// Copyright (c) 2011 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 CHROME_BROWSER_EXTENSIONS_EXTENSION_MESSAGE_SERVICE_H_ #define CHROME_BROWSER_EXTENSIONS_EXTENSION_MESSAGE_SERVICE_H_ #pragma once #include <map> #include <set> #include <string> #include "base/memory/ref_counted.h" #include "content/common/notification_observer.h" #include "content/common/notification_registrar.h" #include "ipc/ipc_message.h" class GURL; class Profile; class TabContents; // This class manages message and event passing between renderer processes. // It maintains a list of processes that are listening to events and a set of // open channels. // // Messaging works this way: // - An extension-owned script context (like a toolstrip or a content script) // adds an event listener to the "onConnect" event. // - Another context calls "extension.connect()" to open a channel to the // extension process, or an extension context calls "tabs.connect(tabId)" to // open a channel to the content scripts for the given tab. The EMS notifies // the target process/tab, which then calls the onConnect event in every // context owned by the connecting extension in that process/tab. // - Once the channel is established, either side can call postMessage to send // a message to the opposite side of the channel, which may have multiple // listeners. // // Terminology: // channel: connection between two ports // port: an IPC::Message::Sender interface and an optional routing_id (in the // case that the port is a tab). The Sender is usually either a // RenderProcessHost or a RenderViewHost. // TODO(mpcomplete): Remove refcounting and make Profile the sole owner of this // class. Then we can get rid of ProfileDestroyed(). class ExtensionMessageService : public base::RefCounted<ExtensionMessageService>, public NotificationObserver { public: // A messaging channel. Note that the opening port can be the same as the // receiver, if an extension toolstrip wants to talk to its tab (for example). struct MessageChannel; struct MessagePort; // Javascript function name constants. static const char kDispatchOnConnect[]; static const char kDispatchOnDisconnect[]; static const char kDispatchOnMessage[]; // Allocates a pair of port ids. // NOTE: this can be called from any thread. static void AllocatePortIdPair(int* port1, int* port2); explicit ExtensionMessageService(Profile* profile); // Notification that our owning profile is going away. void DestroyingProfile(); // Given an extension's ID, opens a channel between the given renderer "port" // and every listening context owned by that extension. |channel_name| is // an optional identifier for use by extension developers. void OpenChannelToExtension( int source_process_id, int source_routing_id, int receiver_port_id, const std::string& source_extension_id, const std::string& target_extension_id, const std::string& channel_name); // Same as above, but opens a channel to the tab with the given ID. Messages // are restricted to that tab, so if there are multiple tabs in that process, // only the targeted tab will receive messages. void OpenChannelToTab( int source_process_id, int source_routing_id, int receiver_port_id, int tab_id, const std::string& extension_id, const std::string& channel_name); // Given an extension ID, opens a channel between the given // automation "port" or DevTools service and that extension. the // channel will be open to the extension process hosting the // background page and tool strip. // // Returns a port ID to be used for posting messages between the // processes, or -1 if the extension doesn't exist. int OpenSpecialChannelToExtension( const std::string& extension_id, const std::string& channel_name, const std::string& tab_json, IPC::Message::Sender* source); // Given an extension ID, opens a channel between the given DevTools // service and the content script for that extension running in the // designated tab. // // Returns a port ID identifying the DevTools end of the channel, to // be used for posting messages. May return -1 on failure, although // the code doesn't detect whether the extension actually exists. int OpenSpecialChannelToTab( const std::string& extension_id, const std::string& channel_name, TabContents* target_tab_contents, IPC::Message::Sender* source); // Closes the message channel associated with the given port, and notifies // the other side. void CloseChannel(int port_id); // Sends a message from a renderer to the given port. void PostMessageFromRenderer(int port_id, const std::string& message); private: friend class base::RefCounted<ExtensionMessageService>; friend class MockExtensionMessageService; // A map of channel ID to its channel object. typedef std::map<int, MessageChannel*> MessageChannelMap; virtual ~ExtensionMessageService(); // Common among Open(Special)Channel* variants. bool OpenChannelImpl( IPC::Message::Sender* source, const std::string& tab_json, const MessagePort& receiver, int receiver_port_id, const std::string& source_extension_id, const std::string& target_extension_id, const std::string& channel_name); void CloseChannelImpl(MessageChannelMap::iterator channel_iter, int port_id, bool notify_other_port); // NotificationObserver interface. virtual void Observe(NotificationType type, const NotificationSource& source, const NotificationDetails& details); // An IPC sender that might be in our list of channels has closed. void OnSenderClosed(IPC::Message::Sender* sender); Profile* profile_; NotificationRegistrar registrar_; MessageChannelMap channels_; DISALLOW_COPY_AND_ASSIGN(ExtensionMessageService); }; #endif // CHROME_BROWSER_EXTENSIONS_EXTENSION_MESSAGE_SERVICE_H_