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.
5 #ifndef WEBKIT_BROWSER_FILEAPI_OBFUSCATED_FILE_UTIL_H_
6 #define WEBKIT_BROWSER_FILEAPI_OBFUSCATED_FILE_UTIL_H_
13 #include "base/callback_forward.h"
14 #include "base/files/file.h"
15 #include "base/files/file_path.h"
16 #include "base/files/file_util_proxy.h"
17 #include "base/gtest_prod_util.h"
18 #include "base/memory/scoped_ptr.h"
19 #include "base/platform_file.h"
20 #include "webkit/browser/fileapi/file_system_file_util.h"
21 #include "webkit/browser/fileapi/file_system_url.h"
22 #include "webkit/browser/fileapi/sandbox_directory_database.h"
23 #include "webkit/browser/fileapi/sandbox_file_system_backend_delegate.h"
24 #include "webkit/browser/webkit_storage_browser_export.h"
25 #include "webkit/common/blob/shareable_file_reference.h"
26 #include "webkit/common/fileapi/file_system_types.h"
29 class SequencedTaskRunner;
34 class ObfuscatedFileUtilTest;
38 class SpecialStoragePolicy;
45 class FileSystemOperationContext;
46 class SandboxOriginDatabaseInterface;
47 class TimedTaskHelper;
49 // This file util stores directory information in LevelDB to obfuscate
50 // and to neutralize virtual file paths given by arbitrary apps.
51 // Files are stored with two-level isolation: per-origin and per-type.
52 // The isolation is done by storing data in separate directory partitions.
53 // For example, a file in Temporary file system for origin 'www.example.com'
54 // is stored in a different partition for a file in Persistent file system
55 // for the same origin, or for Temporary file system for another origin.
57 // * Per-origin directory name information is stored in a separate LevelDB,
58 // which is maintained by SandboxOriginDatabase.
59 // * Per-type directory name information is given by
60 // GetTypeStringForURLCallback that is given in CTOR.
61 // We use a small static mapping (e.g. 't' for Temporary type) for
62 // regular sandbox filesystems.
64 // The overall implementation philosophy of this class is that partial failures
65 // should leave us with an intact database; we'd prefer to leak the occasional
66 // backing file than have a database entry whose backing file is missing. When
67 // doing FSCK operations, if you find a loose backing file with no reference,
68 // you may safely delete it.
70 // This class must be deleted on the FILE thread, because that's where
71 // DropDatabases needs to be called.
72 class WEBKIT_STORAGE_BROWSER_EXPORT_PRIVATE ObfuscatedFileUtil
73 : public FileSystemFileUtil {
75 // Origin enumerator interface.
76 // An instance of this interface is assumed to be called on the file thread.
77 class AbstractOriginEnumerator {
79 virtual ~AbstractOriginEnumerator() {}
81 // Returns the next origin. Returns empty if there are no more origins.
82 virtual GURL Next() = 0;
84 // Returns the current origin's information.
85 // |type_string| must be ascii string.
86 virtual bool HasTypeDirectory(const std::string& type_string) const = 0;
89 typedef base::Callback<std::string(const FileSystemURL&)>
90 GetTypeStringForURLCallback;
92 // |get_type_string_for_url| is user-defined callback that should return
93 // a type string for the given FileSystemURL. The type string is used
94 // to provide per-type isolation in the sandboxed filesystem directory.
95 // Note that this method is called on file_task_runner.
97 // |known_type_strings| are known type string names that this file system
99 // This info is used to determine whether we could delete the entire
100 // origin directory or not in DeleteDirectoryForOriginAndType. If no directory
101 // for any known type exists the origin directory may get deleted when
102 // one origin/type pair is deleted.
105 quota::SpecialStoragePolicy* special_storage_policy,
106 const base::FilePath& file_system_directory,
107 base::SequencedTaskRunner* file_task_runner,
108 const GetTypeStringForURLCallback& get_type_string_for_url,
109 const std::set<std::string>& known_type_strings,
110 SandboxFileSystemBackendDelegate* sandbox_delegate);
111 virtual ~ObfuscatedFileUtil();
113 // FileSystemFileUtil overrides.
114 virtual base::File::Error CreateOrOpen(
115 FileSystemOperationContext* context,
116 const FileSystemURL& url,
118 base::PlatformFile* file_handle,
119 bool* created) OVERRIDE;
120 virtual base::File::Error Close(
121 FileSystemOperationContext* context,
122 base::PlatformFile file) OVERRIDE;
123 virtual base::File::Error EnsureFileExists(
124 FileSystemOperationContext* context,
125 const FileSystemURL& url, bool* created) OVERRIDE;
126 virtual base::File::Error CreateDirectory(
127 FileSystemOperationContext* context,
128 const FileSystemURL& url,
130 bool recursive) OVERRIDE;
131 virtual base::File::Error GetFileInfo(
132 FileSystemOperationContext* context,
133 const FileSystemURL& url,
134 base::File::Info* file_info,
135 base::FilePath* platform_file) OVERRIDE;
136 virtual scoped_ptr<AbstractFileEnumerator> CreateFileEnumerator(
137 FileSystemOperationContext* context,
138 const FileSystemURL& root_url) OVERRIDE;
139 virtual base::File::Error GetLocalFilePath(
140 FileSystemOperationContext* context,
141 const FileSystemURL& file_system_url,
142 base::FilePath* local_path) OVERRIDE;
143 virtual base::File::Error Touch(
144 FileSystemOperationContext* context,
145 const FileSystemURL& url,
146 const base::Time& last_access_time,
147 const base::Time& last_modified_time) OVERRIDE;
148 virtual base::File::Error Truncate(
149 FileSystemOperationContext* context,
150 const FileSystemURL& url,
151 int64 length) OVERRIDE;
152 virtual base::File::Error CopyOrMoveFile(
153 FileSystemOperationContext* context,
154 const FileSystemURL& src_url,
155 const FileSystemURL& dest_url,
156 CopyOrMoveOption option,
158 virtual base::File::Error CopyInForeignFile(
159 FileSystemOperationContext* context,
160 const base::FilePath& src_file_path,
161 const FileSystemURL& dest_url) OVERRIDE;
162 virtual base::File::Error DeleteFile(
163 FileSystemOperationContext* context,
164 const FileSystemURL& url) OVERRIDE;
165 virtual base::File::Error DeleteDirectory(
166 FileSystemOperationContext* context,
167 const FileSystemURL& url) OVERRIDE;
168 virtual webkit_blob::ScopedFile CreateSnapshotFile(
169 FileSystemOperationContext* context,
170 const FileSystemURL& url,
171 base::File::Error* error,
172 base::File::Info* file_info,
173 base::FilePath* platform_path) OVERRIDE;
175 // Same as the other CreateFileEnumerator, but with recursive support.
176 scoped_ptr<AbstractFileEnumerator> CreateFileEnumerator(
177 FileSystemOperationContext* context,
178 const FileSystemURL& root_url,
181 // Returns true if the directory |url| is empty.
182 bool IsDirectoryEmpty(
183 FileSystemOperationContext* context,
184 const FileSystemURL& url);
186 // Gets the topmost directory specific to this origin and type. This will
187 // contain both the directory database's files and all the backing file
189 // Returns the topmost origin directory if |type_string| is empty.
190 // Returns an empty path if the directory is undefined.
191 // If the directory is defined, it will be returned, even if
192 // there is a file system error (e.g. the directory doesn't exist on disk and
193 // |create| is false). Callers should always check |error_code| to make sure
194 // the returned path is usable.
195 base::FilePath GetDirectoryForOriginAndType(
197 const std::string& type_string,
199 base::File::Error* error_code);
201 // Deletes the topmost directory specific to this origin and type. This will
202 // delete its directory database.
203 // Deletes the topmost origin directory if |type_string| is empty.
204 bool DeleteDirectoryForOriginAndType(
206 const std::string& type_string);
208 // This method and all methods of its returned class must be called only on
209 // the FILE thread. The caller is responsible for deleting the returned
211 AbstractOriginEnumerator* CreateOriginEnumerator();
213 // Deletes a directory database from the database list in the ObfuscatedFSFU
214 // and destroys the database on the disk.
215 bool DestroyDirectoryDatabase(const GURL& origin,
216 const std::string& type_string);
218 // Computes a cost for storing a given file in the obfuscated FSFU.
219 // As the cost of a file is independent of the cost of its parent directories,
220 // this ignores all but the BaseName of the supplied path. In order to
221 // compute the cost of adding a multi-segment directory recursively, call this
222 // on each path segment and add the results.
223 static int64 ComputeFilePathCost(const base::FilePath& path);
225 // Tries to prepopulate directory database for the given type strings.
226 // This tries from the first one in the given type_strings and stops
227 // once it succeeds to do so for one database (i.e. it prepopulates
228 // at most one database).
229 void MaybePrepopulateDatabase(
230 const std::vector<std::string>& type_strings_to_prepopulate);
233 typedef SandboxDirectoryDatabase::FileId FileId;
234 typedef SandboxDirectoryDatabase::FileInfo FileInfo;
236 friend class ObfuscatedFileEnumerator;
237 friend class QuotaBackendImplTest;
238 friend class content::ObfuscatedFileUtilTest;
240 // Helper method to create an obfuscated file util for regular
241 // (temporary, persistent) file systems. Used only for testing.
242 // Note: this is implemented in sandbox_file_system_backend_delegate.cc.
243 static ObfuscatedFileUtil* CreateForTesting(
244 quota::SpecialStoragePolicy* special_storage_policy,
245 const base::FilePath& file_system_directory,
246 base::SequencedTaskRunner* file_task_runner);
248 base::FilePath GetDirectoryForURL(
249 const FileSystemURL& url,
251 base::File::Error* error_code);
253 // This just calls get_type_string_for_url_ callback that is given in ctor.
254 std::string CallGetTypeStringForURL(const FileSystemURL& url);
256 base::File::Error GetFileInfoInternal(
257 SandboxDirectoryDatabase* db,
258 FileSystemOperationContext* context,
259 const FileSystemURL& url,
261 FileInfo* local_info,
262 base::File::Info* file_info,
263 base::FilePath* platform_file_path);
265 // Creates a new file, both the underlying backing file and the entry in the
266 // database. |dest_file_info| is an in-out parameter. Supply the name and
267 // parent_id; data_path is ignored. On success, data_path will
268 // always be set to the relative path [from the root of the type-specific
269 // filesystem directory] of a NEW backing file, and handle, if supplied, will
270 // hold open PlatformFile for the backing file, which the caller is
271 // responsible for closing. If you supply a path in |source_path|, it will be
272 // used as a source from which to COPY data.
273 // Caveat: do not supply handle if you're also supplying a data path. It was
274 // easier not to support this, and no code has needed it so far, so it will
275 // DCHECK and handle will hold base::kInvalidPlatformFileValue.
276 base::File::Error CreateFile(
277 FileSystemOperationContext* context,
278 const base::FilePath& source_file_path,
279 const FileSystemURL& dest_url,
280 FileInfo* dest_file_info,
282 base::PlatformFile* handle);
284 // This converts from a relative path [as is stored in the FileInfo.data_path
285 // field] to an absolute platform path that can be given to the native
287 base::FilePath DataPathToLocalPath(
288 const FileSystemURL& url,
289 const base::FilePath& data_file_path);
291 std::string GetDirectoryDatabaseKey(const GURL& origin,
292 const std::string& type_string);
294 // This returns NULL if |create| flag is false and a filesystem does not
295 // exist for the given |url|.
296 // For read operations |create| should be false.
297 SandboxDirectoryDatabase* GetDirectoryDatabase(const FileSystemURL& url,
300 // Gets the topmost directory specific to this origin. This will
301 // contain both the filesystem type subdirectories.
302 base::FilePath GetDirectoryForOrigin(const GURL& origin,
304 base::File::Error* error_code);
306 void InvalidateUsageCache(FileSystemOperationContext* context,
308 FileSystemType type);
311 void DropDatabases();
313 // Initializes the origin database. |origin_hint| may be used as a hint
314 // for initializing database if it's not empty.
315 bool InitOriginDatabase(const GURL& origin_hint, bool create);
317 base::File::Error GenerateNewLocalPath(
318 SandboxDirectoryDatabase* db,
319 FileSystemOperationContext* context,
320 const FileSystemURL& url,
321 base::FilePath* local_path);
323 base::File::Error CreateOrOpenInternal(
324 FileSystemOperationContext* context,
325 const FileSystemURL& url,
327 base::PlatformFile* file_handle,
330 bool HasIsolatedStorage(const GURL& origin);
332 typedef std::map<std::string, SandboxDirectoryDatabase*> DirectoryMap;
333 DirectoryMap directories_;
334 scoped_ptr<SandboxOriginDatabaseInterface> origin_database_;
335 scoped_refptr<quota::SpecialStoragePolicy> special_storage_policy_;
336 base::FilePath file_system_directory_;
338 // Used to delete database after a certain period of inactivity.
339 int64 db_flush_delay_seconds_;
341 scoped_refptr<base::SequencedTaskRunner> file_task_runner_;
342 scoped_ptr<TimedTaskHelper> timer_;
344 GetTypeStringForURLCallback get_type_string_for_url_;
345 std::set<std::string> known_type_strings_;
348 SandboxFileSystemBackendDelegate* sandbox_delegate_;
350 DISALLOW_COPY_AND_ASSIGN(ObfuscatedFileUtil);
353 } // namespace fileapi
355 #endif // WEBKIT_BROWSER_FILEAPI_OBFUSCATED_FILE_UTIL_H_