1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
// 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.
#ifndef CHROME_BROWSER_VALUE_STORE_LEVELDB_VALUE_STORE_H_
#define CHROME_BROWSER_VALUE_STORE_LEVELDB_VALUE_STORE_H_
#include <string>
#include <vector>
#include "base/compiler_specific.h"
#include "base/files/file_path.h"
#include "base/memory/scoped_ptr.h"
#include "chrome/browser/value_store/value_store.h"
#include "third_party/leveldatabase/src/include/leveldb/db.h"
// Value store area, backed by a leveldb database.
// All methods must be run on the FILE thread.
class LeveldbValueStore : public ValueStore {
public:
// Creates a database bound to |path|. The underlying database won't be
// opened (i.e. may not be created) until one of the get/set/etc methods are
// called - this is because opening the database may fail, and extensions
// need to be notified of that, but we don't want to permanently give up.
//
// Must be created on the FILE thread.
explicit LeveldbValueStore(const base::FilePath& path);
// Must be deleted on the FILE thread.
virtual ~LeveldbValueStore();
// ValueStore implementation.
virtual size_t GetBytesInUse(const std::string& key) OVERRIDE;
virtual size_t GetBytesInUse(const std::vector<std::string>& keys) OVERRIDE;
virtual size_t GetBytesInUse() OVERRIDE;
virtual ReadResult Get(const std::string& key) OVERRIDE;
virtual ReadResult Get(const std::vector<std::string>& keys) OVERRIDE;
virtual ReadResult Get() OVERRIDE;
virtual WriteResult Set(
WriteOptions options,
const std::string& key,
const Value& value) OVERRIDE;
virtual WriteResult Set(
WriteOptions options, const DictionaryValue& values) OVERRIDE;
virtual WriteResult Remove(const std::string& key) OVERRIDE;
virtual WriteResult Remove(const std::vector<std::string>& keys) OVERRIDE;
virtual WriteResult Clear() OVERRIDE;
private:
// Tries to open the database if it hasn't been opened already. Returns the
// error message on failure, or "" on success (guaranteeding that |db_| is
// non-NULL),
std::string EnsureDbIsOpen();
// Reads a setting from the database. Returns the error message on failure,
// or "" on success in which case |setting| will be reset to the Value read
// from the database. This value may be NULL.
std::string ReadFromDb(
leveldb::ReadOptions options,
const std::string& key,
// Will be reset() with the result, if any.
scoped_ptr<Value>* setting);
// Adds a setting to a WriteBatch, and logs the change in |changes|. For use
// with WriteToDb. Returns the error message on failure, or "" on success.
std::string AddToBatch(
ValueStore::WriteOptions options,
const std::string& key,
const base::Value& value,
leveldb::WriteBatch* batch,
ValueStoreChangeList* changes);
// Commits the changes in |batch| to the database, returning the error message
// on failure or "" on success.
std::string WriteToDb(leveldb::WriteBatch* batch);
// Returns whether the database is empty.
bool IsEmpty();
// The location of the leveldb backend.
const base::FilePath db_path_;
// leveldb backend.
scoped_ptr<leveldb::DB> db_;
DISALLOW_COPY_AND_ASSIGN(LeveldbValueStore);
};
#endif // CHROME_BROWSER_VALUE_STORE_LEVELDB_VALUE_STORE_H_
|
