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authorWim <wim@42.be>2022-04-12 00:30:21 +0200
committerGitHub <noreply@github.com>2022-04-12 00:30:21 +0200
commit281ef53e7de5d30114dbf57a4b506b2d8d2720cc (patch)
tree5fe13b85ffe312053452e0d7107ca4b174a412e0 /vendor/github.com/klauspost/compress/huff0/decompress_generic.go
parentf044b948e257814e8e1f70d4b66821bfd9c2ff06 (diff)
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Update dependencies (#1800)
Diffstat (limited to 'vendor/github.com/klauspost/compress/huff0/decompress_generic.go')
-rw-r--r--vendor/github.com/klauspost/compress/huff0/decompress_generic.go193
1 files changed, 193 insertions, 0 deletions
diff --git a/vendor/github.com/klauspost/compress/huff0/decompress_generic.go b/vendor/github.com/klauspost/compress/huff0/decompress_generic.go
new file mode 100644
index 00000000..126b4d68
--- /dev/null
+++ b/vendor/github.com/klauspost/compress/huff0/decompress_generic.go
@@ -0,0 +1,193 @@
+//go:build !amd64 || appengine || !gc || noasm
+// +build !amd64 appengine !gc noasm
+
+// This file contains a generic implementation of Decoder.Decompress4X.
+package huff0
+
+import (
+ "errors"
+ "fmt"
+)
+
+// 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
+ // Decode "jump table"
+ 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.
+ buf := d.buffer()
+ var off uint8
+ var decoded int
+
+ // Decode 2 values from each decoder/loop.
+ const bufoff = 256
+ 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)
+ val2 := br[stream2].peekBitsFast(d.actualTableLog)
+ v := single[val&tlMask]
+ v2 := single[val2&tlMask]
+ br[stream].advance(uint8(v.entry))
+ br[stream2].advance(uint8(v2.entry))
+ buf[stream][off] = uint8(v.entry >> 8)
+ buf[stream2][off] = uint8(v2.entry >> 8)
+
+ val = br[stream].peekBitsFast(d.actualTableLog)
+ val2 = br[stream2].peekBitsFast(d.actualTableLog)
+ v = single[val&tlMask]
+ v2 = single[val2&tlMask]
+ br[stream].advance(uint8(v.entry))
+ br[stream2].advance(uint8(v2.entry))
+ buf[stream][off+1] = uint8(v.entry >> 8)
+ buf[stream2][off+1] = uint8(v2.entry >> 8)
+ }
+
+ {
+ const stream = 2
+ const stream2 = 3
+ br[stream].fillFast()
+ br[stream2].fillFast()
+
+ val := br[stream].peekBitsFast(d.actualTableLog)
+ val2 := br[stream2].peekBitsFast(d.actualTableLog)
+ v := single[val&tlMask]
+ v2 := single[val2&tlMask]
+ br[stream].advance(uint8(v.entry))
+ br[stream2].advance(uint8(v2.entry))
+ buf[stream][off] = uint8(v.entry >> 8)
+ buf[stream2][off] = uint8(v2.entry >> 8)
+
+ val = br[stream].peekBitsFast(d.actualTableLog)
+ val2 = br[stream2].peekBitsFast(d.actualTableLog)
+ v = single[val&tlMask]
+ v2 = single[val2&tlMask]
+ br[stream].advance(uint8(v.entry))
+ br[stream2].advance(uint8(v2.entry))
+ buf[stream][off+1] = uint8(v.entry >> 8)
+ buf[stream2][off+1] = uint8(v2.entry >> 8)
+ }
+
+ off += 2
+
+ if off == 0 {
+ if bufoff > dstEvery {
+ d.bufs.Put(buf)
+ return nil, errors.New("corruption detected: stream overrun 1")
+ }
+ copy(out, buf[0][:])
+ copy(out[dstEvery:], buf[1][:])
+ copy(out[dstEvery*2:], buf[2][:])
+ copy(out[dstEvery*3:], buf[3][:])
+ out = out[bufoff:]
+ 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])
+ copy(out[dstEvery:], buf[1][:off])
+ copy(out[dstEvery*2:], buf[2][:off])
+ copy(out[dstEvery*3:], buf[3][:off])
+ decoded += int(off) * 4
+ out = out[off:]
+ }
+
+ // Decode remaining.
+ remainBytes := dstEvery - (decoded / 4)
+ for i := range br {
+ offset := dstEvery * i
+ endsAt := offset + remainBytes
+ if endsAt > len(out) {
+ endsAt = len(out)
+ }
+ br := &br[i]
+ bitsLeft := br.remaining()
+ for bitsLeft > 0 {
+ br.fill()
+ if offset >= endsAt {
+ d.bufs.Put(buf)
+ 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++
+ }
+ if offset != endsAt {
+ d.bufs.Put(buf)
+ return nil, fmt.Errorf("corruption detected: short output block %d, end %d != %d", i, offset, endsAt)
+ }
+ decoded += offset - dstEvery*i
+ err = br.close()
+ if err != nil {
+ return nil, err
+ }
+ }
+ d.bufs.Put(buf)
+ if dstSize != decoded {
+ return nil, errors.New("corruption detected: short output block")
+ }
+ return dst, nil
+}