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1 // Copyright (c) 2012 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_CHROMEOS_DRIVE_FILE_CACHE_H_ | |
6 #define CHROME_BROWSER_CHROMEOS_DRIVE_FILE_CACHE_H_ | |
7 | |
8 #include <set> | |
9 #include <string> | |
10 | |
11 #include "base/files/file_path.h" | |
12 #include "base/memory/scoped_ptr.h" | |
13 #include "base/memory/weak_ptr.h" | |
14 #include "base/synchronization/cancellation_flag.h" | |
15 #include "base/threading/thread_checker.h" | |
16 #include "chrome/browser/chromeos/drive/resource_metadata_storage.h" | |
17 #include "components/drive/file_errors.h" | |
18 | |
19 namespace base { | |
20 class ScopedClosureRunner; | |
21 class SequencedTaskRunner; | |
22 } // namespace base | |
23 | |
24 namespace drive { | |
25 | |
26 namespace internal { | |
27 | |
28 // Interface class used for getting the free disk space. Tests can inject an | |
29 // implementation that reports fake free disk space. | |
30 class FreeDiskSpaceGetterInterface { | |
31 public: | |
32 virtual ~FreeDiskSpaceGetterInterface() {} | |
33 virtual int64 AmountOfFreeDiskSpace() = 0; | |
34 }; | |
35 | |
36 // FileCache is used to maintain cache states of FileSystem. | |
37 // | |
38 // All non-static public member functions, unless mentioned otherwise (see | |
39 // GetCacheFilePath() for example), should be run with |blocking_task_runner|. | |
40 class FileCache { | |
41 public: | |
42 // Enum defining type of file operation e.g. copy or move, etc. | |
43 enum FileOperationType { | |
44 FILE_OPERATION_MOVE = 0, | |
45 FILE_OPERATION_COPY, | |
46 }; | |
47 | |
48 // |cache_file_directory| stores cached files. | |
49 // | |
50 // |blocking_task_runner| indicates the blocking worker pool for cache | |
51 // operations. All operations on this FileCache must be run on this runner. | |
52 // Must not be null. | |
53 // | |
54 // |free_disk_space_getter| is used to inject a custom free disk space | |
55 // getter for testing. NULL must be passed for production code. | |
56 // | |
57 // Must be called on the UI thread. | |
58 FileCache(ResourceMetadataStorage* storage, | |
59 const base::FilePath& cache_file_directory, | |
60 base::SequencedTaskRunner* blocking_task_runner, | |
61 FreeDiskSpaceGetterInterface* free_disk_space_getter); | |
62 | |
63 // Returns true if the given path is under drive cache directory, i.e. | |
64 // <user_profile_dir>/GCache/v1 | |
65 // | |
66 // Can be called on any thread. | |
67 bool IsUnderFileCacheDirectory(const base::FilePath& path) const; | |
68 | |
69 // Frees up disk space to store a file with |num_bytes| size content, while | |
70 // keeping cryptohome::kMinFreeSpaceInBytes bytes on the disk, if needed. | |
71 // Returns true if we successfully manage to have enough space, otherwise | |
72 // false. | |
73 bool FreeDiskSpaceIfNeededFor(int64 num_bytes); | |
74 | |
75 // Checks if file corresponding to |id| exists in cache, and returns | |
76 // FILE_ERROR_OK with |cache_file_path| storing the path to the file. | |
77 // |cache_file_path| must not be null. | |
78 FileError GetFile(const std::string& id, base::FilePath* cache_file_path); | |
79 | |
80 // Stores |source_path| as a cache of the remote content of the file | |
81 // with |id| and |md5|. | |
82 // Pass an empty string as MD5 to mark the entry as dirty. | |
83 FileError Store(const std::string& id, | |
84 const std::string& md5, | |
85 const base::FilePath& source_path, | |
86 FileOperationType file_operation_type); | |
87 | |
88 // Pins the specified entry. | |
89 FileError Pin(const std::string& id); | |
90 | |
91 // Unpins the specified entry. | |
92 FileError Unpin(const std::string& id); | |
93 | |
94 // Sets the state of the cache entry corresponding to |id| as mounted. | |
95 FileError MarkAsMounted(const std::string& id, | |
96 base::FilePath* cache_file_path); | |
97 | |
98 // Sets the state of the cache entry corresponding to file_path as unmounted. | |
99 FileError MarkAsUnmounted(const base::FilePath& file_path); | |
100 | |
101 // Opens the cache file corresponding to |id| for write. |file_closer| should | |
102 // be kept alive until writing finishes. | |
103 // This method must be called before writing to cache files. | |
104 FileError OpenForWrite(const std::string& id, | |
105 scoped_ptr<base::ScopedClosureRunner>* file_closer); | |
106 | |
107 // Returns true if the cache file corresponding to |id| is write-opened. | |
108 bool IsOpenedForWrite(const std::string& id); | |
109 | |
110 // Calculates MD5 of the cache file and updates the stored value. | |
111 FileError UpdateMd5(const std::string& id); | |
112 | |
113 // Clears dirty state of the specified entry. | |
114 FileError ClearDirty(const std::string& id); | |
115 | |
116 // Removes the specified cache entry and delete cache files if available. | |
117 FileError Remove(const std::string& id); | |
118 | |
119 // Removes all the files in the cache directory. | |
120 bool ClearAll(); | |
121 | |
122 // Initializes the cache. Returns true on success. | |
123 bool Initialize(); | |
124 | |
125 // Destroys this cache. This function posts a task to the blocking task | |
126 // runner to safely delete the object. | |
127 // Must be called on the UI thread. | |
128 void Destroy(); | |
129 | |
130 // Moves files in the cache directory which are not managed by FileCache to | |
131 // |dest_directory|. | |
132 // |recovered_cache_info| should contain cache info recovered from the trashed | |
133 // metadata DB. It is used to ignore non-dirty files. | |
134 bool RecoverFilesFromCacheDirectory( | |
135 const base::FilePath& dest_directory, | |
136 const ResourceMetadataStorage::RecoveredCacheInfoMap& | |
137 recovered_cache_info); | |
138 | |
139 private: | |
140 friend class FileCacheTest; | |
141 | |
142 ~FileCache(); | |
143 | |
144 // Returns absolute path of the file if it were cached or to be cached. | |
145 // | |
146 // Can be called on any thread. | |
147 base::FilePath GetCacheFilePath(const std::string& id) const; | |
148 | |
149 // Checks whether the current thread is on the right sequenced worker pool | |
150 // with the right sequence ID. If not, DCHECK will fail. | |
151 void AssertOnSequencedWorkerPool(); | |
152 | |
153 // Destroys the cache on the blocking pool. | |
154 void DestroyOnBlockingPool(); | |
155 | |
156 // Returns true if we have sufficient space to store the given number of | |
157 // bytes, while keeping cryptohome::kMinFreeSpaceInBytes bytes on the disk. | |
158 bool HasEnoughSpaceFor(int64 num_bytes, const base::FilePath& path); | |
159 | |
160 // Renames cache files from old "prefix:id.md5" format to the new format. | |
161 // TODO(hashimoto): Remove this method at some point. | |
162 bool RenameCacheFilesToNewFormat(); | |
163 | |
164 // This method must be called after writing to a cache file. | |
165 // Used to implement OpenForWrite(). | |
166 void CloseForWrite(const std::string& id); | |
167 | |
168 const base::FilePath cache_file_directory_; | |
169 | |
170 scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_; | |
171 | |
172 base::CancellationFlag in_shutdown_; | |
173 | |
174 ResourceMetadataStorage* storage_; | |
175 | |
176 FreeDiskSpaceGetterInterface* free_disk_space_getter_; // Not owned. | |
177 | |
178 // IDs of files being write-opened. | |
179 std::map<std::string, int> write_opened_files_; | |
180 | |
181 // IDs of files marked mounted. | |
182 std::set<std::string> mounted_files_; | |
183 | |
184 base::ThreadChecker thread_checker_; | |
185 | |
186 // Note: This should remain the last member so it'll be destroyed and | |
187 // invalidate its weak pointers before any other members are destroyed. | |
188 // This object should be accessed only on |blocking_task_runner_|. | |
189 base::WeakPtrFactory<FileCache> weak_ptr_factory_; | |
190 DISALLOW_COPY_AND_ASSIGN(FileCache); | |
191 }; | |
192 | |
193 } // namespace internal | |
194 } // namespace drive | |
195 | |
196 #endif // CHROME_BROWSER_CHROMEOS_DRIVE_FILE_CACHE_H_ | |
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