Refactored the ComponentCloudPolicyService.

chrome/browser/policy/cloud/component_cloud_policy_service.h

 // Copyright (c) 2013 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_CLOUD_COMPONENT_CLOUD_POLICY_SERVICE_H_
 #define CHROME_BROWSER_POLICY_CLOUD_COMPONENT_CLOUD_POLICY_SERVICE_H_
 
-#include <set>
-
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/non_thread_safe.h"
+#include "base/timer/timer.h"
 #include "chrome/browser/policy/cloud/cloud_policy_client.h"
-#include "chrome/browser/policy/cloud/cloud_policy_constants.h"
 #include "chrome/browser/policy/cloud/cloud_policy_store.h"
 #include "chrome/browser/policy/policy_bundle.h"
+#include "chrome/browser/policy/schema_registry.h"
 #include "components/policy/core/common/policy_namespace.h"
 
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace net {
 class URLRequestContextGetter;
 }
 
 namespace policy {
 
 class ExternalPolicyDataFetcherBackend;
 class ResourceCache;
 class SchemaMap;
 
 // Manages cloud policy for components.
 //
 // This class takes care of fetching, validating, storing and updating policy
-// for components. The components to manage have to be explicitly registered.
+// for components. The components to manage come from a SchemaRegistry.
 class ComponentCloudPolicyService : public CloudPolicyClient::Observer,
                                     public CloudPolicyStore::Observer,
+                                    public SchemaRegistry::Observer,
                                     public base::NonThreadSafe {
  public:
-  // Key for the ResourceCache where the list of known components is cached.
-  static const char kComponentNamespaceCache[];
-
   class Delegate {
    public:
     virtual ~Delegate();
 
     // Invoked whenever the service has appended new namespaces to fetch to
     // the CloudPolicyClient, signaling that a policy fetch should be done soon.
     virtual void OnComponentCloudPolicyRefreshNeeded() = 0;
 
     // Invoked whenever the policy served by policy() changes. This is also
     // invoked for the first time once the backend is initialized, and
     // is_initialized() becomes true.
     virtual void OnComponentCloudPolicyUpdated() = 0;
   };
 
+  // All of these components must outlive this instance.
+  //
+  // The |delegate| is notified of updates to the downloaded policies, and is
+  // notified whenever a refresh is needed.
+  // |schema_registry| contains the list of components to fetch policy for.
   // |store| is used to get the current DMToken and the username.
   // |cache| is used to load and store local copies of the downloaded policies.
   // Download scheduling, validation and caching of policies are done via the
   // |backend_task_runner|, which must support file I/O. Network I/O is done via
   // the |io_task_runner|.
+  // |client| is updated with the list of components to fetch.
+  // |request_context| is used by the background URLFetchers.
   ComponentCloudPolicyService(
       Delegate* delegate,
+      SchemaRegistry* schema_registry,
       CloudPolicyStore* store,
       scoped_ptr<ResourceCache> cache,
+      CloudPolicyClient* client,
+      scoped_refptr<net::URLRequestContextGetter> request_context,
       scoped_refptr<base::SequencedTaskRunner> backend_task_runner,
       scoped_refptr<base::SequencedTaskRunner> io_task_runner);
   virtual ~ComponentCloudPolicyService();
 
   // Returns true if |domain| is supported by the service.
   static bool SupportsDomain(PolicyDomain domain);
 
   // Returns true if the backend is initialized, and the initial policies and
   // components are being served.
   bool is_initialized() const { return is_initialized_; }
 
   // Returns the current policies for components.
   const PolicyBundle& policy() const { return policy_; }
 
-  // Connects to the cloud policy service using |client|. |client| must outlive
-  // this object. Only cached policies will be served until a |client| is
-  // connected.
-  // |request_context| is used with the URLFetchers triggered by the updater.
-  void Connect(CloudPolicyClient* client,
-               scoped_refptr<net::URLRequestContextGetter> request_context);
-
-  // Disconnects from the cloud policy service and stops trying to download
-  // remote policy data.
-  void Disconnect();
-
-  // |schema_map| contains the schemas for all the components that this
-  // service should load policy for.
-  // This purges unused components from the cache, and starts updating the
-  // components listed in the map.
-  // Unsupported domains in the map are ignored.
-  void OnSchemasUpdated(const scoped_refptr<SchemaMap>& schema_map);
-
   // CloudPolicyClient::Observer implementation:
   virtual void OnPolicyFetched(CloudPolicyClient* client) OVERRIDE;
   virtual void OnRegistrationStateChanged(CloudPolicyClient* client) OVERRIDE;
   virtual void OnClientError(CloudPolicyClient* client) OVERRIDE;
 
   // CloudPolicyStore::Observer implementation:
   virtual void OnStoreLoaded(CloudPolicyStore* store) OVERRIDE;
   virtual void OnStoreError(CloudPolicyStore* store) OVERRIDE;
 
+  // SchemaRegistry::Observer implementation:
+  virtual void OnSchemaRegistryReady() OVERRIDE;
+  virtual void OnSchemaRegistryUpdated(bool has_new_schemas) OVERRIDE;
+
  private:
   class Backend;
-  typedef std::set<PolicyNamespaceKey> PolicyNamespaceKeys;
 
-  void InitializeBackend();
-  void OnBackendInitialized(scoped_ptr<PolicyNamespaceKeys> initial_keys,
-                            scoped_ptr<PolicyBundle> initial_policy);
-  void InitializeClient();
+  void InitializeIfReady();
+  void OnBackendInitialized(scoped_ptr<PolicyBundle> initial_policy);
+  void SetCurrentSchema(const scoped_refptr<SchemaMap>& new_schema_map,
+                        bool send_to_backend);
   void OnPolicyUpdated(scoped_ptr<PolicyBundle> policy);
 
-  void SetCredentialsAndReloadClient();
-  bool UpdateClientNamespaces(const PolicyNamespaceKeys& old_keys,
-                              const PolicyNamespaceKeys& new_keys);
-  void AddNamespacesToFetch(const PolicyNamespaceKeys& keys);
-  void RemoveNamespacesToFetch(const PolicyNamespaceKeys& keys);
-
   Delegate* delegate_;
-
+  SchemaRegistry* schema_registry_;
+  CloudPolicyStore* store_;
+  CloudPolicyClient* client_;
+  scoped_refptr<net::URLRequestContextGetter> request_context_;
   scoped_refptr<base::SequencedTaskRunner> backend_task_runner_;
   scoped_refptr<base::SequencedTaskRunner> io_task_runner_;
 
   // The |external_policy_data_fetcher_backend_| handles network I/O for the
   // |backend_| because URLRequestContextGetter and URLFetchers cannot be
   // referenced from background threads. It is instantiated on the thread |this|
   // runs on but after that, must only be accessed and eventually destroyed via
   // the |io_task_runner_|.
   scoped_ptr<ExternalPolicyDataFetcherBackend>
       external_policy_data_fetcher_backend_;
 
   // The |backend_| handles all download scheduling, validation and caching of
   // policies. It is instantiated on the thread |this| runs on but after that,
   // must only be accessed and eventually destroyed via the
   // |backend_task_runner_|.
   scoped_ptr<Backend> backend_;
 
-  CloudPolicyClient* client_;
-  CloudPolicyStore* store_;
-
-  // The currently registered components for each policy domain.
-  PolicyNamespaceKeys keys_;
+  // The currently registered components for each policy domain. Used to
+  // determine which components changed when a new SchemaMap becomes
+  // available.
+  scoped_refptr<SchemaMap> current_schema_map_;
 
   // Contains all the current policies for components.
   PolicyBundle policy_;
 
+  // Used to delay changes triggered by updates to the SchemaRegistry. See
+  // the implementation of OnSchemaRegistryUpdated() for details.
+  base::Timer schema_update_timer_;
+
   bool is_initialized_;
-  bool has_initial_keys_;
+  bool has_credentials_;
   base::WeakPtrFactory<ComponentCloudPolicyService> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ComponentCloudPolicyService);
 };
 
 }  // namespace policy
 
 #endif  // CHROME_BROWSER_POLICY_CLOUD_COMPONENT_CLOUD_POLICY_SERVICE_H_