Implement Bus and ObjectProxy classes for our D-Bus library.

dbus/object_proxy.h

+// 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 DBUS_OBJECT_PROXY_H_
+#define DBUS_OBJECT_PROXY_H_
+#pragma once
+
+#include <string>
+#include <vector>
+#include <dbus/dbus.h>
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+
+class MessageLoop;
+
+namespace dbus {
+
+class Bus;
+class MethodCall;
+class Response;
+
+// ObjectProxy is used to communicate with remote objects, mainly for
+// calling methods of these objects.
+//
+// ObjectProxy is a ref counted object, to ensure that |this| of the
+// object is is alive when callbacks referencing |this| are called.
+class ObjectProxy : public base::RefCountedThreadSafe<ObjectProxy> {
+ public:
+  // Client code should use Bus::GetObjectProxy() instead of this
+  // constructor.
+  ObjectProxy(Bus* bus,
+              const std::string& service_name,
+              const std::string& object_path);
+
+  // Special timeout constants.
+  //
+  // The constants correspond to DBUS_TIMEOUT_USE_DEFAULT and
+  // DBUS_TIMEOUT_INFINITE. Here we use literal numbers instead of these
+  // macros as these aren't defined with D-Bus earlier than 1.4.12.
+  enum {
+    TIMEOUT_USE_DEFAULT = -1,
+    TIMEOUT_INFINITE = 0x7fffffff,
+  };
+
+  // Called when the response is returned. Used for CallMethod().
+  typedef base::Callback<void(Response*)> ResponseCallback;
+
+  // Calls the method of the remote object and blocks until the response
+  // is returned.
+  //
+  // BLOCKING CALL.
+  virtual bool CallMethodAndBlock(MethodCall* method_call,
+                                  int timeout_ms,
+                                  Response* response);
+
+  // Requests to call the method of the remote object.
+  //
+  // |callback| will be called in the origin thread, once the method call
+  // is complete. As it's called in the origin thread, |callback| can
+  // safely reference objects in the origin thread (i.e. UI thread in most
+  // cases).
+  //
+  // If the method call is successful, a pointer to Response object will
+  // be passed to the callback. If unsuccessful, NULL will be passed to
+  // the callback.
+  //
+  // Must be called in the origin thread.
+  virtual void CallMethod(MethodCall* method_call,
+                          int timeout_ms,
+                          ResponseCallback callback);
+
+ private:
+  friend class base::RefCountedThreadSafe<ObjectProxy>;
+  virtual ~ObjectProxy();
+
+  // Struct of data we'll be passing from StartAsyncMethodCall() to
+  // OnPendingCallIsCompleteThunk().
+  struct OnPendingCallIsCompleteData {
+    OnPendingCallIsCompleteData(ObjectProxy* in_object_proxy,
+                                ResponseCallback in_response_callback);
+    ~OnPendingCallIsCompleteData();
+
+    ObjectProxy* object_proxy;
+    ResponseCallback response_callback;
+  };
+
+  // Starts the async method call. This is a helper function to implement
+  // CallMethod().
+  void StartAsyncMethodCall(int timeout_ms,
+                            void* request_message,
+                            ResponseCallback response_callback);
+
+  // Called when the pending call is complete.
+  void OnPendingCallIsComplete(DBusPendingCall* pending_call,
+                               ResponseCallback response_callback);
+
+  // Runs the response callback with the given response object.
+  void RunResponseCallback(ResponseCallback response_callback,
+                           Response* response);
+
+  // Redirects the function call to OnPendingCallIsComplete().
+  static void OnPendingCallIsCompleteThunk(DBusPendingCall* pending_call,
+                                           void* user_data);
+
+  Bus* bus_;
+  std::string service_name_;
+  std::string object_path_;
+
+  DISALLOW_COPY_AND_ASSIGN(ObjectProxy);
+};
+
+}  // namespace dbus
+
+#endif  // DBUS_OBJECT_PROXY_H_