Updating trunk VERSION from 2139.0 to 2140.0
[chromium-blink-merge.git] / net / spdy / hpack_huffman_aggregator.cc
blob41a3f48afc1d5a7ebbb97c633b0178b6998d756b
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.
4 #include "net/spdy/hpack_huffman_aggregator.h"
6 #include "base/metrics/bucket_ranges.h"
7 #include "base/metrics/field_trial.h"
8 #include "base/metrics/histogram.h"
9 #include "base/metrics/sample_vector.h"
10 #include "base/stl_util.h"
11 #include "base/strings/string_number_conversions.h"
12 #include "base/strings/string_util.h"
13 #include "net/base/load_flags.h"
14 #include "net/http/http_request_headers.h"
15 #include "net/http/http_request_info.h"
16 #include "net/http/http_response_headers.h"
17 #include "net/spdy/hpack_encoder.h"
18 #include "net/spdy/spdy_http_utils.h"
20 namespace net {
22 namespace {
24 const char kHistogramName[] = "Net.SpdyHpackEncodedCharacterFrequency";
26 const size_t kTotalCountsPublishThreshold = 50000;
28 // Each encoder uses the default dynamic table size of 4096 total bytes.
29 const size_t kMaxEncoders = 20;
31 } // namespace
33 HpackHuffmanAggregator::HpackHuffmanAggregator()
34 : counts_(256, 0),
35 total_counts_(0),
36 max_encoders_(kMaxEncoders) {
39 HpackHuffmanAggregator::~HpackHuffmanAggregator() {
40 STLDeleteContainerPairSecondPointers(encoders_.begin(), encoders_.end());
41 encoders_.clear();
44 void HpackHuffmanAggregator::AggregateTransactionCharacterCounts(
45 const HttpRequestInfo& request,
46 const HttpRequestHeaders& request_headers,
47 const ProxyServer& proxy,
48 const HttpResponseHeaders& response_headers) {
49 if (IsCrossOrigin(request)) {
50 return;
52 HostPortPair endpoint = HostPortPair(request.url.HostNoBrackets(),
53 request.url.EffectiveIntPort());
54 HpackEncoder* encoder = ObtainEncoder(
55 SpdySessionKey(endpoint, proxy, request.privacy_mode));
57 // Convert and encode the request and response header sets.
59 SpdyHeaderBlock headers;
60 CreateSpdyHeadersFromHttpRequest(
61 request, request_headers, SPDY4, false, &headers);
63 std::string tmp_out;
64 encoder->EncodeHeaderSet(headers, &tmp_out);
67 SpdyHeaderBlock headers;
68 CreateSpdyHeadersFromHttpResponse(response_headers, &headers);
70 std::string tmp_out;
71 encoder->EncodeHeaderSet(headers, &tmp_out);
73 if (total_counts_ >= kTotalCountsPublishThreshold) {
74 PublishCounts();
78 // static
79 bool HpackHuffmanAggregator::UseAggregator() {
80 const std::string group_name =
81 base::FieldTrialList::FindFullName("HpackHuffmanAggregator");
82 if (group_name == "Enabled") {
83 return true;
85 return false;
88 // static
89 void HpackHuffmanAggregator::CreateSpdyHeadersFromHttpResponse(
90 const HttpResponseHeaders& headers,
91 SpdyHeaderBlock* headers_out) {
92 // Lower-case header names, and coalesce multiple values delimited by \0.
93 // Also add the fixed status header.
94 std::string name, value;
95 void* it = NULL;
96 while (headers.EnumerateHeaderLines(&it, &name, &value)) {
97 base::StringToLowerASCII(&name);
98 if (headers_out->find(name) == headers_out->end()) {
99 (*headers_out)[name] = value;
100 } else {
101 (*headers_out)[name] += std::string(1, '\0') + value;
104 (*headers_out)[":status"] = base::IntToString(headers.response_code());
107 // static
108 bool HpackHuffmanAggregator::IsCrossOrigin(const HttpRequestInfo& request) {
109 // Require that the request is top-level, or that it shares
110 // an origin with its referer.
111 HostPortPair endpoint = HostPortPair(request.url.HostNoBrackets(),
112 request.url.EffectiveIntPort());
113 if ((request.load_flags & LOAD_MAIN_FRAME) == 0) {
114 std::string referer_str;
115 if (!request.extra_headers.GetHeader(HttpRequestHeaders::kReferer,
116 &referer_str)) {
117 // Require a referer.
118 return true;
120 GURL referer(referer_str);
121 HostPortPair referer_endpoint = HostPortPair(referer.HostNoBrackets(),
122 referer.EffectiveIntPort());
123 if (!endpoint.Equals(referer_endpoint)) {
124 // Cross-origin request.
125 return true;
128 return false;
131 HpackEncoder* HpackHuffmanAggregator::ObtainEncoder(const SpdySessionKey& key) {
132 for (OriginEncoders::iterator it = encoders_.begin();
133 it != encoders_.end(); ++it) {
134 if (key.Equals(it->first)) {
135 // Move to head of list and return.
136 OriginEncoder origin_encoder = *it;
137 encoders_.erase(it);
138 encoders_.push_front(origin_encoder);
139 return origin_encoder.second;
142 // Not found. Create a new encoder, evicting one if needed.
143 encoders_.push_front(std::make_pair(
144 key, new HpackEncoder(ObtainHpackHuffmanTable())));
145 if (encoders_.size() > max_encoders_) {
146 delete encoders_.back().second;
147 encoders_.pop_back();
149 encoders_.front().second->SetCharCountsStorage(&counts_, &total_counts_);
150 return encoders_.front().second;
153 void HpackHuffmanAggregator::PublishCounts() {
154 // base::Histogram requires that values be 1-indexed.
155 const size_t kRangeMin = 1;
156 const size_t kRangeMax = counts_.size() + 1;
157 const size_t kBucketCount = kRangeMax + 1;
159 base::BucketRanges ranges(kBucketCount + 1);
160 for (size_t i = 0; i != ranges.size(); ++i) {
161 ranges.set_range(i, i);
163 ranges.ResetChecksum();
165 // Copy |counts_| into a SampleVector.
166 base::SampleVector samples(&ranges);
167 for (size_t i = 0; i != counts_.size(); ++i) {
168 samples.Accumulate(i + 1, counts_[i]);
171 STATIC_HISTOGRAM_POINTER_BLOCK(
172 kHistogramName,
173 AddSamples(samples),
174 base::LinearHistogram::FactoryGet(
175 kHistogramName, kRangeMin, kRangeMax, kBucketCount,
176 base::HistogramBase::kUmaTargetedHistogramFlag));
178 // Clear counts.
179 counts_.assign(counts_.size(), 0);
180 total_counts_ = 0;
183 } // namespace net