diff options
Diffstat (limited to 'vendor/golang.org/x/net/http2/hpack/encode.go')
| -rw-r--r-- | vendor/golang.org/x/net/http2/hpack/encode.go | 240 |
1 files changed, 0 insertions, 240 deletions
diff --git a/vendor/golang.org/x/net/http2/hpack/encode.go b/vendor/golang.org/x/net/http2/hpack/encode.go deleted file mode 100644 index 1565cf2..0000000 --- a/vendor/golang.org/x/net/http2/hpack/encode.go +++ /dev/null @@ -1,240 +0,0 @@ -// 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, "Inremental 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 -} |