file_cache.h revision f2477e01787aa58f445919b809d89e252beef54f
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#include <vector> 11 12#include "base/callback_forward.h" 13#include "base/files/file_path.h" 14#include "base/memory/scoped_ptr.h" 15#include "base/memory/weak_ptr.h" 16#include "chrome/browser/chromeos/drive/file_errors.h" 17#include "chrome/browser/chromeos/drive/resource_metadata_storage.h" 18 19namespace base { 20class SequencedTaskRunner; 21} // namespace base 22 23namespace drive { 24 25class FileCacheEntry; 26 27namespace internal { 28 29// Callback for GetFileFromCache. 30typedef base::Callback<void(FileError error, 31 const base::FilePath& cache_file_path)> 32 GetFileFromCacheCallback; 33 34// Interface class used for getting the free disk space. Tests can inject an 35// implementation that reports fake free disk space. 36class FreeDiskSpaceGetterInterface { 37 public: 38 virtual ~FreeDiskSpaceGetterInterface() {} 39 virtual int64 AmountOfFreeDiskSpace() = 0; 40}; 41 42// FileCache is used to maintain cache states of FileSystem. 43// 44// All non-static public member functions, unless mentioned otherwise (see 45// GetCacheFilePath() for example), should be run with |blocking_task_runner|. 46class FileCache { 47 public: 48 // Enum defining type of file operation e.g. copy or move, etc. 49 enum FileOperationType { 50 FILE_OPERATION_MOVE = 0, 51 FILE_OPERATION_COPY, 52 }; 53 54 typedef ResourceMetadataStorage::CacheEntryIterator Iterator; 55 56 // |cache_file_directory| stores cached files. 57 // 58 // |blocking_task_runner| is used to post a task to the blocking worker 59 // pool for file operations. Must not be null. 60 // 61 // |free_disk_space_getter| is used to inject a custom free disk space 62 // getter for testing. NULL must be passed for production code. 63 // 64 // Must be called on the UI thread. 65 FileCache(ResourceMetadataStorage* storage, 66 const base::FilePath& cache_file_directory, 67 base::SequencedTaskRunner* blocking_task_runner, 68 FreeDiskSpaceGetterInterface* free_disk_space_getter); 69 70 // Returns true if the given path is under drive cache directory, i.e. 71 // <user_profile_dir>/GCache/v1 72 // 73 // Can be called on any thread. 74 bool IsUnderFileCacheDirectory(const base::FilePath& path) const; 75 76 // Gets the cache entry for file corresponding to |id| and returns true if 77 // entry exists in cache map. 78 bool GetCacheEntry(const std::string& id, FileCacheEntry* entry); 79 80 // Returns an object to iterate over entries. 81 scoped_ptr<Iterator> GetIterator(); 82 83 // Frees up disk space to store a file with |num_bytes| size content, while 84 // keeping kMinFreeSpace bytes on the disk, if needed. 85 // Returns true if we successfully manage to have enough space, otherwise 86 // false. 87 bool FreeDiskSpaceIfNeededFor(int64 num_bytes); 88 89 // Checks if file corresponding to |id| exists in cache, and returns 90 // FILE_ERROR_OK with |cache_file_path| storing the path to the file. 91 // |cache_file_path| must not be null. 92 FileError GetFile(const std::string& id, base::FilePath* cache_file_path); 93 94 // Stores |source_path| as a cache of the remote content of the file 95 // with |id| and |md5|. 96 FileError Store(const std::string& id, 97 const std::string& md5, 98 const base::FilePath& source_path, 99 FileOperationType file_operation_type); 100 101 // Runs Pin() on |blocking_task_runner_|, and calls |callback| with the result 102 // asynchronously. 103 // |callback| must not be null. 104 // Must be called on the UI thread. 105 void PinOnUIThread(const std::string& id, 106 const FileOperationCallback& callback); 107 108 // Pins the specified entry. 109 FileError Pin(const std::string& id); 110 111 // Runs Unpin() on |blocking_task_runner_|, and calls |callback| with the 112 // result asynchronously. 113 // |callback| must not be null. 114 // Must be called on the UI thread. 115 void UnpinOnUIThread(const std::string& id, 116 const FileOperationCallback& callback); 117 118 // Unpins the specified entry. 119 FileError Unpin(const std::string& id); 120 121 // Runs MarkAsMounted() on |blocking_task_runner_|, and calls |callback| with 122 // the result asynchronously. 123 // |callback| must not be null. 124 // Must be called on the UI thread. 125 void MarkAsMountedOnUIThread(const std::string& id, 126 const GetFileFromCacheCallback& callback); 127 128 // Sets the state of the cache entry corresponding to |id| as mounted. 129 FileError MarkAsMounted(const std::string& id, 130 base::FilePath* cache_file_path); 131 132 // Set the state of the cache entry corresponding to file_path as unmounted. 133 // |callback| must not be null. 134 // Must be called on the UI thread. 135 void MarkAsUnmountedOnUIThread(const base::FilePath& file_path, 136 const FileOperationCallback& callback); 137 138 // Marks the specified entry dirty. 139 FileError MarkDirty(const std::string& id); 140 141 // Clears dirty state of the specified entry and updates its MD5. 142 FileError ClearDirty(const std::string& id, const std::string& md5); 143 144 // Removes the specified cache entry and delete cache files if available. 145 FileError Remove(const std::string& id); 146 147 // Removes all the files in the cache directory and cache entries in DB. 148 bool ClearAll(); 149 150 // Initializes the cache. Returns true on success. 151 bool Initialize(); 152 153 // Destroys this cache. This function posts a task to the blocking task 154 // runner to safely delete the object. 155 // Must be called on the UI thread. 156 void Destroy(); 157 158 // Moves files in the cache directory which are not manged by FileCache to 159 // |dest_directory|. 160 // |recovered_cache_info| should contain cache info recovered from the trashed 161 // metadata DB. It is used to ignore non-dirty files. 162 bool RecoverFilesFromCacheDirectory( 163 const base::FilePath& dest_directory, 164 const ResourceMetadataStorage::RecoveredCacheInfoMap& 165 recovered_cache_info); 166 167 private: 168 friend class FileCacheTest; 169 friend class FileCacheTestOnUIThread; 170 171 ~FileCache(); 172 173 // Returns absolute path of the file if it were cached or to be cached. 174 // 175 // Can be called on any thread. 176 base::FilePath GetCacheFilePath(const std::string& id) const; 177 178 // Checks whether the current thread is on the right sequenced worker pool 179 // with the right sequence ID. If not, DCHECK will fail. 180 void AssertOnSequencedWorkerPool(); 181 182 // Destroys the cache on the blocking pool. 183 void DestroyOnBlockingPool(); 184 185 // Used to implement Store and StoreLocallyModifiedOnUIThread. 186 // TODO(hidehiko): Merge this method with Store(), after 187 // StoreLocallyModifiedOnUIThread is removed. 188 FileError StoreInternal(const std::string& id, 189 const std::string& md5, 190 const base::FilePath& source_path, 191 FileOperationType file_operation_type); 192 193 // Used to implement MarkAsUnmountedOnUIThread. 194 FileError MarkAsUnmounted(const base::FilePath& file_path); 195 196 // Returns true if we have sufficient space to store the given number of 197 // bytes, while keeping kMinFreeSpace bytes on the disk. 198 bool HasEnoughSpaceFor(int64 num_bytes, const base::FilePath& path); 199 200 // Renames cache files from old "prefix:id.md5" format to the new format. 201 // TODO(hashimoto): Remove this method at some point. 202 bool RenameCacheFilesToNewFormat(); 203 204 const base::FilePath cache_file_directory_; 205 206 scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_; 207 208 ResourceMetadataStorage* storage_; 209 210 FreeDiskSpaceGetterInterface* free_disk_space_getter_; // Not owned. 211 212 // IDs of files marked mounted. 213 std::set<std::string> mounted_files_; 214 215 // Note: This should remain the last member so it'll be destroyed and 216 // invalidate its weak pointers before any other members are destroyed. 217 base::WeakPtrFactory<FileCache> weak_ptr_factory_; 218 DISALLOW_COPY_AND_ASSIGN(FileCache); 219}; 220 221// The minimum free space to keep. Operations that add cache files return 222// FILE_ERROR_NO_LOCAL_SPACE if the available space is smaller than 223// this value. 224// 225// Copied from cryptohome/homedirs.h. 226// TODO(satorux): Share the constant. 227const int64 kMinFreeSpace = 512 * 1LL << 20; 228 229} // namespace internal 230} // namespace drive 231 232#endif // CHROME_BROWSER_CHROMEOS_DRIVE_FILE_CACHE_H_ 233