components/network_hints/renderer/renderer_preconnect.h

   1 // Copyright 2015 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 // A RendererPreconnect instance is maintained for each RenderThread.
   6 // URL strings are typically added to the embedded queue during rendering.
   7 // The first addition to the queue (transitioning from empty to having
   8 // some names) causes a processing task to be added to the Renderer Thread.
   9 // The processing task gathers all buffered URLs, and send them via IPC
  10 // to the browser.
  11 // This class counts repeated requests for the same URL and requests that
  12 // number of connections be preconnected. If multiple requests are sent
  13 // separately the net stack will just keep re-using the first pending
  14 // connection so we allow for the time between the parsing of the tags and
  15 // when the task is scheduled to accumulate multiple requests.
  16
  17 #ifndef COMPONENTS_NETWORK_HINTS_RENDERER_RENDERER_PRECONNECT_H_
  18 #define COMPONENTS_NETWORK_HINTS_RENDERER_RENDERER_PRECONNECT_H_
  19
  20 #include <map>
  21
  22 #include "base/basictypes.h"
  23 #include "base/memory/weak_ptr.h"
  24 #include "url/gurl.h"
  25
  26 namespace network_hints {
  27
  28 // An internal interface to the network_hints component for efficiently sending
  29 // DNS prefetch requests to the net stack.
  30 class RendererPreconnect {
  31  public:
  32   RendererPreconnect();
  33   ~RendererPreconnect();
  34
  35   // Push a name into the queue to be preconnected.
  36   void Preconnect(const GURL &url);
  37
  38   // SubmitPreconnect processes the buffered URLs, and submits them for
  39   // preconnecting.  Multiple requests for the same URL will increase the number
  40   // of connections requested.
  41   void SubmitPreconnect();
  42
  43  private:
  44   // url_request_count_map_ contains (for each URL) a count for the number of
  45   // times it was requested.
  46   typedef std::map<GURL, int> UrlRequestCountMap;
  47   UrlRequestCountMap url_request_count_map_;
  48
  49   base::WeakPtrFactory<RendererPreconnect> weak_factory_;
  50
  51   DISALLOW_COPY_AND_ASSIGN(RendererPreconnect);
  52 };  // class RendererPreconnect
  53
  54 }  // namespace network_hints
  55
  56 #endif  // COMPONENTS_NETWORK_HINTS_RENDERER_RENDERER_PRECONNECT_H_