[VOL-4291] Rw-core updates for gRPC migration
Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/github.com/klauspost/compress/zstd/history.go b/vendor/github.com/klauspost/compress/zstd/history.go
new file mode 100644
index 0000000..f783e32
--- /dev/null
+++ b/vendor/github.com/klauspost/compress/zstd/history.go
@@ -0,0 +1,89 @@
+// Copyright 2019+ Klaus Post. All rights reserved.
+// License information can be found in the LICENSE file.
+// Based on work by Yann Collet, released under BSD License.
+
+package zstd
+
+import (
+ "github.com/klauspost/compress/huff0"
+)
+
+// history contains the information transferred between blocks.
+type history struct {
+ b []byte
+ huffTree *huff0.Scratch
+ recentOffsets [3]int
+ decoders sequenceDecs
+ windowSize int
+ maxSize int
+ error bool
+ dict *dict
+}
+
+// reset will reset the history to initial state of a frame.
+// The history must already have been initialized to the desired size.
+func (h *history) reset() {
+ h.b = h.b[:0]
+ h.error = false
+ h.recentOffsets = [3]int{1, 4, 8}
+ if f := h.decoders.litLengths.fse; f != nil && !f.preDefined {
+ fseDecoderPool.Put(f)
+ }
+ if f := h.decoders.offsets.fse; f != nil && !f.preDefined {
+ fseDecoderPool.Put(f)
+ }
+ if f := h.decoders.matchLengths.fse; f != nil && !f.preDefined {
+ fseDecoderPool.Put(f)
+ }
+ h.decoders = sequenceDecs{}
+ if h.huffTree != nil {
+ if h.dict == nil || h.dict.litEnc != h.huffTree {
+ huffDecoderPool.Put(h.huffTree)
+ }
+ }
+ h.huffTree = nil
+ h.dict = nil
+ //printf("history created: %+v (l: %d, c: %d)", *h, len(h.b), cap(h.b))
+}
+
+func (h *history) setDict(dict *dict) {
+ if dict == nil {
+ return
+ }
+ h.dict = dict
+ h.decoders.litLengths = dict.llDec
+ h.decoders.offsets = dict.ofDec
+ h.decoders.matchLengths = dict.mlDec
+ h.recentOffsets = dict.offsets
+ h.huffTree = dict.litEnc
+}
+
+// append bytes to history.
+// This function will make sure there is space for it,
+// if the buffer has been allocated with enough extra space.
+func (h *history) append(b []byte) {
+ if len(b) >= h.windowSize {
+ // Discard all history by simply overwriting
+ h.b = h.b[:h.windowSize]
+ copy(h.b, b[len(b)-h.windowSize:])
+ return
+ }
+
+ // If there is space, append it.
+ if len(b) < cap(h.b)-len(h.b) {
+ h.b = append(h.b, b...)
+ return
+ }
+
+ // Move data down so we only have window size left.
+ // We know we have less than window size in b at this point.
+ discard := len(b) + len(h.b) - h.windowSize
+ copy(h.b, h.b[discard:])
+ h.b = h.b[:h.windowSize]
+ copy(h.b[h.windowSize-len(b):], b)
+}
+
+// append bytes to history without ever discarding anything.
+func (h *history) appendKeep(b []byte) {
+ h.b = append(h.b, b...)
+}