| // Copyright (c) 2012 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 IPC_MESSAGE_ROUTER_H_ |
| #define IPC_MESSAGE_ROUTER_H_ |
| |
| #include <stdint.h> |
| |
| #include "base/component_export.h" |
| #include "base/containers/id_map.h" |
| #include "ipc/ipc_listener.h" |
| #include "ipc/ipc_sender.h" |
| |
| // The MessageRouter handles all incoming messages sent to it by routing them |
| // to the correct listener. Routing is based on the Message's routing ID. |
| // Since routing IDs are typically assigned asynchronously by the browser |
| // process, the MessageRouter has the notion of pending IDs for listeners that |
| // have not yet been assigned a routing ID. |
| // |
| // When a message arrives, the routing ID is used to index the set of routes to |
| // find a listener. If a listener is found, then the message is passed to it. |
| // Otherwise, the message is ignored if its routing ID is not equal to |
| // MSG_ROUTING_CONTROL. |
| // |
| // The MessageRouter supports the IPC::Sender interface for outgoing messages, |
| // but does not define a meaningful implementation of it. The subclass of |
| // MessageRouter is intended to provide that if appropriate. |
| // |
| // The MessageRouter can be used as a concrete class provided its Send method |
| // is not called and it does not receive any control messages. |
| |
| namespace IPC { |
| |
| class COMPONENT_EXPORT(IPC) MessageRouter : public Listener, public Sender { |
| public: |
| MessageRouter(); |
| |
| MessageRouter(const MessageRouter&) = delete; |
| MessageRouter& operator=(const MessageRouter&) = delete; |
| |
| ~MessageRouter() override; |
| |
| // Implemented by subclasses to handle control messages |
| virtual bool OnControlMessageReceived(const Message& msg); |
| |
| // Listener implementation: |
| bool OnMessageReceived(const Message& msg) override; |
| |
| // Like OnMessageReceived, except it only handles routed messages. Returns |
| // true if the message was dispatched, or false if there was no listener for |
| // that route id. |
| virtual bool RouteMessage(const Message& msg); |
| |
| // Sender implementation: |
| bool Send(Message* msg) override; |
| |
| // Called to add a listener for a particular message routing ID. |
| // Returns true if succeeded. |
| bool AddRoute(int32_t routing_id, Listener* listener); |
| |
| // Called to remove a listener for a particular message routing ID. |
| void RemoveRoute(int32_t routing_id); |
| |
| // Returns the Listener associated with |routing_id|. |
| Listener* GetRoute(int32_t routing_id); |
| |
| private: |
| // A list of all listeners with assigned routing IDs. |
| base::IDMap<Listener*> routes_; |
| }; |
| |
| } // namespace IPC |
| |
| #endif // IPC_MESSAGE_ROUTER_H_ |