(offset, m.length)
}
matchAt := func(offset, s int, first uint32) match {
if best.length != 0 && best.s-best.offset == s-offset {
// Don't retest if we have the same offset.
return match{offset: offset, s: s}
}
if load32(src, offset) != first {
return match{offset: offset, s: s}
}
m := match{offset: offset, s: s, length: 4 + offset}
s += 4
for s <= sLimit {
if diff := load64(src, s) ^ load64(src, m.length); diff != 0 {
m.length += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
m.length += 8
}
m.length -= offset
m.score = score(m)
if m.score <= -m.s {
// Eliminate if no savings, we might find a better one.
m.length = 0
}
return m
}
bestOf := func(a, b match) match {
if b.length == 0 {
return a
}
if a.length == 0 {
return b
}
as := a.score + b.s
bs := b.score + a.s
if as >= bs {
return a
}
return b
}
best = bestOf(matchAt(getCur(candidateL), s, uint32(cv)), matchAt(getPrev(candidateL), s, uint32(cv)))
best = bestOf(best, matchAt(getCur(candidateS), s, uint32(cv)))
best = bestOf(best, matchAt(getPrev(candidateS), s, uint32(cv)))
{
best = bestOf(best, matchAt(s-repeat+1, s+1, uint32(cv>>8)))
if best.length > 0 {
// s+1
nextShort := sTable[hash4(cv>>8, sTableBits)]
s := s + 1
cv := load64(src, s)
nextLong := lTable[hash8(cv, lTableBits)]
best = bestOf(best, matchAt(getCur(nextShort), s, uint32(cv)))
best = bestOf(best, matchAt(getPrev(nextShort), s, uint32(cv)))
best = bestOf(best, matchAt(getCur(nextLong), s, uint32(cv)))
best = bestOf(best, matchAt(getPrev(nextLong), s, uint32(cv)))
// Repeat at + 2
best = bestOf(best, matchAt(s-repeat+1, s+1, uint32(cv>>8)))
// s+2
if true {
nextShort = sTable[hash4(cv>>8, sTableBits)]
s++
cv = load64(src, s)
nextLong = lTable[hash8(cv, lTableBits)]
best = bestOf(best, matchAt(getCur(nextShort), s, uint32(cv)))
best = bestOf(best, matchAt(getPrev(nextShort), s, uint32(cv)))
best = bestOf(best, matchAt(getCur(nextLong), s, uint32(cv)))
best = bestOf(best, matchAt(getPrev(nextLong), s, uint32(cv)))
}
// Search for a match at best match end, see if that is better.
if sAt := best.s + best.length; sAt < sLimit {
sBack := best.s
backL := best.length
// Load initial values
cv = load64(src, sBack)
// Search for mismatch
next := lTable[hash8(load64(src, sAt), lTableBits)]
//next := sTable[hash4(load64(src, sAt), sTableBits)]
if checkAt := getCur(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv)))
}
if checkAt := getPrev(next) - backL; checkAt > 0 {
best = bestOf(best, matchAt(checkAt, sBack, uint32(cv)))
}
}
}
}
// Update table
lTable[hashL] = uint64(s) | candidateL<<32
sTable[hashS] = uint64(s) | candidateS<<32
if best.length > 0 {
break
}
cv = load64(src, nextS)
s = nextS
}
// Extend backwards, not needed for repeats...
s = best.s
if true {
for best.offset > 0 && s > nextEmit && src[best.offset-1] == src[s-1] {
best.offset--
best.length++
s--
}
}
if false && best.offset >= s {
panic(fmt.Errorf("t %d >= s %d", best.offset, s))
}
// Bail if we exceed the maximum size.
if d+(s-nextEmit) > dstLimit {
return 0
}
base := s
offset := s - best.offset
s += best.length
if offset > 65535 && s-base <= 5 {
// Bail if the match is equal or worse to the encoding.
s = best.s + 1
if s >= sLimit {
goto emitRemainder
}
cv = load64(src, s)
continue
}
d += emitLiteral(dst[d:], src[nextEmit:base])
d += emitCopyNoRepeat(dst[d:], offset, best.length)
repeat = offset
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
if d > dstLimit {
// Do we have space for more, if not bail.
return 0
}
// Fill tables...
for i := best.s + 1; i < s; i++ {
cv0 := load64(src, i)
long0 := hash8(cv0, lTableBits)
short0 := hash4(cv0, sTableBits)
lTable[long0] = uint64(i) | lTable[long0]<<32
sTable[short0] = uint64(i) | sTable[short0]<<32
}
cv = load64(src, s)
}
emitRemainder:
if nextEmit < len(src) {
// Bail if we exceed the maximum size.
if d+len(src)-nextEmit > dstLimit {
return 0
}
d += emitLiteral(dst[d:], src[nextEmit:])
}
return d
}
// emitCopySize returns the size to encode the offset+length
//
// It assumes that:
//
// 1 <= offset && offset <= math.MaxUint32
// 4 <= length && length <= 1 << 24
func emitCopySize(offset, length int) int {
if offset >= 65536 {
i := 0
if length > 64 {
length -= 64
if length >= 4 {
// Emit remaining as repeats
return 5 + emitRepeatSize(offset, length)
}
i = 5
}
if length == 0 {
return i
}
return i + 5
}
// Offset no more than 2 bytes.
if length > 64 {
if offset < 2048 {
// Emit 8 bytes, then rest as repeats...
return 2 + emitRepeatSize(offset, length-8)
}
// Emit remaining as repeats, at least 4 bytes remain.
return 3 + emitRepeatSize(offset, length-60)
}
if length >= 12 || offset >= 2048 {
return 3
}
// Emit the remaining copy, encoded as 2 bytes.
return 2
}
// emitCopyNoRepeatSize returns the size to encode the offset+length
//
// It assumes that:
//
// 1 <= offset && offset <= math.MaxUint32
// 4 <= length && length <= 1 << 24
func emitCopyNoRepeatSize(offset, length int) int {
if offset >= 65536 {
return 5 + 5*(length/64)
}
// Offset no more than 2 bytes.
if length > 64 {
// Emit remaining as repeats, at least 4 bytes remain.
return 3 + 3*(length/60)
}
if length >= 12 || offset >= 2048 {
return 3
}
// Emit the remaining copy, encoded as 2 bytes.
return 2
}
// emitRepeatSize returns the number of bytes required to encode a repeat.
// Length must be at least 4 and < 1<<24
func emitRepeatSize(offset, length int) int {
// Repeat offset, make length cheaper
if length <= 4+4 || (length < 8+4 && offset < 2048) {
return 2
}
if length < (1<<8)+4+4 {
return 3
}
if length < (1<<16)+(1<<8)+4 {
return 4
}
const maxRepeat = (1 << 24) - 1
length -= (1 << 16) - 4
left := 0
if length > maxRepeat {
left = length - maxRepeat + 4
}
if left > 0 {
return 5 + emitRepeatSize(offset, left)
}
return 5
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/encode_better.go
Generated Vendored
+1519
View File
File diff suppressed because it is too large Load Diff
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/encode_go.go
Generated Vendored
+740
View File
@@ -0,0 +1,740 @@
//go:build (!amd64 && !arm64) || appengine || !gc || noasm
package s2
import (
"bytes"
"math/bits"
)
const hasAsm = false
// 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))
func encodeBlock(dst, src []byte) (d int) {
if len(src) < minNonLiteralBlockSize {
return 0
}
if len(src) <= 64<<10 {
return encodeBlockGo64K(dst, src)
}
return encodeBlockGo(dst, src)
}
// encodeBlockBetter 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))
func encodeBlockBetter(dst, src []byte) (d int) {
if len(src) <= 64<<10 {
return encodeBlockBetterGo64K(dst, src)
}
return encodeBlockBetterGo(dst, src)
}
// encodeBlockBetter 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))
func encodeBlockBetterSnappy(dst, src []byte) (d int) {
if len(src) <= 64<<10 {
return encodeBlockBetterSnappyGo64K(dst, src)
}
return encodeBlockBetterSnappyGo(dst, src)
}
// 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))
func encodeBlockSnappy(dst, src []byte) (d int) {
if len(src) < minNonLiteralBlockSize {
return 0
}
if len(src) <= 64<<10 {
return encodeBlockSnappyGo64K(dst, src)
}
return encodeBlockSnappyGo(dst, src)
}
// emitLiteral writes a literal chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 0 <= len(lit) && len(lit) <= math.MaxUint32
func emitLiteral(dst, lit []byte) int {
if len(lit) == 0 {
return 0
}
const num = 63<<2 | tagLiteral
i, n := 0, uint(len(lit)-1)
switch {
case n < 60:
dst[0] = uint8(n)<<2 | tagLiteral
i = 1
case n < 1<<8:
dst[1] = uint8(n)
dst[0] = 60<<2 | tagLiteral
i = 2
case n < 1<<16:
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 61<<2 | tagLiteral
i = 3
case n < 1<<24:
dst[3] = uint8(n >> 16)
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 62<<2 | tagLiteral
i = 4
default:
dst[4] = uint8(n >> 24)
dst[3] = uint8(n >> 16)
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 63<<2 | tagLiteral
i = 5
}
return i + copy(dst[i:], lit)
}
// emitRepeat writes a repeat chunk and returns the number of bytes written.
// Length must be at least 4 and < 1<<24
func emitRepeat(dst []byte, offset, length int) int {
// Repeat offset, make length cheaper
length -= 4
if length <= 4 {
dst[0] = uint8(length)<<2 | tagCopy1
dst[1] = 0
return 2
}
if length < 8 && offset < 2048 {
// Encode WITH offset
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length)<<2 | tagCopy1
return 2
}
if length < (1<<8)+4 {
length -= 4
dst[2] = uint8(length)
dst[1] = 0
dst[0] = 5<<2 | tagCopy1
return 3
}
if length < (1<<16)+(1<<8) {
length -= 1 << 8
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 6<<2 | tagCopy1
return 4
}
const maxRepeat = (1 << 24) - 1
length -= 1 << 16
left := 0
if length > maxRepeat {
left = length - maxRepeat + 4
length = maxRepeat - 4
}
dst[4] = uint8(length >> 16)
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 7<<2 | tagCopy1
if left > 0 {
return 5 + emitRepeat(dst[5:], offset, left)
}
return 5
}
// 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 <= math.MaxUint32
// 4 <= length && length <= 1 << 24
func emitCopy(dst []byte, offset, length int) int {
if offset >= 65536 {
i := 0
if length > 64 {
// Emit a length 64 copy, encoded as 5 bytes.
dst[4] = uint8(offset >> 24)
dst[3] = uint8(offset >> 16)
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 63<<2 | tagCopy4
length -= 64
if length >= 4 {
// Emit remaining as repeats
return 5 + emitRepeat(dst[5:], offset, length)
}
i = 5
}
if length == 0 {
return i
}
// Emit a copy, offset encoded as 4 bytes.
dst[i+0] = uint8(length-1)<<2 | tagCopy4
dst[i+1] = uint8(offset)
dst[i+2] = uint8(offset >> 8)
dst[i+3] = uint8(offset >> 16)
dst[i+4] = uint8(offset >> 24)
return i + 5
}
// Offset no more than 2 bytes.
if length > 64 {
off := 3
if offset < 2048 {
// emit 8 bytes as tagCopy1, rest as repeats.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(8-4)<<2 | tagCopy1
length -= 8
off = 2
} else {
// Emit a length 60 copy, encoded as 3 bytes.
// Emit remaining as repeat value (minimum 4 bytes).
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 59<<2 | tagCopy2
length -= 60
}
// Emit remaining as repeats, at least 4 bytes remain.
return off + emitRepeat(dst[off:], offset, length)
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = uint8(length-1)<<2 | tagCopy2
return 3
}
// Emit the remaining copy, encoded as 2 bytes.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
return 2
}
// emitCopyNoRepeat 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 <= math.MaxUint32
// 4 <= length && length <= 1 << 24
func emitCopyNoRepeat(dst []byte, offset, length int) int {
if offset >= 65536 {
i := 0
if length > 64 {
// Emit a length 64 copy, encoded as 5 bytes.
dst[4] = uint8(offset >> 24)
dst[3] = uint8(offset >> 16)
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 63<<2 | tagCopy4
length -= 64
if length >= 4 {
// Emit remaining as repeats
return 5 + emitCopyNoRepeat(dst[5:], offset, length)
}
i = 5
}
if length == 0 {
return i
}
// Emit a copy, offset encoded as 4 bytes.
dst[i+0] = uint8(length-1)<<2 | tagCopy4
dst[i+1] = uint8(offset)
dst[i+2] = uint8(offset >> 8)
dst[i+3] = uint8(offset >> 16)
dst[i+4] = uint8(offset >> 24)
return i + 5
}
// Offset no more than 2 bytes.
if length > 64 {
// Emit a length 60 copy, encoded as 3 bytes.
// Emit remaining as repeat value (minimum 4 bytes).
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 59<<2 | tagCopy2
length -= 60
// Emit remaining as repeats, at least 4 bytes remain.
return 3 + emitCopyNoRepeat(dst[3:], offset, length)
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = uint8(length-1)<<2 | tagCopy2
return 3
}
// Emit the remaining copy, encoded as 2 bytes.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
return 2
}
// matchLen returns how many bytes match in a and b
//
// It assumes that:
//
// len(a) <= len(b)
func matchLen(a []byte, b []byte) int {
b = b[:len(a)]
var checked int
if len(a) > 4 {
// Try 4 bytes first
if diff := load32(a, 0) ^ load32(b, 0); diff != 0 {
return bits.TrailingZeros32(diff) >> 3
}
// Switch to 8 byte matching.
checked = 4
a = a[4:]
b = b[4:]
for len(a) >= 8 {
b = b[:len(a)]
if diff := load64(a, 0) ^ load64(b, 0); diff != 0 {
return checked + (bits.TrailingZeros64(diff) >> 3)
}
checked += 8
a = a[8:]
b = b[8:]
}
}
b = b[:len(a)]
for i := range a {
if a[i] != b[i] {
return int(i) + checked
}
}
return len(a) + checked
}
// input must be > inputMargin
func calcBlockSize(src []byte, _ *[32768]byte) (d int) {
// Initialize the hash table.
const (
tableBits = 13
maxTableSize = 1 << tableBits
)
var table [maxTableSize]uint32
// 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
// Bail if we can't compress to at least this.
dstLimit := len(src) - len(src)>>5 - 5
// 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
cv := load64(src, s)
// We search for a repeat at -1, but don't output repeats when nextEmit == 0
repeat := 1
for {
candidate := 0
for {
// Next src position to check
nextS := s + (s-nextEmit)>>6 + 4
if nextS > sLimit {
goto emitRemainder
}
hash0 := hash6(cv, tableBits)
hash1 := hash6(cv>>8, tableBits)
candidate = int(table[hash0])
candidate2 := int(table[hash1])
table[hash0] = uint32(s)
table[hash1] = uint32(s + 1)
hash2 := hash6(cv>>16, tableBits)
// Check repeat at offset checkRep.
const checkRep = 1
if uint32(cv>>(checkRep*8)) == load32(src, s-repeat+checkRep) {
base := s + checkRep
// Extend back
for i := base - repeat; base > nextEmit && i > 0 && src[i-1] == src[base-1]; {
i--
base--
}
d += emitLiteralSize(src[nextEmit:base])
// Extend forward
candidate := s - repeat + 4 + checkRep
s += 4 + checkRep
for s <= sLimit {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
d += emitCopyNoRepeatSize(repeat, s-base)
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
cv = load64(src, s)
continue
}
if uint32(cv) == load32(src, candidate) {
break
}
candidate = int(table[hash2])
if uint32(cv>>8) == load32(src, candidate2) {
table[hash2] = uint32(s + 2)
candidate = candidate2
s++
break
}
table[hash2] = uint32(s + 2)
if uint32(cv>>16) == load32(src, candidate) {
s += 2
break
}
cv = load64(src, nextS)
s = nextS
}
// Extend backwards
for candidate > 0 && s > nextEmit && src[candidate-1] == src[s-1] {
candidate--
s--
}
// Bail if we exceed the maximum size.
if d+(s-nextEmit) > dstLimit {
return 0
}
// 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 += emitLiteralSize(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
repeat = base - candidate
// Extend the 4-byte match as long as possible.
s += 4
candidate += 4
for s <= len(src)-8 {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
d += emitCopyNoRepeatSize(repeat, s-base)
if false {
// Validate match.
a := src[base:s]
b := src[base-repeat : base-repeat+(s-base)]
if !bytes.Equal(a, b) {
panic("mismatch")
}
}
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
if d > dstLimit {
// Do we have space for more, if not bail.
return 0
}
// Check for an immediate match, otherwise start search at s+1
x := load64(src, s-2)
m2Hash := hash6(x, tableBits)
currHash := hash6(x>>16, tableBits)
candidate = int(table[currHash])
table[m2Hash] = uint32(s - 2)
table[currHash] = uint32(s)
if uint32(x>>16) != load32(src, candidate) {
cv = load64(src, s+1)
s++
break
}
}
}
emitRemainder:
if nextEmit < len(src) {
// Bail if we exceed the maximum size.
if d+len(src)-nextEmit > dstLimit {
return 0
}
d += emitLiteralSize(src[nextEmit:])
}
return d
}
// length must be > inputMargin.
func calcBlockSizeSmall(src []byte, _ *[2048]byte) (d int) {
// Initialize the hash table.
const (
tableBits = 9
maxTableSize = 1 << tableBits
)
var table [maxTableSize]uint32
// 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
// Bail if we can't compress to at least this.
dstLimit := len(src) - len(src)>>5 - 5
// 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
cv := load64(src, s)
// We search for a repeat at -1, but don't output repeats when nextEmit == 0
repeat := 1
for {
candidate := 0
for {
// Next src position to check
nextS := s + (s-nextEmit)>>6 + 4
if nextS > sLimit {
goto emitRemainder
}
hash0 := hash6(cv, tableBits)
hash1 := hash6(cv>>8, tableBits)
candidate = int(table[hash0])
candidate2 := int(table[hash1])
table[hash0] = uint32(s)
table[hash1] = uint32(s + 1)
hash2 := hash6(cv>>16, tableBits)
// Check repeat at offset checkRep.
const checkRep = 1
if uint32(cv>>(checkRep*8)) == load32(src, s-repeat+checkRep) {
base := s + checkRep
// Extend back
for i := base - repeat; base > nextEmit && i > 0 && src[i-1] == src[base-1]; {
i--
base--
}
d += emitLiteralSize(src[nextEmit:base])
// Extend forward
candidate := s - repeat + 4 + checkRep
s += 4 + checkRep
for s <= sLimit {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
d += emitCopyNoRepeatSize(repeat, s-base)
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
cv = load64(src, s)
continue
}
if uint32(cv) == load32(src, candidate) {
break
}
candidate = int(table[hash2])
if uint32(cv>>8) == load32(src, candidate2) {
table[hash2] = uint32(s + 2)
candidate = candidate2
s++
break
}
table[hash2] = uint32(s + 2)
if uint32(cv>>16) == load32(src, candidate) {
s += 2
break
}
cv = load64(src, nextS)
s = nextS
}
// Extend backwards
for candidate > 0 && s > nextEmit && src[candidate-1] == src[s-1] {
candidate--
s--
}
// Bail if we exceed the maximum size.
if d+(s-nextEmit) > dstLimit {
return 0
}
// 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 += emitLiteralSize(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
repeat = base - candidate
// Extend the 4-byte match as long as possible.
s += 4
candidate += 4
for s <= len(src)-8 {
if diff := load64(src, s) ^ load64(src, candidate); diff != 0 {
s += bits.TrailingZeros64(diff) >> 3
break
}
s += 8
candidate += 8
}
d += emitCopyNoRepeatSize(repeat, s-base)
if false {
// Validate match.
a := src[base:s]
b := src[base-repeat : base-repeat+(s-base)]
if !bytes.Equal(a, b) {
panic("mismatch")
}
}
nextEmit = s
if s >= sLimit {
goto emitRemainder
}
if d > dstLimit {
// Do we have space for more, if not bail.
return 0
}
// Check for an immediate match, otherwise start search at s+1
x := load64(src, s-2)
m2Hash := hash6(x, tableBits)
currHash := hash6(x>>16, tableBits)
candidate = int(table[currHash])
table[m2Hash] = uint32(s - 2)
table[currHash] = uint32(s)
if uint32(x>>16) != load32(src, candidate) {
cv = load64(src, s+1)
s++
break
}
}
}
emitRemainder:
if nextEmit < len(src) {
// Bail if we exceed the maximum size.
if d+len(src)-nextEmit > dstLimit {
return 0
}
d += emitLiteralSize(src[nextEmit:])
}
return d
}
// emitLiteral writes a literal chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 0 <= len(lit) && len(lit) <= math.MaxUint32
func emitLiteralSize(lit []byte) int {
if len(lit) == 0 {
return 0
}
switch {
case len(lit) <= 60:
return len(lit) + 1
case len(lit) <= 1<<8:
return len(lit) + 2
case len(lit) <= 1<<16:
return len(lit) + 3
case len(lit) <= 1<<24:
return len(lit) + 4
default:
return len(lit) + 5
}
}
func cvtLZ4BlockAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
panic("cvtLZ4BlockAsm should be unreachable")
}
func cvtLZ4BlockSnappyAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
panic("cvtLZ4BlockSnappyAsm should be unreachable")
}
func cvtLZ4sBlockAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
panic("cvtLZ4sBlockAsm should be unreachable")
}
func cvtLZ4sBlockSnappyAsm(dst []byte, src []byte) (uncompressed int, dstUsed int) {
panic("cvtLZ4sBlockSnappyAsm should be unreachable")
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/encodeblock_amd64.s
Generated Vendored
+20883
View File
File diff suppressed because it is too large Load Diff
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/encodeblock_arm64.s
Generated Vendored
+23562
View File
File diff suppressed because it is too large Load Diff
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/encodeblock_asm.go
Generated Vendored
+228
View File
@@ -0,0 +1,228 @@
// Code generated by command: go run gen.go -out ../encodeblock_amd64.s -stubs ../encodeblock_asm.go -pkg=s2. DO NOT EDIT.
//go:build (amd64 || arm64) && !appengine && !noasm && gc && !noasm
package s2
func _dummy_()
// encodeBlockAsm encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4294967295 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBlockAsm(dst []byte, src []byte, tmp *[65536]byte) int
// encodeBlockAsm4MB encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4194304 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBlockAsm4MB(dst []byte, src []byte, tmp *[65536]byte) int
// encodeBlockAsm12B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 16383 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBlockAsm12B(dst []byte, src []byte, tmp *[16384]byte) int
// encodeBlockAsm10B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4095 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBlockAsm10B(dst []byte, src []byte, tmp *[4096]byte) int
// encodeBlockAsm8B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 511 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBlockAsm8B(dst []byte, src []byte, tmp *[1024]byte) int
// encodeBetterBlockAsm encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4294967295 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBetterBlockAsm(dst []byte, src []byte, tmp *[589824]byte) int
// encodeBetterBlockAsm4MB encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4194304 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBetterBlockAsm4MB(dst []byte, src []byte, tmp *[589824]byte) int
// encodeBetterBlockAsm12B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 16383 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBetterBlockAsm12B(dst []byte, src []byte, tmp *[81920]byte) int
// encodeBetterBlockAsm10B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4095 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBetterBlockAsm10B(dst []byte, src []byte, tmp *[20480]byte) int
// encodeBetterBlockAsm8B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 511 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeBetterBlockAsm8B(dst []byte, src []byte, tmp *[5120]byte) int
// encodeSnappyBlockAsm encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4294967295 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBlockAsm(dst []byte, src []byte, tmp *[65536]byte) int
// encodeSnappyBlockAsm64K encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 65535 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBlockAsm64K(dst []byte, src []byte, tmp *[65536]byte) int
// encodeSnappyBlockAsm12B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 16383 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBlockAsm12B(dst []byte, src []byte, tmp *[16384]byte) int
// encodeSnappyBlockAsm10B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4095 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBlockAsm10B(dst []byte, src []byte, tmp *[4096]byte) int
// encodeSnappyBlockAsm8B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 511 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBlockAsm8B(dst []byte, src []byte, tmp *[1024]byte) int
// encodeSnappyBetterBlockAsm encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4294967295 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBetterBlockAsm(dst []byte, src []byte, tmp *[589824]byte) int
// encodeSnappyBetterBlockAsm64K encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 65535 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBetterBlockAsm64K(dst []byte, src []byte, tmp *[294912]byte) int
// encodeSnappyBetterBlockAsm12B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 16383 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBetterBlockAsm12B(dst []byte, src []byte, tmp *[81920]byte) int
// encodeSnappyBetterBlockAsm10B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4095 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBetterBlockAsm10B(dst []byte, src []byte, tmp *[20480]byte) int
// encodeSnappyBetterBlockAsm8B encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 511 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func encodeSnappyBetterBlockAsm8B(dst []byte, src []byte, tmp *[5120]byte) int
// calcBlockSize encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 4294967295 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func calcBlockSize(src []byte, tmp *[32768]byte) int
// calcBlockSizeSmall encodes a non-empty src to a guaranteed-large-enough dst.
// Maximum input 1024 bytes.
// It assumes that the varint-encoded length of the decompressed bytes has already been written.
//
//go:noescape
func calcBlockSizeSmall(src []byte, tmp *[2048]byte) int
// emitLiteral writes a literal chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes with margin of 0 bytes
// 0 <= len(lit) && len(lit) <= math.MaxUint32
//
//go:noescape
func emitLiteral(dst []byte, lit []byte) int
// emitRepeat writes a repeat chunk and returns the number of bytes written.
// Length must be at least 4 and < 1<<32
//
//go:noescape
func emitRepeat(dst []byte, offset int, length int) int
// 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 <= math.MaxUint32
// 4 <= length && length <= 1 << 24
//
//go:noescape
func emitCopy(dst []byte, offset int, length int) int
// emitCopyNoRepeat 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 <= math.MaxUint32
// 4 <= length && length <= 1 << 24
//
//go:noescape
func emitCopyNoRepeat(dst []byte, offset int, length int) int
// matchLen returns how many bytes match in a and b
//
// It assumes that:
//
// len(a) <= len(b)
//
//go:noescape
func matchLen(a []byte, b []byte) int
// cvtLZ4Block converts an LZ4 block to S2
//
//go:noescape
func cvtLZ4BlockAsm(dst []byte, src []byte) (uncompressed int, dstUsed int)
// cvtLZ4sBlock converts an LZ4s block to S2
//
//go:noescape
func cvtLZ4sBlockAsm(dst []byte, src []byte) (uncompressed int, dstUsed int)
// cvtLZ4Block converts an LZ4 block to Snappy
//
//go:noescape
func cvtLZ4BlockSnappyAsm(dst []byte, src []byte) (uncompressed int, dstUsed int)
// cvtLZ4sBlock converts an LZ4s block to Snappy
//
//go:noescape
func cvtLZ4sBlockSnappyAsm(dst []byte, src []byte) (uncompressed int, dstUsed int)
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/hashtable_pool.go
Generated Vendored
+65
View File
@@ -0,0 +1,65 @@
package s2
import "sync"
// Table size constants
const (
betterLongTableBits = 17
betterLongTableSize = 1 << betterLongTableBits // 131072
betterShortTableBits = 14
betterShortTableSize = 1 << betterShortTableBits // 16384
betterSnappyLongTableBits = 16
betterSnappyLongTableSize = 1 << betterSnappyLongTableBits // 65536
bestLongTableBits = 19
bestLongTableSize = 1 << bestLongTableBits // 524288
bestShortTableBits = 16
bestShortTableSize = 1 << bestShortTableBits // 65536
)
type betterTables struct {
lTable [betterLongTableSize]uint32
sTable [betterShortTableSize]uint32
}
var betterTablePool = sync.Pool{New: func() any { return &betterTables{} }}
// betterSnappyTables holds better-snappy compression hash tables.
type betterSnappyTables struct {
lTable [betterSnappyLongTableSize]uint32
sTable [betterShortTableSize]uint32
}
var betterSnappyTablePool = sync.Pool{New: func() any { return &betterSnappyTables{} }}
// bestTables holds best compression hash tables.
type bestTables struct {
lTable [bestLongTableSize]uint64
sTable [bestShortTableSize]uint64
}
var bestTablePool = sync.Pool{New: func() any { return &bestTables{} }}
// getBetterTables gets a zeroed betterTables from the pool.
func getBetterTables() *betterTables {
t := betterTablePool.Get().(*betterTables)
*t = betterTables{}
return t
}
// getBetterSnappyTables gets a zeroed betterSnappyTables from the pool.
func getBetterSnappyTables() *betterSnappyTables {
t := betterSnappyTablePool.Get().(*betterSnappyTables)
*t = betterSnappyTables{}
return t
}
// getBestTables gets a zeroed bestTables from the pool.
func getBestTables() *bestTables {
t := bestTablePool.Get().(*bestTables)
*t = bestTables{}
return t
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/index.go
Generated Vendored
+602
View File
@@ -0,0 +1,602 @@
// Copyright (c) 2022+ Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"bytes"
"encoding/binary"
"encoding/json"
"fmt"
"io"
"sort"
)
const (
S2IndexHeader = "s2idx\x00"
S2IndexTrailer = "\x00xdi2s"
maxIndexEntries = 1 << 16
// If distance is less than this, we do not add the entry.
minIndexDist = 1 << 20
)
// Index represents an S2/Snappy index.
type Index struct {
TotalUncompressed int64 // Total Uncompressed size if known. Will be -1 if unknown.
TotalCompressed int64 // Total Compressed size if known. Will be -1 if unknown.
info []struct {
compressedOffset int64
uncompressedOffset int64
}
estBlockUncomp int64
}
func (i *Index) reset(maxBlock int) {
i.estBlockUncomp = int64(maxBlock)
i.TotalCompressed = -1
i.TotalUncompressed = -1
if len(i.info) > 0 {
i.info = i.info[:0]
}
}
// allocInfos will allocate an empty slice of infos.
func (i *Index) allocInfos(n int) {
if n > maxIndexEntries {
panic("n > maxIndexEntries")
}
i.info = make([]struct {
compressedOffset int64
uncompressedOffset int64
}, 0, n)
}
// add an uncompressed and compressed pair.
// Entries must be sent in order.
func (i *Index) add(compressedOffset, uncompressedOffset int64) error {
if i == nil {
return nil
}
lastIdx := len(i.info) - 1
if lastIdx >= 0 {
latest := i.info[lastIdx]
if latest.uncompressedOffset == uncompressedOffset {
// Uncompressed didn't change, don't add entry,
// but update start index.
latest.compressedOffset = compressedOffset
i.info[lastIdx] = latest
return nil
}
if latest.uncompressedOffset > uncompressedOffset {
return fmt.Errorf("internal error: Earlier uncompressed received (%d > %d)", latest.uncompressedOffset, uncompressedOffset)
}
if latest.compressedOffset > compressedOffset {
return fmt.Errorf("internal error: Earlier compressed received (%d > %d)", latest.compressedOffset, compressedOffset)
}
if latest.uncompressedOffset+minIndexDist > uncompressedOffset {
// Only add entry if distance is large enough.
return nil
}
}
i.info = append(i.info, struct {
compressedOffset int64
uncompressedOffset int64
}{compressedOffset: compressedOffset, uncompressedOffset: uncompressedOffset})
return nil
}
// Find the offset at or before the wanted (uncompressed) offset.
// If offset is 0 or positive it is the offset from the beginning of the file.
// If the uncompressed size is known, the offset must be within the file.
// If an offset outside the file is requested io.ErrUnexpectedEOF is returned.
// If the offset is negative, it is interpreted as the distance from the end of the file,
// where -1 represents the last byte.
// If offset from the end of the file is requested, but size is unknown,
// ErrUnsupported will be returned.
func (i *Index) Find(offset int64) (compressedOff, uncompressedOff int64, err error) {
if i.TotalUncompressed < 0 {
return 0, 0, ErrCorrupt
}
if offset < 0 {
offset = i.TotalUncompressed + offset
if offset < 0 {
return 0, 0, io.ErrUnexpectedEOF
}
}
if offset > i.TotalUncompressed {
return 0, 0, io.ErrUnexpectedEOF
}
if len(i.info) > 200 {
n := sort.Search(len(i.info), func(n int) bool {
return i.info[n].uncompressedOffset > offset
})
if n == 0 {
n = 1
}
return i.info[n-1].compressedOffset, i.info[n-1].uncompressedOffset, nil
}
for _, info := range i.info {
if info.uncompressedOffset > offset {
break
}
compressedOff = info.compressedOffset
uncompressedOff = info.uncompressedOffset
}
return compressedOff, uncompressedOff, nil
}
// reduce to stay below maxIndexEntries
func (i *Index) reduce() {
if len(i.info) < maxIndexEntries && i.estBlockUncomp >= minIndexDist {
return
}
// Algorithm, keep 1, remove removeN entries...
removeN := (len(i.info) + 1) / maxIndexEntries
src := i.info
j := 0
// Each block should be at least 1MB, but don't reduce below 1000 entries.
for i.estBlockUncomp*(int64(removeN)+1) < minIndexDist && len(i.info)/(removeN+1) > 1000 {
removeN++
}
for idx := 0; idx < len(src); idx++ {
i.info[j] = src[idx]
j++
idx += removeN
}
i.info = i.info[:j]
// Update maxblock estimate.
i.estBlockUncomp += i.estBlockUncomp * int64(removeN)
}
func (i *Index) appendTo(b []byte, uncompTotal, compTotal int64) []byte {
i.reduce()
var tmp [binary.MaxVarintLen64]byte
initSize := len(b)
// We make the start a skippable header+size.
b = append(b, ChunkTypeIndex, 0, 0, 0)
b = append(b, []byte(S2IndexHeader)...)
// Total Uncompressed size
n := binary.PutVarint(tmp[:], uncompTotal)
b = append(b, tmp[:n]...)
// Total Compressed size
n = binary.PutVarint(tmp[:], compTotal)
b = append(b, tmp[:n]...)
// Put EstBlockUncomp size
n = binary.PutVarint(tmp[:], i.estBlockUncomp)
b = append(b, tmp[:n]...)
// Put length
n = binary.PutVarint(tmp[:], int64(len(i.info)))
b = append(b, tmp[:n]...)
// Check if we should add uncompressed offsets
var hasUncompressed byte
for idx, info := range i.info {
if idx == 0 {
if info.uncompressedOffset != 0 {
hasUncompressed = 1
break
}
continue
}
if info.uncompressedOffset != i.info[idx-1].uncompressedOffset+i.estBlockUncomp {
hasUncompressed = 1
break
}
}
b = append(b, hasUncompressed)
// Add each entry
if hasUncompressed == 1 {
for idx, info := range i.info {
uOff := info.uncompressedOffset
if idx > 0 {
prev := i.info[idx-1]
uOff -= prev.uncompressedOffset + (i.estBlockUncomp)
}
n = binary.PutVarint(tmp[:], uOff)
b = append(b, tmp[:n]...)
}
}
// Initial compressed size estimate.
cPredict := i.estBlockUncomp / 2
for idx, info := range i.info {
cOff := info.compressedOffset
if idx > 0 {
prev := i.info[idx-1]
cOff -= prev.compressedOffset + cPredict
// Update compressed size prediction, with half the error.
cPredict += cOff / 2
}
n = binary.PutVarint(tmp[:], cOff)
b = append(b, tmp[:n]...)
}
// Add Total Size.
// Stored as fixed size for easier reading.
binary.LittleEndian.PutUint32(tmp[:], uint32(len(b)-initSize+4+len(S2IndexTrailer)))
b = append(b, tmp[:4]...)
// Trailer
b = append(b, []byte(S2IndexTrailer)...)
// Update size
chunkLen := len(b) - initSize - skippableFrameHeader
b[initSize+1] = uint8(chunkLen >> 0)
b[initSize+2] = uint8(chunkLen >> 8)
b[initSize+3] = uint8(chunkLen >> 16)
//fmt.Printf("chunklen: 0x%x Uncomp:%d, Comp:%d\n", chunkLen, uncompTotal, compTotal)
return b
}
// Load a binary index.
// A zero value Index can be used or a previous one can be reused.
func (i *Index) Load(b []byte) ([]byte, error) {
if len(b) <= 4+len(S2IndexHeader)+len(S2IndexTrailer) {
return b, io.ErrUnexpectedEOF
}
if b[0] != ChunkTypeIndex {
return b, ErrCorrupt
}
chunkLen := int(b[1]) | int(b[2])<<8 | int(b[3])<<16
b = b[4:]
// Validate we have enough...
if len(b) < chunkLen {
return b, io.ErrUnexpectedEOF
}
if !bytes.Equal(b[:len(S2IndexHeader)], []byte(S2IndexHeader)) {
return b, ErrUnsupported
}
b = b[len(S2IndexHeader):]
// Total Uncompressed
if v, n := binary.Varint(b); n <= 0 || v < 0 {
return b, ErrCorrupt
} else {
i.TotalUncompressed = v
b = b[n:]
}
// Total Compressed
if v, n := binary.Varint(b); n <= 0 {
return b, ErrCorrupt
} else {
i.TotalCompressed = v
b = b[n:]
}
// Read EstBlockUncomp
if v, n := binary.Varint(b); n <= 0 {
return b, ErrCorrupt
} else {
if v < 0 {
return b, ErrCorrupt
}
i.estBlockUncomp = v
b = b[n:]
}
var entries int
if v, n := binary.Varint(b); n <= 0 {
return b, ErrCorrupt
} else {
if v < 0 || v > maxIndexEntries {
return b, ErrCorrupt
}
entries = int(v)
b = b[n:]
}
if cap(i.info) < entries {
i.allocInfos(entries)
}
i.info = i.info[:entries]
if len(b) < 1 {
return b, io.ErrUnexpectedEOF
}
hasUncompressed := b[0]
b = b[1:]
if hasUncompressed&1 != hasUncompressed {
return b, ErrCorrupt
}
// Add each uncompressed entry
for idx := range i.info {
var uOff int64
if hasUncompressed != 0 {
// Load delta
if v, n := binary.Varint(b); n <= 0 {
return b, ErrCorrupt
} else {
uOff = v
b = b[n:]
}
}
if idx > 0 {
prev := i.info[idx-1].uncompressedOffset
uOff += prev + (i.estBlockUncomp)
if uOff <= prev {
return b, ErrCorrupt
}
}
if uOff < 0 {
return b, ErrCorrupt
}
i.info[idx].uncompressedOffset = uOff
}
// Initial compressed size estimate.
cPredict := i.estBlockUncomp / 2
// Add each compressed entry
for idx := range i.info {
var cOff int64
if v, n := binary.Varint(b); n <= 0 {
return b, ErrCorrupt
} else {
cOff = v
b = b[n:]
}
if idx > 0 {
// Update compressed size prediction, with half the error.
cPredictNew := cPredict + cOff/2
prev := i.info[idx-1].compressedOffset
cOff += prev + cPredict
if cOff <= prev {
return b, ErrCorrupt
}
cPredict = cPredictNew
}
if cOff < 0 {
return b, ErrCorrupt
}
i.info[idx].compressedOffset = cOff
}
if len(b) < 4+len(S2IndexTrailer) {
return b, io.ErrUnexpectedEOF
}
// Skip size...
b = b[4:]
// Check trailer...
if !bytes.Equal(b[:len(S2IndexTrailer)], []byte(S2IndexTrailer)) {
return b, ErrCorrupt
}
return b[len(S2IndexTrailer):], nil
}
// LoadStream will load an index from the end of the supplied stream.
// ErrUnsupported will be returned if the signature cannot be found.
// ErrCorrupt will be returned if unexpected values are found.
// io.ErrUnexpectedEOF is returned if there are too few bytes.
// IO errors are returned as-is.
func (i *Index) LoadStream(rs io.ReadSeeker) error {
// Go to end.
_, err := rs.Seek(-10, io.SeekEnd)
if err != nil {
return err
}
var tmp [10]byte
_, err = io.ReadFull(rs, tmp[:])
if err != nil {
return err
}
// Check trailer...
if !bytes.Equal(tmp[4:4+len(S2IndexTrailer)], []byte(S2IndexTrailer)) {
return ErrUnsupported
}
sz := binary.LittleEndian.Uint32(tmp[:4])
if sz > maxChunkSize+skippableFrameHeader {
return ErrCorrupt
}
_, err = rs.Seek(-int64(sz), io.SeekEnd)
if err != nil {
return err
}
// Read index.
buf := make([]byte, sz)
_, err = io.ReadFull(rs, buf)
if err != nil {
return err
}
_, err = i.Load(buf)
return err
}
// IndexStream will return an index for a stream.
// The stream structure will be checked, but
// data within blocks is not verified.
// The returned index can either be appended to the end of the stream
// or stored separately.
func IndexStream(r io.Reader) ([]byte, error) {
var i Index
var buf [maxChunkSize]byte
var readHeader bool
for {
_, err := io.ReadFull(r, buf[:4])
if err != nil {
if err == io.EOF {
return i.appendTo(nil, i.TotalUncompressed, i.TotalCompressed), nil
}
return nil, err
}
// Start of this chunk.
startChunk := i.TotalCompressed
i.TotalCompressed += 4
chunkType := buf[0]
if !readHeader {
if chunkType != chunkTypeStreamIdentifier {
return nil, ErrCorrupt
}
readHeader = true
}
chunkLen := int(buf[1]) | int(buf[2])<<8 | int(buf[3])<<16
if chunkLen < checksumSize {
return nil, ErrCorrupt
}
i.TotalCompressed += int64(chunkLen)
_, err = io.ReadFull(r, buf[:chunkLen])
if err != nil {
return nil, io.ErrUnexpectedEOF
}
// 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).
// Skip checksum.
dLen, err := DecodedLen(buf[checksumSize:])
if err != nil {
return nil, err
}
if dLen > maxBlockSize {
return nil, ErrCorrupt
}
if i.estBlockUncomp == 0 {
// Use first block for estimate...
i.estBlockUncomp = int64(dLen)
}
err = i.add(startChunk, i.TotalUncompressed)
if err != nil {
return nil, err
}
i.TotalUncompressed += int64(dLen)
continue
case chunkTypeUncompressedData:
n2 := chunkLen - checksumSize
if n2 > maxBlockSize {
return nil, ErrCorrupt
}
if i.estBlockUncomp == 0 {
// Use first block for estimate...
i.estBlockUncomp = int64(n2)
}
err = i.add(startChunk, i.TotalUncompressed)
if err != nil {
return nil, err
}
i.TotalUncompressed += int64(n2)
continue
case chunkTypeStreamIdentifier:
// Section 4.1. Stream identifier (chunk type 0xff).
if chunkLen != len(magicBody) {
return nil, ErrCorrupt
}
if string(buf[:len(magicBody)]) != magicBody {
if string(buf[:len(magicBody)]) != magicBodySnappy {
return nil, ErrCorrupt
}
}
continue
}
if chunkType <= 0x7f {
// Section 4.5. Reserved unskippable chunks (chunk types 0x02-0x7f).
return nil, ErrUnsupported
}
if chunkLen > maxChunkSize {
return nil, ErrUnsupported
}
// Section 4.4 Padding (chunk type 0xfe).
// Section 4.6. Reserved skippable chunks (chunk types 0x80-0xfd).
}
}
// JSON returns the index as JSON text.
func (i *Index) JSON() []byte {
type offset struct {
CompressedOffset int64 `json:"compressed"`
UncompressedOffset int64 `json:"uncompressed"`
}
x := struct {
TotalUncompressed int64 `json:"total_uncompressed"` // Total Uncompressed size if known. Will be -1 if unknown.
TotalCompressed int64 `json:"total_compressed"` // Total Compressed size if known. Will be -1 if unknown.
Offsets []offset `json:"offsets"`
EstBlockUncomp int64 `json:"est_block_uncompressed"`
}{
TotalUncompressed: i.TotalUncompressed,
TotalCompressed: i.TotalCompressed,
EstBlockUncomp: i.estBlockUncomp,
}
for _, v := range i.info {
x.Offsets = append(x.Offsets, offset{CompressedOffset: v.compressedOffset, UncompressedOffset: v.uncompressedOffset})
}
b, _ := json.MarshalIndent(x, "", " ")
return b
}
// RemoveIndexHeaders will trim all headers and trailers from a given index.
// This is expected to save 20 bytes.
// These can be restored using RestoreIndexHeaders.
// This removes a layer of security, but is the most compact representation.
// Returns nil if headers contains errors.
// The returned slice references the provided slice.
func RemoveIndexHeaders(b []byte) []byte {
const save = 4 + len(S2IndexHeader) + len(S2IndexTrailer) + 4
if len(b) <= save {
return nil
}
if b[0] != ChunkTypeIndex {
return nil
}
chunkLen := int(b[1]) | int(b[2])<<8 | int(b[3])<<16
b = b[4:]
// Validate we have enough...
if len(b) < chunkLen {
return nil
}
b = b[:chunkLen]
if !bytes.Equal(b[:len(S2IndexHeader)], []byte(S2IndexHeader)) {
return nil
}
b = b[len(S2IndexHeader):]
if !bytes.HasSuffix(b, []byte(S2IndexTrailer)) {
return nil
}
b = bytes.TrimSuffix(b, []byte(S2IndexTrailer))
if len(b) < 4 {
return nil
}
return b[:len(b)-4]
}
// RestoreIndexHeaders will index restore headers removed by RemoveIndexHeaders.
// No error checking is performed on the input.
// If a 0 length slice is sent, it is returned without modification.
func RestoreIndexHeaders(in []byte) []byte {
if len(in) == 0 {
return in
}
b := make([]byte, 0, 4+len(S2IndexHeader)+len(in)+len(S2IndexTrailer)+4)
b = append(b, ChunkTypeIndex, 0, 0, 0)
b = append(b, []byte(S2IndexHeader)...)
b = append(b, in...)
var tmp [4]byte
binary.LittleEndian.PutUint32(tmp[:], uint32(len(b)+4+len(S2IndexTrailer)))
b = append(b, tmp[:4]...)
// Trailer
b = append(b, []byte(S2IndexTrailer)...)
chunkLen := len(b) - skippableFrameHeader
b[1] = uint8(chunkLen >> 0)
b[2] = uint8(chunkLen >> 8)
b[3] = uint8(chunkLen >> 16)
return b
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/lz4convert.go
Generated Vendored
+585
View File
@@ -0,0 +1,585 @@
// Copyright (c) 2022 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"encoding/binary"
"errors"
"fmt"
)
// LZ4Converter provides conversion from LZ4 blocks as defined here:
// https://github.com/lz4/lz4/blob/dev/doc/lz4_Block_format.md
type LZ4Converter struct {
}
// ErrDstTooSmall is returned when provided destination is too small.
var ErrDstTooSmall = errors.New("s2: destination too small")
// ConvertBlock will convert an LZ4 block and append it as an S2
// block without block length to dst.
// The uncompressed size is returned as well.
// dst must have capacity to contain the entire compressed block.
func (l *LZ4Converter) ConvertBlock(dst, src []byte) ([]byte, int, error) {
if len(src) == 0 {
return dst, 0, nil
}
const debug = false
const inline = true
const lz4MinMatch = 4
s, d := 0, len(dst)
dst = dst[:cap(dst)]
if !debug && hasAsm {
res, sz := cvtLZ4BlockAsm(dst[d:], src)
if res < 0 {
const (
errCorrupt = -1
errDstTooSmall = -2
)
switch res {
case errCorrupt:
return nil, 0, ErrCorrupt
case errDstTooSmall:
return nil, 0, ErrDstTooSmall
default:
return nil, 0, fmt.Errorf("unexpected result: %d", res)
}
}
if d+sz > len(dst) {
return nil, 0, ErrDstTooSmall
}
return dst[:d+sz], res, nil
}
dLimit := len(dst) - 10
var lastOffset uint16
var uncompressed int
if debug {
fmt.Printf("convert block start: len(src): %d, len(dst):%d \n", len(src), len(dst))
}
for {
if s >= len(src) {
return dst[:d], 0, ErrCorrupt
}
// Read literal info
token := src[s]
ll := int(token >> 4)
ml := int(lz4MinMatch + (token & 0xf))
// If upper nibble is 15, literal length is extended
if token >= 0xf0 {
for {
s++
if s >= len(src) {
if debug {
fmt.Printf("error reading ll: s (%d) >= len(src) (%d)\n", s, len(src))
}
return dst[:d], 0, ErrCorrupt
}
val := src[s]
ll += int(val)
if val != 255 {
break
}
}
}
// Skip past token
if s+ll >= len(src) {
if debug {
fmt.Printf("error literals: s+ll (%d+%d) >= len(src) (%d)\n", s, ll, len(src))
}
return nil, 0, ErrCorrupt
}
s++
if ll > 0 {
if d+ll > dLimit {
return nil, 0, ErrDstTooSmall
}
if debug {
fmt.Printf("emit %d literals\n", ll)
}
d += emitLiteralGo(dst[d:], src[s:s+ll])
s += ll
uncompressed += ll
}
// Check if we are done...
if s == len(src) && ml == lz4MinMatch {
break
}
// 2 byte offset
if s >= len(src)-2 {
if debug {
fmt.Printf("s (%d) >= len(src)-2 (%d)", s, len(src)-2)
}
return nil, 0, ErrCorrupt
}
offset := binary.LittleEndian.Uint16(src[s:])
s += 2
if offset == 0 {
if debug {
fmt.Printf("error: offset 0, ml: %d, len(src)-s: %d\n", ml, len(src)-s)
}
return nil, 0, ErrCorrupt
}
if int(offset) > uncompressed {
if debug {
fmt.Printf("error: offset (%d)> uncompressed (%d)\n", offset, uncompressed)
}
return nil, 0, ErrCorrupt
}
if ml == lz4MinMatch+15 {
for {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
s++
ml += int(val)
if val != 255 {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
break
}
}
}
if offset == lastOffset {
if debug {
fmt.Printf("emit repeat, length: %d, offset: %d\n", ml, offset)
}
if !inline {
d += emitRepeat16(dst[d:], offset, ml)
} else {
length := ml
dst := dst[d:]
for len(dst) > 5 {
// Repeat offset, make length cheaper
length -= 4
if length <= 4 {
dst[0] = uint8(length)<<2 | tagCopy1
dst[1] = 0
d += 2
break
}
if length < 8 && offset < 2048 {
// Encode WITH offset
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length)<<2 | tagCopy1
d += 2
break
}
if length < (1<<8)+4 {
length -= 4
dst[2] = uint8(length)
dst[1] = 0
dst[0] = 5<<2 | tagCopy1
d += 3
break
}
if length < (1<<16)+(1<<8) {
length -= 1 << 8
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 6<<2 | tagCopy1
d += 4
break
}
const maxRepeat = (1 << 24) - 1
length -= 1 << 16
left := 0
if length > maxRepeat {
left = length - maxRepeat + 4
length = maxRepeat - 4
}
dst[4] = uint8(length >> 16)
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 7<<2 | tagCopy1
if left > 0 {
d += 5 + emitRepeat16(dst[5:], offset, left)
break
}
d += 5
break
}
}
} else {
if debug {
fmt.Printf("emit copy, length: %d, offset: %d\n", ml, offset)
}
if !inline {
d += emitCopy16(dst[d:], offset, ml)
} else {
length := ml
dst := dst[d:]
for len(dst) > 5 {
// Offset no more than 2 bytes.
if length > 64 {
off := 3
if offset < 2048 {
// emit 8 bytes as tagCopy1, rest as repeats.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(8-4)<<2 | tagCopy1
length -= 8
off = 2
} else {
// Emit a length 60 copy, encoded as 3 bytes.
// Emit remaining as repeat value (minimum 4 bytes).
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 59<<2 | tagCopy2
length -= 60
}
// Emit remaining as repeats, at least 4 bytes remain.
d += off + emitRepeat16(dst[off:], offset, length)
break
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = uint8(length-1)<<2 | tagCopy2
d += 3
break
}
// Emit the remaining copy, encoded as 2 bytes.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
d += 2
break
}
}
lastOffset = offset
}
uncompressed += ml
if d > dLimit {
return nil, 0, ErrDstTooSmall
}
}
return dst[:d], uncompressed, nil
}
// ConvertBlockSnappy will convert an LZ4 block and append it
// as a Snappy block without block length to dst.
// The uncompressed size is returned as well.
// dst must have capacity to contain the entire compressed block.
func (l *LZ4Converter) ConvertBlockSnappy(dst, src []byte) ([]byte, int, error) {
if len(src) == 0 {
return dst, 0, nil
}
const debug = false
const lz4MinMatch = 4
s, d := 0, len(dst)
dst = dst[:cap(dst)]
// Use assembly when possible
if !debug && hasAsm {
res, sz := cvtLZ4BlockSnappyAsm(dst[d:], src)
if res < 0 {
const (
errCorrupt = -1
errDstTooSmall = -2
)
switch res {
case errCorrupt:
return nil, 0, ErrCorrupt
case errDstTooSmall:
return nil, 0, ErrDstTooSmall
default:
return nil, 0, fmt.Errorf("unexpected result: %d", res)
}
}
if d+sz > len(dst) {
return nil, 0, ErrDstTooSmall
}
return dst[:d+sz], res, nil
}
dLimit := len(dst) - 10
var uncompressed int
if debug {
fmt.Printf("convert block start: len(src): %d, len(dst):%d \n", len(src), len(dst))
}
for {
if s >= len(src) {
return nil, 0, ErrCorrupt
}
// Read literal info
token := src[s]
ll := int(token >> 4)
ml := int(lz4MinMatch + (token & 0xf))
// If upper nibble is 15, literal length is extended
if token >= 0xf0 {
for {
s++
if s >= len(src) {
if debug {
fmt.Printf("error reading ll: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
ll += int(val)
if val != 255 {
break
}
}
}
// Skip past token
if s+ll >= len(src) {
if debug {
fmt.Printf("error literals: s+ll (%d+%d) >= len(src) (%d)\n", s, ll, len(src))
}
return nil, 0, ErrCorrupt
}
s++
if ll > 0 {
if d+ll > dLimit {
return nil, 0, ErrDstTooSmall
}
if debug {
fmt.Printf("emit %d literals\n", ll)
}
d += emitLiteralGo(dst[d:], src[s:s+ll])
s += ll
uncompressed += ll
}
// Check if we are done...
if s == len(src) && ml == lz4MinMatch {
break
}
// 2 byte offset
if s >= len(src)-2 {
if debug {
fmt.Printf("s (%d) >= len(src)-2 (%d)", s, len(src)-2)
}
return nil, 0, ErrCorrupt
}
offset := binary.LittleEndian.Uint16(src[s:])
s += 2
if offset == 0 {
if debug {
fmt.Printf("error: offset 0, ml: %d, len(src)-s: %d\n", ml, len(src)-s)
}
return nil, 0, ErrCorrupt
}
if int(offset) > uncompressed {
if debug {
fmt.Printf("error: offset (%d)> uncompressed (%d)\n", offset, uncompressed)
}
return nil, 0, ErrCorrupt
}
if ml == lz4MinMatch+15 {
for {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
s++
ml += int(val)
if val != 255 {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
break
}
}
}
if debug {
fmt.Printf("emit copy, length: %d, offset: %d\n", ml, offset)
}
length := ml
// d += emitCopyNoRepeat(dst[d:], int(offset), ml)
for length > 0 {
if d >= dLimit {
return nil, 0, ErrDstTooSmall
}
// Offset no more than 2 bytes.
if length > 64 {
// Emit a length 64 copy, encoded as 3 bytes.
dst[d+2] = uint8(offset >> 8)
dst[d+1] = uint8(offset)
dst[d+0] = 63<<2 | tagCopy2
length -= 64
d += 3
continue
}
if length >= 12 || offset >= 2048 || length < 4 {
// Emit the remaining copy, encoded as 3 bytes.
dst[d+2] = uint8(offset >> 8)
dst[d+1] = uint8(offset)
dst[d+0] = uint8(length-1)<<2 | tagCopy2
d += 3
break
}
// Emit the remaining copy, encoded as 2 bytes.
dst[d+1] = uint8(offset)
dst[d+0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
d += 2
break
}
uncompressed += ml
if d > dLimit {
return nil, 0, ErrDstTooSmall
}
}
return dst[:d], uncompressed, nil
}
// emitRepeat writes a repeat chunk and returns the number of bytes written.
// Length must be at least 4 and < 1<<24
func emitRepeat16(dst []byte, offset uint16, length int) int {
// Repeat offset, make length cheaper
length -= 4
if length <= 4 {
dst[0] = uint8(length)<<2 | tagCopy1
dst[1] = 0
return 2
}
if length < 8 && offset < 2048 {
// Encode WITH offset
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length)<<2 | tagCopy1
return 2
}
if length < (1<<8)+4 {
length -= 4
dst[2] = uint8(length)
dst[1] = 0
dst[0] = 5<<2 | tagCopy1
return 3
}
if length < (1<<16)+(1<<8) {
length -= 1 << 8
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 6<<2 | tagCopy1
return 4
}
const maxRepeat = (1 << 24) - 1
length -= 1 << 16
left := 0
if length > maxRepeat {
left = length - maxRepeat + 4
length = maxRepeat - 4
}
dst[4] = uint8(length >> 16)
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 7<<2 | tagCopy1
if left > 0 {
return 5 + emitRepeat16(dst[5:], offset, left)
}
return 5
}
// 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 <= math.MaxUint16
// 4 <= length && length <= math.MaxUint32
func emitCopy16(dst []byte, offset uint16, length int) int {
// Offset no more than 2 bytes.
if length > 64 {
off := 3
if offset < 2048 {
// emit 8 bytes as tagCopy1, rest as repeats.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(8-4)<<2 | tagCopy1
length -= 8
off = 2
} else {
// Emit a length 60 copy, encoded as 3 bytes.
// Emit remaining as repeat value (minimum 4 bytes).
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 59<<2 | tagCopy2
length -= 60
}
// Emit remaining as repeats, at least 4 bytes remain.
return off + emitRepeat16(dst[off:], offset, length)
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = uint8(length-1)<<2 | tagCopy2
return 3
}
// Emit the remaining copy, encoded as 2 bytes.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
return 2
}
// emitLiteral writes a literal chunk and returns the number of bytes written.
//
// It assumes that:
//
// dst is long enough to hold the encoded bytes
// 0 <= len(lit) && len(lit) <= math.MaxUint32
func emitLiteralGo(dst, lit []byte) int {
if len(lit) == 0 {
return 0
}
i, n := 0, uint(len(lit)-1)
switch {
case n < 60:
dst[0] = uint8(n)<<2 | tagLiteral
i = 1
case n < 1<<8:
dst[1] = uint8(n)
dst[0] = 60<<2 | tagLiteral
i = 2
case n < 1<<16:
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 61<<2 | tagLiteral
i = 3
case n < 1<<24:
dst[3] = uint8(n >> 16)
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 62<<2 | tagLiteral
i = 4
default:
dst[4] = uint8(n >> 24)
dst[3] = uint8(n >> 16)
dst[2] = uint8(n >> 8)
dst[1] = uint8(n)
dst[0] = 63<<2 | tagLiteral
i = 5
}
return i + copy(dst[i:], lit)
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/lz4sconvert.go
Generated Vendored
+467
View File
@@ -0,0 +1,467 @@
// Copyright (c) 2022 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package s2
import (
"encoding/binary"
"fmt"
)
// LZ4sConverter provides conversion from LZ4s.
// (Intel modified LZ4 Blocks)
// https://cdrdv2-public.intel.com/743912/743912-qat-programmers-guide-v2.0.pdf
// LZ4s is a variant of LZ4 block format. LZ4s should be considered as an intermediate compressed block format.
// The LZ4s format is selected when the application sets the compType to CPA_DC_LZ4S in CpaDcSessionSetupData.
// The LZ4s block returned by the Intel® QAT hardware can be used by an external
// software post-processing to generate other compressed data formats.
// The following table lists the differences between LZ4 and LZ4s block format. LZ4s block format uses
// the same high-level formatting as LZ4 block format with the following encoding changes:
// For Min Match of 4 bytes, Copy length value 1-15 means length 4-18 with 18 bytes adding an extra byte.
// ONLY "Min match of 4 bytes" is supported.
type LZ4sConverter struct {
}
// ConvertBlock will convert an LZ4s block and append it as an S2
// block without block length to dst.
// The uncompressed size is returned as well.
// dst must have capacity to contain the entire compressed block.
func (l *LZ4sConverter) ConvertBlock(dst, src []byte) ([]byte, int, error) {
if len(src) == 0 {
return dst, 0, nil
}
const debug = false
const inline = true
const lz4MinMatch = 3
s, d := 0, len(dst)
dst = dst[:cap(dst)]
if !debug && hasAsm {
res, sz := cvtLZ4sBlockAsm(dst[d:], src)
if res < 0 {
const (
errCorrupt = -1
errDstTooSmall = -2
)
switch res {
case errCorrupt:
return nil, 0, ErrCorrupt
case errDstTooSmall:
return nil, 0, ErrDstTooSmall
default:
return nil, 0, fmt.Errorf("unexpected result: %d", res)
}
}
if d+sz > len(dst) {
return nil, 0, ErrDstTooSmall
}
return dst[:d+sz], res, nil
}
dLimit := len(dst) - 10
var lastOffset uint16
var uncompressed int
if debug {
fmt.Printf("convert block start: len(src): %d, len(dst):%d \n", len(src), len(dst))
}
for {
if s >= len(src) {
return dst[:d], 0, ErrCorrupt
}
// Read literal info
token := src[s]
ll := int(token >> 4)
ml := int(lz4MinMatch + (token & 0xf))
// If upper nibble is 15, literal length is extended
if token >= 0xf0 {
for {
s++
if s >= len(src) {
if debug {
fmt.Printf("error reading ll: s (%d) >= len(src) (%d)\n", s, len(src))
}
return dst[:d], 0, ErrCorrupt
}
val := src[s]
ll += int(val)
if val != 255 {
break
}
}
}
// Skip past token
if s+ll >= len(src) {
if debug {
fmt.Printf("error literals: s+ll (%d+%d) >= len(src) (%d)\n", s, ll, len(src))
}
return nil, 0, ErrCorrupt
}
s++
if ll > 0 {
if d+ll > dLimit {
return nil, 0, ErrDstTooSmall
}
if debug {
fmt.Printf("emit %d literals\n", ll)
}
d += emitLiteralGo(dst[d:], src[s:s+ll])
s += ll
uncompressed += ll
}
// Check if we are done...
if ml == lz4MinMatch {
if s == len(src) {
break
}
// 0 bytes.
continue
}
// 2 byte offset
if s >= len(src)-2 {
if debug {
fmt.Printf("s (%d) >= len(src)-2 (%d)", s, len(src)-2)
}
return nil, 0, ErrCorrupt
}
offset := binary.LittleEndian.Uint16(src[s:])
s += 2
if offset == 0 {
if debug {
fmt.Printf("error: offset 0, ml: %d, len(src)-s: %d\n", ml, len(src)-s)
}
return nil, 0, ErrCorrupt
}
if int(offset) > uncompressed {
if debug {
fmt.Printf("error: offset (%d)> uncompressed (%d)\n", offset, uncompressed)
}
return nil, 0, ErrCorrupt
}
if ml == lz4MinMatch+15 {
for {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
s++
ml += int(val)
if val != 255 {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
break
}
}
}
if offset == lastOffset {
if debug {
fmt.Printf("emit repeat, length: %d, offset: %d\n", ml, offset)
}
if !inline {
d += emitRepeat16(dst[d:], offset, ml)
} else {
length := ml
dst := dst[d:]
for len(dst) > 5 {
// Repeat offset, make length cheaper
length -= 4
if length <= 4 {
dst[0] = uint8(length)<<2 | tagCopy1
dst[1] = 0
d += 2
break
}
if length < 8 && offset < 2048 {
// Encode WITH offset
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length)<<2 | tagCopy1
d += 2
break
}
if length < (1<<8)+4 {
length -= 4
dst[2] = uint8(length)
dst[1] = 0
dst[0] = 5<<2 | tagCopy1
d += 3
break
}
if length < (1<<16)+(1<<8) {
length -= 1 << 8
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 6<<2 | tagCopy1
d += 4
break
}
const maxRepeat = (1 << 24) - 1
length -= 1 << 16
left := 0
if length > maxRepeat {
left = length - maxRepeat + 4
length = maxRepeat - 4
}
dst[4] = uint8(length >> 16)
dst[3] = uint8(length >> 8)
dst[2] = uint8(length >> 0)
dst[1] = 0
dst[0] = 7<<2 | tagCopy1
if left > 0 {
d += 5 + emitRepeat16(dst[5:], offset, left)
break
}
d += 5
break
}
}
} else {
if debug {
fmt.Printf("emit copy, length: %d, offset: %d\n", ml, offset)
}
if !inline {
d += emitCopy16(dst[d:], offset, ml)
} else {
length := ml
dst := dst[d:]
for len(dst) > 5 {
// Offset no more than 2 bytes.
if length > 64 {
off := 3
if offset < 2048 {
// emit 8 bytes as tagCopy1, rest as repeats.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(8-4)<<2 | tagCopy1
length -= 8
off = 2
} else {
// Emit a length 60 copy, encoded as 3 bytes.
// Emit remaining as repeat value (minimum 4 bytes).
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = 59<<2 | tagCopy2
length -= 60
}
// Emit remaining as repeats, at least 4 bytes remain.
d += off + emitRepeat16(dst[off:], offset, length)
break
}
if length >= 12 || offset >= 2048 {
// Emit the remaining copy, encoded as 3 bytes.
dst[2] = uint8(offset >> 8)
dst[1] = uint8(offset)
dst[0] = uint8(length-1)<<2 | tagCopy2
d += 3
break
}
// Emit the remaining copy, encoded as 2 bytes.
dst[1] = uint8(offset)
dst[0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
d += 2
break
}
}
lastOffset = offset
}
uncompressed += ml
if d > dLimit {
return nil, 0, ErrDstTooSmall
}
}
return dst[:d], uncompressed, nil
}
// ConvertBlockSnappy will convert an LZ4s block and append it
// as a Snappy block without block length to dst.
// The uncompressed size is returned as well.
// dst must have capacity to contain the entire compressed block.
func (l *LZ4sConverter) ConvertBlockSnappy(dst, src []byte) ([]byte, int, error) {
if len(src) == 0 {
return dst, 0, nil
}
const debug = false
const lz4MinMatch = 3
s, d := 0, len(dst)
dst = dst[:cap(dst)]
// Use assembly when possible
if !debug && hasAsm {
res, sz := cvtLZ4sBlockSnappyAsm(dst[d:], src)
if res < 0 {
const (
errCorrupt = -1
errDstTooSmall = -2
)
switch res {
case errCorrupt:
return nil, 0, ErrCorrupt
case errDstTooSmall:
return nil, 0, ErrDstTooSmall
default:
return nil, 0, fmt.Errorf("unexpected result: %d", res)
}
}
if d+sz > len(dst) {
return nil, 0, ErrDstTooSmall
}
return dst[:d+sz], res, nil
}
dLimit := len(dst) - 10
var uncompressed int
if debug {
fmt.Printf("convert block start: len(src): %d, len(dst):%d \n", len(src), len(dst))
}
for {
if s >= len(src) {
return nil, 0, ErrCorrupt
}
// Read literal info
token := src[s]
ll := int(token >> 4)
ml := int(lz4MinMatch + (token & 0xf))
// If upper nibble is 15, literal length is extended
if token >= 0xf0 {
for {
s++
if s >= len(src) {
if debug {
fmt.Printf("error reading ll: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
ll += int(val)
if val != 255 {
break
}
}
}
// Skip past token
if s+ll >= len(src) {
if debug {
fmt.Printf("error literals: s+ll (%d+%d) >= len(src) (%d)\n", s, ll, len(src))
}
return nil, 0, ErrCorrupt
}
s++
if ll > 0 {
if d+ll > dLimit {
return nil, 0, ErrDstTooSmall
}
if debug {
fmt.Printf("emit %d literals\n", ll)
}
d += emitLiteralGo(dst[d:], src[s:s+ll])
s += ll
uncompressed += ll
}
// Check if we are done...
if ml == lz4MinMatch {
if s == len(src) {
break
}
// 0 bytes.
continue
}
// 2 byte offset
if s >= len(src)-2 {
if debug {
fmt.Printf("s (%d) >= len(src)-2 (%d)", s, len(src)-2)
}
return nil, 0, ErrCorrupt
}
offset := binary.LittleEndian.Uint16(src[s:])
s += 2
if offset == 0 {
if debug {
fmt.Printf("error: offset 0, ml: %d, len(src)-s: %d\n", ml, len(src)-s)
}
return nil, 0, ErrCorrupt
}
if int(offset) > uncompressed {
if debug {
fmt.Printf("error: offset (%d)> uncompressed (%d)\n", offset, uncompressed)
}
return nil, 0, ErrCorrupt
}
if ml == lz4MinMatch+15 {
for {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
val := src[s]
s++
ml += int(val)
if val != 255 {
if s >= len(src) {
if debug {
fmt.Printf("error reading ml: s (%d) >= len(src) (%d)\n", s, len(src))
}
return nil, 0, ErrCorrupt
}
break
}
}
}
if debug {
fmt.Printf("emit copy, length: %d, offset: %d\n", ml, offset)
}
length := ml
// d += emitCopyNoRepeat(dst[d:], int(offset), ml)
for length > 0 {
if d >= dLimit {
return nil, 0, ErrDstTooSmall
}
// Offset no more than 2 bytes.
if length > 64 {
// Emit a length 64 copy, encoded as 3 bytes.
dst[d+2] = uint8(offset >> 8)
dst[d+1] = uint8(offset)
dst[d+0] = 63<<2 | tagCopy2
length -= 64
d += 3
continue
}
if length >= 12 || offset >= 2048 || length < 4 {
// Emit the remaining copy, encoded as 3 bytes.
dst[d+2] = uint8(offset >> 8)
dst[d+1] = uint8(offset)
dst[d+0] = uint8(length-1)<<2 | tagCopy2
d += 3
break
}
// Emit the remaining copy, encoded as 2 bytes.
dst[d+1] = uint8(offset)
dst[d+0] = uint8(offset>>8)<<5 | uint8(length-4)<<2 | tagCopy1
d += 2
break
}
uncompressed += ml
if d > dLimit {
return nil, 0, ErrDstTooSmall
}
}
return dst[:d], uncompressed, nil
}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/reader.go
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modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/s2.go
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// Copyright 2011 The Snappy-Go Authors. All rights reserved.
// Copyright (c) 2019 Klaus Post. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package s2 implements the S2 compression format.
//
// S2 is an extension of Snappy. Similar to Snappy S2 is aimed for high throughput,
// which is why it features concurrent compression for bigger payloads.
//
// Decoding is compatible with Snappy compressed content,
// but content compressed with S2 cannot be decompressed by Snappy.
//
// For more information on Snappy/S2 differences see README in: https://github.com/klauspost/compress/tree/master/s2
//
// There are actually two S2 formats: block and stream. They are related,
// but different: trying to decompress block-compressed data as a S2 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.
//
// A "better" compression option is available. This will trade some compression
// speed
//
// 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.
//
// Blocks to not offer much data protection, so it is up to you to
// add data validation of decompressed blocks.
//
// Streams perform CRC validation of the decompressed data.
// Stream compression will also be performed on multiple CPU cores concurrently
// significantly improving throughput.
package s2
import (
"bytes"
"hash/crc32"
"github.com/klauspost/compress/internal/race"
)
/*
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, 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
magicChunkSnappy = "\xff\x06\x00\x00" + magicBodySnappy
magicBodySnappy = "sNaPpY"
magicBody = "S2sTwO"
// maxBlockSize is the maximum size of the input to encodeBlock.
//
// For the framing format (Writer type instead of Encode function),
// this is the maximum uncompressed size of a block.
maxBlockSize = 4 << 20
// minBlockSize is the minimum size of block setting when creating a writer.
minBlockSize = 4 << 10
skippableFrameHeader = 4
maxChunkSize = 1<<24 - 1 // 16777215
// Default block size
defaultBlockSize = 1 << 20
// maxSnappyBlockSize is the maximum snappy block size.
maxSnappyBlockSize = 1 << 16
obufHeaderLen = checksumSize + chunkHeaderSize
)
const (
chunkTypeCompressedData = 0x00
chunkTypeUncompressedData = 0x01
ChunkTypeIndex = 0x99
chunkTypePadding = 0xfe
chunkTypeStreamIdentifier = 0xff
)
var (
crcTable = crc32.MakeTable(crc32.Castagnoli)
magicChunkSnappyBytes = []byte(magicChunkSnappy) // Can be passed to functions where it escapes.
magicChunkBytes = []byte(magicChunk) // Can be passed to functions where it escapes.
)
// crc implements the checksum specified in section 3 of
// https://github.com/google/snappy/blob/master/framing_format.txt
func crc(b []byte) uint32 {
race.ReadSlice(b)
c := crc32.Update(0, crcTable, b)
return c>>15 | c<<17 + 0xa282ead8
}
// literalExtraSize returns the extra size of encoding n literals.
// n should be >= 0 and <= math.MaxUint32.
func literalExtraSize(n int64) int64 {
if n == 0 {
return 0
}
switch {
case n < 60:
return 1
case n < 1<<8:
return 2
case n < 1<<16:
return 3
case n < 1<<24:
return 4
default:
return 5
}
}
type byter interface {
Bytes() []byte
}
var _ byter = &bytes.Buffer{}
modules/mesh-delivery-teller/vendor/github.com/klauspost/compress/s2/writer.go
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