Revert 271602 "Implementation of leveldb-backed PrefStore."

trunk/src/chrome/browser/prefs/leveldb_pref_store.h

-// Copyright 2014 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_LEVELDB_PREF_STORE_H_
-#define CHROME_BROWSER_PREFS_LEVELDB_PREF_STORE_H_
-
-#include <set>
-#include <string>
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "base/files/file_path.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/message_loop/message_loop_proxy.h"
-#include "base/observer_list.h"
-#include "base/prefs/persistent_pref_store.h"
-#include "base/prefs/pref_value_map.h"
-#include "base/timer/timer.h"
-
-namespace base {
-class DictionaryValue;
-class SequencedTaskRunner;
-class Value;
-}
-
-namespace leveldb {
-class DB;
-}
-
-// A writable PrefStore implementation that is used for user preferences.
-class LevelDBPrefStore : public PersistentPrefStore {
- public:
-  // |sequenced_task_runner| is must be a shutdown-blocking task runner, ideally
-  // created by GetTaskRunnerForFile() method above.
-  LevelDBPrefStore(const base::FilePath& pref_filename,
-                   base::SequencedTaskRunner* sequenced_task_runner);
-
-  // PrefStore overrides:
-  virtual bool GetValue(const std::string& key,
-                        const base::Value** result) const OVERRIDE;
-  virtual void AddObserver(PrefStore::Observer* observer) OVERRIDE;
-  virtual void RemoveObserver(PrefStore::Observer* observer) OVERRIDE;
-  virtual bool HasObservers() const OVERRIDE;
-  virtual bool IsInitializationComplete() const OVERRIDE;
-
-  // PersistentPrefStore overrides:
-  virtual bool GetMutableValue(const std::string& key,
-                               base::Value** result) OVERRIDE;
-  // Takes ownership of value.
-  virtual void SetValue(const std::string& key, base::Value* value) OVERRIDE;
-  virtual void SetValueSilently(const std::string& key,
-                                base::Value* value) OVERRIDE;
-  virtual void RemoveValue(const std::string& key) OVERRIDE;
-  virtual bool ReadOnly() const OVERRIDE;
-  virtual PrefReadError GetReadError() const OVERRIDE;
-  virtual PrefReadError ReadPrefs() OVERRIDE;
-  virtual void ReadPrefsAsync(ReadErrorDelegate* error_delegate) OVERRIDE;
-  virtual void CommitPendingWrite() OVERRIDE;
-  virtual void ReportValueChanged(const std::string& key) OVERRIDE;
-
- private:
-  struct ReadingResults;
-  class FileThreadSerializer;
-
-  virtual ~LevelDBPrefStore();
-
-  static scoped_ptr<ReadingResults> DoReading(const base::FilePath& path);
-  static void OpenDB(const base::FilePath& path,
-                     ReadingResults* reading_results);
-  void OnStorageRead(scoped_ptr<ReadingResults> reading_results);
-
-  void PersistFromUIThread();
-  void RemoveFromUIThread(const std::string& key);
-  void ScheduleWrite();
-
-  void SetValueInternal(const std::string& key,
-                        base::Value* value,
-                        bool notify);
-  void NotifyObservers(const std::string& key);
-  void MarkForInsertion(const std::string& key, const std::string& value);
-  void MarkForDeletion(const std::string& key);
-
-  base::FilePath path_;
-
-  const scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner_;
-  const scoped_refptr<base::SequencedTaskRunner> original_task_runner_;
-
-  PrefValueMap prefs_;
-
-  bool read_only_;
-
-  ObserverList<PrefStore::Observer, true> observers_;
-
-  scoped_ptr<ReadErrorDelegate> error_delegate_;
-
-  bool initialized_;
-  PrefReadError read_error_;
-
-  // This object is created on the UI thread right after preferences are loaded
-  // from disk. A message to delete it is sent to the FILE thread by
-  // ~LevelDBPrefStore.
-  scoped_ptr<FileThreadSerializer> serializer_;
-
-  // Changes are accumulated in |keys_to_delete_| and |keys_to_set_| and are
-  // stored in the database according to |timer_|.
-  std::set<std::string> keys_to_delete_;
-  std::map<std::string, std::string> keys_to_set_;
-  base::OneShotTimer<LevelDBPrefStore> timer_;
-
-  base::WeakPtrFactory<LevelDBPrefStore> weak_ptr_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(LevelDBPrefStore);
-};
-
-#endif  // CHROME_BROWSER_PREFS_LEVELDB_PREF_STORE_H_