net/spdy/hpack_huffman_aggregator.h

   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