mirror of
https://github.com/go-gitea/gitea
synced 2024-11-09 03:34:24 +00:00
c5d5d63c9c
* update macaron to v1.5 of fork * update macaron to v1.5 of fork * test gzip PR * add push method impl to context_tests * use proper gzip commit Co-authored-by: zeripath <art27@cantab.net> Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
1165 lines
30 KiB
Go
Vendored
1165 lines
30 KiB
Go
Vendored
package huff0
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
|
|
"github.com/klauspost/compress/fse"
|
|
)
|
|
|
|
type dTable struct {
|
|
single []dEntrySingle
|
|
double []dEntryDouble
|
|
}
|
|
|
|
// single-symbols decoding
|
|
type dEntrySingle struct {
|
|
entry uint16
|
|
}
|
|
|
|
// double-symbols decoding
|
|
type dEntryDouble struct {
|
|
seq uint16
|
|
nBits uint8
|
|
len uint8
|
|
}
|
|
|
|
// Uses special code for all tables that are < 8 bits.
|
|
const use8BitTables = true
|
|
|
|
// ReadTable will read a table from the input.
|
|
// The size of the input may be larger than the table definition.
|
|
// Any content remaining after the table definition will be returned.
|
|
// If no Scratch is provided a new one is allocated.
|
|
// The returned Scratch can be used for encoding or decoding input using this table.
|
|
func ReadTable(in []byte, s *Scratch) (s2 *Scratch, remain []byte, err error) {
|
|
s, err = s.prepare(in)
|
|
if err != nil {
|
|
return s, nil, err
|
|
}
|
|
if len(in) <= 1 {
|
|
return s, nil, errors.New("input too small for table")
|
|
}
|
|
iSize := in[0]
|
|
in = in[1:]
|
|
if iSize >= 128 {
|
|
// Uncompressed
|
|
oSize := iSize - 127
|
|
iSize = (oSize + 1) / 2
|
|
if int(iSize) > len(in) {
|
|
return s, nil, errors.New("input too small for table")
|
|
}
|
|
for n := uint8(0); n < oSize; n += 2 {
|
|
v := in[n/2]
|
|
s.huffWeight[n] = v >> 4
|
|
s.huffWeight[n+1] = v & 15
|
|
}
|
|
s.symbolLen = uint16(oSize)
|
|
in = in[iSize:]
|
|
} else {
|
|
if len(in) < int(iSize) {
|
|
return s, nil, fmt.Errorf("input too small for table, want %d bytes, have %d", iSize, len(in))
|
|
}
|
|
// FSE compressed weights
|
|
s.fse.DecompressLimit = 255
|
|
hw := s.huffWeight[:]
|
|
s.fse.Out = hw
|
|
b, err := fse.Decompress(in[:iSize], s.fse)
|
|
s.fse.Out = nil
|
|
if err != nil {
|
|
return s, nil, err
|
|
}
|
|
if len(b) > 255 {
|
|
return s, nil, errors.New("corrupt input: output table too large")
|
|
}
|
|
s.symbolLen = uint16(len(b))
|
|
in = in[iSize:]
|
|
}
|
|
|
|
// collect weight stats
|
|
var rankStats [16]uint32
|
|
weightTotal := uint32(0)
|
|
for _, v := range s.huffWeight[:s.symbolLen] {
|
|
if v > tableLogMax {
|
|
return s, nil, errors.New("corrupt input: weight too large")
|
|
}
|
|
v2 := v & 15
|
|
rankStats[v2]++
|
|
// (1 << (v2-1)) is slower since the compiler cannot prove that v2 isn't 0.
|
|
weightTotal += (1 << v2) >> 1
|
|
}
|
|
if weightTotal == 0 {
|
|
return s, nil, errors.New("corrupt input: weights zero")
|
|
}
|
|
|
|
// get last non-null symbol weight (implied, total must be 2^n)
|
|
{
|
|
tableLog := highBit32(weightTotal) + 1
|
|
if tableLog > tableLogMax {
|
|
return s, nil, errors.New("corrupt input: tableLog too big")
|
|
}
|
|
s.actualTableLog = uint8(tableLog)
|
|
// determine last weight
|
|
{
|
|
total := uint32(1) << tableLog
|
|
rest := total - weightTotal
|
|
verif := uint32(1) << highBit32(rest)
|
|
lastWeight := highBit32(rest) + 1
|
|
if verif != rest {
|
|
// last value must be a clean power of 2
|
|
return s, nil, errors.New("corrupt input: last value not power of two")
|
|
}
|
|
s.huffWeight[s.symbolLen] = uint8(lastWeight)
|
|
s.symbolLen++
|
|
rankStats[lastWeight]++
|
|
}
|
|
}
|
|
|
|
if (rankStats[1] < 2) || (rankStats[1]&1 != 0) {
|
|
// by construction : at least 2 elts of rank 1, must be even
|
|
return s, nil, errors.New("corrupt input: min elt size, even check failed ")
|
|
}
|
|
|
|
// TODO: Choose between single/double symbol decoding
|
|
|
|
// Calculate starting value for each rank
|
|
{
|
|
var nextRankStart uint32
|
|
for n := uint8(1); n < s.actualTableLog+1; n++ {
|
|
current := nextRankStart
|
|
nextRankStart += rankStats[n] << (n - 1)
|
|
rankStats[n] = current
|
|
}
|
|
}
|
|
|
|
// fill DTable (always full size)
|
|
tSize := 1 << tableLogMax
|
|
if len(s.dt.single) != tSize {
|
|
s.dt.single = make([]dEntrySingle, tSize)
|
|
}
|
|
cTable := s.prevTable
|
|
if cap(cTable) < maxSymbolValue+1 {
|
|
cTable = make([]cTableEntry, 0, maxSymbolValue+1)
|
|
}
|
|
cTable = cTable[:maxSymbolValue+1]
|
|
s.prevTable = cTable[:s.symbolLen]
|
|
s.prevTableLog = s.actualTableLog
|
|
|
|
for n, w := range s.huffWeight[:s.symbolLen] {
|
|
if w == 0 {
|
|
cTable[n] = cTableEntry{
|
|
val: 0,
|
|
nBits: 0,
|
|
}
|
|
continue
|
|
}
|
|
length := (uint32(1) << w) >> 1
|
|
d := dEntrySingle{
|
|
entry: uint16(s.actualTableLog+1-w) | (uint16(n) << 8),
|
|
}
|
|
|
|
rank := &rankStats[w]
|
|
cTable[n] = cTableEntry{
|
|
val: uint16(*rank >> (w - 1)),
|
|
nBits: uint8(d.entry),
|
|
}
|
|
|
|
single := s.dt.single[*rank : *rank+length]
|
|
for i := range single {
|
|
single[i] = d
|
|
}
|
|
*rank += length
|
|
}
|
|
|
|
return s, in, nil
|
|
}
|
|
|
|
// Decompress1X will decompress a 1X encoded stream.
|
|
// The length of the supplied input must match the end of a block exactly.
|
|
// Before this is called, the table must be initialized with ReadTable unless
|
|
// the encoder re-used the table.
|
|
// deprecated: Use the stateless Decoder() to get a concurrent version.
|
|
func (s *Scratch) Decompress1X(in []byte) (out []byte, err error) {
|
|
if cap(s.Out) < s.MaxDecodedSize {
|
|
s.Out = make([]byte, s.MaxDecodedSize)
|
|
}
|
|
s.Out = s.Out[:0:s.MaxDecodedSize]
|
|
s.Out, err = s.Decoder().Decompress1X(s.Out, in)
|
|
return s.Out, err
|
|
}
|
|
|
|
// Decompress4X will decompress a 4X encoded stream.
|
|
// Before this is called, the table must be initialized with ReadTable unless
|
|
// the encoder re-used the table.
|
|
// The length of the supplied input must match the end of a block exactly.
|
|
// The destination size of the uncompressed data must be known and provided.
|
|
// deprecated: Use the stateless Decoder() to get a concurrent version.
|
|
func (s *Scratch) Decompress4X(in []byte, dstSize int) (out []byte, err error) {
|
|
if dstSize > s.MaxDecodedSize {
|
|
return nil, ErrMaxDecodedSizeExceeded
|
|
}
|
|
if cap(s.Out) < dstSize {
|
|
s.Out = make([]byte, s.MaxDecodedSize)
|
|
}
|
|
s.Out = s.Out[:0:dstSize]
|
|
s.Out, err = s.Decoder().Decompress4X(s.Out, in)
|
|
return s.Out, err
|
|
}
|
|
|
|
// Decoder will return a stateless decoder that can be used by multiple
|
|
// decompressors concurrently.
|
|
// Before this is called, the table must be initialized with ReadTable.
|
|
// The Decoder is still linked to the scratch buffer so that cannot be reused.
|
|
// However, it is safe to discard the scratch.
|
|
func (s *Scratch) Decoder() *Decoder {
|
|
return &Decoder{
|
|
dt: s.dt,
|
|
actualTableLog: s.actualTableLog,
|
|
}
|
|
}
|
|
|
|
// Decoder provides stateless decoding.
|
|
type Decoder struct {
|
|
dt dTable
|
|
actualTableLog uint8
|
|
}
|
|
|
|
// Decompress1X will decompress a 1X encoded stream.
|
|
// The cap of the output buffer will be the maximum decompressed size.
|
|
// The length of the supplied input must match the end of a block exactly.
|
|
func (d *Decoder) Decompress1X(dst, src []byte) ([]byte, error) {
|
|
if len(d.dt.single) == 0 {
|
|
return nil, errors.New("no table loaded")
|
|
}
|
|
if use8BitTables && d.actualTableLog <= 8 {
|
|
return d.decompress1X8Bit(dst, src)
|
|
}
|
|
var br bitReaderShifted
|
|
err := br.init(src)
|
|
if err != nil {
|
|
return dst, err
|
|
}
|
|
maxDecodedSize := cap(dst)
|
|
dst = dst[:0]
|
|
|
|
// Avoid bounds check by always having full sized table.
|
|
const tlSize = 1 << tableLogMax
|
|
const tlMask = tlSize - 1
|
|
dt := d.dt.single[:tlSize]
|
|
|
|
// Use temp table to avoid bound checks/append penalty.
|
|
var buf [256]byte
|
|
var off uint8
|
|
|
|
for br.off >= 8 {
|
|
br.fillFast()
|
|
v := dt[br.peekBitsFast(d.actualTableLog)&tlMask]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+0] = uint8(v.entry >> 8)
|
|
|
|
v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+1] = uint8(v.entry >> 8)
|
|
|
|
// Refill
|
|
br.fillFast()
|
|
|
|
v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+2] = uint8(v.entry >> 8)
|
|
|
|
v = dt[br.peekBitsFast(d.actualTableLog)&tlMask]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+3] = uint8(v.entry >> 8)
|
|
|
|
off += 4
|
|
if off == 0 {
|
|
if len(dst)+256 > maxDecodedSize {
|
|
br.close()
|
|
return nil, ErrMaxDecodedSizeExceeded
|
|
}
|
|
dst = append(dst, buf[:]...)
|
|
}
|
|
}
|
|
|
|
if len(dst)+int(off) > maxDecodedSize {
|
|
br.close()
|
|
return nil, ErrMaxDecodedSizeExceeded
|
|
}
|
|
dst = append(dst, buf[:off]...)
|
|
|
|
// br < 8, so uint8 is fine
|
|
bitsLeft := uint8(br.off)*8 + 64 - br.bitsRead
|
|
for bitsLeft > 0 {
|
|
br.fill()
|
|
if false && br.bitsRead >= 32 {
|
|
if br.off >= 4 {
|
|
v := br.in[br.off-4:]
|
|
v = v[:4]
|
|
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
|
|
br.value = (br.value << 32) | uint64(low)
|
|
br.bitsRead -= 32
|
|
br.off -= 4
|
|
} else {
|
|
for br.off > 0 {
|
|
br.value = (br.value << 8) | uint64(br.in[br.off-1])
|
|
br.bitsRead -= 8
|
|
br.off--
|
|
}
|
|
}
|
|
}
|
|
if len(dst) >= maxDecodedSize {
|
|
br.close()
|
|
return nil, ErrMaxDecodedSizeExceeded
|
|
}
|
|
v := d.dt.single[br.peekBitsFast(d.actualTableLog)&tlMask]
|
|
nBits := uint8(v.entry)
|
|
br.advance(nBits)
|
|
bitsLeft -= nBits
|
|
dst = append(dst, uint8(v.entry>>8))
|
|
}
|
|
return dst, br.close()
|
|
}
|
|
|
|
// decompress1X8Bit will decompress a 1X encoded stream with tablelog <= 8.
|
|
// The cap of the output buffer will be the maximum decompressed size.
|
|
// The length of the supplied input must match the end of a block exactly.
|
|
func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
|
|
if d.actualTableLog == 8 {
|
|
return d.decompress1X8BitExactly(dst, src)
|
|
}
|
|
var br bitReaderBytes
|
|
err := br.init(src)
|
|
if err != nil {
|
|
return dst, err
|
|
}
|
|
maxDecodedSize := cap(dst)
|
|
dst = dst[:0]
|
|
|
|
// Avoid bounds check by always having full sized table.
|
|
dt := d.dt.single[:256]
|
|
|
|
// Use temp table to avoid bound checks/append penalty.
|
|
var buf [256]byte
|
|
var off uint8
|
|
|
|
shift := (8 - d.actualTableLog) & 7
|
|
|
|
//fmt.Printf("mask: %b, tl:%d\n", mask, d.actualTableLog)
|
|
for br.off >= 4 {
|
|
br.fillFast()
|
|
v := dt[br.peekByteFast()>>shift]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+0] = uint8(v.entry >> 8)
|
|
|
|
v = dt[br.peekByteFast()>>shift]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+1] = uint8(v.entry >> 8)
|
|
|
|
v = dt[br.peekByteFast()>>shift]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+2] = uint8(v.entry >> 8)
|
|
|
|
v = dt[br.peekByteFast()>>shift]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+3] = uint8(v.entry >> 8)
|
|
|
|
off += 4
|
|
if off == 0 {
|
|
if len(dst)+256 > maxDecodedSize {
|
|
br.close()
|
|
return nil, ErrMaxDecodedSizeExceeded
|
|
}
|
|
dst = append(dst, buf[:]...)
|
|
}
|
|
}
|
|
|
|
if len(dst)+int(off) > maxDecodedSize {
|
|
br.close()
|
|
return nil, ErrMaxDecodedSizeExceeded
|
|
}
|
|
dst = append(dst, buf[:off]...)
|
|
|
|
// br < 4, so uint8 is fine
|
|
bitsLeft := int8(uint8(br.off)*8 + (64 - br.bitsRead))
|
|
for bitsLeft > 0 {
|
|
if br.bitsRead >= 64-8 {
|
|
for br.off > 0 {
|
|
br.value |= uint64(br.in[br.off-1]) << (br.bitsRead - 8)
|
|
br.bitsRead -= 8
|
|
br.off--
|
|
}
|
|
}
|
|
if len(dst) >= maxDecodedSize {
|
|
br.close()
|
|
return nil, ErrMaxDecodedSizeExceeded
|
|
}
|
|
v := dt[br.peekByteFast()>>shift]
|
|
nBits := uint8(v.entry)
|
|
br.advance(nBits)
|
|
bitsLeft -= int8(nBits)
|
|
dst = append(dst, uint8(v.entry>>8))
|
|
}
|
|
return dst, br.close()
|
|
}
|
|
|
|
// decompress1X8Bit will decompress a 1X encoded stream with tablelog <= 8.
|
|
// The cap of the output buffer will be the maximum decompressed size.
|
|
// The length of the supplied input must match the end of a block exactly.
|
|
func (d *Decoder) decompress1X8BitExactly(dst, src []byte) ([]byte, error) {
|
|
var br bitReaderBytes
|
|
err := br.init(src)
|
|
if err != nil {
|
|
return dst, err
|
|
}
|
|
maxDecodedSize := cap(dst)
|
|
dst = dst[:0]
|
|
|
|
// Avoid bounds check by always having full sized table.
|
|
dt := d.dt.single[:256]
|
|
|
|
// Use temp table to avoid bound checks/append penalty.
|
|
var buf [256]byte
|
|
var off uint8
|
|
|
|
const shift = 0
|
|
|
|
//fmt.Printf("mask: %b, tl:%d\n", mask, d.actualTableLog)
|
|
for br.off >= 4 {
|
|
br.fillFast()
|
|
v := dt[br.peekByteFast()>>shift]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+0] = uint8(v.entry >> 8)
|
|
|
|
v = dt[br.peekByteFast()>>shift]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+1] = uint8(v.entry >> 8)
|
|
|
|
v = dt[br.peekByteFast()>>shift]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+2] = uint8(v.entry >> 8)
|
|
|
|
v = dt[br.peekByteFast()>>shift]
|
|
br.advance(uint8(v.entry))
|
|
buf[off+3] = uint8(v.entry >> 8)
|
|
|
|
off += 4
|
|
if off == 0 {
|
|
if len(dst)+256 > maxDecodedSize {
|
|
br.close()
|
|
return nil, ErrMaxDecodedSizeExceeded
|
|
}
|
|
dst = append(dst, buf[:]...)
|
|
}
|
|
}
|
|
|
|
if len(dst)+int(off) > maxDecodedSize {
|
|
br.close()
|
|
return nil, ErrMaxDecodedSizeExceeded
|
|
}
|
|
dst = append(dst, buf[:off]...)
|
|
|
|
// br < 4, so uint8 is fine
|
|
bitsLeft := int8(uint8(br.off)*8 + (64 - br.bitsRead))
|
|
for bitsLeft > 0 {
|
|
if br.bitsRead >= 64-8 {
|
|
for br.off > 0 {
|
|
br.value |= uint64(br.in[br.off-1]) << (br.bitsRead - 8)
|
|
br.bitsRead -= 8
|
|
br.off--
|
|
}
|
|
}
|
|
if len(dst) >= maxDecodedSize {
|
|
br.close()
|
|
return nil, ErrMaxDecodedSizeExceeded
|
|
}
|
|
v := dt[br.peekByteFast()>>shift]
|
|
nBits := uint8(v.entry)
|
|
br.advance(nBits)
|
|
bitsLeft -= int8(nBits)
|
|
dst = append(dst, uint8(v.entry>>8))
|
|
}
|
|
return dst, br.close()
|
|
}
|
|
|
|
// Decompress4X will decompress a 4X encoded stream.
|
|
// The length of the supplied input must match the end of a block exactly.
|
|
// The *capacity* of the dst slice must match the destination size of
|
|
// the uncompressed data exactly.
|
|
func (d *Decoder) Decompress4X(dst, src []byte) ([]byte, error) {
|
|
if len(d.dt.single) == 0 {
|
|
return nil, errors.New("no table loaded")
|
|
}
|
|
if len(src) < 6+(4*1) {
|
|
return nil, errors.New("input too small")
|
|
}
|
|
if use8BitTables && d.actualTableLog <= 8 {
|
|
return d.decompress4X8bit(dst, src)
|
|
}
|
|
|
|
var br [4]bitReaderShifted
|
|
start := 6
|
|
for i := 0; i < 3; i++ {
|
|
length := int(src[i*2]) | (int(src[i*2+1]) << 8)
|
|
if start+length >= len(src) {
|
|
return nil, errors.New("truncated input (or invalid offset)")
|
|
}
|
|
err := br[i].init(src[start : start+length])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
start += length
|
|
}
|
|
err := br[3].init(src[start:])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// destination, offset to match first output
|
|
dstSize := cap(dst)
|
|
dst = dst[:dstSize]
|
|
out := dst
|
|
dstEvery := (dstSize + 3) / 4
|
|
|
|
const tlSize = 1 << tableLogMax
|
|
const tlMask = tlSize - 1
|
|
single := d.dt.single[:tlSize]
|
|
|
|
// Use temp table to avoid bound checks/append penalty.
|
|
var buf [256]byte
|
|
var off uint8
|
|
var decoded int
|
|
|
|
// Decode 2 values from each decoder/loop.
|
|
const bufoff = 256 / 4
|
|
for {
|
|
if br[0].off < 4 || br[1].off < 4 || br[2].off < 4 || br[3].off < 4 {
|
|
break
|
|
}
|
|
|
|
{
|
|
const stream = 0
|
|
const stream2 = 1
|
|
br[stream].fillFast()
|
|
br[stream2].fillFast()
|
|
|
|
val := br[stream].peekBitsFast(d.actualTableLog)
|
|
v := single[val&tlMask]
|
|
br[stream].advance(uint8(v.entry))
|
|
buf[off+bufoff*stream] = uint8(v.entry >> 8)
|
|
|
|
val2 := br[stream2].peekBitsFast(d.actualTableLog)
|
|
v2 := single[val2&tlMask]
|
|
br[stream2].advance(uint8(v2.entry))
|
|
buf[off+bufoff*stream2] = uint8(v2.entry >> 8)
|
|
|
|
val = br[stream].peekBitsFast(d.actualTableLog)
|
|
v = single[val&tlMask]
|
|
br[stream].advance(uint8(v.entry))
|
|
buf[off+bufoff*stream+1] = uint8(v.entry >> 8)
|
|
|
|
val2 = br[stream2].peekBitsFast(d.actualTableLog)
|
|
v2 = single[val2&tlMask]
|
|
br[stream2].advance(uint8(v2.entry))
|
|
buf[off+bufoff*stream2+1] = uint8(v2.entry >> 8)
|
|
}
|
|
|
|
{
|
|
const stream = 2
|
|
const stream2 = 3
|
|
br[stream].fillFast()
|
|
br[stream2].fillFast()
|
|
|
|
val := br[stream].peekBitsFast(d.actualTableLog)
|
|
v := single[val&tlMask]
|
|
br[stream].advance(uint8(v.entry))
|
|
buf[off+bufoff*stream] = uint8(v.entry >> 8)
|
|
|
|
val2 := br[stream2].peekBitsFast(d.actualTableLog)
|
|
v2 := single[val2&tlMask]
|
|
br[stream2].advance(uint8(v2.entry))
|
|
buf[off+bufoff*stream2] = uint8(v2.entry >> 8)
|
|
|
|
val = br[stream].peekBitsFast(d.actualTableLog)
|
|
v = single[val&tlMask]
|
|
br[stream].advance(uint8(v.entry))
|
|
buf[off+bufoff*stream+1] = uint8(v.entry >> 8)
|
|
|
|
val2 = br[stream2].peekBitsFast(d.actualTableLog)
|
|
v2 = single[val2&tlMask]
|
|
br[stream2].advance(uint8(v2.entry))
|
|
buf[off+bufoff*stream2+1] = uint8(v2.entry >> 8)
|
|
}
|
|
|
|
off += 2
|
|
|
|
if off == bufoff {
|
|
if bufoff > dstEvery {
|
|
return nil, errors.New("corruption detected: stream overrun 1")
|
|
}
|
|
copy(out, buf[:bufoff])
|
|
copy(out[dstEvery:], buf[bufoff:bufoff*2])
|
|
copy(out[dstEvery*2:], buf[bufoff*2:bufoff*3])
|
|
copy(out[dstEvery*3:], buf[bufoff*3:bufoff*4])
|
|
off = 0
|
|
out = out[bufoff:]
|
|
decoded += 256
|
|
// There must at least be 3 buffers left.
|
|
if len(out) < dstEvery*3 {
|
|
return nil, errors.New("corruption detected: stream overrun 2")
|
|
}
|
|
}
|
|
}
|
|
if off > 0 {
|
|
ioff := int(off)
|
|
if len(out) < dstEvery*3+ioff {
|
|
return nil, errors.New("corruption detected: stream overrun 3")
|
|
}
|
|
copy(out, buf[:off])
|
|
copy(out[dstEvery:dstEvery+ioff], buf[bufoff:bufoff*2])
|
|
copy(out[dstEvery*2:dstEvery*2+ioff], buf[bufoff*2:bufoff*3])
|
|
copy(out[dstEvery*3:dstEvery*3+ioff], buf[bufoff*3:bufoff*4])
|
|
decoded += int(off) * 4
|
|
out = out[off:]
|
|
}
|
|
|
|
// Decode remaining.
|
|
for i := range br {
|
|
offset := dstEvery * i
|
|
br := &br[i]
|
|
bitsLeft := br.off*8 + uint(64-br.bitsRead)
|
|
for bitsLeft > 0 {
|
|
br.fill()
|
|
if false && br.bitsRead >= 32 {
|
|
if br.off >= 4 {
|
|
v := br.in[br.off-4:]
|
|
v = v[:4]
|
|
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
|
|
br.value = (br.value << 32) | uint64(low)
|
|
br.bitsRead -= 32
|
|
br.off -= 4
|
|
} else {
|
|
for br.off > 0 {
|
|
br.value = (br.value << 8) | uint64(br.in[br.off-1])
|
|
br.bitsRead -= 8
|
|
br.off--
|
|
}
|
|
}
|
|
}
|
|
// end inline...
|
|
if offset >= len(out) {
|
|
return nil, errors.New("corruption detected: stream overrun 4")
|
|
}
|
|
|
|
// Read value and increment offset.
|
|
val := br.peekBitsFast(d.actualTableLog)
|
|
v := single[val&tlMask].entry
|
|
nBits := uint8(v)
|
|
br.advance(nBits)
|
|
bitsLeft -= uint(nBits)
|
|
out[offset] = uint8(v >> 8)
|
|
offset++
|
|
}
|
|
decoded += offset - dstEvery*i
|
|
err = br.close()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
if dstSize != decoded {
|
|
return nil, errors.New("corruption detected: short output block")
|
|
}
|
|
return dst, nil
|
|
}
|
|
|
|
// Decompress4X will decompress a 4X encoded stream.
|
|
// The length of the supplied input must match the end of a block exactly.
|
|
// The *capacity* of the dst slice must match the destination size of
|
|
// the uncompressed data exactly.
|
|
func (d *Decoder) decompress4X8bit(dst, src []byte) ([]byte, error) {
|
|
if d.actualTableLog == 8 {
|
|
return d.decompress4X8bitExactly(dst, src)
|
|
}
|
|
|
|
var br [4]bitReaderBytes
|
|
start := 6
|
|
for i := 0; i < 3; i++ {
|
|
length := int(src[i*2]) | (int(src[i*2+1]) << 8)
|
|
if start+length >= len(src) {
|
|
return nil, errors.New("truncated input (or invalid offset)")
|
|
}
|
|
err := br[i].init(src[start : start+length])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
start += length
|
|
}
|
|
err := br[3].init(src[start:])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// destination, offset to match first output
|
|
dstSize := cap(dst)
|
|
dst = dst[:dstSize]
|
|
out := dst
|
|
dstEvery := (dstSize + 3) / 4
|
|
|
|
shift := (8 - d.actualTableLog) & 7
|
|
|
|
const tlSize = 1 << 8
|
|
const tlMask = tlSize - 1
|
|
single := d.dt.single[:tlSize]
|
|
|
|
// Use temp table to avoid bound checks/append penalty.
|
|
var buf [256]byte
|
|
var off uint8
|
|
var decoded int
|
|
|
|
// Decode 4 values from each decoder/loop.
|
|
const bufoff = 256 / 4
|
|
for {
|
|
if br[0].off < 4 || br[1].off < 4 || br[2].off < 4 || br[3].off < 4 {
|
|
break
|
|
}
|
|
|
|
{
|
|
// Interleave 2 decodes.
|
|
const stream = 0
|
|
const stream2 = 1
|
|
br[stream].fillFast()
|
|
br[stream2].fillFast()
|
|
|
|
v := single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 := single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+1] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+1] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+2] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+2] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+3] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+3] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
}
|
|
|
|
{
|
|
const stream = 2
|
|
const stream2 = 3
|
|
br[stream].fillFast()
|
|
br[stream2].fillFast()
|
|
|
|
v := single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 := single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+1] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+1] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+2] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+2] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+3] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+3] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
}
|
|
|
|
off += 4
|
|
|
|
if off == bufoff {
|
|
if bufoff > dstEvery {
|
|
return nil, errors.New("corruption detected: stream overrun 1")
|
|
}
|
|
copy(out, buf[:bufoff])
|
|
copy(out[dstEvery:], buf[bufoff:bufoff*2])
|
|
copy(out[dstEvery*2:], buf[bufoff*2:bufoff*3])
|
|
copy(out[dstEvery*3:], buf[bufoff*3:bufoff*4])
|
|
off = 0
|
|
out = out[bufoff:]
|
|
decoded += 256
|
|
// There must at least be 3 buffers left.
|
|
if len(out) < dstEvery*3 {
|
|
return nil, errors.New("corruption detected: stream overrun 2")
|
|
}
|
|
}
|
|
}
|
|
if off > 0 {
|
|
ioff := int(off)
|
|
if len(out) < dstEvery*3+ioff {
|
|
return nil, errors.New("corruption detected: stream overrun 3")
|
|
}
|
|
copy(out, buf[:off])
|
|
copy(out[dstEvery:dstEvery+ioff], buf[bufoff:bufoff*2])
|
|
copy(out[dstEvery*2:dstEvery*2+ioff], buf[bufoff*2:bufoff*3])
|
|
copy(out[dstEvery*3:dstEvery*3+ioff], buf[bufoff*3:bufoff*4])
|
|
decoded += int(off) * 4
|
|
out = out[off:]
|
|
}
|
|
|
|
// Decode remaining.
|
|
for i := range br {
|
|
offset := dstEvery * i
|
|
br := &br[i]
|
|
bitsLeft := int(br.off*8) + int(64-br.bitsRead)
|
|
for bitsLeft > 0 {
|
|
if br.finished() {
|
|
return nil, io.ErrUnexpectedEOF
|
|
}
|
|
if br.bitsRead >= 56 {
|
|
if br.off >= 4 {
|
|
v := br.in[br.off-4:]
|
|
v = v[:4]
|
|
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
|
|
br.value |= uint64(low) << (br.bitsRead - 32)
|
|
br.bitsRead -= 32
|
|
br.off -= 4
|
|
} else {
|
|
for br.off > 0 {
|
|
br.value |= uint64(br.in[br.off-1]) << (br.bitsRead - 8)
|
|
br.bitsRead -= 8
|
|
br.off--
|
|
}
|
|
}
|
|
}
|
|
// end inline...
|
|
if offset >= len(out) {
|
|
return nil, errors.New("corruption detected: stream overrun 4")
|
|
}
|
|
|
|
// Read value and increment offset.
|
|
v := single[br.peekByteFast()>>shift].entry
|
|
nBits := uint8(v)
|
|
br.advance(nBits)
|
|
bitsLeft -= int(nBits)
|
|
out[offset] = uint8(v >> 8)
|
|
offset++
|
|
}
|
|
decoded += offset - dstEvery*i
|
|
err = br.close()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
if dstSize != decoded {
|
|
return nil, errors.New("corruption detected: short output block")
|
|
}
|
|
return dst, nil
|
|
}
|
|
|
|
// Decompress4X will decompress a 4X encoded stream.
|
|
// The length of the supplied input must match the end of a block exactly.
|
|
// The *capacity* of the dst slice must match the destination size of
|
|
// the uncompressed data exactly.
|
|
func (d *Decoder) decompress4X8bitExactly(dst, src []byte) ([]byte, error) {
|
|
var br [4]bitReaderBytes
|
|
start := 6
|
|
for i := 0; i < 3; i++ {
|
|
length := int(src[i*2]) | (int(src[i*2+1]) << 8)
|
|
if start+length >= len(src) {
|
|
return nil, errors.New("truncated input (or invalid offset)")
|
|
}
|
|
err := br[i].init(src[start : start+length])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
start += length
|
|
}
|
|
err := br[3].init(src[start:])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// destination, offset to match first output
|
|
dstSize := cap(dst)
|
|
dst = dst[:dstSize]
|
|
out := dst
|
|
dstEvery := (dstSize + 3) / 4
|
|
|
|
const shift = 0
|
|
const tlSize = 1 << 8
|
|
const tlMask = tlSize - 1
|
|
single := d.dt.single[:tlSize]
|
|
|
|
// Use temp table to avoid bound checks/append penalty.
|
|
var buf [256]byte
|
|
var off uint8
|
|
var decoded int
|
|
|
|
// Decode 4 values from each decoder/loop.
|
|
const bufoff = 256 / 4
|
|
for {
|
|
if br[0].off < 4 || br[1].off < 4 || br[2].off < 4 || br[3].off < 4 {
|
|
break
|
|
}
|
|
|
|
{
|
|
// Interleave 2 decodes.
|
|
const stream = 0
|
|
const stream2 = 1
|
|
br[stream].fillFast()
|
|
br[stream2].fillFast()
|
|
|
|
v := single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 := single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+1] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+1] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+2] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+2] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+3] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+3] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
}
|
|
|
|
{
|
|
const stream = 2
|
|
const stream2 = 3
|
|
br[stream].fillFast()
|
|
br[stream2].fillFast()
|
|
|
|
v := single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 := single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+1] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+1] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+2] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+2] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
|
|
v = single[br[stream].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream+3] = uint8(v >> 8)
|
|
br[stream].advance(uint8(v))
|
|
|
|
v2 = single[br[stream2].peekByteFast()>>shift].entry
|
|
buf[off+bufoff*stream2+3] = uint8(v2 >> 8)
|
|
br[stream2].advance(uint8(v2))
|
|
}
|
|
|
|
off += 4
|
|
|
|
if off == bufoff {
|
|
if bufoff > dstEvery {
|
|
return nil, errors.New("corruption detected: stream overrun 1")
|
|
}
|
|
copy(out, buf[:bufoff])
|
|
copy(out[dstEvery:], buf[bufoff:bufoff*2])
|
|
copy(out[dstEvery*2:], buf[bufoff*2:bufoff*3])
|
|
copy(out[dstEvery*3:], buf[bufoff*3:bufoff*4])
|
|
off = 0
|
|
out = out[bufoff:]
|
|
decoded += 256
|
|
// There must at least be 3 buffers left.
|
|
if len(out) < dstEvery*3 {
|
|
return nil, errors.New("corruption detected: stream overrun 2")
|
|
}
|
|
}
|
|
}
|
|
if off > 0 {
|
|
ioff := int(off)
|
|
if len(out) < dstEvery*3+ioff {
|
|
return nil, errors.New("corruption detected: stream overrun 3")
|
|
}
|
|
copy(out, buf[:off])
|
|
copy(out[dstEvery:dstEvery+ioff], buf[bufoff:bufoff*2])
|
|
copy(out[dstEvery*2:dstEvery*2+ioff], buf[bufoff*2:bufoff*3])
|
|
copy(out[dstEvery*3:dstEvery*3+ioff], buf[bufoff*3:bufoff*4])
|
|
decoded += int(off) * 4
|
|
out = out[off:]
|
|
}
|
|
|
|
// Decode remaining.
|
|
for i := range br {
|
|
offset := dstEvery * i
|
|
br := &br[i]
|
|
bitsLeft := int(br.off*8) + int(64-br.bitsRead)
|
|
for bitsLeft > 0 {
|
|
if br.finished() {
|
|
return nil, io.ErrUnexpectedEOF
|
|
}
|
|
if br.bitsRead >= 56 {
|
|
if br.off >= 4 {
|
|
v := br.in[br.off-4:]
|
|
v = v[:4]
|
|
low := (uint32(v[0])) | (uint32(v[1]) << 8) | (uint32(v[2]) << 16) | (uint32(v[3]) << 24)
|
|
br.value |= uint64(low) << (br.bitsRead - 32)
|
|
br.bitsRead -= 32
|
|
br.off -= 4
|
|
} else {
|
|
for br.off > 0 {
|
|
br.value |= uint64(br.in[br.off-1]) << (br.bitsRead - 8)
|
|
br.bitsRead -= 8
|
|
br.off--
|
|
}
|
|
}
|
|
}
|
|
// end inline...
|
|
if offset >= len(out) {
|
|
return nil, errors.New("corruption detected: stream overrun 4")
|
|
}
|
|
|
|
// Read value and increment offset.
|
|
v := single[br.peekByteFast()>>shift].entry
|
|
nBits := uint8(v)
|
|
br.advance(nBits)
|
|
bitsLeft -= int(nBits)
|
|
out[offset] = uint8(v >> 8)
|
|
offset++
|
|
}
|
|
decoded += offset - dstEvery*i
|
|
err = br.close()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
if dstSize != decoded {
|
|
return nil, errors.New("corruption detected: short output block")
|
|
}
|
|
return dst, nil
|
|
}
|
|
|
|
// matches will compare a decoding table to a coding table.
|
|
// Errors are written to the writer.
|
|
// Nothing will be written if table is ok.
|
|
func (s *Scratch) matches(ct cTable, w io.Writer) {
|
|
if s == nil || len(s.dt.single) == 0 {
|
|
return
|
|
}
|
|
dt := s.dt.single[:1<<s.actualTableLog]
|
|
tablelog := s.actualTableLog
|
|
ok := 0
|
|
broken := 0
|
|
for sym, enc := range ct {
|
|
errs := 0
|
|
broken++
|
|
if enc.nBits == 0 {
|
|
for _, dec := range dt {
|
|
if uint8(dec.entry>>8) == byte(sym) {
|
|
fmt.Fprintf(w, "symbol %x has decoder, but no encoder\n", sym)
|
|
errs++
|
|
break
|
|
}
|
|
}
|
|
if errs == 0 {
|
|
broken--
|
|
}
|
|
continue
|
|
}
|
|
// Unused bits in input
|
|
ub := tablelog - enc.nBits
|
|
top := enc.val << ub
|
|
// decoder looks at top bits.
|
|
dec := dt[top]
|
|
if uint8(dec.entry) != enc.nBits {
|
|
fmt.Fprintf(w, "symbol 0x%x bit size mismatch (enc: %d, dec:%d).\n", sym, enc.nBits, uint8(dec.entry))
|
|
errs++
|
|
}
|
|
if uint8(dec.entry>>8) != uint8(sym) {
|
|
fmt.Fprintf(w, "symbol 0x%x decoder output mismatch (enc: %d, dec:%d).\n", sym, sym, uint8(dec.entry>>8))
|
|
errs++
|
|
}
|
|
if errs > 0 {
|
|
fmt.Fprintf(w, "%d errros in base, stopping\n", errs)
|
|
continue
|
|
}
|
|
// Ensure that all combinations are covered.
|
|
for i := uint16(0); i < (1 << ub); i++ {
|
|
vval := top | i
|
|
dec := dt[vval]
|
|
if uint8(dec.entry) != enc.nBits {
|
|
fmt.Fprintf(w, "symbol 0x%x bit size mismatch (enc: %d, dec:%d).\n", vval, enc.nBits, uint8(dec.entry))
|
|
errs++
|
|
}
|
|
if uint8(dec.entry>>8) != uint8(sym) {
|
|
fmt.Fprintf(w, "symbol 0x%x decoder output mismatch (enc: %d, dec:%d).\n", vval, sym, uint8(dec.entry>>8))
|
|
errs++
|
|
}
|
|
if errs > 20 {
|
|
fmt.Fprintf(w, "%d errros, stopping\n", errs)
|
|
break
|
|
}
|
|
}
|
|
if errs == 0 {
|
|
ok++
|
|
broken--
|
|
}
|
|
}
|
|
if broken > 0 {
|
|
fmt.Fprintf(w, "%d broken, %d ok\n", broken, ok)
|
|
}
|
|
}
|