prefs.h revision 39910dcd1d68987ccee7c3031dc269233a8490bb 
1//
2// Copyright (C) 2012 The Android Open Source Project
3//
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8//      http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15//
16
17#ifndef UPDATE_ENGINE_COMMON_PREFS_H_
18#define UPDATE_ENGINE_COMMON_PREFS_H_
19
20#include <map>
21#include <string>
22#include <vector>
23
24#include <base/files/file_path.h>
25
26#include "gtest/gtest_prod.h"  // for FRIEND_TEST
27#include "update_engine/common/prefs_interface.h"
28
29namespace chromeos_update_engine {
30
31// Implements a preference store by storing the value associated with
32// a key in a separate file named after the key under a preference
33// store directory.
34
35class Prefs : public PrefsInterface {
36 public:
37  Prefs() = default;
38
39  // Initializes the store by associating this object with |prefs_dir|
40  // as the preference store directory. Returns true on success, false
41  // otherwise.
42  bool Init(const base::FilePath& prefs_dir);
43
44  // PrefsInterface methods.
45  bool GetString(const std::string& key, std::string* value) const override;
46  bool SetString(const std::string& key, const std::string& value) override;
47  bool GetInt64(const std::string& key, int64_t* value) const override;
48  bool SetInt64(const std::string& key, const int64_t value) override;
49  bool GetBoolean(const std::string& key, bool* value) const override;
50  bool SetBoolean(const std::string& key, const bool value) override;
51
52  bool Exists(const std::string& key) const override;
53  bool Delete(const std::string& key) override;
54
55  void AddObserver(const std::string& key,
56                   ObserverInterface* observer) override;
57  void RemoveObserver(const std::string& key,
58                      ObserverInterface* observer) override;
59
60 private:
61  FRIEND_TEST(PrefsTest, GetFileNameForKey);
62  FRIEND_TEST(PrefsTest, GetFileNameForKeyBadCharacter);
63  FRIEND_TEST(PrefsTest, GetFileNameForKeyEmpty);
64
65  // Sets |filename| to the full path to the file containing the data
66  // associated with |key|. Returns true on success, false otherwise.
67  bool GetFileNameForKey(const std::string& key,
68                         base::FilePath* filename) const;
69
70  // Preference store directory.
71  base::FilePath prefs_dir_;
72
73  // The registered observers watching for changes.
74  std::map<std::string, std::vector<ObserverInterface*>> observers_;
75
76  DISALLOW_COPY_AND_ASSIGN(Prefs);
77};
78
79}  // namespace chromeos_update_engine
80
81#endif  // UPDATE_ENGINE_COMMON_PREFS_H_
82