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