1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef NET_SPDY_HPACK_DECODER_H_
6 #define NET_SPDY_HPACK_DECODER_H_
12 #include "base/basictypes.h"
13 #include "base/macros.h"
14 #include "base/strings/string_piece.h"
15 #include "net/base/net_export.h"
16 #include "net/spdy/hpack_header_table.h"
17 #include "net/spdy/hpack_input_stream.h"
18 #include "net/spdy/spdy_protocol.h"
20 // An HpackDecoder decodes header sets as outlined in
21 // http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-07
25 class HpackHuffmanTable
;
28 class HpackDecoderPeer
;
31 class NET_EXPORT_PRIVATE HpackDecoder
{
33 friend class test::HpackDecoderPeer
;
35 // |table| is an initialized HPACK Huffman table, having an
36 // externally-managed lifetime which spans beyond HpackDecoder.
37 explicit HpackDecoder(const HpackHuffmanTable
& table
);
40 // Called upon acknowledgement of SETTINGS_HEADER_TABLE_SIZE.
41 void ApplyHeaderTableSizeSetting(size_t size_setting
) {
42 header_table_
.SetSettingsHeaderTableSize(size_setting
);
45 // Called as headers data arrives. Returns false if an error occurred.
46 // TODO(jgraettinger): A future version of this method will incrementally
47 // parse and deliver headers via SpdyHeadersHandlerInterface. For now,
48 // header data is buffered until HandleControlFrameHeadersComplete().
49 bool HandleControlFrameHeadersData(SpdyStreamId stream_id
,
50 const char* headers_data
,
51 size_t headers_data_length
);
53 // Called after a headers block has been completely delivered via
54 // HandleControlFrameHeadersData(). Returns false if an error occurred.
55 // TODO(jgraettinger): A future version of this method will simply deliver
56 // the Cookie header (which has been incrementally reconstructed) and notify
57 // the visitor that the block is finished. For now, this method decodes the
58 // complete buffered block, and stores results to |decoded_block_|.
59 bool HandleControlFrameHeadersComplete(SpdyStreamId stream_id
);
61 // Accessor for the most recently decoded headers block. Valid until the next
62 // call to HandleControlFrameHeadersData().
63 // TODO(jgraettinger): This was added to facilitate re-encoding the block in
64 // SPDY3 format for delivery to the SpdyFramer visitor, and will be removed
65 // with the migration to SpdyHeadersHandlerInterface.
66 const std::map
<std::string
, std::string
>& decoded_block() {
67 return decoded_block_
;
71 // Adds the header representation to |decoded_block_|, applying the
72 // following rules, as per sections 8.1.3.3 & 8.1.3.4 of the HTTP2 draft
74 // - Multiple values of the Cookie header are joined, delmited by '; '.
75 // This reconstruction is required to properly handle Cookie crumbling.
76 // - Multiple values of other headers are joined and delimited by '\0'.
77 // Note that this may be too accomodating, as the sender's HTTP2 layer
78 // should have already joined and delimited these values.
80 // TODO(jgraettinger): This method will eventually emit to the
81 // SpdyHeadersHandlerInterface visitor.
82 void HandleHeaderRepresentation(base::StringPiece name
,
83 base::StringPiece value
);
85 const uint32 max_string_literal_size_
;
86 HpackHeaderTable header_table_
;
88 // Incrementally reconstructed cookie value.
89 std::string cookie_value_
;
91 // TODO(jgraettinger): Buffer for headers data, and storage for the last-
92 // processed headers block. Both will be removed with the switch to
93 // SpdyHeadersHandlerInterface.
94 std::string headers_block_buffer_
;
95 std::map
<std::string
, std::string
> decoded_block_
;
97 // Huffman table to be applied to decoded Huffman literals,
98 // and scratch space for storing those decoded literals.
99 const HpackHuffmanTable
& huffman_table_
;
100 std::string key_buffer_
, value_buffer_
;
102 // Handlers for decoding HPACK opcodes and header representations
103 // (or parts thereof). These methods return true on success and
105 bool DecodeNextOpcode(HpackInputStream
* input_stream
);
106 bool DecodeNextContextUpdate(HpackInputStream
* input_stream
);
107 bool DecodeNextIndexedHeader(HpackInputStream
* input_stream
);
108 bool DecodeNextLiteralHeader(HpackInputStream
* input_stream
,
110 bool DecodeNextName(HpackInputStream
* input_stream
,
111 base::StringPiece
* next_name
);
112 bool DecodeNextStringLiteral(HpackInputStream
* input_stream
,
113 bool is_header_key
, // As distinct from a value.
114 base::StringPiece
* output
);
116 DISALLOW_COPY_AND_ASSIGN(HpackDecoder
);
121 #endif // NET_SPDY_HPACK_DECODER_H_