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 * 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
120 * File access permissions, UNIX-style.
122 enum GNUNET_DISK_AccessPermissions
125 * Nobody is allowed to do anything to the file.
127 GNUNET_DISK_PERM_NONE = 0,
132 GNUNET_DISK_PERM_USER_READ = 1,
137 GNUNET_DISK_PERM_USER_WRITE = 2,
142 GNUNET_DISK_PERM_USER_EXEC = 4,
147 GNUNET_DISK_PERM_GROUP_READ = 8,
152 GNUNET_DISK_PERM_GROUP_WRITE = 16,
157 GNUNET_DISK_PERM_GROUP_EXEC = 32,
160 * Everybody can read.
162 GNUNET_DISK_PERM_OTHER_READ = 64,
165 * Everybody can write.
167 GNUNET_DISK_PERM_OTHER_WRITE = 128,
170 * Everybody can execute.
172 GNUNET_DISK_PERM_OTHER_EXEC = 256
177 * Constants for specifying how to seek.
179 enum GNUNET_DISK_Seek
182 * Seek an absolute position (from the start of the file).
184 GNUNET_DISK_SEEK_SET,
187 * Seek a relative position (from the current offset).
189 GNUNET_DISK_SEEK_CUR,
192 * Seek an absolute position from the end of the file.
199 * Enumeration identifying the two ends of a pipe.
201 enum GNUNET_DISK_PipeEnd
204 * The reading-end of a pipe.
206 GNUNET_DISK_PIPE_END_READ = 0,
209 * The writing-end of a pipe.
211 GNUNET_DISK_PIPE_END_WRITE = 1
216 * Get the number of blocks that are left on the partition that
217 * contains the given file (for normal users).
219 * @param part a file on the partition to check
220 * @return -1 on errors, otherwise the number of free blocks
222 long GNUNET_DISK_get_blocks_available (const char *part);
226 * Checks whether a handle is invalid
228 * @param h handle to check
229 * @return GNUNET_YES if invalid, GNUNET_NO if valid
231 int GNUNET_DISK_handle_invalid (const struct GNUNET_DISK_FileHandle *h);
235 * Check that fil corresponds to a filename
236 * (of a file that exists and that is not a directory).
238 * @param fil filename to check
239 * @return GNUNET_YES if yes, GNUNET_NO if not a file, GNUNET_SYSERR if something
240 * else (will print an error message in that case, too).
242 int GNUNET_DISK_file_test (const char *fil);
246 * Move the read/write pointer in a file
247 * @param h handle of an open file
248 * @param offset position to move to
249 * @param whence specification to which position the offset parameter relates to
250 * @return the new position on success, GNUNET_SYSERR otherwise
253 GNUNET_DISK_file_seek (const struct GNUNET_DISK_FileHandle *h,
255 enum GNUNET_DISK_Seek whence);
259 * Get the size of the file (or directory)
260 * of the given file (in bytes).
262 * @param filename name of the file or directory
263 * @param size set to the size of the file (or,
264 * in the case of directories, the sum
265 * of all sizes of files in the directory)
266 * @param includeSymLinks should symbolic links be
268 * @return GNUNET_OK on success, GNUNET_SYSERR on error
270 int GNUNET_DISK_file_size (const char *filename,
272 int includeSymLinks);
276 * Obtain some unique identifiers for the given file
277 * that can be used to identify it in the local system.
278 * This function is used between GNUnet processes to
279 * quickly check if two files with the same absolute path
280 * are actually identical. The two processes represent
281 * the same peer but may communicate over the network
282 * (and the file may be on an NFS volume). This function
283 * may not be supported on all operating systems.
285 * @param filename name of the file
286 * @param dev set to the device ID
287 * @param ino set to the inode ID
288 * @return GNUNET_OK on success
290 int GNUNET_DISK_file_get_identifiers (const char *filename,
296 * Create an (empty) temporary file on disk.
298 * @param t component to use for the name;
299 * does NOT contain "XXXXXX" or "/tmp/".
300 * @return NULL on error, otherwise name of fresh
301 * file on disk in directory for temporary files
304 GNUNET_DISK_mktemp (const char *t);
308 * Open a file. Note that the access permissions will only be
309 * used if a new file is created and if the underlying operating
310 * system supports the given permissions.
312 * @param fn file name to be opened
313 * @param flags opening flags, a combination of GNUNET_DISK_OPEN_xxx bit flags
314 * @param perm permissions for the newly created file, use
315 * GNUNET_DISK_PERM_USER_NONE if a file could not be created by this
316 * call (because of flags)
317 * @return IO handle on success, NULL on error
319 struct GNUNET_DISK_FileHandle *GNUNET_DISK_file_open (const char *fn,
320 enum GNUNET_DISK_OpenFlags flags,
321 enum GNUNET_DISK_AccessPermissions perm);
324 * Creates an interprocess channel
325 * @param blocking creates an asynchronous pipe if set to GNUNET_NO
326 * @return handle to the new pipe, NULL on error
328 struct GNUNET_DISK_PipeHandle *GNUNET_DISK_pipe (int blocking);
331 * Closes an interprocess channel
333 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
335 int GNUNET_DISK_pipe_close (struct GNUNET_DISK_PipeHandle *p);
338 * Close an open file.
340 * @param h file handle
341 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
343 int GNUNET_DISK_file_close (struct GNUNET_DISK_FileHandle *h);
346 * Get the handle to a particular pipe end
348 * @param n end to access
349 * @return handle for the respective end
351 const struct GNUNET_DISK_FileHandle *
352 GNUNET_DISK_pipe_handle (const struct
353 GNUNET_DISK_PipeHandle
355 enum GNUNET_DISK_PipeEnd n);
358 * Read the contents of a binary file into a buffer.
359 * @param h handle to an open file
360 * @param result the buffer to write the result to
361 * @param len the maximum number of bytes to read
362 * @return the number of bytes read on success, GNUNET_SYSERR on failure
364 ssize_t GNUNET_DISK_file_read (const struct GNUNET_DISK_FileHandle *h, void *result,
369 * Read the contents of a binary file into a buffer.
371 * @param fn file name
372 * @param result the buffer to write the result to
373 * @param len the maximum number of bytes to read
374 * @return number of bytes read, GNUNET_SYSERR on failure
376 ssize_t GNUNET_DISK_fn_read (const char *fn,
382 * Write a buffer to a file.
384 * @param h handle to open file
385 * @param buffer the data to write
386 * @param n number of bytes to write
387 * @return GNUNET_OK on success, GNUNET_SYSERR on error
389 ssize_t GNUNET_DISK_file_write (const struct GNUNET_DISK_FileHandle *h,
395 * Write a buffer to a file. If the file is longer than
396 * the given buffer size, it will be truncated.
398 * @param fn file name
399 * @param buffer the data to write
400 * @param n number of bytes to write
401 * @param mode file permissions
402 * @return number of bytes written on success, GNUNET_SYSERR on error
404 ssize_t GNUNET_DISK_fn_write (const char *fn,
407 enum GNUNET_DISK_AccessPermissions mode);
413 * @param src file to copy
414 * @param dst destination file name
415 * @return GNUNET_OK on success, GNUNET_SYSERR on error
417 int GNUNET_DISK_file_copy (const char *src, const char *dst);
421 * Scan a directory for files.
423 * @param dirName the name of the directory
424 * @param callback the method to call for each file
425 * @param callback_cls closure for callback
426 * @return the number of files found, -1 on error
428 int GNUNET_DISK_directory_scan (const char *dirName,
429 GNUNET_FileNameCallback callback,
434 * Opaque handle used for iterating over a directory.
436 struct GNUNET_DISK_DirectoryIterator;
440 * Function called to iterate over a directory.
443 * @param di argument to pass to "GNUNET_DISK_directory_iterator_next" to
444 * get called on the next entry (or finish cleanly)
445 * @param filename complete filename (absolute path)
446 * @param dirname directory name (absolute path)
448 typedef void (*GNUNET_DISK_DirectoryIteratorCallback) (void *cls,
450 GNUNET_DISK_DirectoryIterator
452 const char *filename,
453 const char *dirname);
457 * This function must be called during the DiskIteratorCallback
458 * (exactly once) to schedule the task to process the next
459 * filename in the directory (if there is one).
461 * @param iter opaque handle for the iterator
462 * @param can set to GNUNET_YES to terminate the iteration early
463 * @return GNUNET_YES if iteration will continue,
464 * GNUNET_NO if this was the last entry (and iteration is complete),
465 * GNUNET_SYSERR if "can" was YES
467 int GNUNET_DISK_directory_iterator_next (struct GNUNET_DISK_DirectoryIterator
472 * Scan a directory for files using the scheduler to run a task for
473 * each entry. The name of the directory must be expanded first (!).
474 * If a scheduler does not need to be used, GNUNET_DISK_directory_scan
475 * may provide a simpler API.
477 * @param sched scheduler to use
478 * @param prio priority to use
479 * @param dirName the name of the directory
480 * @param callback the method to call for each file
481 * @param callback_cls closure for callback
483 void GNUNET_DISK_directory_iterator_start (struct GNUNET_SCHEDULER_Handle
485 enum GNUNET_SCHEDULER_Priority
486 prio, const char *dirName,
487 GNUNET_DISK_DirectoryIteratorCallback
488 callback, void *callback_cls);
492 * Create the directory structure for storing
495 * @param filename name of a file in the directory
496 * @returns GNUNET_OK on success, GNUNET_SYSERR on failure,
497 * GNUNET_NO if directory exists but is not writeable
499 int GNUNET_DISK_directory_create_for_file (const char *filename);
503 * Test if "fil" is a directory that can be accessed.
504 * Will not print an error message if the directory
505 * does not exist. Will log errors if GNUNET_SYSERR is
508 * @param fil filename to test
509 * @return GNUNET_YES if yes, GNUNET_NO if does not exist, GNUNET_SYSERR
510 * on any error and if exists but not directory
512 int GNUNET_DISK_directory_test (const char *fil);
516 * Remove all files in a directory (rm -rf). Call with
519 * @param fileName the file to remove
520 * @return GNUNET_OK on success, GNUNET_SYSERR on error
522 int GNUNET_DISK_directory_remove (const char *fileName);
526 * Implementation of "mkdir -p"
528 * @param dir the directory to create
529 * @returns GNUNET_SYSERR on failure, GNUNET_OK otherwise
531 int GNUNET_DISK_directory_create (const char *dir);
535 * Lock a part of a file.
537 * @param fh file handle
538 * @param lockStart absolute position from where to lock
539 * @param lockEnd absolute position until where to lock
540 * @param excl GNUNET_YES for an exclusive lock
541 * @return GNUNET_OK on success, GNUNET_SYSERR on error
544 GNUNET_DISK_file_lock (struct GNUNET_DISK_FileHandle *fh, off_t lockStart,
545 off_t lockEnd, int excl);
549 * Unlock a part of a file
550 * @param fh file handle
551 * @param lockStart absolute position from where to unlock
552 * @param lockEnd absolute position until where to unlock
553 * @return GNUNET_OK on success, GNUNET_SYSERR on error
556 GNUNET_DISK_file_unlock (struct GNUNET_DISK_FileHandle *fh, off_t unlockStart,
561 * @brief Removes special characters as ':' from a filename.
562 * @param fn the filename to canonicalize
564 void GNUNET_DISK_filename_canonicalize (char *fn);
568 * @brief Change owner of a file
569 * @param filename file to change
570 * @param user new owner of the file
571 * @return GNUNET_OK on success, GNUNET_SYSERR on failure
573 int GNUNET_DISK_file_change_owner (const char *filename, const char *user);
577 * Construct full path to a file inside of the private
578 * directory used by GNUnet. Also creates the corresponding
579 * directory. If the resulting name is supposed to be
580 * a directory, end the last argument in '/' (or pass
581 * DIR_SEPARATOR_STR as the last argument before NULL).
583 * @param cfg configuration to use
584 * @param serviceName name of the service asking
585 * @param varargs is NULL-terminated list of
586 * path components to append to the
587 * private directory name.
588 * @return the constructed filename
590 char *GNUNET_DISK_get_home_filename (const struct GNUNET_CONFIGURATION_Handle *cfg,
591 const char *serviceName, ...);
595 * Opaque handle for a memory-mapping operation.
597 struct GNUNET_DISK_MapHandle;
600 * Map a file into memory
601 * @param h open file handle
602 * @param m handle to the new mapping (will be set)
603 * @param access access specification, GNUNET_DISK_MAP_TYPE_xxx
604 * @param len size of the mapping
605 * @return pointer to the mapped memory region, NULL on failure
607 void *GNUNET_DISK_file_map (const struct GNUNET_DISK_FileHandle *h,
608 struct GNUNET_DISK_MapHandle **m,
609 enum GNUNET_DISK_MapType access, size_t len);
614 * @param h mapping handle
615 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
617 int GNUNET_DISK_file_unmap (struct GNUNET_DISK_MapHandle *h);
620 * Write file changes to disk
621 * @param h handle to an open file
622 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
624 int GNUNET_DISK_file_sync (const struct GNUNET_DISK_FileHandle *h);
626 #if 0 /* keep Emacsens' auto-indent happy */
634 /* ifndef GNUNET_DISK_LIB_H */
636 /* end of gnunet_disk_lib.h */