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 #define OFF_T uint64_t
35 * Handle used to manage a pipe.
37 struct GNUNET_DISK_PipeHandle;
45 * Handle represents a file.
47 GNUNET_DISK_HANLDE_TYPE_FILE,
50 * Handle represents a pipe.
52 GNUNET_DISK_HANLDE_TYPE_PIPE
56 * Handle used to access files (and pipes).
58 struct GNUNET_DISK_FileHandle
63 * File handle under W32.
70 enum GNUNET_FILE_Type type;
73 * Structure for overlapped reading (for pipes)
75 OVERLAPPED *oOverlapRead;
78 * Structure for overlapped writing (for pipes)
80 OVERLAPPED *oOverlapWrite;
84 * File handle on other OSes.
93 /* we need size_t, and since it can be both unsigned int
94 or unsigned long long, this IS platform dependent;
95 but "stdlib.h" should be portable 'enough' to be
96 unconditionally available... */
98 #include "gnunet_configuration_lib.h"
99 #include "gnunet_scheduler_lib.h"
104 #if 0 /* keep Emacsens' auto-indent happy */
111 * Specifies how a file should be opened.
113 enum GNUNET_DISK_OpenFlags
117 * Open the file for reading
119 GNUNET_DISK_OPEN_READ = 1,
122 * Open the file for writing
124 GNUNET_DISK_OPEN_WRITE = 2,
127 * Open the file for both reading and writing
129 GNUNET_DISK_OPEN_READWRITE = 3,
132 * Fail if file already exists
134 GNUNET_DISK_OPEN_FAILIFEXISTS = 4,
137 * Truncate file if it exists
139 GNUNET_DISK_OPEN_TRUNCATE = 8,
142 * Create file if it doesn't exist
144 GNUNET_DISK_OPEN_CREATE = 16,
149 GNUNET_DISK_OPEN_APPEND = 32
153 * Specifies what type of memory map is desired.
155 enum GNUNET_DISK_MapType
158 * Read-only memory map.
160 GNUNET_DISK_MAP_TYPE_READ = 1,
163 * Write-able memory map.
165 GNUNET_DISK_MAP_TYPE_WRITE = 2,
167 * Read-write memory map.
169 GNUNET_DISK_MAP_TYPE_READWRITE = 3
174 * File access permissions, UNIX-style.
176 enum GNUNET_DISK_AccessPermissions
179 * Nobody is allowed to do anything to the file.
181 GNUNET_DISK_PERM_NONE = 0,
186 GNUNET_DISK_PERM_USER_READ = 1,
191 GNUNET_DISK_PERM_USER_WRITE = 2,
196 GNUNET_DISK_PERM_USER_EXEC = 4,
201 GNUNET_DISK_PERM_GROUP_READ = 8,
206 GNUNET_DISK_PERM_GROUP_WRITE = 16,
211 GNUNET_DISK_PERM_GROUP_EXEC = 32,
214 * Everybody can read.
216 GNUNET_DISK_PERM_OTHER_READ = 64,
219 * Everybody can write.
221 GNUNET_DISK_PERM_OTHER_WRITE = 128,
224 * Everybody can execute.
226 GNUNET_DISK_PERM_OTHER_EXEC = 256
231 * Constants for specifying how to seek.
233 enum GNUNET_DISK_Seek
236 * Seek an absolute position (from the start of the file).
238 GNUNET_DISK_SEEK_SET,
241 * Seek a relative position (from the current offset).
243 GNUNET_DISK_SEEK_CUR,
246 * Seek an absolute position from the end of the file.
253 * Enumeration identifying the two ends of a pipe.
255 enum GNUNET_DISK_PipeEnd
258 * The reading-end of a pipe.
260 GNUNET_DISK_PIPE_END_READ = 0,
263 * The writing-end of a pipe.
265 GNUNET_DISK_PIPE_END_WRITE = 1
270 * Get the number of blocks that are left on the partition that
271 * contains the given file (for normal users).
273 * @param part a file on the partition to check
274 * @return -1 on errors, otherwise the number of free blocks
277 GNUNET_DISK_get_blocks_available (const char *part);
281 * Checks whether a handle is invalid
283 * @param h handle to check
284 * @return GNUNET_YES if invalid, GNUNET_NO if valid
287 GNUNET_DISK_handle_invalid (const struct GNUNET_DISK_FileHandle *h);
291 * Check that fil corresponds to a filename
292 * (of a file that exists and that is not a directory).
294 * @param fil filename to check
295 * @return GNUNET_YES if yes, GNUNET_NO if not a file, GNUNET_SYSERR if something
296 * else (will print an error message in that case, too).
299 GNUNET_DISK_file_test (const char *fil);
303 * Move the read/write pointer in a file
304 * @param h handle of an open file
305 * @param offset position to move to
306 * @param whence specification to which position the offset parameter relates to
307 * @return the new position on success, GNUNET_SYSERR otherwise
310 GNUNET_DISK_file_seek (const struct GNUNET_DISK_FileHandle *h, OFF_T offset,
311 enum GNUNET_DISK_Seek whence);
315 * Get the size of the file (or directory) of the given file (in
318 * @param filename name of the file or directory
319 * @param size set to the size of the file (or,
320 * in the case of directories, the sum
321 * of all sizes of files in the directory)
322 * @param includeSymLinks should symbolic links be
324 * @param singleFileMode GNUNET_YES to only get size of one file
325 * and return GNUNET_SYSERR for directories.
326 * @return GNUNET_SYSERR on error, GNUNET_OK on success
329 GNUNET_DISK_file_size (const char *filename, uint64_t * size,
330 int includeSymLinks, int singleFileMode);
334 * Obtain some unique identifiers for the given file
335 * that can be used to identify it in the local system.
336 * This function is used between GNUnet processes to
337 * quickly check if two files with the same absolute path
338 * are actually identical. The two processes represent
339 * the same peer but may communicate over the network
340 * (and the file may be on an NFS volume). This function
341 * may not be supported on all operating systems.
343 * @param filename name of the file
344 * @param dev set to the device ID
345 * @param ino set to the inode ID
346 * @return GNUNET_OK on success
349 GNUNET_DISK_file_get_identifiers (const char *filename, uint64_t * dev,
354 * Create an (empty) temporary file on disk. If the given name is not
355 * an absolute path, the current 'TMPDIR' will be prepended. In any case,
356 * 6 random characters will be appended to the name to create a unique
359 * @param t component to use for the name;
360 * does NOT contain "XXXXXX" or "/tmp/".
361 * @return NULL on error, otherwise name of fresh
362 * file on disk in directory for temporary files
365 GNUNET_DISK_mktemp (const char *t);
369 * Create an (empty) temporary directory on disk. If the given name is not an
370 * absolute path, the current 'TMPDIR' will be prepended. In any case, 6
371 * random characters will be appended to the name to create a unique name.
373 * @param t component to use for the name;
374 * does NOT contain "XXXXXX" or "/tmp/".
375 * @return NULL on error, otherwise name of freshly created directory
378 GNUNET_DISK_mkdtemp (const char *t);
382 * Open a file. Note that the access permissions will only be
383 * used if a new file is created and if the underlying operating
384 * system supports the given permissions.
386 * @param fn file name to be opened
387 * @param flags opening flags, a combination of GNUNET_DISK_OPEN_xxx bit flags
388 * @param perm permissions for the newly created file, use
389 * GNUNET_DISK_PERM_NONE if a file could not be created by this
390 * call (because of flags)
391 * @return IO handle on success, NULL on error
393 struct GNUNET_DISK_FileHandle *
394 GNUNET_DISK_file_open (const char *fn, enum GNUNET_DISK_OpenFlags flags,
395 enum GNUNET_DISK_AccessPermissions perm);
399 * Get the size of an open file.
401 * @param fh open file handle
402 * @param size where to write size of the file
403 * @return GNUNET_OK on success, GNUNET_SYSERR on error
406 GNUNET_DISK_file_handle_size (struct GNUNET_DISK_FileHandle *fh,
411 * Creates an interprocess channel
413 * @param blocking_read creates an asynchronous pipe for reading if set to GNUNET_NO
414 * @param blocking_write creates an asynchronous pipe for writing if set to GNUNET_NO
415 * @param inherit_read 1 to make read handle inheritable, 0 otherwise (NT only)
416 * @param inherit_write 1 to make write handle inheritable, 0 otherwise (NT only)
417 * @return handle to the new pipe, NULL on error
419 struct GNUNET_DISK_PipeHandle *
420 GNUNET_DISK_pipe (int blocking_read, int blocking_write, int inherit_read, int inherit_write);
424 * Creates a pipe object from a couple of file descriptors.
425 * Useful for wrapping existing pipe FDs.
427 * @param blocking_read creates an asynchronous pipe for reading if set to GNUNET_NO
428 * @param blocking_write creates an asynchronous pipe for writing if set to GNUNET_NO
429 * @param fd an array of two fd values. One of them may be -1 for read-only or write-only pipes
431 * @return handle to the new pipe, NULL on error
433 struct GNUNET_DISK_PipeHandle *
434 GNUNET_DISK_pipe_from_fd (int blocking_read, int blocking_write, int fd[2]);
438 * Closes an interprocess channel
440 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
443 GNUNET_DISK_pipe_close (struct GNUNET_DISK_PipeHandle *p);
447 * Closes one half of an interprocess channel
449 * @param p pipe to close end of
450 * @param end which end of the pipe to close
451 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
454 GNUNET_DISK_pipe_close_end (struct GNUNET_DISK_PipeHandle *p,
455 enum GNUNET_DISK_PipeEnd end);
458 * Close an open file.
460 * @param h file handle
461 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
464 GNUNET_DISK_file_close (struct GNUNET_DISK_FileHandle *h);
468 * Get the handle to a particular pipe end
471 * @param n end to access
472 * @return handle for the respective end
474 const struct GNUNET_DISK_FileHandle *
475 GNUNET_DISK_pipe_handle (const struct GNUNET_DISK_PipeHandle *p,
476 enum GNUNET_DISK_PipeEnd n);
480 * Get a handle from a native FD.
482 * @param fd native file descriptor
483 * @return file handle corresponding to the descriptor
485 struct GNUNET_DISK_FileHandle *
486 GNUNET_DISK_get_handle_from_native (FILE *fd);
490 * Read the contents of a binary file into a buffer.
491 * @param h handle to an open file
492 * @param result the buffer to write the result to
493 * @param len the maximum number of bytes to read
494 * @return the number of bytes read on success, GNUNET_SYSERR on failure
497 GNUNET_DISK_file_read (const struct GNUNET_DISK_FileHandle *h, void *result,
502 * Read the contents of a binary file into a buffer.
503 * Guarantees not to block (returns GNUNET_SYSERR and sets errno to EAGAIN
504 * when no data can be read).
506 * @param h handle to an open file
507 * @param result the buffer to write the result to
508 * @param len the maximum number of bytes to read
509 * @return the number of bytes read on success, GNUNET_SYSERR on failure
512 GNUNET_DISK_file_read_non_blocking (const struct GNUNET_DISK_FileHandle * h,
513 void *result, size_t len);
517 * Read the contents of a binary file into a buffer.
519 * @param fn file name
520 * @param result the buffer to write the result to
521 * @param len the maximum number of bytes to read
522 * @return number of bytes read, GNUNET_SYSERR on failure
525 GNUNET_DISK_fn_read (const char *fn, void *result, size_t len);
529 * Write a buffer to a file.
531 * @param h handle to open file
532 * @param buffer the data to write
533 * @param n number of bytes to write
534 * @return number of bytes written on success, GNUNET_SYSERR on error
537 GNUNET_DISK_file_write (const struct GNUNET_DISK_FileHandle *h,
538 const void *buffer, size_t n);
542 * Write a buffer to a file, blocking, if necessary.
543 * @param h handle to open file
544 * @param buffer the data to write
545 * @param n number of bytes to write
546 * @return number of bytes written on success, GNUNET_SYSERR on error
549 GNUNET_DISK_file_write_blocking (const struct GNUNET_DISK_FileHandle * h,
550 const void *buffer, size_t n);
553 * Write a buffer to a file. If the file is longer than
554 * the given buffer size, it will be truncated.
556 * @param fn file name
557 * @param buffer the data to write
558 * @param n number of bytes to write
559 * @param mode file permissions
560 * @return number of bytes written on success, GNUNET_SYSERR on error
563 GNUNET_DISK_fn_write (const char *fn, const void *buffer, size_t n,
564 enum GNUNET_DISK_AccessPermissions mode);
570 * @param src file to copy
571 * @param dst destination file name
572 * @return GNUNET_OK on success, GNUNET_SYSERR on error
575 GNUNET_DISK_file_copy (const char *src, const char *dst);
579 * Scan a directory for files.
581 * @param dirName the name of the directory
582 * @param callback the method to call for each file
583 * @param callback_cls closure for callback
584 * @return the number of files found, -1 on error
587 GNUNET_DISK_directory_scan (const char *dirName,
588 GNUNET_FileNameCallback callback,
593 * Opaque handle used for iterating over a directory.
595 struct GNUNET_DISK_DirectoryIterator;
599 * Function called to iterate over a directory.
602 * @param di argument to pass to "GNUNET_DISK_directory_iterator_next" to
603 * get called on the next entry (or finish cleanly);
604 * NULL on error (will be the last call in that case)
605 * @param filename complete filename (absolute path)
606 * @param dirname directory name (absolute path)
608 typedef void (*GNUNET_DISK_DirectoryIteratorCallback) (void *cls,
610 GNUNET_DISK_DirectoryIterator
612 const char *filename,
613 const char *dirname);
617 * This function must be called during the DiskIteratorCallback
618 * (exactly once) to schedule the task to process the next
619 * filename in the directory (if there is one).
621 * @param iter opaque handle for the iterator
622 * @param can set to GNUNET_YES to terminate the iteration early
623 * @return GNUNET_YES if iteration will continue,
624 * GNUNET_NO if this was the last entry (and iteration is complete),
625 * GNUNET_SYSERR if "can" was YES
628 GNUNET_DISK_directory_iterator_next (struct GNUNET_DISK_DirectoryIterator *iter,
633 * Scan a directory for files using the scheduler to run a task for
634 * each entry. The name of the directory must be expanded first (!).
635 * If a scheduler does not need to be used, GNUNET_DISK_directory_scan
636 * may provide a simpler API.
638 * @param prio priority to use
639 * @param dirName the name of the directory
640 * @param callback the method to call for each file
641 * @param callback_cls closure for callback
642 * @return GNUNET_YES if directory is not empty and 'callback'
643 * will be called later, GNUNET_NO otherwise, GNUNET_SYSERR on error.
646 GNUNET_DISK_directory_iterator_start (enum GNUNET_SCHEDULER_Priority prio,
648 GNUNET_DISK_DirectoryIteratorCallback
649 callback, void *callback_cls);
653 * Create the directory structure for storing
656 * @param filename name of a file in the directory
657 * @returns GNUNET_OK on success, GNUNET_SYSERR on failure,
658 * GNUNET_NO if directory exists but is not writeable
661 GNUNET_DISK_directory_create_for_file (const char *filename);
665 * Test if "fil" is a directory that can be accessed.
666 * Will not print an error message if the directory
667 * does not exist. Will log errors if GNUNET_SYSERR is
670 * @param fil filename to test
671 * @return GNUNET_YES if yes, GNUNET_NO if does not exist, GNUNET_SYSERR
672 * on any error and if exists but not directory
675 GNUNET_DISK_directory_test (const char *fil);
679 * Remove all files in a directory (rm -rf). Call with
682 * @param filename the file to remove
683 * @return GNUNET_OK on success, GNUNET_SYSERR on error
686 GNUNET_DISK_directory_remove (const char *filename);
690 * Implementation of "mkdir -p"
692 * @param dir the directory to create
693 * @returns GNUNET_SYSERR on failure, GNUNET_OK otherwise
696 GNUNET_DISK_directory_create (const char *dir);
700 * Lock a part of a file.
702 * @param fh file handle
703 * @param lockStart absolute position from where to lock
704 * @param lockEnd absolute position until where to lock
705 * @param excl GNUNET_YES for an exclusive lock
706 * @return GNUNET_OK on success, GNUNET_SYSERR on error
709 GNUNET_DISK_file_lock (struct GNUNET_DISK_FileHandle *fh, OFF_T lockStart,
710 OFF_T lockEnd, int excl);
714 * Unlock a part of a file
715 * @param fh file handle
716 * @param unlockStart absolute position from where to unlock
717 * @param unlockEnd absolute position until where to unlock
718 * @return GNUNET_OK on success, GNUNET_SYSERR on error
721 GNUNET_DISK_file_unlock (struct GNUNET_DISK_FileHandle *fh, OFF_T unlockStart,
726 * @brief Removes special characters as ':' from a filename.
727 * @param fn the filename to canonicalize
730 GNUNET_DISK_filename_canonicalize (char *fn);
734 * @brief Change owner of a file
735 * @param filename file to change
736 * @param user new owner of the file
737 * @return GNUNET_OK on success, GNUNET_SYSERR on failure
740 GNUNET_DISK_file_change_owner (const char *filename, const char *user);
744 * Construct full path to a file inside of the private
745 * directory used by GNUnet. Also creates the corresponding
746 * directory. If the resulting name is supposed to be
747 * a directory, end the last argument in '/' (or pass
748 * DIR_SEPARATOR_STR as the last argument before NULL).
750 * @param cfg configuration to use
751 * @param serviceName name of the service asking
752 * @param ... is NULL-terminated list of
753 * path components to append to the
754 * private directory name.
755 * @return the constructed filename
758 GNUNET_DISK_get_home_filename (const struct GNUNET_CONFIGURATION_Handle *cfg,
759 const char *serviceName, ...);
763 * Opaque handle for a memory-mapping operation.
765 struct GNUNET_DISK_MapHandle;
768 * Map a file into memory
769 * @param h open file handle
770 * @param m handle to the new mapping (will be set)
771 * @param access access specification, GNUNET_DISK_MAP_TYPE_xxx
772 * @param len size of the mapping
773 * @return pointer to the mapped memory region, NULL on failure
776 GNUNET_DISK_file_map (const struct GNUNET_DISK_FileHandle *h,
777 struct GNUNET_DISK_MapHandle **m,
778 enum GNUNET_DISK_MapType access, size_t len);
783 * @param h mapping handle
784 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
787 GNUNET_DISK_file_unmap (struct GNUNET_DISK_MapHandle *h);
790 * Write file changes to disk
791 * @param h handle to an open file
792 * @return GNUNET_OK on success, GNUNET_SYSERR otherwise
795 GNUNET_DISK_file_sync (const struct GNUNET_DISK_FileHandle *h);
798 #if 0 /* keep Emacsens' auto-indent happy */
806 /* ifndef GNUNET_DISK_LIB_H */
808 /* end of gnunet_disk_lib.h */