Remote Assistance on Chrome OS Part III - NativeMessageHost

chrome/browser/extensions/api/messaging/native_message_process_host.h

 // 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 CHROME_BROWSER_EXTENSIONS_API_MESSAGING_NATIVE_MESSAGE_PROCESS_HOST_H_
 #define CHROME_BROWSER_EXTENSIONS_API_MESSAGING_NATIVE_MESSAGE_PROCESS_HOST_H_
 
 #include <queue>
 #include <string>
 
 #include "base/files/file.h"
 #include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/process/process.h"
 #include "chrome/browser/extensions/api/messaging/native_process_launcher.h"
+#include "extensions/browser/api/messaging/native_message_host.h"
 #include "ui/gfx/native_widget_types.h"
 
-class PrefService;
-
 namespace net {
 
 class DrainableIOBuffer;
 class FileStream;
 class IOBuffer;
 class IOBufferWithSize;
 
 }  // namespace net
 
 namespace extensions {
 
 // Manages the native side of a connection between an extension and a native
 // process.
 //
 // This class must only be created, called, and deleted on the IO thread.
 // Public methods typically accept callbacks which will be invoked on the UI
 // thread.
-class NativeMessageProcessHost
+class NativeMessageProcessHost :
 #if defined(OS_POSIX)
-    : public base::MessageLoopForIO::Watcher
+    public base::MessageLoopForIO::Watcher,
 #endif  // !defined(OS_POSIX)
-{
+    public NativeMessageHost {
  public:
-  // Interface for the object that receives messages from the native process.
-  class Client {
-   public:
-    virtual ~Client() {}
-    // Called on the UI thread.
-    virtual void PostMessageFromNativeProcess(int port_id,
-                                              const std::string& message) = 0;
-    virtual void CloseChannel(int port_id,
-                              const std::string& error_message) = 0;
-  };
-
-  // Result returned from IsHostAllowed().
-  enum PolicyPermission {
-    DISALLOW,           // The host is not allowed.
-    ALLOW_SYSTEM_ONLY,  // Allowed only when installed on system level.
-    ALLOW_ALL,          // Allowed when installed on system or user level.
-  };
-
   virtual ~NativeMessageProcessHost();
 
-  // Returns policy permissions for the host with the specified name.
-  static PolicyPermission IsHostAllowed(const PrefService* pref_service,
-                                        const std::string& native_host_name);
-
-  static scoped_ptr<NativeMessageProcessHost> Create(
-      gfx::NativeView native_view,
-      base::WeakPtr<Client> weak_client_ui,
+  // Create using specified |launcher|. Used in tests.
+  static scoped_ptr<NativeMessageHost> CreateWithLauncher(
       const std::string& source_extension_id,
       const std::string& native_host_name,
-      int destination_port,
-      bool allow_user_level);
-
-  // Create using specified |launcher|. Used in tests.
-  static scoped_ptr<NativeMessageProcessHost> CreateWithLauncher(
-      base::WeakPtr<Client> weak_client_ui,
-      const std::string& source_extension_id,
-      const std::string& native_host_name,
-      int destination_port,
       scoped_ptr<NativeProcessLauncher> launcher);
 
-  // Send a message with the specified payload.
-  void Send(const std::string& json);
+  // extensions::NativeMessageHost implementation.
+  virtual void OnMessage(const std::string& message) OVERRIDE;
+  virtual void Start(Client* client) OVERRIDE;
+  virtual scoped_refptr<base::SingleThreadTaskRunner> task_runner()
+      const OVERRIDE;
 
 #if defined(OS_POSIX)
   // MessageLoopForIO::Watcher interface
   virtual void OnFileCanReadWithoutBlocking(int fd) override;
   virtual void OnFileCanWriteWithoutBlocking(int fd) override;
 #endif  // !defined(OS_POSIX)
 
   // Try and read a single message from |read_file_|. This should only be called
   // in unittests when you know there is data in the file.
   void ReadNowForTesting();
 
  private:
-  NativeMessageProcessHost(base::WeakPtr<Client> weak_client_ui,
-                           const std::string& source_extension_id,
+  NativeMessageProcessHost(const std::string& source_extension_id,
                            const std::string& native_host_name,
-                           int destination_port,
                            scoped_ptr<NativeProcessLauncher> launcher);
 
   // Starts the host process.
   void LaunchHostProcess();
 
   // Callback for NativeProcessLauncher::Launch().
   void OnHostProcessLaunched(NativeProcessLauncher::LaunchResult result,
                              base::ProcessHandle process_handle,
                              base::File read_file,
                              base::File write_file);
 
   // Helper methods to read incoming messages.
   void WaitRead();
   void DoRead();
   void OnRead(int result);
   void HandleReadResult(int result);
   void ProcessIncomingData(const char* data, int data_size);
 
   // Helper methods to write outgoing messages.
   void DoWrite();
   void HandleWriteResult(int result);
   void OnWritten(int result);
 
   // Closes the connection. Called from OnError() and destructor.
   void Close(const std::string& error_message);
 
   // The Client messages will be posted to. Should only be accessed from the
   // UI thread.
-  base::WeakPtr<Client> weak_client_ui_;
+  Client* client_;
 
   // ID of the calling extension.
   std::string source_extension_id_;
 
   // Name of the native messaging host.
   std::string native_host_name_;
 
-  // The id of the port on the other side of this connection. This is passed to
-  // |weak_client_ui_| when posting messages.
-  int destination_port_;
-
   // Launcher used to launch the native process.
   scoped_ptr<NativeProcessLauncher> launcher_;
 
   // Set to true after the native messaging connection has been stopped, e.g.
   // due to an error.
   bool closed_;
 
   base::ProcessHandle process_handle_;
 
   // Input stream reader.
@@ skipping 18 matching lines @@
 
   // Queue for outgoing messages.
   std::queue<scoped_refptr<net::IOBufferWithSize> > write_queue_;
 
   // The message that's currently being sent.
   scoped_refptr<net::DrainableIOBuffer> current_write_buffer_;
 
   // Set to true when a write is pending.
   bool write_pending_;
 
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
   DISALLOW_COPY_AND_ASSIGN(NativeMessageProcessHost);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_MESSAGING_NATIVE_MESSAGE_PROCESS_HOST_H_