summaryrefslogtreecommitdiff
path: root/src/include/gnunet_disk_lib.h
blob: be28854600c1f6c27deaff9ba55118d643b67415 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
/*
     This file is part of GNUnet.
     Copyright (C) 2001-2012 GNUnet e.V.

     GNUnet is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     by the Free Software Foundation; either version 3, or (at your
     option) any later version.

     GNUnet is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA 02110-1301, USA.
*/
/**
 * @author Christian Grothoff
 *
 * @file
 * Disk IO APIs
 *
 * @defgroup disk  Disk library
 * Disk IO APIs
 * @{
 */
#ifndef GNUNET_DISK_LIB_H
#define GNUNET_DISK_LIB_H

/**
 * Handle used to manage a pipe.
 */
struct GNUNET_DISK_PipeHandle;

/**
 * Type of a handle.
 */
enum GNUNET_FILE_Type
{
  /**
   * Handle represents an event.
   */
  GNUNET_DISK_HANLDE_TYPE_EVENT,

  /**
   * Handle represents a file.
   */
  GNUNET_DISK_HANLDE_TYPE_FILE,

  /**
   * Handle represents a pipe.
   */
  GNUNET_DISK_HANLDE_TYPE_PIPE
};

/**
 * Handle used to access files (and pipes).
 */
struct GNUNET_DISK_FileHandle
{

#if WINDOWS
  /**
   * File handle under W32.
   */
  HANDLE h;

  /**
   * Type
   */
  enum GNUNET_FILE_Type type;

  /**
   * Structure for overlapped reading (for pipes)
   */
  OVERLAPPED *oOverlapRead;

  /**
   * Structure for overlapped writing (for pipes)
   */
  OVERLAPPED *oOverlapWrite;
#else

  /**
   * File handle on other OSes.
   */
  int fd;

#endif
};


/* we need size_t, and since it can be both unsigned int
   or unsigned long long, this IS platform dependent;
   but "stdlib.h" should be portable 'enough' to be
   unconditionally available... */
#include <stdlib.h>
#include "gnunet_configuration_lib.h"
#include "gnunet_scheduler_lib.h"

#ifdef __cplusplus
extern "C"
{
#if 0                           /* keep Emacsens' auto-indent happy */
}
#endif
#endif


/**
 * Specifies how a file should be opened.
 */
enum GNUNET_DISK_OpenFlags
{

  /**
   * Open the file for reading
   */
  GNUNET_DISK_OPEN_READ = 1,

  /**
   * Open the file for writing
   */
  GNUNET_DISK_OPEN_WRITE = 2,

  /**
   * Open the file for both reading and writing
   */
  GNUNET_DISK_OPEN_READWRITE = 3,

  /**
   * Fail if file already exists
   */
  GNUNET_DISK_OPEN_FAILIFEXISTS = 4,

  /**
   * Truncate file if it exists
   */
  GNUNET_DISK_OPEN_TRUNCATE = 8,

  /**
   * Create file if it doesn't exist
   */
  GNUNET_DISK_OPEN_CREATE = 16,

  /**
   * Append to the file
   */
  GNUNET_DISK_OPEN_APPEND = 32
};

/**
 * Specifies what type of memory map is desired.
 */
enum GNUNET_DISK_MapType
{
  /**
   * Read-only memory map.
   */
  GNUNET_DISK_MAP_TYPE_READ = 1,

  /**
   * Write-able memory map.
   */
  GNUNET_DISK_MAP_TYPE_WRITE = 2,

  /**
   * Read-write memory map.
   */
  GNUNET_DISK_MAP_TYPE_READWRITE = 3
};


/**
 * File access permissions, UNIX-style.
 */
enum GNUNET_DISK_AccessPermissions
{
  /**
   * Nobody is allowed to do anything to the file.
   */
  GNUNET_DISK_PERM_NONE = 0,

  /**
   * Owner can read.
   */
  GNUNET_DISK_PERM_USER_READ = 1,

  /**
   * Owner can write.
   */
  GNUNET_DISK_PERM_USER_WRITE = 2,

  /**
   * Owner can execute.
   */
  GNUNET_DISK_PERM_USER_EXEC = 4,

  /**
   * Group can read.
   */
  GNUNET_DISK_PERM_GROUP_READ = 8,

  /**
   * Group can write.
   */
  GNUNET_DISK_PERM_GROUP_WRITE = 16,

  /**
   * Group can execute.
   */
  GNUNET_DISK_PERM_GROUP_EXEC = 32,

  /**
   * Everybody can read.
   */
  GNUNET_DISK_PERM_OTHER_READ = 64,

  /**
   * Everybody can write.
   */
  GNUNET_DISK_PERM_OTHER_WRITE = 128,

  /**
   * Everybody can execute.
   */
  GNUNET_DISK_PERM_OTHER_EXEC = 256
};


/**
 * Constants for specifying how to seek.  Do not change values or order,
 * some of the code depends on the specific numeric values!
 */
enum GNUNET_DISK_Seek
{
  /**
   * Seek an absolute position (from the start of the file).
   */
  GNUNET_DISK_SEEK_SET = 0,

  /**
   * Seek a relative position (from the current offset).
   */
  GNUNET_DISK_SEEK_CUR = 1,

  /**
   * Seek an absolute position from the end of the file.
   */
  GNUNET_DISK_SEEK_END = 2
};


/**
 * Enumeration identifying the two ends of a pipe.
 */
enum GNUNET_DISK_PipeEnd
{
  /**
   * The reading-end of a pipe.
   */
  GNUNET_DISK_PIPE_END_READ = 0,

  /**
   * The writing-end of a pipe.
   */
  GNUNET_DISK_PIPE_END_WRITE = 1
};


/**
 * Checks whether a handle is invalid
 *
 * @param h handle to check
 * @return #GNUNET_YES if invalid, #GNUNET_NO if valid
 */
int
GNUNET_DISK_handle_invalid (const struct GNUNET_DISK_FileHandle *h);


/**
 * Check that fil corresponds to a filename
 * (of a file that exists and that is not a directory).
 *
 * @param fil filename to check
 * @return #GNUNET_YES if yes, #GNUNET_NO if not a file, #GNUNET_SYSERR if something
 * else (will print an error message in that case, too).
 */
int
GNUNET_DISK_file_test (const char *fil);


/**
 * Move a file out of the way (create a backup) by
 * renaming it to "orig.NUM~" where NUM is the smallest
 * number that is not used yet.
 *
 * @param fil name of the file to back up
 */
void
GNUNET_DISK_file_backup (const char *fil);


/**
 * Move the read/write pointer in a file
 * @param h handle of an open file
 * @param offset position to move to
 * @param whence specification to which position the offset parameter relates to
 * @return the new position on success, GNUNET_SYSERR otherwise
 */
off_t
GNUNET_DISK_file_seek (const struct GNUNET_DISK_FileHandle *h, off_t offset,
                       enum GNUNET_DISK_Seek whence);


/**
 * Get the size of the file (or directory) of the given file (in
 * bytes).
 *
 * @param filename name of the file or directory
 * @param size set to the size of the file (or,
 *             in the case of directories, the sum
 *             of all sizes of files in the directory)
 * @param include_symbolic_links should symbolic links be
 *        included?
 * @param single_file_mode #GNUNET_YES to only get size of one file
 *        and return #GNUNET_SYSERR for directories.
 * @return #GNUNET_SYSERR on error, #GNUNET_OK on success
 */
int
GNUNET_DISK_file_size (const char *filename,
                       uint64_t *size,
                       int include_symbolic_links,
                       int single_file_mode);


/**
 * Obtain some unique identifiers for the given file
 * that can be used to identify it in the local system.
 * This function is used between GNUnet processes to
 * quickly check if two files with the same absolute path
 * are actually identical.  The two processes represent
 * the same peer but may communicate over the network
 * (and the file may be on an NFS volume).  This function
 * may not be supported on all operating systems.
 *
 * @param filename name of the file
 * @param dev set to the device ID
 * @param ino set to the inode ID
 * @return #GNUNET_OK on success
 */
int
GNUNET_DISK_file_get_identifiers (const char *filename,
                                  uint64_t *dev,
                                  uint64_t *ino);


/**
 * Create an (empty) temporary file on disk.  If the given name is not
 * an absolute path, the current 'TMPDIR' will be prepended.  In any case,
 * 6 random characters will be appended to the name to create a unique
 * filename.
 *
 * @param t component to use for the name;
 *        does NOT contain "XXXXXX" or "/tmp/".
 * @return NULL on error, otherwise name of fresh
 *         file on disk in directory for temporary files
 */
char *
GNUNET_DISK_mktemp (const char *t);


/**
 * Create an (empty) temporary directory on disk.  If the given name is not an
 * absolute path, the current 'TMPDIR' will be prepended.  In any case, 6
 * random characters will be appended to the name to create a unique name.
 *
 * @param t component to use for the name;
 *        does NOT contain "XXXXXX" or "/tmp/".
 * @return NULL on error, otherwise name of freshly created directory
 */
char *
GNUNET_DISK_mkdtemp (const char *t);


/**
 * Open a file.  Note that the access permissions will only be
 * used if a new file is created and if the underlying operating
 * system supports the given permissions.
 *
 * @param fn file name to be opened
 * @param flags opening flags, a combination of GNUNET_DISK_OPEN_xxx bit flags
 * @param perm permissions for the newly created file, use
 *             #GNUNET_DISK_PERM_NONE if a file could not be created by this
 *             call (because of flags)
 * @return IO handle on success, NULL on error
 */
struct GNUNET_DISK_FileHandle *
GNUNET_DISK_file_open (const char *fn,
                       enum GNUNET_DISK_OpenFlags flags,
                       enum GNUNET_DISK_AccessPermissions perm);


/**
 * Get the size of an open file.
 *
 * @param fh open file handle
 * @param size where to write size of the file
 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
 */
int
GNUNET_DISK_file_handle_size (struct GNUNET_DISK_FileHandle *fh,
			      off_t *size);


/**
 * Creates an interprocess channel
 *
 * @param blocking_read creates an asynchronous pipe for reading if set to #GNUNET_NO
 * @param blocking_write creates an asynchronous pipe for writing if set to #GNUNET_NO
 * @param inherit_read 1 to make read handle inheritable, 0 otherwise (NT only)
 * @param inherit_write 1 to make write handle inheritable, 0 otherwise (NT only)
 * @return handle to the new pipe, NULL on error
 */
struct GNUNET_DISK_PipeHandle *
GNUNET_DISK_pipe (int blocking_read,
                  int blocking_write,
                  int inherit_read,
                  int inherit_write);


/**
 * Creates a pipe object from a couple of file descriptors.
 * Useful for wrapping existing pipe FDs.
 *
 * @param blocking_read creates an asynchronous pipe for reading if set to #GNUNET_NO
 * @param blocking_write creates an asynchronous pipe for writing if set to #GNUNET_NO
 * @param fd an array of two fd values. One of them may be -1 for read-only or write-only pipes
 *
 * @return handle to the new pipe, NULL on error
 */
struct GNUNET_DISK_PipeHandle *
GNUNET_DISK_pipe_from_fd (int blocking_read,
                          int blocking_write,
                          int fd[2]);


/**
 * Closes an interprocess channel
 * @param p pipe
 * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
 */
int
GNUNET_DISK_pipe_close (struct GNUNET_DISK_PipeHandle *p);


/**
 * Closes one half of an interprocess channel
 *
 * @param p pipe to close end of
 * @param end which end of the pipe to close
 * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
 */
int
GNUNET_DISK_pipe_close_end (struct GNUNET_DISK_PipeHandle *p,
                            enum GNUNET_DISK_PipeEnd end);


/**
 * Detaches one of the ends from the pipe.
 * Detached end is a fully-functional FileHandle, it will
 * not be affected by anything you do with the pipe afterwards.
 * Each end of a pipe can only be detched from it once (i.e.
 * it is not duplicated).
 *
 * @param p pipe to detach an end from
 * @param end which end of the pipe to detach
 * @return Detached end on success, NULL on failure
 * (or if that end is not present or is closed).
 */
struct GNUNET_DISK_FileHandle *
GNUNET_DISK_pipe_detach_end (struct GNUNET_DISK_PipeHandle *p,
                             enum GNUNET_DISK_PipeEnd end);

/**
 * Close an open file.
 *
 * @param h file handle
 * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
 */
int
GNUNET_DISK_file_close (struct GNUNET_DISK_FileHandle *h);


/**
 * Get the handle to a particular pipe end
 *
 * @param p pipe
 * @param n end to access
 * @return handle for the respective end
 */
const struct GNUNET_DISK_FileHandle *
GNUNET_DISK_pipe_handle (const struct GNUNET_DISK_PipeHandle *p,
                         enum GNUNET_DISK_PipeEnd n);


#if WINDOWS
/**
 * Get a GNUnet file handle from a W32 handle (W32-only).
 * Do not call on non-W32 platforms (returns NULL).
 *
 * @param handle native handle
 * @return GNUnet file handle corresponding to the W32 handle
 */
struct GNUNET_DISK_FileHandle *
GNUNET_DISK_get_handle_from_w32_handle (HANDLE osfh);
#endif

/**
 * Update POSIX permissions mask of a file on disk.  If both argumets
 * are #GNUNET_NO, the file is made world-read-write-executable (777).
 * Does nothing on W32.
 *
 * @param fn name of the file to update
 * @param require_uid_match #GNUNET_YES means 700
 * @param require_gid_match #GNUNET_YES means 770 unless @a require_uid_match is set
 */
void
GNUNET_DISK_fix_permissions (const char *fn,
                             int require_uid_match,
                             int require_gid_match);


/**
 * Get a handle from a native integer FD.
 *
 * @param fno native integer file descriptor
 * @return file handle corresponding to the descriptor
 */
struct GNUNET_DISK_FileHandle *
GNUNET_DISK_get_handle_from_int_fd (int fno);


/**
 * Get a handle from a native FD.
 *
 * @param fd native file descriptor
 * @return file handle corresponding to the descriptor
 */
struct GNUNET_DISK_FileHandle *
GNUNET_DISK_get_handle_from_native (FILE *fd);


/**
 * Read the contents of a binary file into a buffer.
 *
 * @param h handle to an open file
 * @param result the buffer to write the result to
 * @param len the maximum number of bytes to read
 * @return the number of bytes read on success, #GNUNET_SYSERR on failure
 */
ssize_t
GNUNET_DISK_file_read (const struct GNUNET_DISK_FileHandle *h,
                       void *result,
                       size_t len);


/**
 * Read the contents of a binary file into a buffer.
 * Guarantees not to block (returns GNUNET_SYSERR and sets errno to EAGAIN
 * when no data can be read).
 *
 * @param h handle to an open file
 * @param result the buffer to write the result to
 * @param len the maximum number of bytes to read
 * @return the number of bytes read on success, #GNUNET_SYSERR on failure
 */
ssize_t
GNUNET_DISK_file_read_non_blocking (const struct GNUNET_DISK_FileHandle * h,
				    void *result,
                                    size_t len);


/**
 * Read the contents of a binary file into a buffer.
 *
 * @param fn file name
 * @param result the buffer to write the result to
 * @param len the maximum number of bytes to read
 * @return number of bytes read, #GNUNET_SYSERR on failure
 */
ssize_t
GNUNET_DISK_fn_read (const char *fn,
                     void *result,
                     size_t len);


/**
 * Write a buffer to a file.
 *
 * @param h handle to open file
 * @param buffer the data to write
 * @param n number of bytes to write
 * @return number of bytes written on success, #GNUNET_SYSERR on error
 */
ssize_t
GNUNET_DISK_file_write (const struct GNUNET_DISK_FileHandle *h,
                        const void *buffer,
                        size_t n);


/**
 * Write a buffer to a file, blocking, if necessary.
 *
 * @param h handle to open file
 * @param buffer the data to write
 * @param n number of bytes to write
 * @return number of bytes written on success, #GNUNET_SYSERR on error
 */
ssize_t
GNUNET_DISK_file_write_blocking (const struct GNUNET_DISK_FileHandle *h,
				 const void *buffer,
				 size_t n);


/**
 * Write a buffer to a file.  If the file is longer than
 * the given buffer size, it will be truncated.
 *
 * @param fn file name
 * @param buffer the data to write
 * @param n number of bytes to write
 * @param mode file permissions
 * @return number of bytes written on success, #GNUNET_SYSERR on error
 */
ssize_t
GNUNET_DISK_fn_write (const char *fn,
                      const void *buffer,
                      size_t n,
                      enum GNUNET_DISK_AccessPermissions mode);


/**
 * Copy a file.
 *
 * @param src file to copy
 * @param dst destination file name
 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
 */
int
GNUNET_DISK_file_copy (const char *src,
                       const char *dst);


/**
 * Scan a directory for files.
 *
 * @param dir_name the name of the directory
 * @param callback the method to call for each file
 * @param callback_cls closure for @a callback
 * @return the number of files found, -1 on error
 */
int
GNUNET_DISK_directory_scan (const char *dir_name,
                            GNUNET_FileNameCallback callback,
                            void *callback_cls);


/**
 * Create the directory structure for storing
 * a file.
 *
 * @param filename name of a file in the directory
 * @returns #GNUNET_OK on success, #GNUNET_SYSERR on failure,
 *          #GNUNET_NO if directory exists but is not writeable
 */
int
GNUNET_DISK_directory_create_for_file (const char *filename);


/**
 * Test if @a fil is a directory and listable. Optionally, also check if the
 * directory is readable.  Will not print an error message if the directory does
 * not exist.  Will log errors if #GNUNET_SYSERR is returned (i.e., a file exists
 * with the same name).
 *
 * @param fil filename to test
 * @param is_readable #GNUNET_YES to additionally check if @a fil is readable;
 *          #GNUNET_NO to disable this check
 * @return #GNUNET_YES if yes, #GNUNET_NO if not; #GNUNET_SYSERR if it
 *           does not exist or `stat`ed
 */
int
GNUNET_DISK_directory_test (const char *fil, int is_readable);


/**
 * Remove all files in a directory (rm -rf). Call with
 * caution.
 *
 * @param filename the file to remove
 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
 */
int
GNUNET_DISK_directory_remove (const char *filename);


/**
 * Implementation of "mkdir -p"
 *
 * @param dir the directory to create
 * @returns #GNUNET_SYSERR on failure, #GNUNET_OK otherwise
 */
int
GNUNET_DISK_directory_create (const char *dir);


/**
 * Lock a part of a file.
 *
 * @param fh file handle
 * @param lock_start absolute position from where to lock
 * @param lock_end absolute position until where to lock
 * @param excl #GNUNET_YES for an exclusive lock
 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
 */
int
GNUNET_DISK_file_lock (struct GNUNET_DISK_FileHandle *fh,
                       off_t lock_start,
                       off_t lock_end, int excl);


/**
 * Unlock a part of a file.
 *
 * @param fh file handle
 * @param unlock_start absolute position from where to unlock
 * @param unlock_end absolute position until where to unlock
 * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
 */
int
GNUNET_DISK_file_unlock (struct GNUNET_DISK_FileHandle *fh,
                         off_t unlock_start,
                         off_t unlock_end);


/**
 * @brief Removes special characters as ':' from a filename.
 * @param fn the filename to canonicalize
 */
void
GNUNET_DISK_filename_canonicalize (char *fn);


/**
 * @brief Change owner of a file
 * @param filename file to change
 * @param user new owner of the file
 * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
 */
int
GNUNET_DISK_file_change_owner (const char *filename,
			       const char *user);


/**
 * Opaque handle for a memory-mapping operation.
 */
struct GNUNET_DISK_MapHandle;

/**
 * Map a file into memory
 * @param h open file handle
 * @param m handle to the new mapping (will be set)
 * @param access access specification, GNUNET_DISK_MAP_TYPE_xxx
 * @param len size of the mapping
 * @return pointer to the mapped memory region, NULL on failure
 */
void *
GNUNET_DISK_file_map (const struct GNUNET_DISK_FileHandle *h,
                      struct GNUNET_DISK_MapHandle **m,
                      enum GNUNET_DISK_MapType access,
		      size_t len);


/**
 * Unmap a file
 *
 * @param h mapping handle
 * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
 */
int
GNUNET_DISK_file_unmap (struct GNUNET_DISK_MapHandle *h);


/**
 * Write file changes to disk
 *
 * @param h handle to an open file
 * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
 */
int
GNUNET_DISK_file_sync (const struct GNUNET_DISK_FileHandle *h);


#if 0                           /* keep Emacsens' auto-indent happy */
{
#endif
#ifdef __cplusplus
}
#endif

/* ifndef GNUNET_DISK_LIB_H */
#endif

/** @} */  /* end of group */

/* end of gnunet_disk_lib.h */