[GCM] Add connection factory for creating MCS connections

google_apis/gcm/engine/connection_factory_impl.h

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef GOOGLE_APIS_GCM_ENGINE_CONNECTION_FACTORY_IMPL_H_
+#define GOOGLE_APIS_GCM_ENGINE_CONNECTION_FACTORY_IMPL_H_
+
+#include "google_apis/gcm/engine/connection_factory.h"
+
+#include "base/memory/weak_ptr.h"
+#include "google_apis/gcm/protocol/mcs.pb.h"
+#include "net/base/backoff_entry.h"
+#include "net/base/network_change_notifier.h"
+#include "net/socket/client_socket_handle.h"
+#include "url/gurl.h"
+
+namespace net {
+class HttpNetworkSession;
+class NetLog;
+}
+
+namespace gcm {
+
+class ConnectionHandlerImpl;
+
+class GCM_EXPORT ConnectionFactoryImpl :

[akalin, 2013/11/02 00:15:43]

tests for ConnectionFactoryImpl?

[Nicolas Zea, 2013/11/15 23:37:35]

Wasn't sure how best to test the backoff logic, or if I should just rely on the
backoff entry unittests themselves. That said, I think I have a decent approach
now,  that at least enforces the backoff entries are being used properly. Done.

+    public ConnectionFactory,
+    public net::NetworkChangeNotifier::ConnectionTypeObserver,
+    public net::NetworkChangeNotifier::IPAddressObserver {
+ public:
+  ConnectionFactoryImpl(
+      const GURL& mcs_endpoint,
+      scoped_refptr<net::HttpNetworkSession> network_session,
+      net::NetLog* net_log);
+  virtual ~ConnectionFactoryImpl();
+
+  // ConnectionFactory implementation.
+  virtual ConnectionHandler* BuildConnectionHandler(
+      const ConnectionHandler::ProtoReceivedCallback& read_callback,
+      const ConnectionHandler::ProtoSentCallback& write_callback) OVERRIDE;
+  virtual void Connect(const mcs_proto::LoginRequest& login_request) OVERRIDE;
+  virtual bool IsEndpointReachable() const OVERRIDE;
+
+  // NetworkChangeNotifier observer implementations.
+  virtual void OnConnectionTypeChanged(
+      net::NetworkChangeNotifier::ConnectionType type) OVERRIDE;
+  virtual void OnIPAddressChanged() OVERRIDE;
+
+ private:
+  // Implementation of Connect(..). If not in backoff, uses |login_request_|
+  // in attempting a connection/handshake. On connection/handshake failure, goes
+  // into backoff.
+  void ConnectImpl();
+
+  // Callback for Socket connection completion.
+  void OnConnectDone(int result);
+
+  // ConnectionHandler callback for connection issues.
+  void ConnectionHandlerCallback(int result);
+
+  // The MCS endpoint to make connections to.
+  const GURL mcs_endpoint_;
+
+  // ---- net:: components for establishing connections. ----
+  // Network session for creating new connections.
+  scoped_refptr<net::HttpNetworkSession> network_session_;
+  // Net log to use in connection attempts.
+  net::NetLog* net_log_;
+  // The handle to the socket for the current connection, if one exists.
+  net::ClientSocketHandle socket_handle_;
+  // Connection attempt backoff policy.
+  net::BackoffEntry backoff_entry_;
+
+  // The current connection handler, if one exists.
+  scoped_ptr<ConnectionHandlerImpl> connection_handler_;
+
+  // The current login request if a connection attempt is in progress/pending.
+  mcs_proto::LoginRequest login_request_;
+
+  base::WeakPtrFactory<ConnectionFactoryImpl> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ConnectionFactoryImpl);
+};
+
+}  // namespace gcm
+
+#endif  // GOOGLE_APIS_GCM_ENGINE_CONNECTION_FACTORY_IMPL_H_