gRPC migration update
Change-Id: Icdd1a824948fa994cd36bd121c962f5ecf74e3cf
diff --git a/vendor/github.com/klauspost/compress/zstd/enc_base.go b/vendor/github.com/klauspost/compress/zstd/enc_base.go
new file mode 100644
index 0000000..60f2986
--- /dev/null
+++ b/vendor/github.com/klauspost/compress/zstd/enc_base.go
@@ -0,0 +1,178 @@
+package zstd
+
+import (
+ "fmt"
+ "math/bits"
+
+ "github.com/klauspost/compress/zstd/internal/xxhash"
+)
+
+const (
+ dictShardBits = 6
+)
+
+type fastBase struct {
+ // cur is the offset at the start of hist
+ cur int32
+ // maximum offset. Should be at least 2x block size.
+ maxMatchOff int32
+ hist []byte
+ crc *xxhash.Digest
+ tmp [8]byte
+ blk *blockEnc
+ lastDictID uint32
+ lowMem bool
+}
+
+// CRC returns the underlying CRC writer.
+func (e *fastBase) CRC() *xxhash.Digest {
+ return e.crc
+}
+
+// AppendCRC will append the CRC to the destination slice and return it.
+func (e *fastBase) AppendCRC(dst []byte) []byte {
+ crc := e.crc.Sum(e.tmp[:0])
+ dst = append(dst, crc[7], crc[6], crc[5], crc[4])
+ return dst
+}
+
+// WindowSize returns the window size of the encoder,
+// or a window size small enough to contain the input size, if > 0.
+func (e *fastBase) WindowSize(size int) int32 {
+ if size > 0 && size < int(e.maxMatchOff) {
+ b := int32(1) << uint(bits.Len(uint(size)))
+ // Keep minimum window.
+ if b < 1024 {
+ b = 1024
+ }
+ return b
+ }
+ return e.maxMatchOff
+}
+
+// Block returns the current block.
+func (e *fastBase) Block() *blockEnc {
+ return e.blk
+}
+
+func (e *fastBase) addBlock(src []byte) int32 {
+ if debugAsserts && e.cur > bufferReset {
+ panic(fmt.Sprintf("ecur (%d) > buffer reset (%d)", e.cur, bufferReset))
+ }
+ // check if we have space already
+ if len(e.hist)+len(src) > cap(e.hist) {
+ if cap(e.hist) == 0 {
+ e.ensureHist(len(src))
+ } else {
+ if cap(e.hist) < int(e.maxMatchOff+maxCompressedBlockSize) {
+ panic(fmt.Errorf("unexpected buffer cap %d, want at least %d with window %d", cap(e.hist), e.maxMatchOff+maxCompressedBlockSize, e.maxMatchOff))
+ }
+ // Move down
+ offset := int32(len(e.hist)) - e.maxMatchOff
+ copy(e.hist[0:e.maxMatchOff], e.hist[offset:])
+ e.cur += offset
+ e.hist = e.hist[:e.maxMatchOff]
+ }
+ }
+ s := int32(len(e.hist))
+ e.hist = append(e.hist, src...)
+ return s
+}
+
+// ensureHist will ensure that history can keep at least this many bytes.
+func (e *fastBase) ensureHist(n int) {
+ if cap(e.hist) >= n {
+ return
+ }
+ l := e.maxMatchOff
+ if (e.lowMem && e.maxMatchOff > maxCompressedBlockSize) || e.maxMatchOff <= maxCompressedBlockSize {
+ l += maxCompressedBlockSize
+ } else {
+ l += e.maxMatchOff
+ }
+ // Make it at least 1MB.
+ if l < 1<<20 && !e.lowMem {
+ l = 1 << 20
+ }
+ // Make it at least the requested size.
+ if l < int32(n) {
+ l = int32(n)
+ }
+ e.hist = make([]byte, 0, l)
+}
+
+// useBlock will replace the block with the provided one,
+// but transfer recent offsets from the previous.
+func (e *fastBase) UseBlock(enc *blockEnc) {
+ enc.reset(e.blk)
+ e.blk = enc
+}
+
+func (e *fastBase) matchlenNoHist(s, t int32, src []byte) int32 {
+ // Extend the match to be as long as possible.
+ return int32(matchLen(src[s:], src[t:]))
+}
+
+func (e *fastBase) matchlen(s, t int32, src []byte) int32 {
+ if debugAsserts {
+ if s < 0 {
+ err := fmt.Sprintf("s (%d) < 0", s)
+ panic(err)
+ }
+ if t < 0 {
+ err := fmt.Sprintf("s (%d) < 0", s)
+ panic(err)
+ }
+ if s-t > e.maxMatchOff {
+ err := fmt.Sprintf("s (%d) - t (%d) > maxMatchOff (%d)", s, t, e.maxMatchOff)
+ panic(err)
+ }
+ if len(src)-int(s) > maxCompressedBlockSize {
+ panic(fmt.Sprintf("len(src)-s (%d) > maxCompressedBlockSize (%d)", len(src)-int(s), maxCompressedBlockSize))
+ }
+ }
+
+ // Extend the match to be as long as possible.
+ return int32(matchLen(src[s:], src[t:]))
+}
+
+// Reset the encoding table.
+func (e *fastBase) resetBase(d *dict, singleBlock bool) {
+ if e.blk == nil {
+ e.blk = &blockEnc{lowMem: e.lowMem}
+ e.blk.init()
+ } else {
+ e.blk.reset(nil)
+ }
+ e.blk.initNewEncode()
+ if e.crc == nil {
+ e.crc = xxhash.New()
+ } else {
+ e.crc.Reset()
+ }
+ if d != nil {
+ low := e.lowMem
+ if singleBlock {
+ e.lowMem = true
+ }
+ e.ensureHist(d.DictContentSize() + maxCompressedBlockSize)
+ e.lowMem = low
+ }
+
+ // We offset current position so everything will be out of reach.
+ // If above reset line, history will be purged.
+ if e.cur < bufferReset {
+ e.cur += e.maxMatchOff + int32(len(e.hist))
+ }
+ e.hist = e.hist[:0]
+ if d != nil {
+ // Set offsets (currently not used)
+ for i, off := range d.offsets {
+ e.blk.recentOffsets[i] = uint32(off)
+ e.blk.prevRecentOffsets[i] = e.blk.recentOffsets[i]
+ }
+ // Transfer litenc.
+ e.blk.dictLitEnc = d.litEnc
+ e.hist = append(e.hist, d.content...)
+ }
+}