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
25 #ifndef GNUNET_DISK_LIB_H
26 #define GNUNET_DISK_LIB_H
29 * Opaque handle used to access files.
31 struct GNUNET_DISK_FileHandle;
34 * Opaque handle used to manage a pipe.
36 struct GNUNET_DISK_PipeHandle;
39 /* we need size_t, and since it can be both unsigned int
40 or unsigned long long, this IS platform dependent;
41 but "stdlib.h" should be portable 'enough' to be
42 unconditionally available... */
44 #include "gnunet_configuration_lib.h"
45 #include "gnunet_scheduler_lib.h"
50 #if 0 /* keep Emacsens' auto-indent happy */
56 /* Open the file for reading */
57 #define GNUNET_DISK_OPEN_READ 1
58 /* Open the file for writing */
59 #define GNUNET_DISK_OPEN_WRITE 2
60 /* Open the file for both reading and writing */
61 #define GNUNET_DISK_OPEN_READWRITE 3
62 /* Fail if file already exists */
63 #define GNUNET_DISK_OPEN_FAILIFEXISTS 4
64 /* Truncate file if it exists */
65 #define GNUNET_DISK_OPEN_TRUNCATE 8
66 /* Create file if it doesn't exist */
67 #define GNUNET_DISK_OPEN_CREATE 16
68 /* Append to the file */
69 #define GNUNET_DISK_OPEN_APPEND 32
71 #define GNUNET_DISK_MAP_READ 1
72 #define GNUNET_DISK_MAP_WRITE 2
73 #define GNUNET_DISK_MAP_READWRITE 3
75 #define GNUNET_DISK_PERM_USER_READ 1
76 #define GNUNET_DISK_PERM_USER_WRITE 2
77 #define GNUNET_DISK_PERM_USER_EXEC 4
78 #define GNUNET_DISK_PERM_GROUP_READ 8
79 #define GNUNET_DISK_PERM_GROUP_WRITE 16
80 #define GNUNET_DISK_PERM_GROUP_EXEC 32
81 #define GNUNET_DISK_PERM_OTHER_READ 64
82 #define GNUNET_DISK_PERM_OTHER_WRITE 128
83 #define GNUNET_DISK_PERM_OTHER_EXEC 256
93 * Get the number of blocks that are left on the partition that
94 * contains the given file (for normal users).
96 * @param part a file on the partition to check
97 * @return -1 on errors, otherwise the number of free blocks
99 long GNUNET_DISK_get_blocks_available (const char *part);
103 * Checks whether a handle is invalid
104 * @param h handle to check
105 * @return GNUNET_YES if invalid, GNUNET_NO if valid
107 int GNUNET_DISK_handle_invalid (const struct GNUNET_DISK_FileHandle *h);
111 * Check that fil corresponds to a filename
112 * (of a file that exists and that is not a directory).
114 * @returns GNUNET_YES if yes, GNUNET_NO if not a file, GNUNET_SYSERR if something
115 * else (will print an error message in that case, too).
117 int GNUNET_DISK_file_test (const char *fil);
121 * Move the read/write pointer in a file
122 * @param h handle of an open file
123 * @param offset position to move to
124 * @param whence specification to which position the offset parameter relates to
125 * @return the new position on success, GNUNET_SYSERR otherwise
128 GNUNET_DISK_file_seek (const struct GNUNET_DISK_FileHandle *h, off_t offset,
129 enum GNUNET_DISK_Seek whence);
133 * Get the size of the file (or directory)
134 * of the given file (in bytes).
136 * @param includeSymLinks should symbolic links be
139 * @return GNUNET_OK on success, GNUNET_SYSERR on error
141 int GNUNET_DISK_file_size (const char *filename,
142 unsigned long long *size, int includeSymLinks);
146 * Create an (empty) temporary file on disk.
148 * @param template component to use for the name;
149 * does NOT contain "XXXXXX" or "/tmp/".
150 * @return NULL on error, otherwise name of fresh
151 * file on disk in directory for temporary files
154 GNUNET_DISK_mktemp (const char *template);
159 * @param fn file name to be opened
160 * @param flags opening flags, a combination of GNUNET_DISK_OPEN_xxx bit flags
161 * @param perm permissions for the newly created file
162 * @return IO handle on success, NULL on error
164 struct GNUNET_DISK_FileHandle *GNUNET_DISK_file_open (const char *fn, int flags, ...);
167 * Creates an interprocess channel
168 * @param blocking creates an asynchronous pipe if set to GNUNET_NO
169 * @return handle to the new pipe, NULL on error
171 struct GNUNET_DISK_PipeHandle *GNUNET_DISK_pipe (int blocking);
174 * Closes an interprocess channel
176 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
178 int GNUNET_DISK_pipe_close (struct GNUNET_DISK_PipeHandle *p);
181 * Close an open file.
183 * @param h file handle
184 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
186 int GNUNET_DISK_file_close (struct GNUNET_DISK_FileHandle *h);
189 * Get the handle to a particular pipe end
191 * @param n number of the end
193 const struct GNUNET_DISK_FileHandle *GNUNET_DISK_pipe_handle (const struct
194 GNUNET_DISK_PipeHandle
198 * Read the contents of a binary file into a buffer.
199 * @param h handle to an open file
200 * @param result the buffer to write the result to
201 * @param len the maximum number of bytes to read
202 * @return the number of bytes read on success, GNUNET_SYSERR on failure
204 ssize_t GNUNET_DISK_file_read (const struct GNUNET_DISK_FileHandle *h, void *result,
209 * Read the contents of a binary file into a buffer.
210 * @param fn file name
211 * @param result the buffer to write the result to
212 * @param len the maximum number of bytes to read
213 * @return number of bytes read, GNUNET_SYSERR on failure
215 ssize_t GNUNET_DISK_fn_read (const char * const fn, void *result,
220 * Write a buffer to a file.
222 * @param h handle to open file
223 * @param buffer the data to write
224 * @param n number of bytes to write
225 * @return GNUNET_OK on success, GNUNET_SYSERR on error
227 ssize_t GNUNET_DISK_file_write (const struct GNUNET_DISK_FileHandle *h,
233 * Write a buffer to a file. If the file is longer than
234 * the given buffer size, it will be truncated.
236 * @param fn file name
237 * @param buffer the data to write
238 * @param n number of bytes to write
239 * @return number of bytes written on success, GNUNET_SYSERR on error
241 ssize_t GNUNET_DISK_fn_write (const char * fn,
249 * @return GNUNET_OK on success, GNUNET_SYSERR on error
251 int GNUNET_DISK_file_copy (const char *src, const char *dst);
255 * Scan a directory for files. The name of the directory
256 * must be expanded first (!).
258 * @param dirName the name of the directory
259 * @param callback the method to call for each file
260 * @param data argument to pass to callback
261 * @return the number of files found, -1 on error
263 int GNUNET_DISK_directory_scan (const char *dirName,
264 GNUNET_FileNameCallback callback,
269 * Opaque handle used for iterating over a directory.
271 struct GNUNET_DISK_DirectoryIterator;
275 * Function called to iterate over a directory.
278 * @param di argument to pass to "GNUNET_DISK_directory_iterator_next" to
279 * get called on the next entry (or finish cleanly)
280 * @param filename complete filename (absolute path)
281 * @param dirname directory name (absolute path)
283 typedef void (*GNUNET_DISK_DirectoryIteratorCallback) (void *cls,
285 GNUNET_DISK_DirectoryIterator
287 const char *filename,
288 const char *dirname);
292 * This function must be called during the DiskIteratorCallback
293 * (exactly once) to schedule the task to process the next
294 * filename in the directory (if there is one).
296 * @param iter opaque handle for the iterator
297 * @param can set to GNUNET_YES to terminate the iteration early
298 * @return GNUNET_YES if iteration will continue,
299 * GNUNET_NO if this was the last entry (and iteration is complete),
300 * GNUNET_SYSERR if "can" was YES
302 int GNUNET_DISK_directory_iterator_next (struct GNUNET_DISK_DirectoryIterator
307 * Scan a directory for files using the scheduler to run a task for
308 * each entry. The name of the directory must be expanded first (!).
309 * If a scheduler does not need to be used, GNUNET_DISK_directory_scan
310 * may provide a simpler API.
312 * @param sched scheduler to use
313 * @param prio priority to use
314 * @param dirName the name of the directory
315 * @param callback the method to call for each file
316 * @param callback_cls closure for callback
318 void GNUNET_DISK_directory_iterator_start (struct GNUNET_SCHEDULER_Handle
320 enum GNUNET_SCHEDULER_Priority
321 prio, const char *dirName,
322 GNUNET_DISK_DirectoryIteratorCallback
323 callback, void *callback_cls);
327 * Create the directory structure for storing
330 * @param filename name of a file in the directory
331 * @returns GNUNET_OK on success, GNUNET_SYSERR on failure,
332 * GNUNET_NO if directory exists but is not writeable
334 int GNUNET_DISK_directory_create_for_file (const char *filename);
338 * Test if fil is a directory that can be accessed.
339 * Will not print an error message if the directory
340 * does not exist. Will log errors if GNUNET_SYSERR is
343 * @return GNUNET_YES if yes, GNUNET_NO if does not exist, GNUNET_SYSERR
344 * on any error and if exists but not directory
346 int GNUNET_DISK_directory_test (const char *fil);
350 * Remove all files in a directory (rm -rf). Call with
353 * @param fileName the file to remove
354 * @return GNUNET_OK on success, GNUNET_SYSERR on error
356 int GNUNET_DISK_directory_remove (const char *fileName);
360 * Implementation of "mkdir -p"
362 * @param dir the directory to create
363 * @returns GNUNET_SYSERR on failure, GNUNET_OK otherwise
365 int GNUNET_DISK_directory_create (const char *dir);
369 * Lock a part of a file
370 * @param fh file handle
371 * @lockStart absolute position from where to lock
372 * @lockEnd absolute position until where to lock
373 * @return GNUNET_OK on success, GNUNET_SYSERR on error
376 GNUNET_DISK_file_lock(struct GNUNET_DISK_FileHandle *fh, off_t lockStart,
381 * @brief Removes special characters as ':' from a filename.
382 * @param fn the filename to canonicalize
384 void GNUNET_DISK_filename_canonicalize (char *fn);
388 * @brief Change owner of a file
389 * @param filename file to change
390 * @param user new owner of the file
391 * @return GNUNET_OK on success, GNUNET_SYSERR on failure
393 int GNUNET_DISK_file_change_owner (const char *filename, const char *user);
397 * Construct full path to a file inside of the private
398 * directory used by GNUnet. Also creates the corresponding
399 * directory. If the resulting name is supposed to be
400 * a directory, end the last argument in '/' (or pass
401 * DIR_SEPARATOR_STR as the last argument before NULL).
403 * @param serviceName name of the service asking
404 * @param varargs is NULL-terminated list of
405 * path components to append to the
406 * private directory name.
407 * @return the constructed filename
409 char *GNUNET_DISK_get_home_filename (const struct GNUNET_CONFIGURATION_Handle *cfg,
410 const char *serviceName, ...);
414 * Opaque handle for a memory-mapping operation.
416 struct GNUNET_DISK_MapHandle;
419 * Map a file into memory
420 * @param h open file handle
421 * @param m handle to the new mapping (will be set)
422 * @param access access specification, GNUNET_DISK_MAP_xxx
423 * @param len size of the mapping
424 * @return pointer to the mapped memory region, NULL on failure
426 void *GNUNET_DISK_file_map (const struct GNUNET_DISK_FileHandle *h,
427 struct GNUNET_DISK_MapHandle **m,
428 int access, size_t len);
433 * @param h mapping handle
434 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
436 int GNUNET_DISK_file_unmap (struct GNUNET_DISK_MapHandle *h);
439 * Write file changes to disk
440 * @param h handle to an open file
441 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
443 int GNUNET_DISK_file_sync (const struct GNUNET_DISK_FileHandle *h);
445 #if 0 /* keep Emacsens' auto-indent happy */
453 /* ifndef GNUNET_DISK_LIB_H */
455 /* end of gnunet_disk_lib.h */