Componentize //chrome/browser/prefs/tracked.

chrome/browser/prefs/tracked/pref_hash_filter.h

-// Copyright 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_PREFS_TRACKED_PREF_HASH_FILTER_H_
-#define CHROME_BROWSER_PREFS_TRACKED_PREF_HASH_FILTER_H_
-
-#include <map>
-#include <set>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/callback.h"
-#include "base/compiler_specific.h"
-#include "base/containers/scoped_ptr_hash_map.h"
-#include "base/memory/scoped_ptr.h"
-#include "chrome/browser/prefs/tracked/interceptable_pref_filter.h"
-#include "chrome/browser/prefs/tracked/tracked_preference.h"
-
-class PrefHashStore;
-class PrefService;
-class PrefStore;
-class TrackedPreferenceValidationDelegate;
-
-namespace base {
-class DictionaryValue;
-class Time;
-class Value;
-}  // namespace base
-
-namespace user_prefs {
-class PrefRegistrySyncable;
-}  // namespace user_prefs
-
-// Intercepts preference values as they are loaded from disk and verifies them
-// using a PrefHashStore. Keeps the PrefHashStore contents up to date as values
-// are changed.
-class PrefHashFilter : public InterceptablePrefFilter {
- public:
-  enum EnforcementLevel {
-    NO_ENFORCEMENT,
-    ENFORCE_ON_LOAD
-  };
-
-  enum PrefTrackingStrategy {
-    // Atomic preferences are tracked as a whole.
-    TRACKING_STRATEGY_ATOMIC,
-    // Split preferences are dictionaries for which each top-level entry is
-    // tracked independently. Note: preferences using this strategy must be kept
-    // in sync with TrackedSplitPreferences in histograms.xml.
-    TRACKING_STRATEGY_SPLIT,
-  };
-
-  enum ValueType {
-    VALUE_IMPERSONAL,
-    // The preference value may contain personal information.
-    VALUE_PERSONAL,
-  };
-
-  struct TrackedPreferenceMetadata {
-    size_t reporting_id;
-    const char* name;
-    EnforcementLevel enforcement_level;
-    PrefTrackingStrategy strategy;
-    ValueType value_type;
-  };
-
-  // Constructs a PrefHashFilter tracking the specified |tracked_preferences|
-  // using |pref_hash_store| to check/store hashes. An optional |delegate| is
-  // notified of the status of each preference as it is checked.
-  // If |on_reset_on_load| is provided, it will be invoked if a reset occurs in
-  // FilterOnLoad.
-  // |reporting_ids_count| is the count of all possible IDs (possibly greater
-  // than |tracked_preferences.size()|). If |report_super_mac_validity| is true,
-  // the state of the super MAC will be reported via UMA during
-  // FinalizeFilterOnLoad.
-  PrefHashFilter(
-      scoped_ptr<PrefHashStore> pref_hash_store,
-      const std::vector<TrackedPreferenceMetadata>& tracked_preferences,
-      const base::Closure& on_reset_on_load,
-      TrackedPreferenceValidationDelegate* delegate,
-      size_t reporting_ids_count,
-      bool report_super_mac_validity);
-
-  ~PrefHashFilter() override;
-
-  // Registers required user preferences.
-  static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
-
-  // Retrieves the time of the last reset event, if any, for the provided user
-  // preferences. If no reset has occurred, Returns a null |Time|.
-  static base::Time GetResetTime(PrefService* user_prefs);
-
-  // Clears the time of the last reset event, if any, for the provided user
-  // preferences.
-  static void ClearResetTime(PrefService* user_prefs);
-
-  // Initializes the PrefHashStore with hashes of the tracked preferences in
-  // |pref_store_contents|. |pref_store_contents| will be the |storage| passed
-  // to PrefHashStore::BeginTransaction().
-  void Initialize(base::DictionaryValue* pref_store_contents);
-
-  // PrefFilter remaining implementation.
-  void FilterUpdate(const std::string& path) override;
-  void FilterSerializeData(base::DictionaryValue* pref_store_contents) override;
-
- private:
-  // InterceptablePrefFilter implementation.
-  void FinalizeFilterOnLoad(
-      const PostFilterOnLoadCallback& post_filter_on_load_callback,
-      scoped_ptr<base::DictionaryValue> pref_store_contents,
-      bool prefs_altered) override;
-
-  // Callback to be invoked only once (and subsequently reset) on the next
-  // FilterOnLoad event. It will be allowed to modify the |prefs| handed to
-  // FilterOnLoad before handing them back to this PrefHashFilter.
-  FilterOnLoadInterceptor filter_on_load_interceptor_;
-
-  // A map of paths to TrackedPreferences; this map owns this individual
-  // TrackedPreference objects.
-  typedef base::ScopedPtrHashMap<std::string, scoped_ptr<TrackedPreference>>
-      TrackedPreferencesMap;
-  // A map from changed paths to their corresponding TrackedPreferences (which
-  // aren't owned by this map).
-  typedef std::map<std::string, const TrackedPreference*> ChangedPathsMap;
-
-  scoped_ptr<PrefHashStore> pref_hash_store_;
-
-  // Invoked if a reset occurs in a call to FilterOnLoad.
-  const base::Closure on_reset_on_load_;
-
-  TrackedPreferencesMap tracked_paths_;
-
-  // The set of all paths whose value has changed since the last call to
-  // FilterSerializeData.
-  ChangedPathsMap changed_paths_;
-
-  // Whether to report the validity of the super MAC at load time (via UMA).
-  bool report_super_mac_validity_;
-
-  DISALLOW_COPY_AND_ASSIGN(PrefHashFilter);
-};
-
-#endif  // CHROME_BROWSER_PREFS_TRACKED_PREF_HASH_FILTER_H_