1// Copyright 2014 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef CHROME_BROWSER_PREFS_LEVELDB_PREF_STORE_H_ 6#define CHROME_BROWSER_PREFS_LEVELDB_PREF_STORE_H_ 7 8#include <set> 9#include <string> 10 11#include "base/basictypes.h" 12#include "base/compiler_specific.h" 13#include "base/files/file_path.h" 14#include "base/memory/scoped_ptr.h" 15#include "base/message_loop/message_loop_proxy.h" 16#include "base/observer_list.h" 17#include "base/prefs/persistent_pref_store.h" 18#include "base/prefs/pref_value_map.h" 19#include "base/timer/timer.h" 20 21namespace base { 22class DictionaryValue; 23class SequencedTaskRunner; 24class Value; 25} 26 27namespace leveldb { 28class DB; 29} 30 31// A writable PrefStore implementation that is used for user preferences. 32class LevelDBPrefStore : public PersistentPrefStore { 33 public: 34 // |sequenced_task_runner| is must be a shutdown-blocking task runner, ideally 35 // created by GetTaskRunnerForFile() method above. 36 LevelDBPrefStore(const base::FilePath& pref_filename, 37 base::SequencedTaskRunner* sequenced_task_runner); 38 39 // PrefStore overrides: 40 virtual bool GetValue(const std::string& key, 41 const base::Value** result) const OVERRIDE; 42 virtual void AddObserver(PrefStore::Observer* observer) OVERRIDE; 43 virtual void RemoveObserver(PrefStore::Observer* observer) OVERRIDE; 44 virtual bool HasObservers() const OVERRIDE; 45 virtual bool IsInitializationComplete() const OVERRIDE; 46 47 // PersistentPrefStore overrides: 48 virtual bool GetMutableValue(const std::string& key, 49 base::Value** result) OVERRIDE; 50 // Takes ownership of value. 51 virtual void SetValue(const std::string& key, base::Value* value) OVERRIDE; 52 virtual void SetValueSilently(const std::string& key, 53 base::Value* value) OVERRIDE; 54 virtual void RemoveValue(const std::string& key) OVERRIDE; 55 virtual bool ReadOnly() const OVERRIDE; 56 virtual PrefReadError GetReadError() const OVERRIDE; 57 virtual PrefReadError ReadPrefs() OVERRIDE; 58 virtual void ReadPrefsAsync(ReadErrorDelegate* error_delegate) OVERRIDE; 59 virtual void CommitPendingWrite() OVERRIDE; 60 virtual void ReportValueChanged(const std::string& key) OVERRIDE; 61 62 private: 63 struct ReadingResults; 64 class FileThreadSerializer; 65 66 virtual ~LevelDBPrefStore(); 67 68 static scoped_ptr<ReadingResults> DoReading(const base::FilePath& path); 69 static void OpenDB(const base::FilePath& path, 70 ReadingResults* reading_results); 71 void OnStorageRead(scoped_ptr<ReadingResults> reading_results); 72 73 void PersistFromUIThread(); 74 void RemoveFromUIThread(const std::string& key); 75 void ScheduleWrite(); 76 77 void SetValueInternal(const std::string& key, 78 base::Value* value, 79 bool notify); 80 void NotifyObservers(const std::string& key); 81 void MarkForInsertion(const std::string& key, const std::string& value); 82 void MarkForDeletion(const std::string& key); 83 84 base::FilePath path_; 85 86 const scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner_; 87 const scoped_refptr<base::SequencedTaskRunner> original_task_runner_; 88 89 PrefValueMap prefs_; 90 91 bool read_only_; 92 93 ObserverList<PrefStore::Observer, true> observers_; 94 95 scoped_ptr<ReadErrorDelegate> error_delegate_; 96 97 bool initialized_; 98 PrefReadError read_error_; 99 100 // This object is created on the UI thread right after preferences are loaded 101 // from disk. A message to delete it is sent to the FILE thread by 102 // ~LevelDBPrefStore. 103 scoped_ptr<FileThreadSerializer> serializer_; 104 105 // Changes are accumulated in |keys_to_delete_| and |keys_to_set_| and are 106 // stored in the database according to |timer_|. 107 std::set<std::string> keys_to_delete_; 108 std::map<std::string, std::string> keys_to_set_; 109 base::OneShotTimer<LevelDBPrefStore> timer_; 110 111 base::WeakPtrFactory<LevelDBPrefStore> weak_ptr_factory_; 112 113 DISALLOW_COPY_AND_ASSIGN(LevelDBPrefStore); 114}; 115 116#endif // CHROME_BROWSER_PREFS_LEVELDB_PREF_STORE_H_ 117