sync: move invalidation version prefs out of SyncPrefs into InvalidatorStorage.

chrome/browser/sync/invalidations/invalidator_storage.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.
+//
+// Wraps PrefService in an InvalidationStateTracker to allow SyncNotifiers
+// to use PrefService as persistence for invalidation state. It is not thread
+// safe, and lives on the UI thread.
+
+#ifndef CHROME_BROWSER_SYNC_INVALIDATIONS_INVALIDATOR_STORAGE_H_
+#define CHROME_BROWSER_SYNC_INVALIDATIONS_INVALIDATOR_STORAGE_H_
+
+#include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/non_thread_safe.h"
+#include "sync/notifier/invalidation_state_tracker.h"
+#include "sync/syncable/model_type.h"
+
+class PrefService;
+
+namespace base {
+  class DictionaryValue;
+}
+
+namespace browser_sync {
+
+// TODO(tim): Bug 124137. We may want to move this outside of sync/ into a
+// browser/invalidations directory, or re-organize to have a browser
+// subdirectory that contains signin/ sync/ invalidations/ and other cloud
+// services.  For now this is still tied to sync while we refactor, so minimize
+// churn and keep it here.
+class InvalidatorStorage : public base::SupportsWeakPtr<InvalidatorStorage>,
+                           public sync_notifier::InvalidationStateTracker {
+ public:
+  // |pref_service| may be NULL (for unit tests), but in that case no setter
+  // methods should be called. Does not own |pref_service|.
+  explicit InvalidatorStorage(PrefService* pref_service);
+  virtual ~InvalidatorStorage();
+
+  // Erases invalidation versions and state stored on disk.
+  void Clear();
+
+  // InvalidationStateTracker implementation.
+  virtual sync_notifier::InvalidationVersionMap GetAllMaxVersions() const
+      OVERRIDE;
+  virtual void SetMaxVersion(syncable::ModelType model_type,
+                             int64 max_version) OVERRIDE;
+  // TODO(tim): These are not yet used. Bug 124140.
+  virtual void SetInvalidationState(const std::string& state) OVERRIDE;
+  virtual std::string GetInvalidationState() const OVERRIDE;
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(InvalidatorStorageTest, SerializeEmptyMap);
+  FRIEND_TEST_ALL_PREFIXES(InvalidatorStorageTest, DeserializeOutOfRange);
+  FRIEND_TEST_ALL_PREFIXES(InvalidatorStorageTest, DeserializeInvalidFormat);
+  FRIEND_TEST_ALL_PREFIXES(InvalidatorStorageTest, DeserializeEmptyDictionary);
+  FRIEND_TEST_ALL_PREFIXES(InvalidatorStorageTest, DeserializeBasic);
+
+  base::NonThreadSafe non_thread_safe_;
+
+  // Helpers to convert between InvalidationVersionMap <--> DictionaryValue.
+  static void DeserializeMap(const base::DictionaryValue* max_versions_dict,
+                             sync_notifier::InvalidationVersionMap* map);
+  static void SerializeMap(const sync_notifier::InvalidationVersionMap& map,
+                           base::DictionaryValue* to_dict);
+
+  // May be NULL.
+  PrefService* const pref_service_;
+
+  DISALLOW_COPY_AND_ASSIGN(InvalidatorStorage);
+};
+
+}  // namespace browser_sync
+
+#endif  // CHROME_BROWSER_SYNC_INVALIDATIONS_INVALIDATOR_STORAGE_H_