Refresh policies from DM server periodically

chrome/browser/policy/device_management_policy_provider.h

 // Copyright (c) 2010 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_POLICY_DEVICE_MANAGEMENT_POLICY_PROVIDER_H_
 #define CHROME_BROWSER_POLICY_DEVICE_MANAGEMENT_POLICY_PROVIDER_H_
 #pragma once
 
 #include <string>
 
 #include "base/file_path.h"
 #include "base/scoped_ptr.h"
+#include "base/time.h"
 #include "base/weak_ptr.h"
 #include "chrome/browser/policy/configuration_policy_provider.h"
 #include "chrome/browser/policy/device_management_backend.h"
-#include "chrome/common/notification_details.h"
-#include "chrome/common/notification_observer.h"
-#include "chrome/common/notification_registrar.h"
-#include "chrome/common/notification_source.h"
+#include "chrome/browser/policy/device_token_fetcher.h"
 
 class TokenService;
 
 namespace policy {
 
 class DeviceManagementBackend;
 class DeviceManagementPolicyCache;
-class DeviceTokenFetcher;
 
 // Provides policy fetched from the device management server. With the exception
 // of the Provide method, which can be called on the FILE thread, all public
 // methods must be called on the UI thread.
 class DeviceManagementPolicyProvider
     :  public ConfigurationPolicyProvider,
-       public NotificationObserver,
        public DeviceManagementBackend::DevicePolicyResponseDelegate,
-       public base::SupportsWeakPtr<DeviceManagementPolicyProvider> {
+       public base::SupportsWeakPtr<DeviceManagementPolicyProvider>,
+       public DeviceTokenFetcher::Observer {
  public:
   DeviceManagementPolicyProvider(const PolicyDefinitionList* policy_list,
                                  DeviceManagementBackend* backend,
                                  TokenService* token_service,
                                  const FilePath& storage_dir);
 
   virtual ~DeviceManagementPolicyProvider();
 
   // ConfigurationPolicyProvider implementation:
   virtual bool Provide(ConfigurationPolicyStoreInterface* store);
 
-  // NotificationObserver implementation:
-  virtual void Observe(NotificationType type,
-                       const NotificationSource& source,
-                       const NotificationDetails& details);
-
   // DevicePolicyResponseDelegate implementation:
   virtual void HandlePolicyResponse(
       const em::DevicePolicyResponse& response);
   virtual void OnError(DeviceManagementBackend::ErrorCode code);
 
+  // DeviceTokenFetcher::Observer implementation:
+  void OnTokenSuccess();
+  void OnTokenError();
+  void OnNotManaged();
+
   // True if a policy request has been sent to the device management backend
   // server and no response or error has yet been received.
   bool IsPolicyRequestPending() const { return policy_request_pending_; }
 
   // Tells the provider that the passed in token service reference is about to
   // become invalid.
   void Shutdown();
 
  private:
   class InitializeAfterIOThreadExistsTask;
+  class RefreshTask;
+
+  friend class DeviceManagementPolicyProviderTest;
 
   // Called by constructors to perform shared initialization. Initialization
   // requiring the IOThread must not be performed directly in this method,
   // rather must be deferred until the IOThread is fully initialized. This is
   // the case in InitializeAfterIOThreadExists.
   void Initialize();
 
   // Called by a deferred task posted to the UI thread to complete the portion
   // of initialization that requires the IOThread.
   void InitializeAfterIOThreadExists();
 
   // Sends a request to the device manager backend to fetch policy if one isn't
   // already outstanding.
   void SendPolicyRequest();
 
-  // True if policy must be re-fetched because the cached policy is too old or
-  // its time stamp is invalid.
-  bool IsPolicyStale() const;
+  // Triggers policy refresh, re-requesting device token and policy information
+  // as necessary.
+  void RefreshTaskExecute();
+
+  // Schedules a new RefreshTask.
+  void ScheduleRefreshTask(int64 delay_in_milliseconds);
+
+  // Calculates when the next RefreshTask shall be executed.
+  int64 GetRefreshTaskDelay();
 
   // Provides the URL at which requests are sent to from the device management
   // backend.
   static std::string GetDeviceManagementURL();
 
   // Returns the path to the sub-directory in the user data directory
   // in which device management persistent state is stored.
   static FilePath GetOrCreateDeviceManagementDir(
       const FilePath& user_data_dir);
 
+  // Give unit tests the ability to override timeout settings.
+  void set_policy_refresh_rate_ms(int64 policy_refresh_rate_ms) {
+    policy_refresh_rate_ms_ = policy_refresh_rate_ms;
+  }
+  void set_policy_refresh_max_earlier_ms(int64 policy_refresh_max_earlier_ms) {
+    policy_refresh_max_earlier_ms_ = policy_refresh_max_earlier_ms;
+  }
+  void set_policy_refresh_error_delay_ms(int64 policy_refresh_error_delay_ms) {
+    policy_refresh_error_delay_ms_ = policy_refresh_error_delay_ms;
+  }
+  void set_token_fetch_error_delay_ms(int64 token_fetch_error_delay_ms) {
+    token_fetch_error_delay_ms_ = token_fetch_error_delay_ms;
+  }
+
   scoped_ptr<DeviceManagementBackend> backend_;
-  TokenService* token_service_; // weak
+  TokenService* token_service_;  // weak
   scoped_ptr<DeviceManagementPolicyCache> cache_;
   scoped_refptr<DeviceTokenFetcher> token_fetcher_;
-  NotificationRegistrar registrar_;
+  DeviceTokenFetcher::ObserverRegistrar registrar_;
   FilePath storage_dir_;
   bool policy_request_pending_;
+  bool refresh_task_pending_;
+  int64 policy_refresh_rate_ms_;
+  int64 policy_refresh_max_earlier_ms_;
+  int64 policy_refresh_error_delay_ms_;
+  int64 token_fetch_error_delay_ms_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceManagementPolicyProvider);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_DEVICE_MANAGEMENT_POLICY_PROVIDER_H_