1 // Copyright (c) 2013 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.
4
5 #include "net/quic/quic_spdy_compressor.h"
6
7 #include "base/basictypes.h"
8 #include "base/memory/scoped_ptr.h"
9
10 using std::string;
11
12 namespace net {
13
QuicSpdyCompressor()14 QuicSpdyCompressor::QuicSpdyCompressor()
15 : spdy_framer_(SPDY3),
16 header_sequence_id_(1) {
17 spdy_framer_.set_enable_compression(true);
18 }
19
~QuicSpdyCompressor()20 QuicSpdyCompressor::~QuicSpdyCompressor() {
21 }
22
CompressHeadersWithPriority(QuicPriority priority,const SpdyHeaderBlock & headers)23 string QuicSpdyCompressor::CompressHeadersWithPriority(
24 QuicPriority priority,
25 const SpdyHeaderBlock& headers) {
26 return CompressHeadersInternal(priority, headers, true);
27 }
28
CompressHeaders(const SpdyHeaderBlock & headers)29 string QuicSpdyCompressor::CompressHeaders(
30 const SpdyHeaderBlock& headers) {
31 // CompressHeadersInternal ignores priority when write_priority is false.
32 return CompressHeadersInternal(0 /* ignored */, headers, false);
33 }
34
CompressHeadersInternal(QuicPriority priority,const SpdyHeaderBlock & headers,bool write_priority)35 string QuicSpdyCompressor::CompressHeadersInternal(
36 QuicPriority priority,
37 const SpdyHeaderBlock& headers,
38 bool write_priority) {
39 // TODO(rch): Modify the SpdyFramer to expose a
40 // CreateCompressedHeaderBlock method, or some such.
41 SpdyStreamId stream_id = 3; // unused.
42 scoped_ptr<SpdyFrame> frame(spdy_framer_.CreateHeaders(
43 stream_id, CONTROL_FLAG_NONE, &headers));
44
45 // The size of the spdy HEADER frame's fixed prefix which
46 // needs to be stripped off from the resulting frame.
47 const size_t header_frame_prefix_len = 12;
48 string serialized = string(frame->data() + header_frame_prefix_len,
49 frame->size() - header_frame_prefix_len);
50 uint32 serialized_len = serialized.length();
51 char priority_str[sizeof(priority)];
52 memcpy(&priority_str, &priority, sizeof(priority));
53 char id_str[sizeof(header_sequence_id_)];
54 memcpy(&id_str, &header_sequence_id_, sizeof(header_sequence_id_));
55 char len_str[sizeof(serialized_len)];
56 memcpy(&len_str, &serialized_len, sizeof(serialized_len));
57 string compressed;
58 int priority_len = write_priority ? arraysize(priority_str) : 0;
59 compressed.reserve(
60 priority_len + arraysize(id_str) + arraysize(len_str) + serialized_len);
61 if (write_priority) {
62 compressed.append(priority_str, arraysize(priority_str));
63 }
64 compressed.append(id_str, arraysize(id_str));
65 compressed.append(len_str, arraysize(len_str));
66 compressed.append(serialized);
67 ++header_sequence_id_;
68 return compressed;
69 }
70
71 } // namespace net
72