saved_files_service.h revision 7dbb3d5cf0c15f500944d211057644d6a2f37371 
1// Copyright 2013 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 APPS_SAVED_FILES_SERVICE_H_
6#define APPS_SAVED_FILES_SERVICE_H_
7
8#include <map>
9#include <set>
10#include <string>
11#include <vector>
12
13#include "base/files/file_path.h"
14#include "base/gtest_prod_util.h"
15#include "base/stl_util.h"
16#include "components/browser_context_keyed_service/browser_context_keyed_service.h"
17#include "content/public/browser/notification_observer.h"
18#include "content/public/browser/notification_registrar.h"
19
20class Profile;
21class SavedFilesServiceUnitTest;
22FORWARD_DECLARE_TEST(SavedFilesServiceUnitTest, RetainTwoFilesTest);
23FORWARD_DECLARE_TEST(SavedFilesServiceUnitTest, EvictionTest);
24FORWARD_DECLARE_TEST(SavedFilesServiceUnitTest, SequenceNumberCompactionTest);
25
26namespace extensions {
27class Extension;
28}
29
30namespace apps {
31
32// Represents a file entry that a user has given an app permission to
33// access. Will be persisted to disk (in the Preferences file), so should remain
34// serializable.
35struct SavedFileEntry {
36  SavedFileEntry();
37
38  SavedFileEntry(const std::string& id,
39                 const base::FilePath& path,
40                 bool writable,
41                 int sequence_number);
42
43  // The opaque id of this file entry.
44  std::string id;
45
46  // The path to a file entry that the app had permission to access.
47  base::FilePath path;
48
49  // Whether or not the app had write access to a file entry.
50  bool writable;
51
52  // The sequence number in the LRU of the file entry. The value 0 indicates
53  // that the entry is not in the LRU.
54  int sequence_number;
55};
56
57// Tracks the files that apps have retained access to both while running and
58// when suspended.
59class SavedFilesService : public BrowserContextKeyedService,
60                          public content::NotificationObserver {
61 public:
62  explicit SavedFilesService(Profile* profile);
63  virtual ~SavedFilesService();
64
65  static SavedFilesService* Get(Profile* profile);
66
67  // Registers a file entry with the saved files service, making it eligible to
68  // be put into the queue. File entries that are in the retained files queue at
69  // object construction are automatically registered.
70  void RegisterFileEntry(const std::string& extension_id,
71                         const std::string& id,
72                         const base::FilePath& file_path,
73                         bool writable);
74
75  // If the file with |id| is not in the queue of files to be retained
76  // permanently, adds the file to the back of the queue, evicting the least
77  // recently used entry at the front of the queue if it is full. If it is
78  // already present, moves it to the back of the queue. The |id| must have been
79  // registered.
80  void EnqueueFileEntry(const std::string& extension_id, const std::string& id);
81
82  // Returns whether the file entry with the given |id| has been registered.
83  bool IsRegistered(const std::string& extension_id, const std::string& id);
84
85  // Gets a borrowed pointer to the file entry with the specified |id|. Returns
86  // NULL if the file entry has not been registered.
87  const SavedFileEntry* GetFileEntry(const std::string& extension_id,
88                                     const std::string& id);
89
90  // Returns all registered file entries.
91  std::vector<SavedFileEntry> GetAllFileEntries(
92      const std::string& extension_id);
93
94  // Clears all retained files if the app does not have the
95  // fileSystem.retainEntries permission.
96  void ClearQueueIfNoRetainPermission(const extensions::Extension* extension);
97
98  // Clears all retained files.
99  void ClearQueue(const extensions::Extension* extension);
100
101 private:
102  FRIEND_TEST_ALL_PREFIXES(::SavedFilesServiceUnitTest, RetainTwoFilesTest);
103  FRIEND_TEST_ALL_PREFIXES(::SavedFilesServiceUnitTest, EvictionTest);
104  FRIEND_TEST_ALL_PREFIXES(::SavedFilesServiceUnitTest,
105                           SequenceNumberCompactionTest);
106  friend class ::SavedFilesServiceUnitTest;
107
108  // A container for the registered files for an app.
109  class SavedFiles;
110
111  // content::NotificationObserver.
112  virtual void Observe(int type,
113                       const content::NotificationSource& source,
114                       const content::NotificationDetails& details) OVERRIDE;
115
116  // Returns the SavedFiles for |extension_id| or NULL if one does not exist.
117  SavedFiles* Get(const std::string& extension_id) const;
118
119  // Returns the SavedFiles for |extension_id|, creating it if necessary.
120  SavedFiles* GetOrInsert(const std::string& extension_id);
121
122  // Clears the SavedFiles for |extension_id|.
123  void Clear(const std::string& extension_id);
124
125  static void SetMaxSequenceNumberForTest(int max_value);
126  static void ClearMaxSequenceNumberForTest();
127  static void SetLruSizeForTest(int size);
128  static void ClearLruSizeForTest();
129
130  std::map<std::string, SavedFiles*> extension_id_to_saved_files_;
131  STLValueDeleter<std::map<std::string, SavedFiles*> >
132      extension_id_to_saved_files_deleter_;
133  content::NotificationRegistrar registrar_;
134  Profile* profile_;
135
136  DISALLOW_COPY_AND_ASSIGN(SavedFilesService);
137};
138
139}  // namespace apps
140
141#endif  // APPS_SAVED_FILES_SERVICE_H_
142