2 This file is part of GNUnet.
3 (C) 2001, 2002, 2003, 2004, 2005, 2006, 2009 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 2, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file include/gnunet_disk_lib.h
26 #ifndef GNUNET_DISK_LIB_H
27 #define GNUNET_DISK_LIB_H
29 #include "gnunet_configuration_lib.h"
30 #include "gnunet_scheduler_lib.h"
32 /* we need size_t, and since it can be both unsigned int
33 or unsigned long long, this IS platform dependent;
34 but "stdlib.h" should be portable 'enough' to be
35 unconditionally available... */
41 #if 0 /* keep Emacsens' auto-indent happy */
46 /* Open the file for reading */
47 #define GNUNET_DISK_OPEN_READ 1
48 /* Open the file for writing */
49 #define GNUNET_DISK_OPEN_WRITE 2
50 /* Open the file for both reading and writing */
51 #define GNUNET_DISK_OPEN_READWRITE 3
52 /* Fail if file already exists */
53 #define GNUNET_DISK_OPEN_FAILIFEXISTS 4
54 /* Truncate file if it exists */
55 #define GNUNET_DISK_OPEN_TRUNCATE 8
56 /* Create file if it doesn't exist */
57 #define GNUNET_DISK_OPEN_CREATE 16
58 /* Append to the file */
59 #define GNUNET_DISK_OPEN_APPEND 32
61 #define GNUNET_DISK_MAP_READ 1
62 #define GNUNET_DISK_MAP_WRITE 2
63 #define GNUNET_DISK_MAP_READWRITE 3
65 #define GNUNET_DISK_PERM_USER_READ 1
66 #define GNUNET_DISK_PERM_USER_WRITE 2
67 #define GNUNET_DISK_PERM_USER_EXEC 4
68 #define GNUNET_DISK_PERM_GROUP_READ 8
69 #define GNUNET_DISK_PERM_GROUP_WRITE 16
70 #define GNUNET_DISK_PERM_GROUP_EXEC 32
71 #define GNUNET_DISK_PERM_OTHER_READ 64
72 #define GNUNET_DISK_PERM_OTHER_WRITE 128
73 #define GNUNET_DISK_PERM_OTHER_EXEC 256
82 struct GNUNET_DISK_FileHandle;
84 struct GNUNET_DISK_PipeHandle;
87 * Get the number of blocks that are left on the partition that
88 * contains the given file (for normal users).
90 * @param part a file on the partition to check
91 * @return -1 on errors, otherwise the number of free blocks
93 long GNUNET_DISK_get_blocks_available (const char *part);
97 * Checks whether a handle is invalid
98 * @param h handle to check
99 * @return GNUNET_YES if invalid, GNUNET_NO if valid
101 int GNUNET_DISK_handle_invalid (const struct GNUNET_DISK_FileHandle *h);
105 * Check that fil corresponds to a filename
106 * (of a file that exists and that is not a directory).
108 * @returns GNUNET_YES if yes, GNUNET_NO if not a file, GNUNET_SYSERR if something
109 * else (will print an error message in that case, too).
111 int GNUNET_DISK_file_test (const char *fil);
115 * Move the read/write pointer in a file
116 * @param h handle of an open file
117 * @param offset position to move to
118 * @param whence specification to which position the offset parameter relates to
119 * @return the new position on success, GNUNET_SYSERR otherwise
122 GNUNET_DISK_file_seek (const struct GNUNET_DISK_FileHandle *h, off_t offset,
123 enum GNUNET_DISK_Seek whence);
127 * Get the size of the file (or directory)
128 * of the given file (in bytes).
130 * @param includeSymLinks should symbolic links be
133 * @return GNUNET_OK on success, GNUNET_SYSERR on error
135 int GNUNET_DISK_file_size (const char *filename,
136 unsigned long long *size, int includeSymLinks);
140 * Create an (empty) temporary file on disk.
142 * @param template component to use for the name;
143 * does NOT contain "XXXXXX" or "/tmp/".
144 * @return NULL on error, otherwise name of fresh
145 * file on disk in directory for temporary files
148 GNUNET_DISK_mktemp (const char *template);
153 * @param fn file name to be opened
154 * @param flags opening flags, a combination of GNUNET_DISK_OPEN_xxx bit flags
155 * @param perm permissions for the newly created file
156 * @return IO handle on success, NULL on error
158 struct GNUNET_DISK_FileHandle *GNUNET_DISK_file_open (const char *fn, int flags, ...);
161 * Creates an interprocess channel
162 * @param blocking creates an asynchronous pipe if set to GNUNET_NO
163 * @return handle to the new pipe, NULL on error
165 struct GNUNET_DISK_PipeHandle *GNUNET_DISK_pipe (int blocking);
168 * Closes an interprocess channel
170 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
172 int GNUNET_DISK_pipe_close (struct GNUNET_DISK_PipeHandle *p);
175 * Close an open file.
177 * @param h file handle
178 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
180 int GNUNET_DISK_file_close (struct GNUNET_DISK_FileHandle *h);
183 * Get the handle to a particular pipe end
185 * @param n number of the end
187 const struct GNUNET_DISK_FileHandle *GNUNET_DISK_pipe_handle (const struct
188 GNUNET_DISK_PipeHandle
192 * Read the contents of a binary file into a buffer.
193 * @param h handle to an open file
194 * @param result the buffer to write the result to
195 * @param len the maximum number of bytes to read
196 * @return the number of bytes read on success, GNUNET_SYSERR on failure
198 ssize_t GNUNET_DISK_file_read (const struct GNUNET_DISK_FileHandle *h, void *result,
203 * Read the contents of a binary file into a buffer.
204 * @param fn file name
205 * @param result the buffer to write the result to
206 * @param len the maximum number of bytes to read
207 * @return number of bytes read, GNUNET_SYSERR on failure
209 ssize_t GNUNET_DISK_fn_read (const char * const fn, void *result,
214 * Write a buffer to a file.
216 * @param h handle to open file
217 * @param buffer the data to write
218 * @param n number of bytes to write
219 * @return GNUNET_OK on success, GNUNET_SYSERR on error
221 ssize_t GNUNET_DISK_file_write (const struct GNUNET_DISK_FileHandle *h,
227 * Write a buffer to a file. If the file is longer than
228 * the given buffer size, it will be truncated.
230 * @param fn file name
231 * @param buffer the data to write
232 * @param n number of bytes to write
233 * @return number of bytes written on success, GNUNET_SYSERR on error
235 ssize_t GNUNET_DISK_fn_write (const char * fn,
243 * @return GNUNET_OK on success, GNUNET_SYSERR on error
245 int GNUNET_DISK_file_copy (const char *src, const char *dst);
249 * Scan a directory for files. The name of the directory
250 * must be expanded first (!).
252 * @param dirName the name of the directory
253 * @param callback the method to call for each file
254 * @param data argument to pass to callback
255 * @return the number of files found, -1 on error
257 int GNUNET_DISK_directory_scan (const char *dirName,
258 GNUNET_FileNameCallback callback,
263 * Opaque handle used for iterating over a directory.
265 struct GNUNET_DISK_DirectoryIterator;
269 * Function called to iterate over a directory.
272 * @param di argument to pass to "GNUNET_DISK_directory_iterator_next" to
273 * get called on the next entry (or finish cleanly)
274 * @param filename complete filename (absolute path)
275 * @param dirname directory name (absolute path)
277 typedef void (*GNUNET_DISK_DirectoryIteratorCallback) (void *cls,
279 GNUNET_DISK_DirectoryIterator
281 const char *filename,
282 const char *dirname);
286 * This function must be called during the DiskIteratorCallback
287 * (exactly once) to schedule the task to process the next
288 * filename in the directory (if there is one).
290 * @param iter opaque handle for the iterator
291 * @param can set to GNUNET_YES to terminate the iteration early
292 * @return GNUNET_YES if iteration will continue,
293 * GNUNET_NO if this was the last entry (and iteration is complete),
294 * GNUNET_SYSERR if "can" was YES
296 int GNUNET_DISK_directory_iterator_next (struct GNUNET_DISK_DirectoryIterator
301 * Scan a directory for files using the scheduler to run a task for
302 * each entry. The name of the directory must be expanded first (!).
303 * If a scheduler does not need to be used, GNUNET_DISK_directory_scan
304 * may provide a simpler API.
306 * @param sched scheduler to use
307 * @param prio priority to use
308 * @param dirName the name of the directory
309 * @param callback the method to call for each file
310 * @param callback_cls closure for callback
312 void GNUNET_DISK_directory_iterator_start (struct GNUNET_SCHEDULER_Handle
314 enum GNUNET_SCHEDULER_Priority
315 prio, const char *dirName,
316 GNUNET_DISK_DirectoryIteratorCallback
317 callback, void *callback_cls);
321 * Create the directory structure for storing
324 * @param filename name of a file in the directory
325 * @returns GNUNET_OK on success, GNUNET_SYSERR on failure,
326 * GNUNET_NO if directory exists but is not writeable
328 int GNUNET_DISK_directory_create_for_file (const char *filename);
332 * Test if fil is a directory that can be accessed.
333 * Will not print an error message if the directory
334 * does not exist. Will log errors if GNUNET_SYSERR is
337 * @return GNUNET_YES if yes, GNUNET_NO if does not exist, GNUNET_SYSERR
338 * on any error and if exists but not directory
340 int GNUNET_DISK_directory_test (const char *fil);
344 * Remove all files in a directory (rm -rf). Call with
347 * @param fileName the file to remove
348 * @return GNUNET_OK on success, GNUNET_SYSERR on error
350 int GNUNET_DISK_directory_remove (const char *fileName);
354 * Implementation of "mkdir -p"
356 * @param dir the directory to create
357 * @returns GNUNET_SYSERR on failure, GNUNET_OK otherwise
359 int GNUNET_DISK_directory_create (const char *dir);
363 * Lock a part of a file
364 * @param fh file handle
365 * @lockStart absolute position from where to lock
366 * @lockEnd absolute position until where to lock
367 * @return GNUNET_OK on success, GNUNET_SYSERR on error
370 GNUNET_DISK_file_lock(struct GNUNET_DISK_FileHandle *fh, off_t lockStart,
375 * @brief Removes special characters as ':' from a filename.
376 * @param fn the filename to canonicalize
378 void GNUNET_DISK_filename_canonicalize (char *fn);
382 * @brief Change owner of a file
383 * @param filename file to change
384 * @param user new owner of the file
385 * @return GNUNET_OK on success, GNUNET_SYSERR on failure
387 int GNUNET_DISK_file_change_owner (const char *filename, const char *user);
391 * Construct full path to a file inside of the private
392 * directory used by GNUnet. Also creates the corresponding
393 * directory. If the resulting name is supposed to be
394 * a directory, end the last argument in '/' (or pass
395 * DIR_SEPARATOR_STR as the last argument before NULL).
397 * @param serviceName name of the service asking
398 * @param varargs is NULL-terminated list of
399 * path components to append to the
400 * private directory name.
401 * @return the constructed filename
403 char *GNUNET_DISK_get_home_filename (const struct GNUNET_CONFIGURATION_Handle *cfg,
404 const char *serviceName, ...);
408 * Opaque handle for a memory-mapping operation.
410 struct GNUNET_DISK_MapHandle;
413 * Map a file into memory
414 * @param h open file handle
415 * @param m handle to the new mapping (will be set)
416 * @param access access specification, GNUNET_DISK_MAP_xxx
417 * @param len size of the mapping
418 * @return pointer to the mapped memory region, NULL on failure
420 void *GNUNET_DISK_file_map (const struct GNUNET_DISK_FileHandle *h,
421 struct GNUNET_DISK_MapHandle **m,
422 int access, size_t len);
427 * @param h mapping handle
428 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
430 int GNUNET_DISK_file_unmap (struct GNUNET_DISK_MapHandle *h);
433 * Write file changes to disk
434 * @param h handle to an open file
435 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
437 int GNUNET_DISK_file_sync (const struct GNUNET_DISK_FileHandle *h);
439 #if 0 /* keep Emacsens' auto-indent happy */
447 /* ifndef GNUNET_DISK_LIB_H */
449 /* end of gnunet_disk_lib.h */