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FileSystem.h
1 
2 /* mbed Microcontroller Library
3  * Copyright (c) 2006-2013 ARM Limited
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 #ifndef MBED_FILESYSTEM_H
18 #define MBED_FILESYSTEM_H
19 
20 #include "platform/platform.h"
21 
22 #include "platform/FileBase.h"
23 #include "platform/FileHandle.h"
24 #include "platform/DirHandle.h"
25 #include "platform/FileSystemLike.h"
26 #include "BlockDevice.h"
27 
28 namespace mbed {
29 /** \addtogroup file system */
30 /** @{*/
31 
32 
33 // Opaque pointer representing files and directories.
34 typedef void *fs_file_t;
35 typedef void *fs_dir_t;
36 
37 // Predeclared classes.
38 class Dir;
39 class File;
40 
41 /** A file system object. Provides file system operations and file operations
42  * for the File and Dir classes on a block device.
43  *
44  * Implementations must provide at minimum file operations and mount
45  * operations for block devices.
46  *
47  * @note Synchronization level: Set by subclass
48  */
49 class FileSystem : public FileSystemLike {
50 public:
51 
52  /** File system lifetime.
53  *
54  * @param name Name to add file system to tree as.
55  */
56  FileSystem(const char *name = NULL);
57  virtual ~FileSystem() {}
58 
59  /** Return the default file system.
60  *
61  * Returns the default file system based on the default block device configuration.
62  * Use the components in target.json or application config to change
63  * the default block device and affect the default filesystem.
64  * SD block device => FAT filesystem
65  * QSPIF, SPIF, DATAFLASH or FLAHIAP block device => LITTLE filesystem
66  *
67  * An application can override all target settings by implementing
68  * FileSystem::get_default_instance() - the default
69  * definition is weak, and calls get_target_default_instance().
70  */
72 
73  /** Mount a file system to a block device.
74  *
75  * @param bd Block device to mount to.
76  * @return 0 on success, negative error code on failure.
77  */
78  virtual int mount(BlockDevice *bd) = 0;
79 
80  /** Unmount a file system from the underlying block device.
81  *
82  * @return 0 on success, negative error code on failure.
83  */
84  virtual int unmount() = 0;
85 
86  /** Reformat a file system. Results in an empty and mounted file system.
87  *
88  * @param bd Block device to reformat and mount. If NULL, the mounted
89  * Block device is used.
90  * Note: If mount fails, bd must be provided.
91  * Default: NULL
92  * @return 0 on success, negative error code on failure.
93  */
94  virtual int reformat(BlockDevice *bd = NULL);
95 
96  /** Remove a file from the file system.
97  *
98  * @param path The name of the file to remove.
99  * @return 0 on success, negative error code on failure.
100  */
101  virtual int remove(const char *path);
102 
103  /** Rename a file in the file system.
104  *
105  * @param path The existing name of the file to rename.
106  * @param newpath The new name of the file.
107  * @return 0 on success, negative error code on failure.
108  */
109  virtual int rename(const char *path, const char *newpath);
110 
111  /** Store information about the file in a stat structure.
112  *
113  * @param path The name of the file to find information about.
114  * @param st The stat buffer to write to.
115  * @return 0 on success, negative error code on failure.
116  */
117  virtual int stat(const char *path, struct stat *st);
118 
119  /** Create a directory in the file system.
120  *
121  * @param path The name of the directory to create.
122  * @param mode The permissions with which to create the directory.
123  * @return 0 on success, negative error code on failure.
124  */
125  virtual int mkdir(const char *path, mode_t mode);
126 
127  /** Store information about the mounted file system in a statvfs structure.
128  *
129  * @param path The name of the file to find information about.
130  * @param buf The stat buffer to write to.
131  * @return 0 on success, negative error code on failure.
132  */
133  virtual int statvfs(const char *path, struct statvfs *buf);
134 
135 protected:
136  friend class File;
137  friend class Dir;
138 
139 #if !(DOXYGEN_ONLY)
140  /** Open a file on the file system.
141  *
142  * @param file Destination of the newly created handle to the referenced file.
143  * @param path The name of the file to open.
144  * @param flags The flags that trigger opening of the file. These flags are O_RDONLY, O_WRONLY, and O_RDWR,
145  * with an O_CREAT, O_TRUNC, or O_APPEND bitwise OR operator.
146  * @return 0 on success, negative error code on failure.
147  */
148  virtual int file_open(fs_file_t *file, const char *path, int flags) = 0;
149 
150  /** Close a file.
151  *
152  * @param file File handle.
153  * return 0 on success, negative error code on failure.
154  */
155  virtual int file_close(fs_file_t file) = 0;
156 
157  /** Read the contents of a file into a buffer.
158  *
159  * @param file File handle.
160  * @param buffer The buffer to read in to.
161  * @param size The number of bytes to read.
162  * @return The number of bytes read, 0 at the end of the file, negative error on failure.
163  */
164  virtual ssize_t file_read(fs_file_t file, void *buffer, size_t size) = 0;
165 
166  /** Write the contents of a buffer to a file.
167  *
168  * @param file File handle.
169  * @param buffer The buffer to write from.
170  * @param size The number of bytes to write.
171  * @return The number of bytes written, negative error on failure.
172  */
173  virtual ssize_t file_write(fs_file_t file, const void *buffer, size_t size) = 0;
174 
175  /** Flush any buffers associated with the file.
176  *
177  * @param file File handle.
178  * @return 0 on success, negative error code on failure.
179  */
180  virtual int file_sync(fs_file_t file);
181 
182  /** Check whether the file is an interactive terminal device.
183  * If so, line buffered behavior is used by default.
184  *
185  * @param file File handle.
186  * @return True if the file is a terminal.
187  */
188  virtual int file_isatty(fs_file_t file);
189 
190  /** Move the file position to a given offset from a given location.
191  *
192  * @param file File handle.
193  * @param offset The offset from whence to move to.
194  * @param whence The start of where to seek.
195  * SEEK_SET to start from the beginning of the file,
196  * SEEK_CUR to start from the current position in the file,
197  * SEEK_END to start from the end of the file.
198  * @return The new offset of the file
199  */
200  virtual off_t file_seek(fs_file_t file, off_t offset, int whence) = 0;
201 
202  /** Get the file position of the file.
203  *
204  * @param file File handle.
205  * @return The current offset in the file.
206  */
207  virtual off_t file_tell(fs_file_t file);
208 
209  /** Rewind the file position to the beginning of the file.
210  *
211  * @param file File handle.
212  * @note This is equivalent to file_seek(file, 0, FS_SEEK_SET)
213  */
214  virtual void file_rewind(fs_file_t file);
215 
216  /** Get the size of the file.
217  *
218  * @param file File handle.
219  * @return Size of the file in bytes.
220  */
221  virtual off_t file_size(fs_file_t file);
222 
223  /** Truncate or extend a file.
224  *
225  * The file's length is set to the specified value. The seek pointer is
226  * not changed. If the file is extended, the extended area appears as if
227  * it were zero-filled.
228  *
229  * @param file File handle.
230  * @param length The requested new length for the file.
231  *
232  * @return 0 on success, negative error code on failure.
233  */
234  virtual int file_truncate(fs_file_t file, off_t length);
235 
236  /** Open a directory on the file system.
237  *
238  * @param dir Destination for the handle to the directory.
239  * @param path Name of the directory to open.
240  * @return 0 on success, negative error code on failure.
241  */
242  virtual int dir_open(fs_dir_t *dir, const char *path);
243 
244  /** Close a directory.
245  *
246  * @param dir Dir handle.
247  * @return 0 on success, negative error code on failure.
248  */
249  virtual int dir_close(fs_dir_t dir);
250 
251  /** Read the next directory entry.
252  *
253  * @param dir Dir handle.
254  * @param ent The directory entry to fill out.
255  * @return 1 on reading a filename, 0 at the end of the directory, negative error on failure.
256  */
257  virtual ssize_t dir_read(fs_dir_t dir, struct dirent *ent);
258 
259  /** Set the current position of the directory.
260  *
261  * @param dir Dir handle.
262  * @param offset Offset of the location to seek to,
263  * must be a value returned from dir_tell.
264  */
265  virtual void dir_seek(fs_dir_t dir, off_t offset);
266 
267  /** Get the current position of the directory.
268  *
269  * @param dir Dir handle.
270  * @return Directory position, which can be passed to dir_rewind.
271  */
272  virtual off_t dir_tell(fs_dir_t dir);
273 
274  /** Rewind the current position to the beginning of the directory.
275  *
276  * @param dir Dir handle.
277  */
278  virtual void dir_rewind(fs_dir_t dir);
279 
280  /** Get the size of the directory.
281  *
282  * @param dir Dir handle.
283  * @return Number of files in the directory.
284  */
285  virtual size_t dir_size(fs_dir_t dir);
286 #endif //!defined(DOXYGEN_ONLY)
287 
288 protected:
289  // Hooks for file systemHandle
290  virtual int open(FileHandle **file, const char *path, int flags);
291  virtual int open(DirHandle **dir, const char *path);
292 };
293 
294 
295 /** @}*/
296 } // namespace mbed
297 
298 #endif
virtual int stat(const char *path, struct stat *st)
Store information about the file in a stat structure.
FileSystem(const char *name=NULL)
File system lifetime.
Represents a directory stream.
Definition: DirHandle.h:56
virtual int mount(BlockDevice *bd)=0
Mount a file system to a block device.
A hardware device capable of writing and reading blocks.
Definition: BlockDevice.h:47
Class FileHandle.
Definition: FileHandle.h:46
virtual int open(FileHandle **file, const char *path, int flags)
defined(DOXYGEN_ONLY)
A filesystem-like object is one that can be used to open file-like objects though it by fopen("/name/...
virtual int mkdir(const char *path, mode_t mode)
Create a directory in the file system.
Dir class.
Definition: Dir.h:30
virtual int reformat(BlockDevice *bd=NULL)
Reformat a file system.
File class.
Definition: File.h:30
A file system object.
Definition: FileSystem.h:49
virtual int rename(const char *path, const char *newpath)
Rename a file in the file system.
virtual int unmount()=0
Unmount a file system from the underlying block device.
static FileSystem * get_default_instance()
Return the default file system.
Definition: AnalogIn.h:28
virtual int statvfs(const char *path, struct statvfs *buf)
Store information about the mounted file system in a statvfs structure.
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