[VOL-4289] Proto changes for gRPC migration
Change-Id: I317a0a865ccf78d0c37aa229c50d293a3f66c8bb
diff --git a/vendor/golang.org/x/net/http2/hpack/encode.go b/vendor/golang.org/x/net/http2/hpack/encode.go
new file mode 100644
index 0000000..97f1783
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/hpack/encode.go
@@ -0,0 +1,240 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hpack
+
+import (
+ "io"
+)
+
+const (
+ uint32Max = ^uint32(0)
+ initialHeaderTableSize = 4096
+)
+
+type Encoder struct {
+ dynTab dynamicTable
+ // minSize is the minimum table size set by
+ // SetMaxDynamicTableSize after the previous Header Table Size
+ // Update.
+ minSize uint32
+ // maxSizeLimit is the maximum table size this encoder
+ // supports. This will protect the encoder from too large
+ // size.
+ maxSizeLimit uint32
+ // tableSizeUpdate indicates whether "Header Table Size
+ // Update" is required.
+ tableSizeUpdate bool
+ w io.Writer
+ buf []byte
+}
+
+// NewEncoder returns a new Encoder which performs HPACK encoding. An
+// encoded data is written to w.
+func NewEncoder(w io.Writer) *Encoder {
+ e := &Encoder{
+ minSize: uint32Max,
+ maxSizeLimit: initialHeaderTableSize,
+ tableSizeUpdate: false,
+ w: w,
+ }
+ e.dynTab.table.init()
+ e.dynTab.setMaxSize(initialHeaderTableSize)
+ return e
+}
+
+// WriteField encodes f into a single Write to e's underlying Writer.
+// This function may also produce bytes for "Header Table Size Update"
+// if necessary. If produced, it is done before encoding f.
+func (e *Encoder) WriteField(f HeaderField) error {
+ e.buf = e.buf[:0]
+
+ if e.tableSizeUpdate {
+ e.tableSizeUpdate = false
+ if e.minSize < e.dynTab.maxSize {
+ e.buf = appendTableSize(e.buf, e.minSize)
+ }
+ e.minSize = uint32Max
+ e.buf = appendTableSize(e.buf, e.dynTab.maxSize)
+ }
+
+ idx, nameValueMatch := e.searchTable(f)
+ if nameValueMatch {
+ e.buf = appendIndexed(e.buf, idx)
+ } else {
+ indexing := e.shouldIndex(f)
+ if indexing {
+ e.dynTab.add(f)
+ }
+
+ if idx == 0 {
+ e.buf = appendNewName(e.buf, f, indexing)
+ } else {
+ e.buf = appendIndexedName(e.buf, f, idx, indexing)
+ }
+ }
+ n, err := e.w.Write(e.buf)
+ if err == nil && n != len(e.buf) {
+ err = io.ErrShortWrite
+ }
+ return err
+}
+
+// searchTable searches f in both stable and dynamic header tables.
+// The static header table is searched first. Only when there is no
+// exact match for both name and value, the dynamic header table is
+// then searched. If there is no match, i is 0. If both name and value
+// match, i is the matched index and nameValueMatch becomes true. If
+// only name matches, i points to that index and nameValueMatch
+// becomes false.
+func (e *Encoder) searchTable(f HeaderField) (i uint64, nameValueMatch bool) {
+ i, nameValueMatch = staticTable.search(f)
+ if nameValueMatch {
+ return i, true
+ }
+
+ j, nameValueMatch := e.dynTab.table.search(f)
+ if nameValueMatch || (i == 0 && j != 0) {
+ return j + uint64(staticTable.len()), nameValueMatch
+ }
+
+ return i, false
+}
+
+// SetMaxDynamicTableSize changes the dynamic header table size to v.
+// The actual size is bounded by the value passed to
+// SetMaxDynamicTableSizeLimit.
+func (e *Encoder) SetMaxDynamicTableSize(v uint32) {
+ if v > e.maxSizeLimit {
+ v = e.maxSizeLimit
+ }
+ if v < e.minSize {
+ e.minSize = v
+ }
+ e.tableSizeUpdate = true
+ e.dynTab.setMaxSize(v)
+}
+
+// SetMaxDynamicTableSizeLimit changes the maximum value that can be
+// specified in SetMaxDynamicTableSize to v. By default, it is set to
+// 4096, which is the same size of the default dynamic header table
+// size described in HPACK specification. If the current maximum
+// dynamic header table size is strictly greater than v, "Header Table
+// Size Update" will be done in the next WriteField call and the
+// maximum dynamic header table size is truncated to v.
+func (e *Encoder) SetMaxDynamicTableSizeLimit(v uint32) {
+ e.maxSizeLimit = v
+ if e.dynTab.maxSize > v {
+ e.tableSizeUpdate = true
+ e.dynTab.setMaxSize(v)
+ }
+}
+
+// shouldIndex reports whether f should be indexed.
+func (e *Encoder) shouldIndex(f HeaderField) bool {
+ return !f.Sensitive && f.Size() <= e.dynTab.maxSize
+}
+
+// appendIndexed appends index i, as encoded in "Indexed Header Field"
+// representation, to dst and returns the extended buffer.
+func appendIndexed(dst []byte, i uint64) []byte {
+ first := len(dst)
+ dst = appendVarInt(dst, 7, i)
+ dst[first] |= 0x80
+ return dst
+}
+
+// appendNewName appends f, as encoded in one of "Literal Header field
+// - New Name" representation variants, to dst and returns the
+// extended buffer.
+//
+// If f.Sensitive is true, "Never Indexed" representation is used. If
+// f.Sensitive is false and indexing is true, "Incremental Indexing"
+// representation is used.
+func appendNewName(dst []byte, f HeaderField, indexing bool) []byte {
+ dst = append(dst, encodeTypeByte(indexing, f.Sensitive))
+ dst = appendHpackString(dst, f.Name)
+ return appendHpackString(dst, f.Value)
+}
+
+// appendIndexedName appends f and index i referring indexed name
+// entry, as encoded in one of "Literal Header field - Indexed Name"
+// representation variants, to dst and returns the extended buffer.
+//
+// If f.Sensitive is true, "Never Indexed" representation is used. If
+// f.Sensitive is false and indexing is true, "Incremental Indexing"
+// representation is used.
+func appendIndexedName(dst []byte, f HeaderField, i uint64, indexing bool) []byte {
+ first := len(dst)
+ var n byte
+ if indexing {
+ n = 6
+ } else {
+ n = 4
+ }
+ dst = appendVarInt(dst, n, i)
+ dst[first] |= encodeTypeByte(indexing, f.Sensitive)
+ return appendHpackString(dst, f.Value)
+}
+
+// appendTableSize appends v, as encoded in "Header Table Size Update"
+// representation, to dst and returns the extended buffer.
+func appendTableSize(dst []byte, v uint32) []byte {
+ first := len(dst)
+ dst = appendVarInt(dst, 5, uint64(v))
+ dst[first] |= 0x20
+ return dst
+}
+
+// appendVarInt appends i, as encoded in variable integer form using n
+// bit prefix, to dst and returns the extended buffer.
+//
+// See
+// http://http2.github.io/http2-spec/compression.html#integer.representation
+func appendVarInt(dst []byte, n byte, i uint64) []byte {
+ k := uint64((1 << n) - 1)
+ if i < k {
+ return append(dst, byte(i))
+ }
+ dst = append(dst, byte(k))
+ i -= k
+ for ; i >= 128; i >>= 7 {
+ dst = append(dst, byte(0x80|(i&0x7f)))
+ }
+ return append(dst, byte(i))
+}
+
+// appendHpackString appends s, as encoded in "String Literal"
+// representation, to dst and returns the extended buffer.
+//
+// s will be encoded in Huffman codes only when it produces strictly
+// shorter byte string.
+func appendHpackString(dst []byte, s string) []byte {
+ huffmanLength := HuffmanEncodeLength(s)
+ if huffmanLength < uint64(len(s)) {
+ first := len(dst)
+ dst = appendVarInt(dst, 7, huffmanLength)
+ dst = AppendHuffmanString(dst, s)
+ dst[first] |= 0x80
+ } else {
+ dst = appendVarInt(dst, 7, uint64(len(s)))
+ dst = append(dst, s...)
+ }
+ return dst
+}
+
+// encodeTypeByte returns type byte. If sensitive is true, type byte
+// for "Never Indexed" representation is returned. If sensitive is
+// false and indexing is true, type byte for "Incremental Indexing"
+// representation is returned. Otherwise, type byte for "Without
+// Indexing" is returned.
+func encodeTypeByte(indexing, sensitive bool) byte {
+ if sensitive {
+ return 0x10
+ }
+ if indexing {
+ return 0x40
+ }
+ return 0
+}