[Blimp Net] Add EngineAuthHandler.

blimp/net/engine_auth_handler.h

+// Copyright 2015 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 BLIMP_NET_ENGINE_AUTH_HANDLER_H_
+#define BLIMP_NET_ENGINE_AUTH_HANDLER_H_
+
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/timer/timer.h"
+#include "blimp/net/blimp_message_processor.h"
+#include "blimp/net/blimp_net_export.h"
+#include "blimp/net/connection_error_observer.h"
+#include "blimp/net/connection_handler.h"
+#include "net/base/completion_callback.h"
+
+namespace blimp {
+
+class BlimpConnection;
+class BlimpMessage;
+
+// Authenticates connections and hand them over to |connection_handler|
+// if it is authenticated.
+class BLIMP_NET_EXPORT EngineAuthHandler : public ConnectionHandler {
+ public:
+  // Caller is responsible for ensuring that |connection_handler| outlives
+  // |this|.
+  explicit EngineAuthHandler(ConnectionHandler* connection_handler);
+
+  ~EngineAuthHandler() override;
+
+  // ConnectionHandler implementation.
+  void HandleConnection(scoped_ptr<BlimpConnection> connection) override;
+
+ private:
+  using AuthCallback =
+      base::Callback<void(scoped_ptr<BlimpConnection> connection,
+                          bool authenticated)>;
+
+  // Authenticates one connection. |auth_callback| is invoked when
+  //   * the connection is authenticated.
+  //   * the connection gets into error state.
+  //   * timeout on waiting for auth message.
+  class Authenticator : public ConnectionErrorObserver,
+                        public BlimpMessageProcessor {
+   public:
+    explicit Authenticator(scoped_ptr<BlimpConnection> connection);
+    ~Authenticator() override;
+
+    void Start(const AuthCallback& auth_callback);
+
+   private:
+    void InvokeAuthCallback(bool authenticated);
+
+    // Invoked on timeout while waiting for auth message.
+    void FailAuthetication();
+
+    // ConnectionErrorObserver implementation.
+    // Used to implement reconnection logic on unexpected disconnections.
+    void OnConnectionError(int error) override;
+
+    // BlimpMessageProcessor implementation.
+    void ProcessMessage(scoped_ptr<BlimpMessage> message,
+                        const net::CompletionCallback& callback) override;
+
+    // The connection to be authenticated.
+    scoped_ptr<BlimpConnection> connection_;

[Kevin M, 2015/12/03 23:12:05]

Can you make this a const?

[haibinlu, 2015/12/03 23:42:21]

can not. autheticator will give the ownership of the connection back in the auth
callback so that EngineAuthHandler can hand it over to the next connection
handler.

+
+    // Callback for authentication result;
+    AuthCallback auth_callback_;
+
+    // A timer to fail authentication on timeout.
+    base::OneShotTimer timer_;
+
+    DISALLOW_COPY_AND_ASSIGN(Authenticator);
+  };
+
+  // Callback when |authenticator| has the authentication result.
+  void OnAuthResult(Authenticator* authenticator,
+                    scoped_ptr<BlimpConnection> connection,
+                    bool authenticated);
+
+  void RemovePendingAuthenticator(Authenticator* authenticator);
+
+  // Handler for authenticated connections.
+  ConnectionHandler* connection_handler_;
+
+  // Pending authentications. An authenticator is removed from this list once
+  // it has the authentication result.
+  std::vector<scoped_ptr<Authenticator>> pending_auths_;
+
+  DISALLOW_COPY_AND_ASSIGN(EngineAuthHandler);
+};
+
+}  // namespace blimp
+
+#endif  // BLIMP_NET_ENGINE_AUTH_HANDLER_H_