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 EXTENSIONS_BROWSER_VALUE_STORE_LEVELDB_VALUE_STORE_H_ 6 #define EXTENSIONS_BROWSER_VALUE_STORE_LEVELDB_VALUE_STORE_H_ 7 8 #include <string> 9 #include <vector> 10 11 #include "base/compiler_specific.h" 12 #include "base/files/file_path.h" 13 #include "base/memory/scoped_ptr.h" 14 #include "extensions/browser/value_store/value_store.h" 15 #include "third_party/leveldatabase/src/include/leveldb/db.h" 16 17 // Value store area, backed by a leveldb database. 18 // All methods must be run on the FILE thread. 19 class LeveldbValueStore : public ValueStore { 20 public: 21 // Creates a database bound to |path|. The underlying database won't be 22 // opened (i.e. may not be created) until one of the get/set/etc methods are 23 // called - this is because opening the database may fail, and extensions 24 // need to be notified of that, but we don't want to permanently give up. 25 // 26 // Must be created on the FILE thread. 27 explicit LeveldbValueStore(const base::FilePath& path); 28 29 // Must be deleted on the FILE thread. 30 virtual ~LeveldbValueStore(); 31 32 // ValueStore implementation. 33 virtual size_t GetBytesInUse(const std::string& key) OVERRIDE; 34 virtual size_t GetBytesInUse(const std::vector<std::string>& keys) OVERRIDE; 35 virtual size_t GetBytesInUse() OVERRIDE; 36 virtual ReadResult Get(const std::string& key) OVERRIDE; 37 virtual ReadResult Get(const std::vector<std::string>& keys) OVERRIDE; 38 virtual ReadResult Get() OVERRIDE; 39 virtual WriteResult Set( 40 WriteOptions options, 41 const std::string& key, 42 const base::Value& value) OVERRIDE; 43 virtual WriteResult Set( 44 WriteOptions options, const base::DictionaryValue& values) OVERRIDE; 45 virtual WriteResult Remove(const std::string& key) OVERRIDE; 46 virtual WriteResult Remove(const std::vector<std::string>& keys) OVERRIDE; 47 virtual WriteResult Clear() OVERRIDE; 48 virtual bool Restore() OVERRIDE; 49 virtual bool RestoreKey(const std::string& key) OVERRIDE; 50 51 // Write directly to the backing levelDB. Only used for testing to cause 52 // corruption in the database. 53 bool WriteToDbForTest(leveldb::WriteBatch* batch); 54 55 private: 56 // Tries to open the database if it hasn't been opened already. 57 scoped_ptr<ValueStore::Error> EnsureDbIsOpen(); 58 59 // Reads a setting from the database. 60 scoped_ptr<ValueStore::Error> ReadFromDb( 61 leveldb::ReadOptions options, 62 const std::string& key, 63 // Will be reset() with the result, if any. 64 scoped_ptr<base::Value>* setting); 65 66 // Adds a setting to a WriteBatch, and logs the change in |changes|. For use 67 // with WriteToDb. 68 scoped_ptr<ValueStore::Error> AddToBatch(ValueStore::WriteOptions options, 69 const std::string& key, 70 const base::Value& value, 71 leveldb::WriteBatch* batch, 72 ValueStoreChangeList* changes); 73 74 // Commits the changes in |batch| to the database. 75 scoped_ptr<ValueStore::Error> WriteToDb(leveldb::WriteBatch* batch); 76 77 // Converts an error leveldb::Status to a ValueStore::Error. Returns a 78 // scoped_ptr for convenience; the result will always be non-empty. 79 scoped_ptr<ValueStore::Error> ToValueStoreError( 80 const leveldb::Status& status, 81 scoped_ptr<std::string> key); 82 83 // Removes the on-disk database at |db_path_|. Any file system locks should 84 // be released before calling this method. 85 void DeleteDbFile(); 86 87 // Returns whether the database is empty. 88 bool IsEmpty(); 89 90 // The location of the leveldb backend. 91 const base::FilePath db_path_; 92 93 // leveldb backend. 94 scoped_ptr<leveldb::DB> db_; 95 96 DISALLOW_COPY_AND_ASSIGN(LeveldbValueStore); 97 }; 98 99 #endif // EXTENSIONS_BROWSER_VALUE_STORE_LEVELDB_VALUE_STORE_H_ 100
