AU: Implement exponential back off for 500 and 503 HTTP response codes.

update_attempter.h

 // Copyright (c) 2010 The Chromium OS 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 CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_H__
 
 #include <time.h>
 
 #include <tr1/memory>
 #include <string>
 #include <vector>
 
 #include <glib.h>
 
 #include "base/time.h"
 #include "update_engine/action_processor.h"
 #include "update_engine/download_action.h"
 #include "update_engine/omaha_request_params.h"
 #include "update_engine/omaha_response_handler_action.h"
 
 class MetricsLibraryInterface;
 struct UpdateEngineService;
 
 namespace chromeos_update_engine {
 
-namespace utils {
-enum ProcessPriority;
-};
+class UpdateCheckScheduler;
 
 extern const char* kUpdateCompletedMarker;
 
 enum UpdateStatus {
   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,
 };
 
 const char* UpdateStatusToString(UpdateStatus status);
 
 class UpdateAttempter : public ActionProcessorDelegate,
                         public DownloadActionDelegate {
  public:
   UpdateAttempter(PrefsInterface* prefs, MetricsLibraryInterface* metrics_lib);
-  ~UpdateAttempter();
+  virtual ~UpdateAttempter();
 
   // Checks for update and, if a newer version is available, attempts
   // to update the system. Non-empty |in_app_version| or
   // |in_update_url| prevents automatic detection of the parameter.
-  void Update(const std::string& app_version, const std::string& omaha_url);
+  virtual void Update(const std::string& app_version,
+                      const std::string& omaha_url);
 
   // ActionProcessorDelegate methods:
   void ProcessingDone(const ActionProcessor* processor, ActionExitCode code);
   void ProcessingStopped(const ActionProcessor* processor);
   void ActionCompleted(ActionProcessor* processor,
                        AbstractAction* action,
                        ActionExitCode code);
 
   // Stop updating. An attempt will be made to record status to the disk
   // so that updates can be resumed later.
   void Terminate();
 
   // Try to resume from a previously Terminate()d update.
   void ResumeUpdating();
 
   // Returns the current status in the out params. Returns true on success.
   bool GetStatus(int64_t* last_checked_time,
                  double* progress,
                  std::string* current_operation,
                  std::string* new_version,
                  int64_t* new_size);
 
+  UpdateStatus status() const { return status_; }
+
+  int http_response_code() const { return http_response_code_; }
+  void set_http_response_code(int code) { http_response_code_ = code; }
+
   void set_dbus_service(struct UpdateEngineService* dbus_service) {
     dbus_service_ = dbus_service;
   }
 
+  UpdateCheckScheduler* update_check_scheduler() const {
+    return update_check_scheduler_;
+  }
+  void set_update_check_scheduler(UpdateCheckScheduler* scheduler) {
+    update_check_scheduler_ = scheduler;
+  }
+
   // This is the D-Bus service entry point for going through an
   // update. If the current status is idle invokes Update.
   void CheckForUpdate(const std::string& app_version,
                       const std::string& omaha_url);
 
   // Initiates a reboot if the current state is
   // UPDATED_NEED_REBOOT. Returns true on sucess, false otherwise.
   bool RebootIfNeeded();
 
-  // Kicks off the periodic update checks, if necessary.
-  void InitiatePeriodicUpdateChecks();
-
-  // Schedules the next periodic update check |seconds| from now. Note
-  // that the actual timeout will be fuzzed.
-  void SchedulePeriodicUpdateCheck(int seconds);
-
   // DownloadActionDelegate methods
   void SetDownloadStatus(bool active);
   void BytesReceived(uint64_t bytes_received, uint64_t total);
 
  private:
   // Sets the status to the given status and notifies a status update
   // over dbus.
   void SetStatusAndNotify(UpdateStatus status);
 
   // Creates an error event object in |error_event_| to be included in
@@ skipping 40 matching lines @@
 
   // pointer to the OmahaResponseHandlerAction in the actions_ vector;
   std::tr1::shared_ptr<OmahaResponseHandlerAction> response_handler_action_;
 
   // Pointer to the preferences store interface.
   PrefsInterface* prefs_;
 
   // Pointer to the UMA metrics collection library.
   MetricsLibraryInterface* metrics_lib_;
 
+  // The current UpdateCheckScheduler to notify of state transitions.
+  UpdateCheckScheduler* update_check_scheduler_;
+
   // Pending error event, if any.
   scoped_ptr<OmahaEvent> error_event_;
 
+  int http_response_code_;
+
   // Current process priority.
   utils::ProcessPriority priority_;
 
   // The process priority management timeout source.
   GSource* manage_priority_source_;
 
   // Set to true if an update download is active (and BytesReceived
   // will be called), set to false otherwise.
   bool download_active_;
 
   // For status:
   UpdateStatus status_;
   double download_progress_;
   int64_t last_checked_time_;
   std::string new_version_;
   int64_t new_size_;
 
   // Device paramaters common to all Omaha requests.
   OmahaRequestDeviceParams omaha_request_params_;
 
   DISALLOW_COPY_AND_ASSIGN(UpdateAttempter);
 };
 
 }  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_H__