Home | History | Annotate | Download | only in spdy 
      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 
      5 #include <list>
      6 #include <vector>
      7 
      8 #include "base/macros.h"
      9 #include "net/base/net_export.h"
     10 #include "net/spdy/spdy_header_block.h"
     11 #include "net/spdy/spdy_protocol.h"
     12 #include "net/spdy/spdy_session_key.h"
     13 
     14 namespace net {
     15 
     16 class HpackEncoder;
     17 class HttpRequestHeaders;
     18 struct HttpRequestInfo;
     19 class HttpResponseHeaders;
     20 class ProxyServer;
     21 
     22 namespace test {
     23 class HpackHuffmanAggregatorPeer;
     24 }  // namespace test
     25 
     26 class NET_EXPORT_PRIVATE HpackHuffmanAggregator {
     27  public:
     28   friend class test::HpackHuffmanAggregatorPeer;
     29 
     30   HpackHuffmanAggregator();
     31   ~HpackHuffmanAggregator();
     32 
     33   // Encodes the request and response headers of the transaction with an
     34   // HpackEncoder keyed on the transaction's SpdySessionKey. Literal headers
     35   // emitted by that encoder are aggregated into internal character counts,
     36   // which are periodically published to a UMA histogram.
     37   void AggregateTransactionCharacterCounts(
     38     const HttpRequestInfo& request,
     39     const HttpRequestHeaders& request_headers,
     40     const ProxyServer& proxy,
     41     const HttpResponseHeaders& response_headers);
     42 
     43   // Returns whether the aggregator is enabled for the session by a field trial.
     44   static bool UseAggregator();
     45 
     46  private:
     47   typedef std::pair<SpdySessionKey, HpackEncoder*> OriginEncoder;
     48   typedef std::list<OriginEncoder> OriginEncoders;
     49 
     50   // Returns true if the request is considered cross-origin,
     51   // and should not be aggregated.
     52   static bool IsCrossOrigin(const HttpRequestInfo& request);
     53 
     54   // Converts |headers| into SPDY headers block |headers_out|.
     55   static void CreateSpdyHeadersFromHttpResponse(
     56       const HttpResponseHeaders& headers,
     57       SpdyHeaderBlock* headers_out);
     58 
     59   // Creates or returns an encoder for the origin key.
     60   HpackEncoder* ObtainEncoder(const SpdySessionKey& key);
     61 
     62   // Publishes aggregated counts to a UMA histogram.
     63   void PublishCounts();
     64 
     65   std::vector<size_t> counts_;
     66   size_t total_counts_;
     67 
     68   OriginEncoders encoders_;
     69   size_t max_encoders_;
     70 
     71   DISALLOW_COPY_AND_ASSIGN(HpackHuffmanAggregator);
     72 };
     73 
     74 }  // namespace net
     75