gRPC migration update
Change-Id: Icdd1a824948fa994cd36bd121c962f5ecf74e3cf
diff --git a/vendor/github.com/klauspost/compress/zstd/dict.go b/vendor/github.com/klauspost/compress/zstd/dict.go
new file mode 100644
index 0000000..fa25a18
--- /dev/null
+++ b/vendor/github.com/klauspost/compress/zstd/dict.go
@@ -0,0 +1,122 @@
+package zstd
+
+import (
+ "bytes"
+ "encoding/binary"
+ "errors"
+ "fmt"
+ "io"
+
+ "github.com/klauspost/compress/huff0"
+)
+
+type dict struct {
+ id uint32
+
+ litEnc *huff0.Scratch
+ llDec, ofDec, mlDec sequenceDec
+ //llEnc, ofEnc, mlEnc []*fseEncoder
+ offsets [3]int
+ content []byte
+}
+
+var dictMagic = [4]byte{0x37, 0xa4, 0x30, 0xec}
+
+// ID returns the dictionary id or 0 if d is nil.
+func (d *dict) ID() uint32 {
+ if d == nil {
+ return 0
+ }
+ return d.id
+}
+
+// DictContentSize returns the dictionary content size or 0 if d is nil.
+func (d *dict) DictContentSize() int {
+ if d == nil {
+ return 0
+ }
+ return len(d.content)
+}
+
+// Load a dictionary as described in
+// https://github.com/facebook/zstd/blob/master/doc/zstd_compression_format.md#dictionary-format
+func loadDict(b []byte) (*dict, error) {
+ // Check static field size.
+ if len(b) <= 8+(3*4) {
+ return nil, io.ErrUnexpectedEOF
+ }
+ d := dict{
+ llDec: sequenceDec{fse: &fseDecoder{}},
+ ofDec: sequenceDec{fse: &fseDecoder{}},
+ mlDec: sequenceDec{fse: &fseDecoder{}},
+ }
+ if !bytes.Equal(b[:4], dictMagic[:]) {
+ return nil, ErrMagicMismatch
+ }
+ d.id = binary.LittleEndian.Uint32(b[4:8])
+ if d.id == 0 {
+ return nil, errors.New("dictionaries cannot have ID 0")
+ }
+
+ // Read literal table
+ var err error
+ d.litEnc, b, err = huff0.ReadTable(b[8:], nil)
+ if err != nil {
+ return nil, err
+ }
+ d.litEnc.Reuse = huff0.ReusePolicyMust
+
+ br := byteReader{
+ b: b,
+ off: 0,
+ }
+ readDec := func(i tableIndex, dec *fseDecoder) error {
+ if err := dec.readNCount(&br, uint16(maxTableSymbol[i])); err != nil {
+ return err
+ }
+ if br.overread() {
+ return io.ErrUnexpectedEOF
+ }
+ err = dec.transform(symbolTableX[i])
+ if err != nil {
+ println("Transform table error:", err)
+ return err
+ }
+ if debug {
+ println("Read table ok", "symbolLen:", dec.symbolLen)
+ }
+ // Set decoders as predefined so they aren't reused.
+ dec.preDefined = true
+ return nil
+ }
+
+ if err := readDec(tableOffsets, d.ofDec.fse); err != nil {
+ return nil, err
+ }
+ if err := readDec(tableMatchLengths, d.mlDec.fse); err != nil {
+ return nil, err
+ }
+ if err := readDec(tableLiteralLengths, d.llDec.fse); err != nil {
+ return nil, err
+ }
+ if br.remain() < 12 {
+ return nil, io.ErrUnexpectedEOF
+ }
+
+ d.offsets[0] = int(br.Uint32())
+ br.advance(4)
+ d.offsets[1] = int(br.Uint32())
+ br.advance(4)
+ d.offsets[2] = int(br.Uint32())
+ br.advance(4)
+ if d.offsets[0] <= 0 || d.offsets[1] <= 0 || d.offsets[2] <= 0 {
+ return nil, errors.New("invalid offset in dictionary")
+ }
+ d.content = make([]byte, br.remain())
+ copy(d.content, br.unread())
+ if d.offsets[0] > len(d.content) || d.offsets[1] > len(d.content) || d.offsets[2] > len(d.content) {
+ return nil, fmt.Errorf("initial offset bigger than dictionary content size %d, offsets: %v", len(d.content), d.offsets)
+ }
+
+ return &d, nil
+}