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 */
57 * Specifies how a file should be opened.
59 enum GNUNET_DISK_OpenFlags
63 * Open the file for reading
65 GNUNET_DISK_OPEN_READ = 1,
68 * Open the file for writing
70 GNUNET_DISK_OPEN_WRITE = 2,
73 * Open the file for both reading and writing
75 GNUNET_DISK_OPEN_READWRITE = 3,
78 * Fail if file already exists
80 GNUNET_DISK_OPEN_FAILIFEXISTS = 4,
83 * Truncate file if it exists
85 GNUNET_DISK_OPEN_TRUNCATE = 8,
88 * Create file if it doesn't exist
90 GNUNET_DISK_OPEN_CREATE = 16,
95 GNUNET_DISK_OPEN_APPEND = 32
99 * Specifies what type of memory map is desired.
101 enum GNUNET_DISK_MapType
104 * Read-only memory map.
106 GNUNET_DISK_MAP_TYPE_READ = 1,
109 * Write-able memory map.
111 GNUNET_DISK_MAP_TYPE_WRITE = 2,
113 * Read-write memory map.
115 GNUNET_DISK_MAP_TYPE_READWRITE = 3
119 // FIXME: use enum here!
120 #define GNUNET_DISK_PERM_USER_READ 1
121 #define GNUNET_DISK_PERM_USER_WRITE 2
122 #define GNUNET_DISK_PERM_USER_EXEC 4
123 #define GNUNET_DISK_PERM_GROUP_READ 8
124 #define GNUNET_DISK_PERM_GROUP_WRITE 16
125 #define GNUNET_DISK_PERM_GROUP_EXEC 32
126 #define GNUNET_DISK_PERM_OTHER_READ 64
127 #define GNUNET_DISK_PERM_OTHER_WRITE 128
128 #define GNUNET_DISK_PERM_OTHER_EXEC 256
131 * Constants for specifying how to seek.
133 enum GNUNET_DISK_Seek
136 * Seek an absolute position (from the start of the file).
138 GNUNET_DISK_SEEK_SET,
141 * Seek a relative position (from the current offset).
143 GNUNET_DISK_SEEK_CUR,
146 * Seek an absolute position from the end of the file.
152 * Get the number of blocks that are left on the partition that
153 * contains the given file (for normal users).
155 * @param part a file on the partition to check
156 * @return -1 on errors, otherwise the number of free blocks
158 long GNUNET_DISK_get_blocks_available (const char *part);
162 * Checks whether a handle is invalid
163 * @param h handle to check
164 * @return GNUNET_YES if invalid, GNUNET_NO if valid
166 int GNUNET_DISK_handle_invalid (const struct GNUNET_DISK_FileHandle *h);
170 * Check that fil corresponds to a filename
171 * (of a file that exists and that is not a directory).
173 * @param fil filename to check
174 * @return GNUNET_YES if yes, GNUNET_NO if not a file, GNUNET_SYSERR if something
175 * else (will print an error message in that case, too).
177 int GNUNET_DISK_file_test (const char *fil);
181 * Move the read/write pointer in a file
182 * @param h handle of an open file
183 * @param offset position to move to
184 * @param whence specification to which position the offset parameter relates to
185 * @return the new position on success, GNUNET_SYSERR otherwise
188 GNUNET_DISK_file_seek (const struct GNUNET_DISK_FileHandle *h,
190 enum GNUNET_DISK_Seek whence);
194 * Get the size of the file (or directory)
195 * of the given file (in bytes).
197 * @param filename name of the file or directory
198 * @param size set to the size of the file (or,
199 * in the case of directories, the sum
200 * of all sizes of files in the directory)
201 * @param includeSymLinks should symbolic links be
204 * @return GNUNET_OK on success, GNUNET_SYSERR on error
206 int GNUNET_DISK_file_size (const char *filename,
208 int includeSymLinks);
212 * Obtain some unique identifiers for the given file
213 * that can be used to identify it in the local system.
214 * This function is used between GNUnet processes to
215 * quickly check if two files with the same absolute path
216 * are actually identical. The two processes represent
217 * the same peer but may communicate over the network
218 * (and the file may be on an NFS volume). This function
219 * may not be supported on all operating systems.
221 * @param filename name of the file
222 * @param dev set to the device ID
223 * @param ino set to the inode ID
224 * @return GNUNET_OK on success
226 int GNUNET_DISK_file_get_identifiers (const char *filename,
232 * Create an (empty) temporary file on disk.
234 * @param tmpl component to use for the name;
235 * does NOT contain "XXXXXX" or "/tmp/".
236 * @return NULL on error, otherwise name of fresh
237 * file on disk in directory for temporary files
240 GNUNET_DISK_mktemp (const char *tmpl);
246 * @param fn file name to be opened
247 * @param flags opening flags, a combination of GNUNET_DISK_OPEN_xxx bit flags
248 * @param ... permissions for the newly created file (only required if creation is possible)
249 * @return IO handle on success, NULL on error
251 struct GNUNET_DISK_FileHandle *GNUNET_DISK_file_open (const char *fn,
252 enum GNUNET_DISK_OpenFlags flags,
256 * Creates an interprocess channel
257 * @param blocking creates an asynchronous pipe if set to GNUNET_NO
258 * @return handle to the new pipe, NULL on error
260 struct GNUNET_DISK_PipeHandle *GNUNET_DISK_pipe (int blocking);
263 * Closes an interprocess channel
265 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
267 int GNUNET_DISK_pipe_close (struct GNUNET_DISK_PipeHandle *p);
270 * Close an open file.
272 * @param h file handle
273 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
275 int GNUNET_DISK_file_close (struct GNUNET_DISK_FileHandle *h);
278 * Get the handle to a particular pipe end
280 * @param n number of the end (0 or 1); FIXME: use enum here!
281 * @return handle for the respective end
283 const struct GNUNET_DISK_FileHandle *GNUNET_DISK_pipe_handle (const struct
284 GNUNET_DISK_PipeHandle
288 * Read the contents of a binary file into a buffer.
289 * @param h handle to an open file
290 * @param result the buffer to write the result to
291 * @param len the maximum number of bytes to read
292 * @return the number of bytes read on success, GNUNET_SYSERR on failure
294 ssize_t GNUNET_DISK_file_read (const struct GNUNET_DISK_FileHandle *h, void *result,
299 * Read the contents of a binary file into a buffer.
300 * @param fn file name
301 * @param result the buffer to write the result to
302 * @param len the maximum number of bytes to read
303 * @return number of bytes read, GNUNET_SYSERR on failure
305 ssize_t GNUNET_DISK_fn_read (const char * const fn, void *result,
310 * Write a buffer to a file.
312 * @param h handle to open file
313 * @param buffer the data to write
314 * @param n number of bytes to write
315 * @return GNUNET_OK on success, GNUNET_SYSERR on error
317 ssize_t GNUNET_DISK_file_write (const struct GNUNET_DISK_FileHandle *h,
323 * Write a buffer to a file. If the file is longer than
324 * the given buffer size, it will be truncated.
326 * @param fn file name
327 * @param buffer the data to write
328 * @param n number of bytes to write
329 * @return number of bytes written on success, GNUNET_SYSERR on error
331 ssize_t GNUNET_DISK_fn_write (const char * fn,
339 * @return GNUNET_OK on success, GNUNET_SYSERR on error
341 int GNUNET_DISK_file_copy (const char *src, const char *dst);
345 * Scan a directory for files. The name of the directory
346 * must be expanded first (!).
348 * @param dirName the name of the directory
349 * @param callback the method to call for each file
350 * @param data argument to pass to callback
351 * @return the number of files found, -1 on error
353 int GNUNET_DISK_directory_scan (const char *dirName,
354 GNUNET_FileNameCallback callback,
359 * Opaque handle used for iterating over a directory.
361 struct GNUNET_DISK_DirectoryIterator;
365 * Function called to iterate over a directory.
368 * @param di argument to pass to "GNUNET_DISK_directory_iterator_next" to
369 * get called on the next entry (or finish cleanly)
370 * @param filename complete filename (absolute path)
371 * @param dirname directory name (absolute path)
373 typedef void (*GNUNET_DISK_DirectoryIteratorCallback) (void *cls,
375 GNUNET_DISK_DirectoryIterator
377 const char *filename,
378 const char *dirname);
382 * This function must be called during the DiskIteratorCallback
383 * (exactly once) to schedule the task to process the next
384 * filename in the directory (if there is one).
386 * @param iter opaque handle for the iterator
387 * @param can set to GNUNET_YES to terminate the iteration early
388 * @return GNUNET_YES if iteration will continue,
389 * GNUNET_NO if this was the last entry (and iteration is complete),
390 * GNUNET_SYSERR if "can" was YES
392 int GNUNET_DISK_directory_iterator_next (struct GNUNET_DISK_DirectoryIterator
397 * Scan a directory for files using the scheduler to run a task for
398 * each entry. The name of the directory must be expanded first (!).
399 * If a scheduler does not need to be used, GNUNET_DISK_directory_scan
400 * may provide a simpler API.
402 * @param sched scheduler to use
403 * @param prio priority to use
404 * @param dirName the name of the directory
405 * @param callback the method to call for each file
406 * @param callback_cls closure for callback
408 void GNUNET_DISK_directory_iterator_start (struct GNUNET_SCHEDULER_Handle
410 enum GNUNET_SCHEDULER_Priority
411 prio, const char *dirName,
412 GNUNET_DISK_DirectoryIteratorCallback
413 callback, void *callback_cls);
417 * Create the directory structure for storing
420 * @param filename name of a file in the directory
421 * @returns GNUNET_OK on success, GNUNET_SYSERR on failure,
422 * GNUNET_NO if directory exists but is not writeable
424 int GNUNET_DISK_directory_create_for_file (const char *filename);
428 * Test if fil is a directory that can be accessed.
429 * Will not print an error message if the directory
430 * does not exist. Will log errors if GNUNET_SYSERR is
433 * @param fil filename to test
434 * @return GNUNET_YES if yes, GNUNET_NO if does not exist, GNUNET_SYSERR
435 * on any error and if exists but not directory
437 int GNUNET_DISK_directory_test (const char *fil);
441 * Remove all files in a directory (rm -rf). Call with
444 * @param fileName the file to remove
445 * @return GNUNET_OK on success, GNUNET_SYSERR on error
447 int GNUNET_DISK_directory_remove (const char *fileName);
451 * Implementation of "mkdir -p"
453 * @param dir the directory to create
454 * @returns GNUNET_SYSERR on failure, GNUNET_OK otherwise
456 int GNUNET_DISK_directory_create (const char *dir);
460 * Lock a part of a file.
462 * @param fh file handle
463 * @param lockStart absolute position from where to lock
464 * @param lockEnd absolute position until where to lock
465 * @param excl GNUNET_YES for an exclusive lock
466 * @return GNUNET_OK on success, GNUNET_SYSERR on error
469 GNUNET_DISK_file_lock (struct GNUNET_DISK_FileHandle *fh, off_t lockStart,
470 off_t lockEnd, int excl);
474 * Unlock a part of a file
475 * @param fh file handle
476 * @param lockStart absolute position from where to unlock
477 * @param lockEnd absolute position until where to unlock
478 * @return GNUNET_OK on success, GNUNET_SYSERR on error
481 GNUNET_DISK_file_unlock (struct GNUNET_DISK_FileHandle *fh, off_t unlockStart,
486 * @brief Removes special characters as ':' from a filename.
487 * @param fn the filename to canonicalize
489 void GNUNET_DISK_filename_canonicalize (char *fn);
493 * @brief Change owner of a file
494 * @param filename file to change
495 * @param user new owner of the file
496 * @return GNUNET_OK on success, GNUNET_SYSERR on failure
498 int GNUNET_DISK_file_change_owner (const char *filename, const char *user);
502 * Construct full path to a file inside of the private
503 * directory used by GNUnet. Also creates the corresponding
504 * directory. If the resulting name is supposed to be
505 * a directory, end the last argument in '/' (or pass
506 * DIR_SEPARATOR_STR as the last argument before NULL).
508 * @param cfg configuration to use
509 * @param serviceName name of the service asking
510 * @param varargs is NULL-terminated list of
511 * path components to append to the
512 * private directory name.
513 * @return the constructed filename
515 char *GNUNET_DISK_get_home_filename (const struct GNUNET_CONFIGURATION_Handle *cfg,
516 const char *serviceName, ...);
520 * Opaque handle for a memory-mapping operation.
522 struct GNUNET_DISK_MapHandle;
525 * Map a file into memory
526 * @param h open file handle
527 * @param m handle to the new mapping (will be set)
528 * @param access access specification, GNUNET_DISK_MAP_TYPE_xxx
529 * @param len size of the mapping
530 * @return pointer to the mapped memory region, NULL on failure
532 void *GNUNET_DISK_file_map (const struct GNUNET_DISK_FileHandle *h,
533 struct GNUNET_DISK_MapHandle **m,
534 enum GNUNET_DISK_MapType access, size_t len);
539 * @param h mapping handle
540 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
542 int GNUNET_DISK_file_unmap (struct GNUNET_DISK_MapHandle *h);
545 * Write file changes to disk
546 * @param h handle to an open file
547 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
549 int GNUNET_DISK_file_sync (const struct GNUNET_DISK_FileHandle *h);
551 #if 0 /* keep Emacsens' auto-indent happy */
559 /* ifndef GNUNET_DISK_LIB_H */
561 /* end of gnunet_disk_lib.h */