components/cast_channel/keep_alive_delegate.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 #ifndef COMPONENTS_CAST_CHANNEL_KEEP_ALIVE_DELEGATE_H_
   6 #define COMPONENTS_CAST_CHANNEL_KEEP_ALIVE_DELEGATE_H_
   7
   8 #include "base/macros.h"
   9 #include "base/memory/weak_ptr.h"
  10 #include "base/threading/thread_checker.h"
  11 #include "base/timer/timer.h"
  12 #include "components/cast_channel/cast_message_util.h"
  13 #include "components/cast_channel/cast_transport.h"
  14 #include "components/cast_channel/proto/cast_channel.pb.h"
  15
  16 namespace cast_channel {
  17
  18 class CastSocket;
  19 class Logger;
  20
  21 // Decorator delegate which provides keep-alive functionality.
  22 // Keep-alive messages are handled by this object; all other messages and
  23 // errors are passed to |inner_delegate_|.
  24 class KeepAliveDelegate : public CastTransport::Delegate {
  25  public:
  26   // |socket|: The socket to be kept alive.
  27   // |logger|: The logging object which collects protocol events and error
  28   //           details.
  29   // |inner_delegate|: The delegate which processes all non-keep-alive
  30   //                   messages. This object assumes ownership of
  31   //                   |inner_delegate|.
  32   // |ping_interval|: The amount of idle time to wait before sending a PING to
  33   //                  the remote end.
  34   // |liveness_timeout|: The amount of idle time to wait before terminating the
  35   //                     connection.
  36   KeepAliveDelegate(CastSocket* socket,
  37                     scoped_refptr<Logger> logger,
  38                     std::unique_ptr<CastTransport::Delegate> inner_delegate,
  39                     base::TimeDelta ping_interval,
  40                     base::TimeDelta liveness_timeout);
  41
  42   ~KeepAliveDelegate() override;
  43
  44   void SetTimersForTest(
  45       std::unique_ptr<base::RetainingOneShotTimer> injected_ping_timer,
  46       std::unique_ptr<base::RetainingOneShotTimer> injected_liveness_timer);
  47
  48   // CastTransport::Delegate implementation.
  49   void Start() override;
  50   void OnError(ChannelError error_state) override;
  51   void OnMessage(const CastMessage& message) override;
  52
  53  private:
  54   // Restarts the ping/liveness timeout timers. Called when a message
  55   // is received from the remote end.
  56   void ResetTimers();
  57
  58   // Sends a formatted PING or PONG message to the remote side.
  59   void SendKeepAliveMessage(const CastMessage& message,
  60                             CastMessageType message_type);
  61
  62   // Callback for SendKeepAliveMessage.
  63   void SendKeepAliveMessageComplete(CastMessageType message_type, int rv);
  64
  65   // Called when the liveness timer expires, indicating that the remote
  66   // end has not responded within the |liveness_timeout_| interval.
  67   void LivenessTimeout();
  68
  69   // Stops the ping and liveness timers if they are started.
  70   // To be called after an error.
  71   void Stop();
  72
  73   // Indicates that Start() was called.
  74   bool started_;
  75
  76   // Socket that is managed by the keep-alive object.
  77   CastSocket* socket_;
  78
  79   // Logging object.
  80   scoped_refptr<Logger> logger_;
  81
  82   // Delegate object which receives all non-keep alive messages.
  83   std::unique_ptr<CastTransport::Delegate> inner_delegate_;
  84
  85   // Amount of idle time to wait before disconnecting.
  86   base::TimeDelta liveness_timeout_;
  87
  88   // Amount of idle time to wait before pinging the receiver.
  89   base::TimeDelta ping_interval_;
  90
  91   // Fired when |ping_interval_| is exceeded or when triggered by test code.
  92   std::unique_ptr<base::RetainingOneShotTimer> ping_timer_;
  93
  94   // Fired when |liveness_timer_| is exceeded.
  95   std::unique_ptr<base::RetainingOneShotTimer> liveness_timer_;
  96
  97   // The PING message to send over the wire.
  98   const CastMessage ping_message_;
  99
 100   // The PONG message to send over the wire.
 101   const CastMessage pong_message_;
 102
 103   THREAD_CHECKER(thread_checker_);
 104
 105   base::WeakPtrFactory<KeepAliveDelegate> weak_factory_;
 106
 107   DISALLOW_COPY_AND_ASSIGN(KeepAliveDelegate);
 108 };
 109
 110 }  // namespace cast_channel
 111
 112 #endif  // COMPONENTS_CAST_CHANNEL_KEEP_ALIVE_DELEGATE_H_