chromeos: Implement the new D-Bus client for update engine.

chrome/browser/chromeos/dbus/update_engine_client.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 CHROME_BROWSER_CHROMEOS_DBUS_UPDATE_ENGINE_CLIENT_H_
+#define CHROME_BROWSER_CHROMEOS_DBUS_UPDATE_ENGINE_CLIENT_H_
+
+#include "base/callback.h"
+#include "base/observer_list.h"
+
+#include <string>
+
+namespace dbus {
+class Bus;
+}  // namespace
+
+namespace chromeos {
+
+// UpdateEngineClient is used to communicate with the update engine.
+class UpdateEngineClient {
+ public:
+  // Edges for state machine
+  //    IDLE->CHECKING_FOR_UPDATE
+  //    CHECKING_FOR_UPDATE->IDLE
+  //    CHECKING_FOR_UPDATE->UPDATE_AVAILABLE
+  //    ...
+  //    FINALIZING->UPDATE_NEED_REBOOT
+  // Any state can transition to REPORTING_ERROR_EVENT and then on to IDLE.
+  enum UpdateStatusOperation {
+    UPDATE_STATUS_ERROR = -1,
+    UPDATE_STATUS_IDLE = 0,
+    UPDATE_STATUS_CHECKING_FOR_UPDATE,
+    UPDATE_STATUS_UPDATE_AVAILABLE,
+    UPDATE_STATUS_DOWNLOADING,
+    UPDATE_STATUS_VERIFYING,
+    UPDATE_STATUS_FINALIZING,
+    UPDATE_STATUS_UPDATED_NEED_REBOOT,
+    UPDATE_STATUS_REPORTING_ERROR_EVENT
+  };
+
+  // The status of the ongoing update attempt.
+  struct Status {
+    Status() : status(UPDATE_STATUS_IDLE),
+               download_progress(0.0),
+               last_checked_time(0),
+               new_size(0) {
+    }
+
+    UpdateStatusOperation status;
+    double download_progress;   // 0.0 - 1.0
+    int64_t last_checked_time;  // As reported by std::time().
+    std::string new_version;
+    int64_t new_size;           // Valid during DOWNLOADING, in bytes.
+  };
+
+  // The result code used for RequestUpdateCheck().
+  enum UpdateCheckResult {
+    UPDATE_RESULT_SUCCESS,
+    UPDATE_RESULT_FAILED,
+  };
+
+  // Interface for observing changes from the update engine.
+  class Observer {
+   public:
+    // Called when the status is updated.
+    virtual void UpdateStatusChanged(const Status& status) {}
+  };
+
+  virtual ~UpdateEngineClient();
+
+  // Adds and removes the observer.
+  virtual void AddObserver(Observer* observer) = 0;
+  virtual void RemoveObserver(Observer* observer) = 0;
+  // Returns true if this object has the given observer.
+  virtual bool HasObserver(Observer* observer) = 0;
+
+  // Called once RequestUpdateCheck() is complete. Takes one parameter:
+  // - UpdateCheckResult: the result of the update check.
+  typedef base::Callback<void(UpdateCheckResult)> UpdateCheckCallback;
+
+  // Requests an update check and calls |callback| when completed.
+  virtual void RequestUpdateCheck(UpdateCheckCallback callback) = 0;
+
+  // Reboots if update has been performed.
+  virtual void RebootAfterUpdate() = 0;
+
+  // Requests to set the release track (channel). |track| should look like
+  // "beta-channel" or "dev-channel".
+  virtual void SetReleaseTrack(const std::string& track) = 0;
+
+  // Called once GetReleaseTrack() is complete. Takes one parameter;
+  // - string: the release track name like "beta-channel".
+  typedef base::Callback<void(const std::string&)> GetReleaseTrackCallback;
+
+  // Requests to get the release track and calls |callback| with the
+  // release track (channel). On error, calls |callback| with an empty
+  // string.
+  virtual void GetReleaseTrack(GetReleaseTrackCallback callback) = 0;
+
+  // Returns the last status the object received from the update engine.
+  //
+  // Ideally, the D-Bus client should be state-less, but there are clients
+  // that need this information.
+  virtual Status GetLastStatus() = 0;
+
+  // Returns an empty UpdateCheckCallback that does nothing.
+  static UpdateCheckCallback EmptyUpdateCheckCallback();
+
+  // Creates the instance.
+  static UpdateEngineClient* Create(dbus::Bus* bus);
+
+ protected:
+  // Create() should be used instead.
+  UpdateEngineClient();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(UpdateEngineClient);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_DBUS_UPDATE_ENGINE_CLIENT_H_