Refactor RulesRegistryWithCache to RulesRegistry

chrome/browser/extensions/api/declarative/rules_registry_with_cache.h

-// Copyright (c) 2012 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_EXTENSIONS_API_DECLARATIVE_RULES_REGISTRY_WITH_CACHE_H__
-#define CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_RULES_REGISTRY_WITH_CACHE_H__
-
-#include "chrome/browser/extensions/api/declarative/rules_registry.h"
-
-#include <map>
-#include <set>
-#include <string>
-#include <vector>
-
-#include "base/compiler_specific.h"
-#include "base/callback_forward.h"
-#include "base/gtest_prod_util.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-#include "extensions/common/one_shot_event.h"
-
-class Profile;
-
-namespace base {
-class Value;
-}  // namespace base
-
-namespace extensions {
-
-// A base class for RulesRegistries that takes care of storing the
-// RulesRegistry::Rule objects. It contains all the methods that need to run on
-// the registry thread; methods that need to run on the UI thread are separated
-// in the RuleStorageOnUI object.
-class RulesRegistryWithCache : public RulesRegistry {
- public:
-  // RuleStorageOnUI implements the part of the RulesRegistry which works on
-  // the UI thread. It should only be used on the UI thread. It gets created
-  // by the RulesRegistry, but right after that it changes owner to the
-  // RulesRegistryService, and is deleted by the service.
-  // If |log_storage_init_delay| is set, the delay caused by loading and
-  // registering rules on initialization will be logged with UMA.
-  class RuleStorageOnUI : public content::NotificationObserver {
-   public:
-    // |event_name| identifies the JavaScript event for which rules are
-    // registered. For example, for WebRequestRulesRegistry the name is
-    // "declarativeWebRequest.onRequest".
-    RuleStorageOnUI(Profile* profile,
-                    const std::string& event_name,
-                    content::BrowserThread::ID rules_registry_thread,
-                    base::WeakPtr<RulesRegistryWithCache> registry,
-                    bool log_storage_init_delay);
-
-    virtual ~RuleStorageOnUI();
-
-    // Returns a key for the state store. The associated preference is a boolean
-    // indicating whether there are some declarative rules stored in the rule
-    // store.
-    static std::string GetRulesStoredKey(const std::string& event_name,
-                                         bool incognito);
-
-    // Initialize the storage functionality.
-    void Init();
-
-    void WriteToStorage(const std::string& extension_id,
-                        scoped_ptr<base::Value> value);
-
-    base::WeakPtr<RuleStorageOnUI> GetWeakPtr() {
-      DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-      return weak_ptr_factory_.GetWeakPtr();
-    }
-
-   private:
-    FRIEND_TEST_ALL_PREFIXES(RulesRegistryWithCacheTest,
-                             DeclarativeRulesStored);
-    FRIEND_TEST_ALL_PREFIXES(RulesRegistryWithCacheTest,
-                             RulesStoredFlagMultipleRegistries);
-
-    static const char kRulesStoredKey[];
-
-    // NotificationObserver
-    virtual void Observe(int type,
-                         const content::NotificationSource& source,
-                         const content::NotificationDetails& details) OVERRIDE;
-
-    // Check if we are done reading all data from storage on startup, and notify
-    // the RulesRegistry on its thread if so. The notification is delivered
-    // exactly once.
-    void CheckIfReady();
-
-    // Schedules retrieving rules for already loaded extensions where
-    // appropriate.
-    void ReadRulesForInstalledExtensions();
-
-    // Read/write a list of rules serialized to Values.
-    void ReadFromStorage(const std::string& extension_id);
-    void ReadFromStorageCallback(const std::string& extension_id,
-                                 scoped_ptr<base::Value> value);
-
-    // Check the preferences whether the extension with |extension_id| has some
-    // rules stored on disk. If this information is not in the preferences, true
-    // is returned as a safe default value.
-    bool GetDeclarativeRulesStored(const std::string& extension_id) const;
-    // Modify the preference to |rules_stored|.
-    void SetDeclarativeRulesStored(const std::string& extension_id,
-                                   bool rules_stored);
-
-    content::NotificationRegistrar registrar_;
-
-    Profile* profile_;
-
-    // The key under which rules are stored.
-    const std::string storage_key_;
-
-    // The key under which we store whether the rules have been stored.
-    const std::string rules_stored_key_;
-
-    // A set of extension IDs that have rules we are reading from storage.
-    std::set<std::string> waiting_for_extensions_;
-
-    // We measure the time spent on loading rules on init. The result is logged
-    // with UMA once per each RuleStorageOnUI instance, unless in Incognito.
-    base::Time storage_init_time_;
-    bool log_storage_init_delay_;
-
-    // Weak pointer to post tasks to the owning rules registry.
-    const base::WeakPtr<RulesRegistryWithCache> registry_;
-
-    // The thread |registry_| lives on.
-    const content::BrowserThread::ID rules_registry_thread_;
-
-    // We notified the RulesRegistry that the rules are loaded.
-    bool notified_registry_;
-
-    // Use this factory to generate weak pointers bound to the UI thread.
-    base::WeakPtrFactory<RuleStorageOnUI> weak_ptr_factory_;
-  };
-
-  // After the RuleStorageOnUI object (the part of the registry which runs on
-  // the UI thread) is created, a pointer to it is passed to |*ui_part|.
-  // If |log_storage_init_delay| is set, the delay caused by loading and
-  // registering rules on initialization will be logged with UMA.
-  // In tests, |profile| and |ui_part| can be NULL (at the same time). In that
-  // case the storage functionality disabled (no RuleStorageOnUI object
-  // created) and the |log_storage_init_delay| flag is ignored.
-  RulesRegistryWithCache(Profile* profile,
-                         const std::string& event_name,
-                         content::BrowserThread::ID owner_thread,
-                         bool log_storage_init_delay,
-                         scoped_ptr<RuleStorageOnUI>* ui_part);
-
-  const OneShotEvent& ready() const {
-    return ready_;
-  }
-
-  // RulesRegistry implementation:
-  virtual std::string AddRules(
-      const std::string& extension_id,
-      const std::vector<linked_ptr<RulesRegistry::Rule> >& rules) OVERRIDE;
-  virtual std::string RemoveRules(
-      const std::string& extension_id,
-      const std::vector<std::string>& rule_identifiers) OVERRIDE;
-  virtual std::string RemoveAllRules(
-      const std::string& extension_id) OVERRIDE;
-  virtual std::string GetRules(
-      const std::string& extension_id,
-      const std::vector<std::string>& rule_identifiers,
-      std::vector<linked_ptr<RulesRegistry::Rule> >* out) OVERRIDE;
-  virtual std::string GetAllRules(
-      const std::string& extension_id,
-      std::vector<linked_ptr<RulesRegistry::Rule> >* out) OVERRIDE;
-  virtual void OnExtensionUnloaded(const std::string& extension_id) OVERRIDE;
-
- protected:
-  virtual ~RulesRegistryWithCache();
-
-  // These functions need to provide the same functionality as their
-  // RulesRegistry counterparts. They need to be atomic.
-  virtual std::string AddRulesImpl(
-      const std::string& extension_id,
-      const std::vector<linked_ptr<RulesRegistry::Rule> >& rules) = 0;
-  virtual std::string RemoveRulesImpl(
-      const std::string& extension_id,
-      const std::vector<std::string>& rule_identifiers) = 0;
-  virtual std::string RemoveAllRulesImpl(
-      const std::string& extension_id) = 0;
-
- private:
-  typedef std::string ExtensionId;
-  typedef std::string RuleId;
-  typedef std::pair<ExtensionId, RuleId> RulesDictionaryKey;
-  typedef std::map<RulesDictionaryKey, linked_ptr<RulesRegistry::Rule> >
-      RulesDictionary;
-  enum ProcessChangedRulesState {
-    // ProcessChangedRules can never be called, |storage_on_ui_| is NULL.
-    NEVER_PROCESS,
-    // A task to call ProcessChangedRules is scheduled for future execution.
-    SCHEDULED_FOR_PROCESSING,
-    // No task to call ProcessChangedRules is scheduled yet, but it is possible
-    // to schedule one.
-    NOT_SCHEDULED_FOR_PROCESSING
-  };
-
-  // Common processing after extension's rules have changed.
-  void ProcessChangedRules(const std::string& extension_id);
-
-  // Calls ProcessChangedRules if |process_changed_rules_requested_| ==
-  // NOT_SCHEDULED_FOR_PROCESSING.
-  void MaybeProcessChangedRules(const std::string& extension_id);
-
-  // Process the callbacks once the registry gets ready.
-  void MarkReady(base::Time storage_init_time);
-
-  // Deserialize the rules from the given Value object and add them to the
-  // RulesRegistry.
-  void DeserializeAndAddRules(const std::string& extension_id,
-                              scoped_ptr<base::Value> rules);
-
-
-  RulesDictionary rules_;
-
-  // Signaled when we have finished reading from storage for all extensions that
-  // are loaded on startup.
-  OneShotEvent ready_;
-
-  // The factory needs to be declared before |storage_on_ui_|, so that it can
-  // produce a pointer as a construction argument for |storage_on_ui_|.
-  base::WeakPtrFactory<RulesRegistryWithCache> weak_ptr_factory_;
-
-  // |storage_on_ui_| is owned by the registry service. If |storage_on_ui_| is
-  // NULL, then the storage functionality is disabled (this is used in tests).
-  // This registry cannot own |storage_on_ui_| because during the time after
-  // rules registry service shuts down on UI thread, and the registry is
-  // destroyed on its thread, the use of the |storage_on_ui_| would not be
-  // safe. The registry only ever associates with one RuleStorageOnUI instance.
-  const base::WeakPtr<RuleStorageOnUI> storage_on_ui_;
-
-  ProcessChangedRulesState process_changed_rules_requested_;
-
-  DISALLOW_COPY_AND_ASSIGN(RulesRegistryWithCache);
-};
-
-}  // namespace extensions
-
-#endif  // CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_RULES_REGISTRY_WITH_CACHE_H__