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
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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;
41 GNUNET_DISK_FILE, GNUNET_PIPE
45 * Handle used to access files (and pipes).
47 struct GNUNET_DISK_FileHandle
52 * File handle under W32.
59 enum GNUNET_FILE_Type type;
62 * Structure for overlapped reading (for pipes)
64 OVERLAPPED *oOverlapRead;
67 * Structure for overlapped writing (for pipes)
69 OVERLAPPED *oOverlapWrite;
73 * File handle on other OSes.
82 /* we need size_t, and since it can be both unsigned int
83 or unsigned long long, this IS platform dependent;
84 but "stdlib.h" should be portable 'enough' to be
85 unconditionally available... */
87 #include "gnunet_configuration_lib.h"
88 #include "gnunet_scheduler_lib.h"
93 #if 0 /* keep Emacsens' auto-indent happy */
100 * Specifies how a file should be opened.
102 enum GNUNET_DISK_OpenFlags
106 * Open the file for reading
108 GNUNET_DISK_OPEN_READ = 1,
111 * Open the file for writing
113 GNUNET_DISK_OPEN_WRITE = 2,
116 * Open the file for both reading and writing
118 GNUNET_DISK_OPEN_READWRITE = 3,
121 * Fail if file already exists
123 GNUNET_DISK_OPEN_FAILIFEXISTS = 4,
126 * Truncate file if it exists
128 GNUNET_DISK_OPEN_TRUNCATE = 8,
131 * Create file if it doesn't exist
133 GNUNET_DISK_OPEN_CREATE = 16,
138 GNUNET_DISK_OPEN_APPEND = 32
142 * Specifies what type of memory map is desired.
144 enum GNUNET_DISK_MapType
147 * Read-only memory map.
149 GNUNET_DISK_MAP_TYPE_READ = 1,
152 * Write-able memory map.
154 GNUNET_DISK_MAP_TYPE_WRITE = 2,
156 * Read-write memory map.
158 GNUNET_DISK_MAP_TYPE_READWRITE = 3
163 * File access permissions, UNIX-style.
165 enum GNUNET_DISK_AccessPermissions
168 * Nobody is allowed to do anything to the file.
170 GNUNET_DISK_PERM_NONE = 0,
175 GNUNET_DISK_PERM_USER_READ = 1,
180 GNUNET_DISK_PERM_USER_WRITE = 2,
185 GNUNET_DISK_PERM_USER_EXEC = 4,
190 GNUNET_DISK_PERM_GROUP_READ = 8,
195 GNUNET_DISK_PERM_GROUP_WRITE = 16,
200 GNUNET_DISK_PERM_GROUP_EXEC = 32,
203 * Everybody can read.
205 GNUNET_DISK_PERM_OTHER_READ = 64,
208 * Everybody can write.
210 GNUNET_DISK_PERM_OTHER_WRITE = 128,
213 * Everybody can execute.
215 GNUNET_DISK_PERM_OTHER_EXEC = 256
220 * Constants for specifying how to seek.
222 enum GNUNET_DISK_Seek
225 * Seek an absolute position (from the start of the file).
227 GNUNET_DISK_SEEK_SET,
230 * Seek a relative position (from the current offset).
232 GNUNET_DISK_SEEK_CUR,
235 * Seek an absolute position from the end of the file.
242 * Enumeration identifying the two ends of a pipe.
244 enum GNUNET_DISK_PipeEnd
247 * The reading-end of a pipe.
249 GNUNET_DISK_PIPE_END_READ = 0,
252 * The writing-end of a pipe.
254 GNUNET_DISK_PIPE_END_WRITE = 1
259 * Get the number of blocks that are left on the partition that
260 * contains the given file (for normal users).
262 * @param part a file on the partition to check
263 * @return -1 on errors, otherwise the number of free blocks
266 GNUNET_DISK_get_blocks_available (const char *part);
270 * Checks whether a handle is invalid
272 * @param h handle to check
273 * @return GNUNET_YES if invalid, GNUNET_NO if valid
276 GNUNET_DISK_handle_invalid (const struct GNUNET_DISK_FileHandle *h);
280 * Check that fil corresponds to a filename
281 * (of a file that exists and that is not a directory).
283 * @param fil filename to check
284 * @return GNUNET_YES if yes, GNUNET_NO if not a file, GNUNET_SYSERR if something
285 * else (will print an error message in that case, too).
288 GNUNET_DISK_file_test (const char *fil);
292 * Move the read/write pointer in a file
293 * @param h handle of an open file
294 * @param offset position to move to
295 * @param whence specification to which position the offset parameter relates to
296 * @return the new position on success, GNUNET_SYSERR otherwise
299 GNUNET_DISK_file_seek (const struct GNUNET_DISK_FileHandle *h, off_t offset,
300 enum GNUNET_DISK_Seek whence);
304 * Get the size of the file (or directory)
305 * of the given file (in bytes).
307 * @param filename name of the file or directory
308 * @param size set to the size of the file (or,
309 * in the case of directories, the sum
310 * of all sizes of files in the directory)
311 * @param includeSymLinks should symbolic links be
313 * @return GNUNET_OK on success, GNUNET_SYSERR on error
316 GNUNET_DISK_file_size (const char *filename, uint64_t * size,
317 int includeSymLinks);
321 * Obtain some unique identifiers for the given file
322 * that can be used to identify it in the local system.
323 * This function is used between GNUnet processes to
324 * quickly check if two files with the same absolute path
325 * are actually identical. The two processes represent
326 * the same peer but may communicate over the network
327 * (and the file may be on an NFS volume). This function
328 * may not be supported on all operating systems.
330 * @param filename name of the file
331 * @param dev set to the device ID
332 * @param ino set to the inode ID
333 * @return GNUNET_OK on success
336 GNUNET_DISK_file_get_identifiers (const char *filename, uint64_t * dev,
341 * Create an (empty) temporary file on disk. If the given name is not
342 * an absolute path, the current 'TMPDIR' will be prepended. In any case,
343 * 6 random characters will be appended to the name to create a unique
346 * @param t component to use for the name;
347 * does NOT contain "XXXXXX" or "/tmp/".
348 * @return NULL on error, otherwise name of fresh
349 * file on disk in directory for temporary files
352 GNUNET_DISK_mktemp (const char *t);
356 * Open a file. Note that the access permissions will only be
357 * used if a new file is created and if the underlying operating
358 * system supports the given permissions.
360 * @param fn file name to be opened
361 * @param flags opening flags, a combination of GNUNET_DISK_OPEN_xxx bit flags
362 * @param perm permissions for the newly created file, use
363 * GNUNET_DISK_PERM_NONE if a file could not be created by this
364 * call (because of flags)
365 * @return IO handle on success, NULL on error
367 struct GNUNET_DISK_FileHandle *
368 GNUNET_DISK_file_open (const char *fn, enum GNUNET_DISK_OpenFlags flags,
369 enum GNUNET_DISK_AccessPermissions perm);
373 * Get the size of an open file.
375 * @param fh open file handle
376 * @param size where to write size of the file
377 * @return GNUNET_OK on success, GNUNET_SYSERR on error
380 GNUNET_DISK_file_handle_size (struct GNUNET_DISK_FileHandle *fh,
385 * Creates an interprocess channel
386 * @param blocking creates an asynchronous pipe if set to GNUNET_NO
387 * @param inherit_read 1 to make read handle inheritable, 0 otherwise (NT only)
388 * @param inherit_write 1 to make write handle inheritable, 0 otherwise (NT only)
389 * @return handle to the new pipe, NULL on error
391 struct GNUNET_DISK_PipeHandle *
392 GNUNET_DISK_pipe (int blocking, int inherit_read, int inherit_write);
396 * Closes an interprocess channel
398 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
401 GNUNET_DISK_pipe_close (struct GNUNET_DISK_PipeHandle *p);
404 * Closes one half of an interprocess channel
406 * @param p pipe to close end of
407 * @param end which end of the pipe to close
408 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
411 GNUNET_DISK_pipe_close_end (struct GNUNET_DISK_PipeHandle *p,
412 enum GNUNET_DISK_PipeEnd end);
415 * Close an open file.
417 * @param h file handle
418 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
421 GNUNET_DISK_file_close (struct GNUNET_DISK_FileHandle *h);
425 * Get the handle to a particular pipe end
428 * @param n end to access
429 * @return handle for the respective end
431 const struct GNUNET_DISK_FileHandle *
432 GNUNET_DISK_pipe_handle (const struct GNUNET_DISK_PipeHandle *p,
433 enum GNUNET_DISK_PipeEnd n);
436 * Read the contents of a binary file into a buffer.
437 * @param h handle to an open file
438 * @param result the buffer to write the result to
439 * @param len the maximum number of bytes to read
440 * @return the number of bytes read on success, GNUNET_SYSERR on failure
443 GNUNET_DISK_file_read (const struct GNUNET_DISK_FileHandle *h, void *result,
448 * Read the contents of a binary file into a buffer.
450 * @param fn file name
451 * @param result the buffer to write the result to
452 * @param len the maximum number of bytes to read
453 * @return number of bytes read, GNUNET_SYSERR on failure
456 GNUNET_DISK_fn_read (const char *fn, void *result, size_t len);
460 * Write a buffer to a file.
462 * @param h handle to open file
463 * @param buffer the data to write
464 * @param n number of bytes to write
465 * @return number of bytes written on success, GNUNET_SYSERR on error
468 GNUNET_DISK_file_write (const struct GNUNET_DISK_FileHandle *h,
469 const void *buffer, size_t n);
473 * Write a buffer to a file. If the file is longer than
474 * the given buffer size, it will be truncated.
476 * @param fn file name
477 * @param buffer the data to write
478 * @param n number of bytes to write
479 * @param mode file permissions
480 * @return number of bytes written on success, GNUNET_SYSERR on error
483 GNUNET_DISK_fn_write (const char *fn, const void *buffer, size_t n,
484 enum GNUNET_DISK_AccessPermissions mode);
490 * @param src file to copy
491 * @param dst destination file name
492 * @return GNUNET_OK on success, GNUNET_SYSERR on error
495 GNUNET_DISK_file_copy (const char *src, const char *dst);
499 * Scan a directory for files.
501 * @param dirName the name of the directory
502 * @param callback the method to call for each file
503 * @param callback_cls closure for callback
504 * @return the number of files found, -1 on error
507 GNUNET_DISK_directory_scan (const char *dirName,
508 GNUNET_FileNameCallback callback,
513 * Opaque handle used for iterating over a directory.
515 struct GNUNET_DISK_DirectoryIterator;
519 * Function called to iterate over a directory.
522 * @param di argument to pass to "GNUNET_DISK_directory_iterator_next" to
523 * get called on the next entry (or finish cleanly);
524 * NULL on error (will be the last call in that case)
525 * @param filename complete filename (absolute path)
526 * @param dirname directory name (absolute path)
528 typedef void (*GNUNET_DISK_DirectoryIteratorCallback) (void *cls,
530 GNUNET_DISK_DirectoryIterator
532 const char *filename,
533 const char *dirname);
537 * This function must be called during the DiskIteratorCallback
538 * (exactly once) to schedule the task to process the next
539 * filename in the directory (if there is one).
541 * @param iter opaque handle for the iterator
542 * @param can set to GNUNET_YES to terminate the iteration early
543 * @return GNUNET_YES if iteration will continue,
544 * GNUNET_NO if this was the last entry (and iteration is complete),
545 * GNUNET_SYSERR if "can" was YES
548 GNUNET_DISK_directory_iterator_next (struct GNUNET_DISK_DirectoryIterator *iter,
553 * Scan a directory for files using the scheduler to run a task for
554 * each entry. The name of the directory must be expanded first (!).
555 * If a scheduler does not need to be used, GNUNET_DISK_directory_scan
556 * may provide a simpler API.
558 * @param prio priority to use
559 * @param dirName the name of the directory
560 * @param callback the method to call for each file
561 * @param callback_cls closure for callback
564 GNUNET_DISK_directory_iterator_start (enum GNUNET_SCHEDULER_Priority prio,
566 GNUNET_DISK_DirectoryIteratorCallback
567 callback, void *callback_cls);
571 * Create the directory structure for storing
574 * @param filename name of a file in the directory
575 * @returns GNUNET_OK on success, GNUNET_SYSERR on failure,
576 * GNUNET_NO if directory exists but is not writeable
579 GNUNET_DISK_directory_create_for_file (const char *filename);
583 * Test if "fil" is a directory that can be accessed.
584 * Will not print an error message if the directory
585 * does not exist. Will log errors if GNUNET_SYSERR is
588 * @param fil filename to test
589 * @return GNUNET_YES if yes, GNUNET_NO if does not exist, GNUNET_SYSERR
590 * on any error and if exists but not directory
593 GNUNET_DISK_directory_test (const char *fil);
597 * Remove all files in a directory (rm -rf). Call with
600 * @param fileName the file to remove
601 * @return GNUNET_OK on success, GNUNET_SYSERR on error
604 GNUNET_DISK_directory_remove (const char *fileName);
608 * Implementation of "mkdir -p"
610 * @param dir the directory to create
611 * @returns GNUNET_SYSERR on failure, GNUNET_OK otherwise
614 GNUNET_DISK_directory_create (const char *dir);
618 * Lock a part of a file.
620 * @param fh file handle
621 * @param lockStart absolute position from where to lock
622 * @param lockEnd absolute position until where to lock
623 * @param excl GNUNET_YES for an exclusive lock
624 * @return GNUNET_OK on success, GNUNET_SYSERR on error
627 GNUNET_DISK_file_lock (struct GNUNET_DISK_FileHandle *fh, off_t lockStart,
628 off_t lockEnd, int excl);
632 * Unlock a part of a file
633 * @param fh file handle
634 * @param unlockStart absolute position from where to unlock
635 * @param unlockEnd absolute position until where to unlock
636 * @return GNUNET_OK on success, GNUNET_SYSERR on error
639 GNUNET_DISK_file_unlock (struct GNUNET_DISK_FileHandle *fh, off_t unlockStart,
644 * @brief Removes special characters as ':' from a filename.
645 * @param fn the filename to canonicalize
648 GNUNET_DISK_filename_canonicalize (char *fn);
652 * @brief Change owner of a file
653 * @param filename file to change
654 * @param user new owner of the file
655 * @return GNUNET_OK on success, GNUNET_SYSERR on failure
658 GNUNET_DISK_file_change_owner (const char *filename, const char *user);
662 * Construct full path to a file inside of the private
663 * directory used by GNUnet. Also creates the corresponding
664 * directory. If the resulting name is supposed to be
665 * a directory, end the last argument in '/' (or pass
666 * DIR_SEPARATOR_STR as the last argument before NULL).
668 * @param cfg configuration to use
669 * @param serviceName name of the service asking
670 * @param ... is NULL-terminated list of
671 * path components to append to the
672 * private directory name.
673 * @return the constructed filename
676 GNUNET_DISK_get_home_filename (const struct GNUNET_CONFIGURATION_Handle *cfg,
677 const char *serviceName, ...);
681 * Opaque handle for a memory-mapping operation.
683 struct GNUNET_DISK_MapHandle;
686 * Map a file into memory
687 * @param h open file handle
688 * @param m handle to the new mapping (will be set)
689 * @param access access specification, GNUNET_DISK_MAP_TYPE_xxx
690 * @param len size of the mapping
691 * @return pointer to the mapped memory region, NULL on failure
694 GNUNET_DISK_file_map (const struct GNUNET_DISK_FileHandle *h,
695 struct GNUNET_DISK_MapHandle **m,
696 enum GNUNET_DISK_MapType access, size_t len);
701 * @param h mapping handle
702 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
705 GNUNET_DISK_file_unmap (struct GNUNET_DISK_MapHandle *h);
708 * Write file changes to disk
709 * @param h handle to an open file
710 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
713 GNUNET_DISK_file_sync (const struct GNUNET_DISK_FileHandle *h);
716 * Creates a named pipe/FIFO and opens it
717 * @param fn pointer to the name of the named pipe or to NULL
718 * @param flags open flags
719 * @param perm access permissions
720 * @return pipe handle on success, NULL on error
722 struct GNUNET_DISK_FileHandle *
723 GNUNET_DISK_npipe_create (char **fn, enum GNUNET_DISK_OpenFlags flags,
724 enum GNUNET_DISK_AccessPermissions perm);
727 * Opens already existing named pipe/FIFO
729 * @param fn name of an existing named pipe
730 * @param flags open flags
731 * @param perm access permissions
732 * @return pipe handle on success, NULL on error
734 struct GNUNET_DISK_FileHandle *
735 GNUNET_DISK_npipe_open (const char *fn, enum GNUNET_DISK_OpenFlags flags,
736 enum GNUNET_DISK_AccessPermissions perm);
739 * Closes a named pipe/FIFO
740 * @param pipe named pipe
741 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
744 GNUNET_DISK_npipe_close (struct GNUNET_DISK_FileHandle *pipe);
746 #if 0 /* keep Emacsens' auto-indent happy */
754 /* ifndef GNUNET_DISK_LIB_H */
756 /* end of gnunet_disk_lib.h */