| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef NET_SPDY_HPACK_ENCODER_H_ |
| #define NET_SPDY_HPACK_ENCODER_H_ |
| |
| #include <map> |
| #include <string> |
| #include <utility> |
| #include <vector> |
| |
| #include "base/basictypes.h" |
| #include "base/macros.h" |
| #include "base/strings/string_piece.h" |
| #include "net/base/net_export.h" |
| #include "net/spdy/hpack_header_table.h" |
| #include "net/spdy/hpack_output_stream.h" |
| |
| // An HpackEncoder encodes header sets as outlined in |
| // http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-08 |
| |
| namespace net { |
| |
| class HpackHuffmanTable; |
| |
| namespace test { |
| class HpackEncoderPeer; |
| } // namespace test |
| |
| class NET_EXPORT_PRIVATE HpackEncoder { |
| public: |
| friend class test::HpackEncoderPeer; |
| |
| // |table| is an initialized HPACK Huffman table, having an |
| // externally-managed lifetime which spans beyond HpackEncoder. |
| explicit HpackEncoder(const HpackHuffmanTable& table); |
| ~HpackEncoder(); |
| |
| // Encodes the given header set into the given string. Returns |
| // whether or not the encoding was successful. |
| bool EncodeHeaderSet(const std::map<std::string, std::string>& header_set, |
| std::string* output); |
| |
| // Encodes the given header set into the given string. Only non-indexed |
| // literal representations are emitted, bypassing the header table. Huffman |
| // coding is also not used. Returns whether the encoding was successful. |
| // TODO(jgraettinger): Enable Huffman coding once the table as stablized. |
| bool EncodeHeaderSetWithoutCompression( |
| const std::map<std::string, std::string>& header_set, |
| std::string* output); |
| |
| // Called upon a change to SETTINGS_HEADER_TABLE_SIZE. Specifically, this |
| // is to be called after receiving (and sending an acknowledgement for) a |
| // SETTINGS_HEADER_TABLE_SIZE update from the remote decoding endpoint. |
| void ApplyHeaderTableSizeSetting(size_t size_setting) { |
| header_table_.SetSettingsHeaderTableSize(size_setting); |
| } |
| |
| // Sets externally-owned storage for aggregating character counts of emitted |
| // literal representations. |
| void SetCharCountsStorage(std::vector<size_t>* char_counts, |
| size_t* total_char_counts); |
| |
| private: |
| typedef std::pair<base::StringPiece, base::StringPiece> Representation; |
| typedef std::vector<Representation> Representations; |
| |
| // Emits a static/dynamic indexed representation (Section 7.1). |
| void EmitIndex(const HpackEntry* entry); |
| |
| // Emits a literal representation (Section 7.2). |
| void EmitIndexedLiteral(const Representation& representation); |
| void EmitNonIndexedLiteral(const Representation& representation); |
| void EmitLiteral(const Representation& representation); |
| |
| // Emits a Huffman or identity string (whichever is smaller). |
| void EmitString(base::StringPiece str); |
| |
| void UpdateCharacterCounts(base::StringPiece str); |
| |
| // Crumbles a cookie header into sorted, de-duplicated crumbs. |
| static void CookieToCrumbs(const Representation& cookie, |
| Representations* crumbs_out); |
| |
| // Crumbles other header field values at \0 delimiters. |
| static void DecomposeRepresentation(const Representation& header_field, |
| Representations* out); |
| |
| HpackHeaderTable header_table_; |
| HpackOutputStream output_stream_; |
| |
| bool allow_huffman_compression_; |
| const HpackHuffmanTable& huffman_table_; |
| |
| // Externally-owned, nullable storage for character counts of literals. |
| std::vector<size_t>* char_counts_; |
| size_t* total_char_counts_; |
| |
| DISALLOW_COPY_AND_ASSIGN(HpackEncoder); |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_SPDY_HPACK_ENCODER_H_ |