summaryrefslogtreecommitdiff
path: root/src/fs/fs_unindex.c
blob: bf619b75acf127c48e66969231b7b984044d99ea (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
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
/*
     This file is part of GNUnet.
     (C) 2003, 2004, 2006, 2009 Christian Grothoff (and other contributing authors)

     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., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/

/**
 * @file fs/fs_unindex.c
 * @author Krista Grothoff
 * @author Christian Grothoff
 * @brief Unindex file.
 */
#include "platform.h"
#include "gnunet_constants.h"
#include "gnunet_fs_service.h"
#include "gnunet_protocols.h"
#include "fs_api.h"
#include "fs_tree.h"
#include "block_fs.h"


/**
 * Function called by the tree encoder to obtain
 * a block of plaintext data (for the lowest level
 * of the tree).
 *
 * @param cls our publishing context
 * @param offset identifies which block to get
 * @param max (maximum) number of bytes to get; returning
 *        fewer will also cause errors
 * @param buf where to copy the plaintext buffer
 * @param emsg location to store an error message (on error)
 * @return number of bytes copied to buf, 0 on error
 */
static size_t
unindex_reader (void *cls, uint64_t offset, size_t max, void *buf, char **emsg)
{
  struct GNUNET_FS_UnindexContext *uc = cls;
  size_t pt_size;

  pt_size = GNUNET_MIN (max, uc->file_size - offset);
  if (offset != GNUNET_DISK_file_seek (uc->fh, offset, GNUNET_DISK_SEEK_SET))
  {
    *emsg = GNUNET_strdup (_("Failed to find given position in file"));
    return 0;
  }
  if (pt_size != GNUNET_DISK_file_read (uc->fh, buf, pt_size))
  {
    *emsg = GNUNET_strdup (_("Failed to read file"));
    return 0;
  }
  return pt_size;
}


/**
 * Fill in all of the generic fields for
 * an unindex event and call the callback.
 *
 * @param pi structure to fill in
 * @param uc overall unindex context
 * @param offset where we are in the file (for progress)
 */
void
GNUNET_FS_unindex_make_status_ (struct GNUNET_FS_ProgressInfo *pi,
                                struct GNUNET_FS_UnindexContext *uc,
                                uint64_t offset)
{
  pi->value.unindex.uc = uc;
  pi->value.unindex.cctx = uc->client_info;
  pi->value.unindex.filename = uc->filename;
  pi->value.unindex.size = uc->file_size;
  pi->value.unindex.eta =
      GNUNET_TIME_calculate_eta (uc->start_time, offset, uc->file_size);
  pi->value.unindex.duration =
      GNUNET_TIME_absolute_get_duration (uc->start_time);
  pi->value.unindex.completed = offset;
  uc->client_info = uc->h->upcb (uc->h->upcb_cls, pi);

}


/**
 * Function called with information about our
 * progress in computing the tree encoding.
 *
 * @param cls closure
 * @param offset where are we in the file
 * @param pt_block plaintext of the currently processed block
 * @param pt_size size of pt_block
 * @param depth depth of the block in the tree, 0 for DBLOCK
 */
static void
unindex_progress (void *cls, uint64_t offset, const void *pt_block,
                  size_t pt_size, unsigned int depth)
{
  struct GNUNET_FS_UnindexContext *uc = cls;
  struct GNUNET_FS_ProgressInfo pi;

  pi.status = GNUNET_FS_STATUS_UNINDEX_PROGRESS;
  pi.value.unindex.specifics.progress.data = pt_block;
  pi.value.unindex.specifics.progress.offset = offset;
  pi.value.unindex.specifics.progress.data_len = pt_size;
  pi.value.unindex.specifics.progress.depth = depth;
  GNUNET_FS_unindex_make_status_ (&pi, uc, offset);
}


/**
 * We've encountered an error during
 * unindexing.  Signal the client.
 *
 * @param uc context for the failed unindexing operation
 */
static void
signal_unindex_error (struct GNUNET_FS_UnindexContext *uc)
{
  struct GNUNET_FS_ProgressInfo pi;

  pi.status = GNUNET_FS_STATUS_UNINDEX_ERROR;
  pi.value.unindex.eta = GNUNET_TIME_UNIT_FOREVER_REL;
  pi.value.unindex.specifics.error.message = uc->emsg;
  GNUNET_FS_unindex_make_status_ (&pi, uc, 0);
}


/**
 * Continuation called to notify client about result of the
 * datastore removal operation.
 *
 * @param cls closure
 * @param success GNUNET_SYSERR on failure
 * @param min_expiration minimum expiration time required for content to be stored
 * @param msg NULL on success, otherwise an error message
 */
static void
process_cont (void *cls, int success, struct GNUNET_TIME_Absolute min_expiration, const char *msg)
{
  struct GNUNET_FS_UnindexContext *uc = cls;

  if (success == GNUNET_SYSERR)
  {
    uc->emsg = GNUNET_strdup (msg);
    signal_unindex_error (uc);
    return;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Datastore REMOVE operation succeeded\n");
  GNUNET_FS_tree_encoder_next (uc->tc);
}


/**
 * Function called asking for the current (encoded)
 * block to be processed.  After processing the
 * client should either call "GNUNET_FS_tree_encode_next"
 * or (on error) "GNUNET_FS_tree_encode_finish".
 *
 * @param cls closure
 * @param chk content hash key for the block (key for lookup in the datastore)
 * @param offset offset of the block
 * @param depth depth of the block, 0 for DBLOCK
 * @param type type of the block (IBLOCK or DBLOCK)
 * @param block the (encrypted) block
 * @param block_size size of block (in bytes)
 */
static void
unindex_process (void *cls, const struct ContentHashKey *chk, uint64_t offset,
                 unsigned int depth, enum GNUNET_BLOCK_Type type,
                 const void *block, uint16_t block_size)
{
  struct GNUNET_FS_UnindexContext *uc = cls;
  uint32_t size;
  const void *data;
  struct OnDemandBlock odb;

  if (type != GNUNET_BLOCK_TYPE_FS_DBLOCK)
  {
    size = block_size;
    data = block;
  }
  else                          /* on-demand encoded DBLOCK */
  {
    size = sizeof (struct OnDemandBlock);
    odb.offset = GNUNET_htonll (offset);
    odb.file_id = uc->file_id;
    data = &odb;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Sending REMOVE request to DATASTORE service\n");
  GNUNET_DATASTORE_remove (uc->dsh, &chk->query, size, data, -2, 1,
                           GNUNET_CONSTANTS_SERVICE_TIMEOUT, &process_cont, uc);
  uc->chk = *chk;
}


/**
 * Function called with the response from the
 * FS service to our unindexing request.
 *
 * @param cls closure, unindex context
 * @param msg NULL on timeout, otherwise the response
 */
static void
process_fs_response (void *cls, const struct GNUNET_MessageHeader *msg)
{
  struct GNUNET_FS_UnindexContext *uc = cls;
  struct GNUNET_FS_ProgressInfo pi;

  if (uc->client != NULL)
  {
    GNUNET_CLIENT_disconnect (uc->client, GNUNET_NO);
    uc->client = NULL;
  }
  if (uc->state != UNINDEX_STATE_FS_NOTIFY)
  {
    uc->state = UNINDEX_STATE_ERROR;
    uc->emsg =
        GNUNET_strdup (_("Unexpected time for a response from `fs' service."));
    GNUNET_FS_unindex_sync_ (uc);
    signal_unindex_error (uc);
    return;
  }
  if (NULL == msg)
  {
    uc->state = UNINDEX_STATE_ERROR;
    uc->emsg = GNUNET_strdup (_("Timeout waiting for `fs' service."));
    GNUNET_FS_unindex_sync_ (uc);
    signal_unindex_error (uc);
    return;
  }
  if (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_FS_UNINDEX_OK)
  {
    uc->state = UNINDEX_STATE_ERROR;
    uc->emsg = GNUNET_strdup (_("Invalid response from `fs' service."));
    GNUNET_FS_unindex_sync_ (uc);
    signal_unindex_error (uc);
    return;
  }
  uc->state = UNINDEX_STATE_COMPLETE;
  pi.status = GNUNET_FS_STATUS_UNINDEX_COMPLETED;
  pi.value.unindex.eta = GNUNET_TIME_UNIT_ZERO;
  GNUNET_FS_unindex_sync_ (uc);
  GNUNET_FS_unindex_make_status_ (&pi, uc, uc->file_size);
}


/**
 * Function called when we are done with removing KBlocks.
 * Disconnect from datastore and notify FS service about
 * the unindex event.
 *
 * @param uc our unindexing context
 */
static void
unindex_finish (struct GNUNET_FS_UnindexContext *uc)
{
  char *emsg;
  struct GNUNET_FS_Uri *uri;
  struct UnindexMessage req;

  /* generate final progress message */
  unindex_progress (uc, uc->file_size, NULL, 0, 0);
  GNUNET_FS_tree_encoder_finish (uc->tc, &uri, &emsg);
  uc->tc = NULL;
  if (uri != NULL)
    GNUNET_FS_uri_destroy (uri);
  GNUNET_DISK_file_close (uc->fh);
  uc->fh = NULL;
  GNUNET_DATASTORE_disconnect (uc->dsh, GNUNET_NO);
  uc->dsh = NULL;
  uc->state = UNINDEX_STATE_FS_NOTIFY;
  GNUNET_FS_unindex_sync_ (uc);
  uc->client = GNUNET_CLIENT_connect ("fs", uc->h->cfg);
  if (uc->client == NULL)
  {
    uc->state = UNINDEX_STATE_ERROR;
    uc->emsg =
        GNUNET_strdup (_("Failed to connect to FS service for unindexing."));
    GNUNET_FS_unindex_sync_ (uc);
    signal_unindex_error (uc);
    return;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              "Sending UNINDEX message to FS service\n");
  req.header.size = htons (sizeof (struct UnindexMessage));
  req.header.type = htons (GNUNET_MESSAGE_TYPE_FS_UNINDEX);
  req.reserved = 0;
  req.file_id = uc->file_id;
  GNUNET_break (GNUNET_OK ==
                GNUNET_CLIENT_transmit_and_get_response (uc->client,
                                                         &req.header,
                                                         GNUNET_CONSTANTS_SERVICE_TIMEOUT,
                                                         GNUNET_YES,
                                                         &process_fs_response,
                                                         uc));
}



/**
 * Function called by the directory scanner as we extract keywords
 * that we will need to remove KBlocks.
 *
 * @param cls the 'struct GNUNET_FS_UnindexContext *'
 * @param filename which file we are making progress on
 * @param is_directory GNUNET_YES if this is a directory,
 *                     GNUNET_NO if this is a file
 *                     GNUNET_SYSERR if it is neither (or unknown)
 * @param reason kind of progress we are making
 */
static void
unindex_directory_scan_cb (void *cls, 
			   const char *filename, 
			   int is_directory,
			   enum GNUNET_FS_DirScannerProgressUpdateReason reason)
{
  struct GNUNET_FS_UnindexContext *uc = cls;
  static struct GNUNET_FS_ShareTreeItem * directory_scan_result;

  switch (reason)
  {
  case GNUNET_FS_DIRSCANNER_FINISHED:
    directory_scan_result = GNUNET_FS_directory_scan_get_result (uc->dscan);
    uc->dscan = NULL;
    if (NULL != directory_scan_result->ksk_uri)
    {
      uc->ksk_uri = GNUNET_FS_uri_dup (directory_scan_result->ksk_uri);
      uc->state = UNINDEX_STATE_DS_REMOVE_KBLOCKS;
      uc->emsg = GNUNET_strdup (_("Failed to connect to `datastore' service."));
      GNUNET_FS_unindex_sync_ (uc);
      GNUNET_FS_unindex_do_remove_kblocks_ (uc);
    }
    else
    {
      unindex_finish (uc);
    }
    GNUNET_FS_share_tree_free (directory_scan_result);
    break;
  case GNUNET_FS_DIRSCANNER_INTERNAL_ERROR:
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
		_("Internal error scanning `%s'.\n"),
		uc->filename);
    break;
  default:
    break;
  }

}


/**
 * If necessary, connect to the datastore and remove the KBlocks.
 *
 * @param uc context for the unindex operation.
 */
void
GNUNET_FS_unindex_do_extract_keywords_ (struct GNUNET_FS_UnindexContext *uc)
{
  char *ex;

  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (uc->h->cfg, "FS", "EXTRACTORS", &ex))
    ex = NULL;
  uc->dscan = GNUNET_FS_directory_scan_start (uc->filename,
					      GNUNET_NO, ex,
					      &unindex_directory_scan_cb, 
					      uc);
  GNUNET_free_non_null (ex);
}


/**
 * Continuation called to notify client about result of the remove
 * operation for the KBlock.
 *
 * @param cls the 'struct GNUNET_FS_UnindexContext *' 
 * @param success GNUNET_SYSERR on failure (including timeout/queue drop)
 *                GNUNET_NO if content was already there
 *                GNUNET_YES (or other positive value) on success
 * @param min_expiration minimum expiration time required for 0-priority content to be stored
 *                by the datacache at this time, zero for unknown, forever if we have no
 *                space for 0-priority content
 * @param msg NULL on success, otherwise an error message
 */
static void
continue_after_remove (void *cls,
		       int32_t success,
		       struct GNUNET_TIME_Absolute min_expiration,
		       const char *msg)
{
  struct GNUNET_FS_UnindexContext *uc = cls;

  uc->dqe = NULL;
  if (success != GNUNET_YES)  
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
		_("Failed to remove KBlock: %s\n"),
		msg);  
  uc->ksk_offset++;
  GNUNET_FS_unindex_do_remove_kblocks_ (uc);
}


/**
 * Function called from datastore with result from us looking for
 * a KBlock.  There are four cases:
 * 1) no result, means we move on to the next keyword
 * 2) UID is the same as the first UID, means we move on to next keyword
 * 3) KBlock for a different CHK, means we keep looking for more
 * 4) KBlock is for our CHK, means we remove the block and then move
 *           on to the next keyword
 *
 * @param cls the 'struct GNUNET_FS_UnindexContext *'
 * @param key key for the content
 * @param size number of bytes in data
 * @param data content stored
 * @param type type of the content
 * @param priority priority of the content
 * @param anonymity anonymity-level for the content
 * @param expiration expiration time for the content
 * @param uid unique identifier for the datum;
 *        maybe 0 if no unique identifier is available
 */
static void
process_kblock_for_unindex (void *cls,
			    const GNUNET_HashCode * key,
			    size_t size, const void *data,
			    enum GNUNET_BLOCK_Type type,
			    uint32_t priority,
			    uint32_t anonymity,
			    struct GNUNET_TIME_Absolute
			    expiration, uint64_t uid)
{
  struct GNUNET_FS_UnindexContext *uc = cls;
  const struct KBlock *kb;
  struct GNUNET_FS_Uri *chk_uri;

  uc->dqe = NULL;
  if (NULL == data)
  {
    /* no result */
    uc->ksk_offset++;
    GNUNET_FS_unindex_do_remove_kblocks_ (uc);
    return;
  }
  if (0 == uc->first_uid)
  {
    /* remember UID of first result to detect cycles */
    uc->first_uid = uid;    
  }
  else if (uid == uc->first_uid)
  {
    /* no more additional results */
    uc->ksk_offset++;
    GNUNET_FS_unindex_do_remove_kblocks_ (uc);
    return;  
  }
  GNUNET_assert (GNUNET_BLOCK_TYPE_FS_KBLOCK == type);
  if (size < sizeof (struct KBlock))
  {
    GNUNET_break (0);
    goto get_next;
  }
  kb = data;
  {
    char pt[size - sizeof (struct KBlock)];  
    struct GNUNET_CRYPTO_AesSessionKey skey;
    struct GNUNET_CRYPTO_AesInitializationVector iv;
 
    GNUNET_CRYPTO_hash_to_aes_key (&uc->key, &skey, &iv);
    if (-1 ==
	GNUNET_CRYPTO_aes_decrypt (&kb[1], size - sizeof (struct KBlock), &skey,
				   &iv, pt))
    {
      GNUNET_break (0);
      goto get_next;
    }       
    if (NULL == memchr (pt, 0, sizeof (pt)))
    {
      GNUNET_break (0);
      goto get_next;
    }
    chk_uri = GNUNET_FS_uri_parse (pt, NULL);
    if (NULL == chk_uri)
    {
      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
		  _("Failed to parse URI `%s' from KBlock!\n"),
		  pt);
      GNUNET_break (0);
      goto get_next;
    }
  }
  if (0 != memcmp (&uc->chk,
		   &chk_uri->data.chk.chk,
		   sizeof (struct ContentHashKey)))
  {
    /* different CHK, ignore */
    GNUNET_FS_uri_destroy (chk_uri);
    goto get_next;
  }
  GNUNET_FS_uri_destroy (chk_uri);
  /* matches! */
  uc->dqe = GNUNET_DATASTORE_remove (uc->dsh,
				     key, size, data,
				     0 /* priority */, 1 /* queue size */,
				     GNUNET_TIME_UNIT_FOREVER_REL,
				     &continue_after_remove,
				     uc);
  return;
 get_next:
  uc->dqe = GNUNET_DATASTORE_get_key (uc->dsh,
				      uc->roff++,
				      &uc->query,
				      GNUNET_BLOCK_TYPE_FS_KBLOCK,
				      0 /* priority */, 1 /* queue size */,
				      GNUNET_TIME_UNIT_FOREVER_REL,
				      &process_kblock_for_unindex,
				      uc);
}


/**
 * If necessary, connect to the datastore and remove the KBlocks.
 *
 * @param uc context for the unindex operation.
 */
void
GNUNET_FS_unindex_do_remove_kblocks_ (struct GNUNET_FS_UnindexContext *uc)
{
  const char *keyword;
  struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pub;
  struct GNUNET_CRYPTO_RsaPrivateKey *pk;

  if (NULL != uc->dsh)
    uc->dsh = GNUNET_DATASTORE_connect (uc->h->cfg);
  if (NULL == uc->dsh)
  {
    uc->state = UNINDEX_STATE_ERROR;
    uc->emsg = GNUNET_strdup (_("Failed to connect to `datastore' service."));
    GNUNET_FS_unindex_sync_ (uc);
    signal_unindex_error (uc);
    return;
  }
  if ( (NULL == uc->ksk_uri) ||
       (uc->ksk_offset >= uc->ksk_uri->data.ksk.keywordCount) )
  {
    unindex_finish (uc);
    return;
  }
  /* FIXME: code duplication with fs_search.c here... */
  keyword = &uc->ksk_uri->data.ksk.keywords[uc->ksk_offset][1];
  GNUNET_CRYPTO_hash (keyword, strlen (keyword), &uc->key);
  pk = GNUNET_CRYPTO_rsa_key_create_from_hash (&uc->key);
  GNUNET_assert (pk != NULL);
  GNUNET_CRYPTO_rsa_key_get_public (pk, &pub);
  GNUNET_CRYPTO_rsa_key_free (pk);
  GNUNET_CRYPTO_hash (&pub,
		      sizeof (struct
			      GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
		      &uc->query);
  uc->first_uid = 0;
  uc->dqe = GNUNET_DATASTORE_get_key (uc->dsh,
				      uc->roff++,
				      &uc->query,
				      GNUNET_BLOCK_TYPE_FS_KBLOCK,
				      0 /* priority */, 1 /* queue size */,
				      GNUNET_TIME_UNIT_FOREVER_REL,
				      &process_kblock_for_unindex,
				      uc);
}


/**
 * Function called when the tree encoder has
 * processed all blocks.  Clean up.
 *
 * @param cls our unindexing context
 * @param tc not used
 */
static void
unindex_extract_keywords (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct GNUNET_FS_UnindexContext *uc = cls;

  uc->state = UNINDEX_STATE_EXTRACT_KEYWORDS;
  GNUNET_FS_unindex_sync_ (uc);
  GNUNET_FS_unindex_do_extract_keywords_ (uc);
}


/**
 * Connect to the datastore and remove the blocks.
 *
 * @param uc context for the unindex operation.
 */
void
GNUNET_FS_unindex_do_remove_ (struct GNUNET_FS_UnindexContext *uc)
{
  uc->dsh = GNUNET_DATASTORE_connect (uc->h->cfg);
  if (NULL == uc->dsh)
  {
    uc->state = UNINDEX_STATE_ERROR;
    uc->emsg = GNUNET_strdup (_("Failed to connect to `datastore' service."));
    GNUNET_FS_unindex_sync_ (uc);
    signal_unindex_error (uc);
    return;
  }
  uc->fh =
      GNUNET_DISK_file_open (uc->filename, GNUNET_DISK_OPEN_READ,
                             GNUNET_DISK_PERM_NONE);
  if (NULL == uc->fh)
  {
    GNUNET_DATASTORE_disconnect (uc->dsh, GNUNET_NO);
    uc->dsh = NULL;
    uc->state = UNINDEX_STATE_ERROR;
    uc->emsg = GNUNET_strdup (_("Failed to open file for unindexing."));
    GNUNET_FS_unindex_sync_ (uc);
    signal_unindex_error (uc);
    return;
  }
  uc->tc =
      GNUNET_FS_tree_encoder_create (uc->h, uc->file_size, uc, &unindex_reader,
                                     &unindex_process, &unindex_progress,
                                     &unindex_extract_keywords);
  GNUNET_FS_tree_encoder_next (uc->tc);
}


/**
 * Function called once the hash of the file
 * that is being unindexed has been computed.
 *
 * @param cls closure, unindex context
 * @param file_id computed hash, NULL on error
 */
void
GNUNET_FS_unindex_process_hash_ (void *cls, const GNUNET_HashCode * file_id)
{
  struct GNUNET_FS_UnindexContext *uc = cls;

  uc->fhc = NULL;
  if (uc->state != UNINDEX_STATE_HASHING)
  {
    GNUNET_FS_unindex_stop (uc);
    return;
  }
  if (file_id == NULL)
  {
    uc->state = UNINDEX_STATE_ERROR;
    uc->emsg = GNUNET_strdup (_("Failed to compute hash of file."));
    GNUNET_FS_unindex_sync_ (uc);
    signal_unindex_error (uc);
    return;
  }
  uc->file_id = *file_id;
  uc->state = UNINDEX_STATE_DS_REMOVE;
  GNUNET_FS_unindex_sync_ (uc);
  GNUNET_FS_unindex_do_remove_ (uc);
}


/**
 * Create SUSPEND event for the given unindex operation
 * and then clean up our state (without stop signal).
 *
 * @param cls the 'struct GNUNET_FS_UnindexContext' to signal for
 */
void
GNUNET_FS_unindex_signal_suspend_ (void *cls)
{
  struct GNUNET_FS_UnindexContext *uc = cls;
  struct GNUNET_FS_ProgressInfo pi;

  /* FIXME: lots of duplication with unindex_stop here! */
  if (uc->dscan != NULL)
  {
    GNUNET_FS_directory_scan_abort (uc->dscan);
    uc->dscan = NULL;
  }
  if (NULL != uc->dqe)
  {
    GNUNET_DATASTORE_cancel (uc->dqe);
    uc->dqe = NULL;
  }
  if (uc->fhc != NULL)
  {
    GNUNET_CRYPTO_hash_file_cancel (uc->fhc);
    uc->fhc = NULL;
  }
  if (NULL != uc->ksk_uri)
  {
    GNUNET_FS_uri_destroy (uc->ksk_uri);
    uc->ksk_uri = NULL;
  }
  if (uc->client != NULL)
  {
    GNUNET_CLIENT_disconnect (uc->client, GNUNET_NO);
    uc->client = NULL;
  }
  if (NULL != uc->dsh)
  {
    GNUNET_DATASTORE_disconnect (uc->dsh, GNUNET_NO);
    uc->dsh = NULL;
  }
  if (NULL != uc->tc)
  {
    GNUNET_FS_tree_encoder_finish (uc->tc, NULL, NULL);
    uc->tc = NULL;
  }
  if (uc->fh != NULL)
  {
    GNUNET_DISK_file_close (uc->fh);
    uc->fh = NULL;
  }
  GNUNET_FS_end_top (uc->h, uc->top);
  pi.status = GNUNET_FS_STATUS_UNINDEX_SUSPEND;
  GNUNET_FS_unindex_make_status_ (&pi, uc,
                                  (uc->state ==
                                   UNINDEX_STATE_COMPLETE) ? uc->file_size : 0);
  GNUNET_break (NULL == uc->client_info);
  GNUNET_free (uc->filename);
  GNUNET_free_non_null (uc->serialization);
  GNUNET_free_non_null (uc->emsg);
  GNUNET_free (uc);
}


/**
 * Unindex a file.
 *
 * @param h handle to the file sharing subsystem
 * @param filename file to unindex
 * @param cctx initial value for the client context
 * @return NULL on error, otherwise handle
 */
struct GNUNET_FS_UnindexContext *
GNUNET_FS_unindex_start (struct GNUNET_FS_Handle *h, const char *filename,
                         void *cctx)
{
  struct GNUNET_FS_UnindexContext *ret;
  struct GNUNET_FS_ProgressInfo pi;
  uint64_t size;

  if (GNUNET_OK != GNUNET_DISK_file_size (filename, &size, GNUNET_YES, GNUNET_YES))
    return NULL;
  ret = GNUNET_malloc (sizeof (struct GNUNET_FS_UnindexContext));
  ret->h = h;
  ret->filename = GNUNET_strdup (filename);
  ret->start_time = GNUNET_TIME_absolute_get ();
  ret->file_size = size;
  ret->client_info = cctx;
  GNUNET_FS_unindex_sync_ (ret);
  pi.status = GNUNET_FS_STATUS_UNINDEX_START;
  pi.value.unindex.eta = GNUNET_TIME_UNIT_FOREVER_REL;
  GNUNET_FS_unindex_make_status_ (&pi, ret, 0);
  ret->fhc =
      GNUNET_CRYPTO_hash_file (GNUNET_SCHEDULER_PRIORITY_IDLE, filename,
                               HASHING_BLOCKSIZE,
                               &GNUNET_FS_unindex_process_hash_, ret);
  ret->top = GNUNET_FS_make_top (h, &GNUNET_FS_unindex_signal_suspend_, ret);
  return ret;
}


/**
 * Clean up after completion of an unindex operation.
 *
 * @param uc handle
 */
void
GNUNET_FS_unindex_stop (struct GNUNET_FS_UnindexContext *uc)
{
  struct GNUNET_FS_ProgressInfo pi;

  if (uc->dscan != NULL)
  {
    GNUNET_FS_directory_scan_abort (uc->dscan);
    uc->dscan = NULL;
  }
  if (NULL != uc->dqe)
  {
    GNUNET_DATASTORE_cancel (uc->dqe);
    uc->dqe = NULL;
  }
  if (uc->fhc != NULL)
  {
    GNUNET_CRYPTO_hash_file_cancel (uc->fhc);
    uc->fhc = NULL;
  }
  if (uc->client != NULL)
  {
    GNUNET_CLIENT_disconnect (uc->client, GNUNET_NO);
    uc->client = NULL;
  }
  if (NULL != uc->dsh)
  {
    GNUNET_DATASTORE_disconnect (uc->dsh, GNUNET_NO);
    uc->dsh = NULL;
  }
  if (NULL != uc->ksk_uri)
  {
    GNUNET_FS_uri_destroy (uc->ksk_uri);
    uc->ksk_uri = NULL;
  }
  if (NULL != uc->tc)
  {
    GNUNET_FS_tree_encoder_finish (uc->tc, NULL, NULL);
    uc->tc = NULL;
  }
  if (uc->fh != NULL)
  {
    GNUNET_DISK_file_close (uc->fh);
    uc->fh = NULL;
  }
  GNUNET_FS_end_top (uc->h, uc->top);
  if (uc->serialization != NULL)
  {
    GNUNET_FS_remove_sync_file_ (uc->h, GNUNET_FS_SYNC_PATH_MASTER_UNINDEX,
                                 uc->serialization);
    GNUNET_free (uc->serialization);
    uc->serialization = NULL;
  }
  pi.status = GNUNET_FS_STATUS_UNINDEX_STOPPED;
  pi.value.unindex.eta = GNUNET_TIME_UNIT_ZERO;
  GNUNET_FS_unindex_make_status_ (&pi, uc,
                                  (uc->state ==
                                   UNINDEX_STATE_COMPLETE) ? uc->file_size : 0);
  GNUNET_break (NULL == uc->client_info);
  GNUNET_free (uc->filename);
  GNUNET_free (uc);
}

/* end of fs_unindex.c */