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huff0: Use buffers for 1X decodes #500

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merged 1 commit into from Feb 21, 2022
Merged

huff0: Use buffers for 1X decodes #500

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65 changes: 58 additions & 7 deletions huff0/decompress.go
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Expand Up @@ -4,6 +4,7 @@ import (
"errors"
"fmt"
"io"
"sync"

"github.com/klauspost/compress/fse"
)
Expand Down Expand Up @@ -216,14 +217,23 @@ func (s *Scratch) Decoder() *Decoder {
return &Decoder{
dt: s.dt,
actualTableLog: s.actualTableLog,
bufs: &s.decPool,
}
}

// Decoder provides stateless decoding.
type Decoder struct {
dt dTable
actualTableLog uint8
buf [4][256]byte
bufs *sync.Pool
}

func (d *Decoder) buffer() *[4][256]byte {
buf, ok := d.bufs.Get().(*[4][256]byte)
if ok {
return buf
}
return &[4][256]byte{}
}

// Decompress1X will decompress a 1X encoded stream.
Expand All @@ -250,7 +260,8 @@ func (d *Decoder) Decompress1X(dst, src []byte) ([]byte, error) {
dt := d.dt.single[:tlSize]

// Use temp table to avoid bound checks/append penalty.
var buf [256]byte
bufs := d.buffer()
buf := &bufs[0]
var off uint8

for br.off >= 8 {
Expand Down Expand Up @@ -278,13 +289,15 @@ func (d *Decoder) Decompress1X(dst, src []byte) ([]byte, error) {
if off == 0 {
if len(dst)+256 > maxDecodedSize {
br.close()
d.bufs.Put(bufs)
return nil, ErrMaxDecodedSizeExceeded
}
dst = append(dst, buf[:]...)
}
}

if len(dst)+int(off) > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
Expand All @@ -311,6 +324,7 @@ func (d *Decoder) Decompress1X(dst, src []byte) ([]byte, error) {
}
}
if len(dst) >= maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
Expand All @@ -320,6 +334,7 @@ func (d *Decoder) Decompress1X(dst, src []byte) ([]byte, error) {
bitsLeft -= nBits
dst = append(dst, uint8(v.entry>>8))
}
d.bufs.Put(bufs)
return dst, br.close()
}

Expand All @@ -342,7 +357,8 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
dt := d.dt.single[:256]

// Use temp table to avoid bound checks/append penalty.
var buf [256]byte
bufs := d.buffer()
buf := &bufs[0]
var off uint8

switch d.actualTableLog {
Expand Down Expand Up @@ -370,6 +386,7 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
if off == 0 {
if len(dst)+256 > maxDecodedSize {
br.close()
d.bufs.Put(bufs)
return nil, ErrMaxDecodedSizeExceeded
}
dst = append(dst, buf[:]...)
Expand Down Expand Up @@ -399,6 +416,7 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
if off == 0 {
if len(dst)+256 > maxDecodedSize {
br.close()
d.bufs.Put(bufs)
return nil, ErrMaxDecodedSizeExceeded
}
dst = append(dst, buf[:]...)
Expand Down Expand Up @@ -427,6 +445,7 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
off += 4
if off == 0 {
if len(dst)+256 > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
Expand Down Expand Up @@ -456,6 +475,7 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
off += 4
if off == 0 {
if len(dst)+256 > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
Expand Down Expand Up @@ -485,6 +505,7 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
off += 4
if off == 0 {
if len(dst)+256 > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
Expand Down Expand Up @@ -514,6 +535,7 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
off += 4
if off == 0 {
if len(dst)+256 > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
Expand Down Expand Up @@ -543,6 +565,7 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
off += 4
if off == 0 {
if len(dst)+256 > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
Expand Down Expand Up @@ -572,17 +595,20 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
off += 4
if off == 0 {
if len(dst)+256 > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
dst = append(dst, buf[:]...)
}
}
default:
d.bufs.Put(bufs)
return nil, fmt.Errorf("invalid tablelog: %d", d.actualTableLog)
}

if len(dst)+int(off) > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
Expand All @@ -602,6 +628,7 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
}
if len(dst) >= maxDecodedSize {
br.close()
d.bufs.Put(bufs)
return nil, ErrMaxDecodedSizeExceeded
}
v := dt[br.peekByteFast()>>shift]
Expand All @@ -610,6 +637,7 @@ func (d *Decoder) decompress1X8Bit(dst, src []byte) ([]byte, error) {
bitsLeft -= int8(nBits)
dst = append(dst, uint8(v.entry>>8))
}
d.bufs.Put(bufs)
return dst, br.close()
}

Expand All @@ -629,7 +657,8 @@ func (d *Decoder) decompress1X8BitExactly(dst, src []byte) ([]byte, error) {
dt := d.dt.single[:256]

// Use temp table to avoid bound checks/append penalty.
var buf [256]byte
bufs := d.buffer()
buf := &bufs[0]
var off uint8

const shift = 56
Expand All @@ -656,6 +685,7 @@ func (d *Decoder) decompress1X8BitExactly(dst, src []byte) ([]byte, error) {
off += 4
if off == 0 {
if len(dst)+256 > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
Expand All @@ -664,6 +694,7 @@ func (d *Decoder) decompress1X8BitExactly(dst, src []byte) ([]byte, error) {
}

if len(dst)+int(off) > maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
Expand All @@ -680,6 +711,7 @@ func (d *Decoder) decompress1X8BitExactly(dst, src []byte) ([]byte, error) {
}
}
if len(dst) >= maxDecodedSize {
d.bufs.Put(bufs)
br.close()
return nil, ErrMaxDecodedSizeExceeded
}
Expand All @@ -689,6 +721,7 @@ func (d *Decoder) decompress1X8BitExactly(dst, src []byte) ([]byte, error) {
bitsLeft -= int8(nBits)
dst = append(dst, uint8(v.entry>>8))
}
d.bufs.Put(bufs)
return dst, br.close()
}

Expand Down Expand Up @@ -736,7 +769,7 @@ func (d *Decoder) Decompress4X(dst, src []byte) ([]byte, error) {
single := d.dt.single[:tlSize]

// Use temp table to avoid bound checks/append penalty.
buf := &d.buf
buf := d.buffer()
var off uint8
var decoded int

Expand Down Expand Up @@ -801,6 +834,7 @@ func (d *Decoder) Decompress4X(dst, src []byte) ([]byte, error) {

if off == 0 {
if bufoff > dstEvery {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 1")
}
copy(out, buf[0][:])
Expand All @@ -811,13 +845,15 @@ func (d *Decoder) Decompress4X(dst, src []byte) ([]byte, error) {
decoded += bufoff * 4
// There must at least be 3 buffers left.
if len(out) < dstEvery*3 {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 2")
}
}
}
if off > 0 {
ioff := int(off)
if len(out) < dstEvery*3+ioff {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 3")
}
copy(out, buf[0][:off])
Expand Down Expand Up @@ -853,6 +889,7 @@ func (d *Decoder) Decompress4X(dst, src []byte) ([]byte, error) {
}
// end inline...
if offset >= len(out) {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 4")
}

Expand All @@ -871,6 +908,7 @@ func (d *Decoder) Decompress4X(dst, src []byte) ([]byte, error) {
return nil, err
}
}
d.bufs.Put(buf)
if dstSize != decoded {
return nil, errors.New("corruption detected: short output block")
}
Expand Down Expand Up @@ -916,7 +954,7 @@ func (d *Decoder) decompress4X8bit(dst, src []byte) ([]byte, error) {
single := d.dt.single[:tlSize]

// Use temp table to avoid bound checks/append penalty.
buf := &d.buf
buf := d.buffer()
var off uint8
var decoded int

Expand Down Expand Up @@ -1022,6 +1060,7 @@ func (d *Decoder) decompress4X8bit(dst, src []byte) ([]byte, error) {

if off == 0 {
if bufoff > dstEvery {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 1")
}
copy(out, buf[0][:])
Expand All @@ -1032,13 +1071,15 @@ func (d *Decoder) decompress4X8bit(dst, src []byte) ([]byte, error) {
decoded += bufoff * 4
// There must at least be 3 buffers left.
if len(out) < dstEvery*3 {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 2")
}
}
}
if off > 0 {
ioff := int(off)
if len(out) < dstEvery*3+ioff {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 3")
}
copy(out, buf[0][:off])
Expand All @@ -1056,6 +1097,7 @@ func (d *Decoder) decompress4X8bit(dst, src []byte) ([]byte, error) {
bitsLeft := int(br.off*8) + int(64-br.bitsRead)
for bitsLeft > 0 {
if br.finished() {
d.bufs.Put(buf)
return nil, io.ErrUnexpectedEOF
}
if br.bitsRead >= 56 {
Expand All @@ -1076,6 +1118,7 @@ func (d *Decoder) decompress4X8bit(dst, src []byte) ([]byte, error) {
}
// end inline...
if offset >= len(out) {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 4")
}

Expand All @@ -1090,9 +1133,11 @@ func (d *Decoder) decompress4X8bit(dst, src []byte) ([]byte, error) {
decoded += offset - dstEvery*i
err = br.close()
if err != nil {
d.bufs.Put(buf)
return nil, err
}
}
d.bufs.Put(buf)
if dstSize != decoded {
return nil, errors.New("corruption detected: short output block")
}
Expand Down Expand Up @@ -1134,7 +1179,7 @@ func (d *Decoder) decompress4X8bitExactly(dst, src []byte) ([]byte, error) {
single := d.dt.single[:tlSize]

// Use temp table to avoid bound checks/append penalty.
buf := &d.buf
buf := d.buffer()
var off uint8
var decoded int

Expand Down Expand Up @@ -1240,6 +1285,7 @@ func (d *Decoder) decompress4X8bitExactly(dst, src []byte) ([]byte, error) {

if off == 0 {
if bufoff > dstEvery {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 1")
}
copy(out, buf[0][:])
Expand All @@ -1250,6 +1296,7 @@ func (d *Decoder) decompress4X8bitExactly(dst, src []byte) ([]byte, error) {
decoded += bufoff * 4
// There must at least be 3 buffers left.
if len(out) < dstEvery*3 {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 2")
}
}
Expand All @@ -1274,6 +1321,7 @@ func (d *Decoder) decompress4X8bitExactly(dst, src []byte) ([]byte, error) {
bitsLeft := int(br.off*8) + int(64-br.bitsRead)
for bitsLeft > 0 {
if br.finished() {
d.bufs.Put(buf)
return nil, io.ErrUnexpectedEOF
}
if br.bitsRead >= 56 {
Expand All @@ -1294,6 +1342,7 @@ func (d *Decoder) decompress4X8bitExactly(dst, src []byte) ([]byte, error) {
}
// end inline...
if offset >= len(out) {
d.bufs.Put(buf)
return nil, errors.New("corruption detected: stream overrun 4")
}

Expand All @@ -1308,9 +1357,11 @@ func (d *Decoder) decompress4X8bitExactly(dst, src []byte) ([]byte, error) {
decoded += offset - dstEvery*i
err = br.close()
if err != nil {
d.bufs.Put(buf)
return nil, err
}
}
d.bufs.Put(buf)
if dstSize != decoded {
return nil, errors.New("corruption detected: short output block")
}
Expand Down
2 changes: 2 additions & 0 deletions huff0/huff0.go
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Expand Up @@ -8,6 +8,7 @@ import (
"fmt"
"math"
"math/bits"
"sync"

"github.com/klauspost/compress/fse"
)
Expand Down Expand Up @@ -116,6 +117,7 @@ type Scratch struct {
nodes []nodeElt
tmpOut [4][]byte
fse *fse.Scratch
decPool sync.Pool // *[4][256]byte buffers.
huffWeight [maxSymbolValue + 1]byte
}

Expand Down