net/websockets/websocket_throttle.h

   1 // Copyright (c) 2011 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 #ifndef NET_WEBSOCKETS_WEBSOCKET_THROTTLE_H_
   6 #define NET_WEBSOCKETS_WEBSOCKET_THROTTLE_H_
   7
   8 #include <deque>
   9 #include <map>
  10 #include <set>
  11 #include <string>
  12
  13 #include "net/base/ip_endpoint.h"
  14 #include "net/base/net_export.h"
  15
  16 template <typename T> struct DefaultSingletonTraits;
  17
  18 namespace net {
  19
  20 class SocketStream;
  21 class WebSocketJob;
  22
  23 // SocketStreamThrottle for WebSocket protocol.
  24 // Implements the client-side requirements in the spec.
  25 // http://tools.ietf.org/html/draft-hixie-thewebsocketprotocol
  26 // 4.1 Handshake
  27 //   1.   If the user agent already has a Web Socket connection to the
  28 //        remote host (IP address) identified by /host/, even if known by
  29 //        another name, wait until that connection has been established or
  30 //        for that connection to have failed.
  31 class NET_EXPORT_PRIVATE WebSocketThrottle {
  32  public:
  33   // Returns the singleton instance.
  34   static WebSocketThrottle* GetInstance();
  35
  36   // Puts |job| in |queue_| and queues for the destination addresses
  37   // of |job|.
  38   // If other job is using the same destination address, set |job| waiting.
  39   //
  40   // Returns true if successful. If the number of pending jobs will exceed
  41   // the limit, does nothing and returns false.
  42   bool PutInQueue(WebSocketJob* job);
  43
  44   // Removes |job| from |queue_| and queues for the destination addresses
  45   // of |job|, and then wakes up jobs that can now resume establishing a
  46   // connection.
  47   void RemoveFromQueue(WebSocketJob* job);
  48
  49  private:
  50   typedef std::deque<WebSocketJob*> ConnectingQueue;
  51   typedef std::map<IPEndPoint, ConnectingQueue> ConnectingAddressMap;
  52
  53   WebSocketThrottle();
  54   ~WebSocketThrottle();
  55   friend struct DefaultSingletonTraits<WebSocketThrottle>;
  56
  57   // Examines if any of the given jobs can resume establishing a connection. If
  58   // for all per-address queues for each resolved addresses
  59   // (job->address_list()) of a job, the job is at the front of the queues, the
  60   // job can resume establishing a connection, so wakes up the job.
  61   void WakeupSocketIfNecessary(
  62       const std::set<WebSocketJob*>& wakeup_candidates);
  63
  64   // Key: string of host's address.  Value: queue of sockets for the address.
  65   ConnectingAddressMap addr_map_;
  66
  67   // Queue of sockets for websockets in opening state.
  68   ConnectingQueue queue_;
  69
  70   DISALLOW_COPY_AND_ASSIGN(WebSocketThrottle);
  71 };
  72
  73 }  // namespace net
  74
  75 #endif  // NET_WEBSOCKETS_WEBSOCKET_THROTTLE_H_