unofficial mirror of notmuch@notmuchmail.org
 help / color / mirror / code / Atom feed
blob 6987e2f417ae5039294b078836c24f7779b01506 46891 bytes (raw)
name: lib/database.cc 	 # note: path name is non-authoritative(*)

   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
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
 
/* database.cc - The database interfaces of the notmuch mail library
 *
 * Copyright © 2009 Carl Worth
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program.  If not, see https://www.gnu.org/licenses/ .
 *
 * Author: Carl Worth <cworth@cworth.org>
 */

#include "database-private.h"
#include "string-util.h"

#include <iostream>

#include <sys/time.h>
#include <sys/stat.h>
#include <signal.h>
#include <ftw.h>

#include <glib.h>               /* g_free, GPtrArray, GHashTable */
#include <glib-object.h>        /* g_type_init */

#include <gmime/gmime.h>        /* g_mime_init */

using namespace std;

typedef struct {
    const char *name;
    const char *prefix;
    notmuch_field_flag_t flags;
} prefix_t;

#define NOTMUCH_DATABASE_VERSION 3

#define STRINGIFY(s) _SUB_STRINGIFY (s)
#define _SUB_STRINGIFY(s) #s

#define LOG_XAPIAN_EXCEPTION(message, error) _log_xapian_exception (__location__, message, error)

static void
_log_xapian_exception (const char *where, notmuch_database_t *notmuch,  const Xapian::Error error)
{
    _notmuch_database_log (notmuch,
			   "A Xapian exception occurred at %s: %s\n",
			   where,
			   error.get_msg ().c_str ());
    notmuch->exception_reported = true;
}

notmuch_database_mode_t
_notmuch_database_mode (notmuch_database_t *notmuch)
{
    if (notmuch->writable_xapian_db)
	return NOTMUCH_DATABASE_MODE_READ_WRITE;
    else
	return NOTMUCH_DATABASE_MODE_READ_ONLY;
}

/* Here's the current schema for our database (for NOTMUCH_DATABASE_VERSION):
 *
 * We currently have three different types of documents (mail, ghost,
 * and directory) and also some metadata.
 *
 * There are two kinds of prefixes used in notmuch. There are the
 * human friendly 'prefix names' like "thread:", which are also used
 * in the query parser, and the actual prefix terms in the database
 * (e.g. "G"). The correspondence is maintained in the file scope data
 * structure 'prefix_table'.
 *
 * Mail document
 * -------------
 * A mail document is associated with a particular email message. It
 * is stored in one or more files on disk and is uniquely identified
 * by its "id" field (which is generally the message ID). It is
 * indexed with the following prefixed terms which the database uses
 * to construct threads, etc.:
 *
 *    Single terms of given prefix:
 *
 *	type:	mail
 *
 *	id:	Unique ID of mail. This is from the Message-ID header
 *		if present and not too long (see NOTMUCH_MESSAGE_ID_MAX).
 *		If it's present and too long, then we use
 *		"notmuch-sha1-<sha1_sum_of_message_id>".
 *              If this header is not present, we use
 *		"notmuch-sha1-<sha1_sum_of_entire_file>".
 *
 *	thread:	The ID of the thread to which the mail belongs
 *
 *	replyto: The ID from the In-Reply-To header of the mail (if any).
 *
 *    Multiple terms of given prefix:
 *
 *	reference: All message IDs from In-Reply-To and References
 *		   headers in the message.
 *
 *	tag:	   Any tags associated with this message by the user.
 *
 *	file-direntry:  A colon-separated pair of values
 *		        (INTEGER:STRING), where INTEGER is the
 *		        document ID of a directory document, and
 *		        STRING is the name of a file within that
 *		        directory for this mail message.
 *
 *      property:       Has a property with key=value
 *                 FIXME: if no = is present, should match on any value
 *
 *    A mail document also has four values:
 *
 *	TIMESTAMP:	The time_t value corresponding to the message's
 *			Date header.
 *
 *	MESSAGE_ID:	The unique ID of the mail mess (see "id" above)
 *
 *	FROM:		The value of the "From" header
 *
 *	SUBJECT:	The value of the "Subject" header
 *
 *	LAST_MOD:	The revision number as of the last tag or
 *			filename change.
 *
 * The prefixed terms described above are also searchable without an
 * explicit field name, but as of notmuch 0.29 this is due to
 * query-parser setup, not extra terms in the database.  In addition,
 * terms from the content of the message are added without a prefix
 * for use by the user in searching. Note that the prefix name "body"
 * is used to refer to the empty prefix string in the database.
 *
 * The path of the containing folder is added with the "folder" prefix
 * (see _notmuch_message_add_folder_terms).  Sub-paths of the the path
 * of the mail message are added with the "path" prefix.
 *
 * The data portion of a mail document is empty.
 *
 * Ghost mail document [if NOTMUCH_FEATURE_GHOSTS]
 * -----------------------------------------------
 * A ghost mail document is like a mail document, but where we don't
 * have the message content.  These are used to track thread reference
 * information for messages we haven't received.
 *
 * A ghost mail document has type: ghost; id and thread fields that
 * are identical to the mail document fields; and a MESSAGE_ID value.
 *
 * Directory document
 * ------------------
 * A directory document is used by a client of the notmuch library to
 * maintain data necessary to allow for efficient polling of mail
 * directories.
 *
 * All directory documents contain one term:
 *
 *	directory:	The directory path (relative to the database path)
 *			Or the SHA1 sum of the directory path (if the
 *			path itself is too long to fit in a Xapian
 *			term).
 *
 * And all directory documents for directories other than top-level
 * directories also contain the following term:
 *
 *	directory-direntry: A colon-separated pair of values
 *		            (INTEGER:STRING), where INTEGER is the
 *		            document ID of the parent directory
 *		            document, and STRING is the name of this
 *		            directory within that parent.
 *
 * All directory documents have a single value:
 *
 *	TIMESTAMP:	The mtime of the directory (at last scan)
 *
 * The data portion of a directory document contains the path of the
 * directory (relative to the database path).
 *
 * Database metadata
 * -----------------
 * Xapian allows us to store arbitrary name-value pairs as
 * "metadata". We currently use the following metadata names with the
 * given meanings:
 *
 *	version		The database schema version, (which is distinct
 *			from both the notmuch package version (see
 *			notmuch --version) and the libnotmuch library
 *			version. The version is stored as an base-10
 *			ASCII integer. The initial database version
 *			was 1, (though a schema existed before that
 *			were no "version" database value existed at
 *			all). Successive versions are allocated as
 *			changes are made to the database (such as by
 *			indexing new fields).
 *
 *	features	The set of features supported by this
 *			database. This consists of a set of
 *			'\n'-separated lines, where each is a feature
 *			name, a '\t', and compatibility flags.  If the
 *			compatibility flags contain 'w', then the
 *			opener must support this feature to safely
 *			write this database.  If the compatibility
 *			flags contain 'r', then the opener must
 *			support this feature to read this database.
 *			Introduced in database version 3.
 *
 *	last_thread_id	The last thread ID generated. This is stored
 *			as a 16-byte hexadecimal ASCII representation
 *			of a 64-bit unsigned integer. The first ID
 *			generated is 1 and the value will be
 *			incremented for each thread ID.
 *
 *	C*		metadata keys starting with C indicate
 *			configuration data. It can be managed with the
 *			n_database_*config* API.  There is a convention
 *			of hierarchical keys separated by '.' (e.g.
 *			query.notmuch stores the value for the named
 *			query 'notmuch'), but it is not enforced by the
 *			API.
 *
 * Obsolete metadata
 * -----------------
 *
 * If ! NOTMUCH_FEATURE_GHOSTS, there are no ghost mail documents.
 * Instead, the database has the following additional database
 * metadata:
 *
 *	thread_id_*	A pre-allocated thread ID for a particular
 *			message. This is actually an arbitrarily large
 *			family of metadata name. Any particular name is
 *			formed by concatenating "thread_id_" with a message
 *			ID (or the SHA1 sum of a message ID if it is very
 *			long---see description of 'id' in the mail
 *			document). The value stored is a thread ID.
 *
 *			These thread ID metadata values are stored
 *			whenever a message references a parent message
 *			that does not yet exist in the database. A
 *			thread ID will be allocated and stored, and if
 *			the message is later added, the stored thread
 *			ID will be used (and the metadata value will
 *			be cleared).
 *
 *			Even before a message is added, it's
 *			pre-allocated thread ID is useful so that all
 *			descendant messages that reference this common
 *			parent can be recognized as belonging to the
 *			same thread.
 */


notmuch_string_map_iterator_t *
_notmuch_database_user_headers (notmuch_database_t *notmuch)
{
    return _notmuch_string_map_iterator_create (notmuch->user_header, "", false);
}

const char *
notmuch_status_to_string (notmuch_status_t status)
{
    switch (status) {
    case NOTMUCH_STATUS_SUCCESS:
	return "No error occurred";
    case NOTMUCH_STATUS_OUT_OF_MEMORY:
	return "Out of memory";
    case NOTMUCH_STATUS_READ_ONLY_DATABASE:
	return "Attempt to write to a read-only database";
    case NOTMUCH_STATUS_XAPIAN_EXCEPTION:
	return "A Xapian exception occurred";
    case NOTMUCH_STATUS_FILE_ERROR:
	return "Something went wrong trying to read or write a file";
    case NOTMUCH_STATUS_FILE_NOT_EMAIL:
	return "File is not an email";
    case NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID:
	return "Message ID is identical to a message in database";
    case NOTMUCH_STATUS_NULL_POINTER:
	return "Erroneous NULL pointer";
    case NOTMUCH_STATUS_TAG_TOO_LONG:
	return "Tag value is too long (exceeds NOTMUCH_TAG_MAX)";
    case NOTMUCH_STATUS_UNBALANCED_FREEZE_THAW:
	return "Unbalanced number of calls to notmuch_message_freeze/thaw";
    case NOTMUCH_STATUS_UNBALANCED_ATOMIC:
	return "Unbalanced number of calls to notmuch_database_begin_atomic/end_atomic";
    case NOTMUCH_STATUS_UNSUPPORTED_OPERATION:
	return "Unsupported operation";
    case NOTMUCH_STATUS_UPGRADE_REQUIRED:
	return "Operation requires a database upgrade";
    case NOTMUCH_STATUS_PATH_ERROR:
	return "Path supplied is illegal for this function";
    case NOTMUCH_STATUS_IGNORED:
	return "Argument was ignored";
    case NOTMUCH_STATUS_ILLEGAL_ARGUMENT:
	return "Illegal argument for function";
    case NOTMUCH_STATUS_MALFORMED_CRYPTO_PROTOCOL:
	return "Crypto protocol missing, malformed, or unintelligible";
    case NOTMUCH_STATUS_FAILED_CRYPTO_CONTEXT_CREATION:
	return "Crypto engine initialization failure";
    case NOTMUCH_STATUS_UNKNOWN_CRYPTO_PROTOCOL:
	return "Unknown crypto protocol";
    case NOTMUCH_STATUS_NO_CONFIG:
	return "No configuration file found";
    case NOTMUCH_STATUS_NO_DATABASE:
	return "No database found";
    case NOTMUCH_STATUS_DATABASE_EXISTS:
	return "Database exists, not recreated";
    case NOTMUCH_STATUS_BAD_QUERY_SYNTAX:
	return "Syntax error in query";
    case NOTMUCH_STATUS_NO_MAIL_ROOT:
	return "No mail root found";
    default:
    case NOTMUCH_STATUS_LAST_STATUS:
	return "Unknown error status value";
    }
}

void
_notmuch_database_log (notmuch_database_t *notmuch,
		       const char *format,
		       ...)
{
    va_list va_args;

    va_start (va_args, format);

    if (notmuch->status_string)
	talloc_free (notmuch->status_string);

    notmuch->status_string = talloc_vasprintf (notmuch, format, va_args);
    va_end (va_args);
}

void
_notmuch_database_log_append (notmuch_database_t *notmuch,
			      const char *format,
			      ...)
{
    va_list va_args;

    va_start (va_args, format);

    if (notmuch->status_string)
	notmuch->status_string = talloc_vasprintf_append (notmuch->status_string, format, va_args);
    else
	notmuch->status_string = talloc_vasprintf (notmuch, format, va_args);

    va_end (va_args);
}

static void
find_doc_ids_for_term (notmuch_database_t *notmuch,
		       const char *term,
		       Xapian::PostingIterator *begin,
		       Xapian::PostingIterator *end)
{
    *begin = notmuch->xapian_db->postlist_begin (term);

    *end = notmuch->xapian_db->postlist_end (term);
}

void
_notmuch_database_find_doc_ids (notmuch_database_t *notmuch,
				const char *prefix_name,
				const char *value,
				Xapian::PostingIterator *begin,
				Xapian::PostingIterator *end)
{
    char *term;

    term = talloc_asprintf (notmuch, "%s%s",
			    _find_prefix (prefix_name), value);

    find_doc_ids_for_term (notmuch, term, begin, end);

    talloc_free (term);
}

notmuch_private_status_t
_notmuch_database_find_unique_doc_id (notmuch_database_t *notmuch,
				      const char *prefix_name,
				      const char *value,
				      unsigned int *doc_id)
{
    Xapian::PostingIterator i, end;

    _notmuch_database_find_doc_ids (notmuch, prefix_name, value, &i, &end);

    if (i == end) {
	*doc_id = 0;
	return NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND;
    }

    *doc_id = *i;

#if DEBUG_DATABASE_SANITY
    i++;

    if (i != end)
	INTERNAL_ERROR ("Term %s:%s is not unique as expected.\n",
			prefix_name, value);
#endif

    return NOTMUCH_PRIVATE_STATUS_SUCCESS;
}

static Xapian::Document
find_document_for_doc_id (notmuch_database_t *notmuch, unsigned doc_id)
{
    return notmuch->xapian_db->get_document (doc_id);
}

/* Generate a compressed version of 'message_id' of the form:
 *
 *	notmuch-sha1-<sha1_sum_of_message_id>
 */
char *
_notmuch_message_id_compressed (void *ctx, const char *message_id)
{
    char *sha1, *compressed;

    sha1 = _notmuch_sha1_of_string (message_id);

    compressed = talloc_asprintf (ctx, "notmuch-sha1-%s", sha1);
    free (sha1);

    return compressed;
}

notmuch_status_t
notmuch_database_find_message (notmuch_database_t *notmuch,
			       const char *message_id,
			       notmuch_message_t **message_ret)
{
    notmuch_private_status_t status;
    unsigned int doc_id;

    if (message_ret == NULL)
	return NOTMUCH_STATUS_NULL_POINTER;

    if (strlen (message_id) > NOTMUCH_MESSAGE_ID_MAX)
	message_id = _notmuch_message_id_compressed (notmuch, message_id);

    try {
	status = _notmuch_database_find_unique_doc_id (notmuch, "id",
						       message_id, &doc_id);

	if (status == NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND)
	    *message_ret = NULL;
	else {
	    *message_ret = _notmuch_message_create (notmuch, notmuch, doc_id,
						    NULL);
	    if (*message_ret == NULL)
		return NOTMUCH_STATUS_OUT_OF_MEMORY;
	}

	return NOTMUCH_STATUS_SUCCESS;
    } catch (const Xapian::Error &error) {
	_notmuch_database_log (notmuch, "A Xapian exception occurred finding message: %s.\n",
			       error.get_msg ().c_str ());
	notmuch->exception_reported = true;
	*message_ret = NULL;
	return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
    }
}

notmuch_status_t
_notmuch_database_ensure_writable (notmuch_database_t *notmuch)
{
    if (_notmuch_database_mode (notmuch) == NOTMUCH_DATABASE_MODE_READ_ONLY) {
	_notmuch_database_log (notmuch, "Cannot write to a read-only database.\n");
	return NOTMUCH_STATUS_READ_ONLY_DATABASE;
    }

    if (! notmuch->open) {
	_notmuch_database_log (notmuch, "Cannot write to a closed database.\n");
	return NOTMUCH_STATUS_CLOSED_DATABASE;
    }

    return NOTMUCH_STATUS_SUCCESS;
}

/* Allocate a revision number for the next change. */
unsigned long
_notmuch_database_new_revision (notmuch_database_t *notmuch)
{
    unsigned long new_revision = notmuch->revision + 1;

    /* If we're in an atomic section, hold off on updating the
     * committed revision number until we commit the atomic section.
     */
    if (notmuch->atomic_nesting)
	notmuch->atomic_dirty = true;
    else
	notmuch->revision = new_revision;

    return new_revision;
}

notmuch_status_t
notmuch_database_close (notmuch_database_t *notmuch)
{
    notmuch_status_t status = NOTMUCH_STATUS_SUCCESS;

    /* Many Xapian objects (and thus notmuch objects) hold references to
     * the database, so merely deleting the database may not suffice to
     * close it.  Thus, we explicitly close it here. */
    if (notmuch->open) {
	try {
	    /* Close the database.  This implicitly flushes
	     * outstanding changes. If there is an open (non-flushed)
	     * transaction, ALL pending changes will be discarded */
	    notmuch->xapian_db->close ();
	} catch (const Xapian::Error &error) {
	    status = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
	    if (! notmuch->exception_reported) {
		_notmuch_database_log (notmuch,
				       "Error: A Xapian exception occurred closing database: %s\n",
				       error.get_msg ().c_str ());
	    }
	}
    }
    notmuch->open = false;
    return status;
}

static int
unlink_cb (const char *path,
	   unused (const struct stat *sb),
	   unused (int type),
	   unused (struct FTW *ftw))
{
    return remove (path);
}

static int
rmtree (const char *path)
{
    return nftw (path, unlink_cb, 64, FTW_DEPTH | FTW_PHYS);
}

class NotmuchCompactor : public Xapian::Compactor
{
    notmuch_compact_status_cb_t status_cb;
    void *status_closure;

public:
    NotmuchCompactor(notmuch_compact_status_cb_t cb, void *closure) :
	status_cb (cb), status_closure (closure)
    {
    }

    virtual void
    set_status (const std::string &table, const std::string &status)
    {
	char *msg;

	if (status_cb == NULL)
	    return;

	if (status.length () == 0)
	    msg = talloc_asprintf (NULL, "compacting table %s", table.c_str ());
	else
	    msg = talloc_asprintf (NULL, "     %s", status.c_str ());

	if (msg == NULL) {
	    return;
	}

	status_cb (msg, status_closure);
	talloc_free (msg);
    }
};

/* Compacts the given database, optionally saving the original database
 * in backup_path. Additionally, a callback function can be provided to
 * give the user feedback on the progress of the (likely long-lived)
 * compaction process.
 *
 * The backup path must point to a directory on the same volume as the
 * original database. Passing a NULL backup_path will result in the
 * uncompacted database being deleted after compaction has finished.
 * Note that the database write lock will be held during the
 * compaction process to protect data integrity.
 */
notmuch_status_t
notmuch_database_compact (const char *path,
			  const char *backup_path,
			  notmuch_compact_status_cb_t status_cb,
			  void *closure)
{
    notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
    notmuch_database_t *notmuch = NULL;
    char *message = NULL;

    ret = notmuch_database_open_with_config (path,
					     NOTMUCH_DATABASE_MODE_READ_WRITE,
					     "",
					     NULL,
					     &notmuch,
					     &message);
    if (ret) {
	if (status_cb) status_cb (message, closure);
	return ret;
    }

    _notmuch_config_cache (notmuch, NOTMUCH_CONFIG_DATABASE_PATH, path);

    return notmuch_database_compact_db (notmuch,
					backup_path,
					status_cb,
					closure);
}

notmuch_status_t
notmuch_database_compact_db (notmuch_database_t *notmuch,
			     const char *backup_path,
			     notmuch_compact_status_cb_t status_cb,
			     void *closure)
{
    void *local;
    const char *xapian_path, *compact_xapian_path;
    const char *path;
    notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
    struct stat statbuf;
    bool keep_backup;
    char *message;

    ret = _notmuch_database_ensure_writable (notmuch);
    if (ret)
	return ret;

    path = notmuch_config_get (notmuch, NOTMUCH_CONFIG_DATABASE_PATH);
    if (! path)
	return NOTMUCH_STATUS_PATH_ERROR;

    local = talloc_new (NULL);
    if (! local)
	return NOTMUCH_STATUS_OUT_OF_MEMORY;

    ret = _notmuch_choose_xapian_path (local, path, &xapian_path, &message);
    if (ret)
	goto DONE;

    if (! (compact_xapian_path = talloc_asprintf (local, "%s.compact", xapian_path))) {
	ret = NOTMUCH_STATUS_OUT_OF_MEMORY;
	goto DONE;
    }

    if (backup_path == NULL) {
	if (! (backup_path = talloc_asprintf (local, "%s.old", xapian_path))) {
	    ret = NOTMUCH_STATUS_OUT_OF_MEMORY;
	    goto DONE;
	}
	keep_backup = false;
    } else {
	keep_backup = true;
    }

    if (stat (backup_path, &statbuf) != -1) {
	_notmuch_database_log (notmuch, "Path already exists: %s\n", backup_path);
	ret = NOTMUCH_STATUS_FILE_ERROR;
	goto DONE;
    }
    if (errno != ENOENT) {
	_notmuch_database_log (notmuch, "Unknown error while stat()ing path: %s\n",
			       strerror (errno));
	ret = NOTMUCH_STATUS_FILE_ERROR;
	goto DONE;
    }

    /* Unconditionally attempt to remove old work-in-progress database (if
     * any). This is "protected" by database lock. If this fails due to write
     * errors (etc), the following code will fail and provide error message.
     */
    (void) rmtree (compact_xapian_path);

    try {
	NotmuchCompactor compactor (status_cb, closure);
	notmuch->xapian_db->compact (compact_xapian_path, Xapian::DBCOMPACT_NO_RENUMBER, 0,
				     compactor);
    } catch (const Xapian::Error &error) {
	_notmuch_database_log (notmuch, "Error while compacting: %s\n", error.get_msg ().c_str ());
	ret = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
	goto DONE;
    }

    if (rename (xapian_path, backup_path)) {
	_notmuch_database_log (notmuch, "Error moving %s to %s: %s\n",
			       xapian_path, backup_path, strerror (errno));
	ret = NOTMUCH_STATUS_FILE_ERROR;
	goto DONE;
    }

    if (rename (compact_xapian_path, xapian_path)) {
	_notmuch_database_log (notmuch, "Error moving %s to %s: %s\n",
			       compact_xapian_path, xapian_path, strerror (errno));
	ret = NOTMUCH_STATUS_FILE_ERROR;
	goto DONE;
    }

    if (! keep_backup) {
	if (rmtree (backup_path)) {
	    _notmuch_database_log (notmuch, "Error removing old database %s: %s\n",
				   backup_path, strerror (errno));
	    ret = NOTMUCH_STATUS_FILE_ERROR;
	    goto DONE;
	}
    }

  DONE:
    if (notmuch) {
	notmuch_status_t ret2;

	const char *str = notmuch_database_status_string (notmuch);
	if (status_cb && str)
	    status_cb (str, closure);

	ret2 = notmuch_database_destroy (notmuch);

	/* don't clobber previous error status */
	if (ret == NOTMUCH_STATUS_SUCCESS && ret2 != NOTMUCH_STATUS_SUCCESS)
	    ret = ret2;
    }

    talloc_free (local);

    return ret;
}

notmuch_status_t
notmuch_database_destroy (notmuch_database_t *notmuch)
{
    notmuch_status_t status;
    const char *talloc_report;

    talloc_report = getenv ("NOTMUCH_TALLOC_REPORT");
    if (talloc_report && strcmp (talloc_report, "") != 0) {
	FILE *report = fopen (talloc_report, "a");
	if (report) {
	    talloc_report_full (notmuch, report);
	}
    }

    status = notmuch_database_close (notmuch);

    delete notmuch->term_gen;
    notmuch->term_gen = NULL;
    delete notmuch->query_parser;
    notmuch->query_parser = NULL;
    delete notmuch->xapian_db;
    notmuch->xapian_db = NULL;
    delete notmuch->value_range_processor;
    notmuch->value_range_processor = NULL;
    delete notmuch->date_range_processor;
    notmuch->date_range_processor = NULL;
    delete notmuch->last_mod_range_processor;
    notmuch->last_mod_range_processor = NULL;
    delete notmuch->stemmer;
    notmuch->stemmer = NULL;

    talloc_free (notmuch);

    return status;
}

const char *
notmuch_database_get_path (notmuch_database_t *notmuch)
{
    return notmuch_config_get (notmuch, NOTMUCH_CONFIG_DATABASE_PATH);
}

unsigned int
notmuch_database_get_version (notmuch_database_t *notmuch)
{
    unsigned int version;
    string version_string;
    const char *str;
    char *end;

    try {
	version_string = notmuch->xapian_db->get_metadata ("version");
    } catch (const Xapian::Error &error) {
	LOG_XAPIAN_EXCEPTION (notmuch, error);
	return 0;
    }

    if (version_string.empty ())
	return 0;

    str = version_string.c_str ();
    if (str == NULL || *str == '\0')
	return 0;

    version = strtoul (str, &end, 10);
    if (*end != '\0')
	INTERNAL_ERROR ("Malformed database version: %s", str);

    return version;
}

notmuch_bool_t
notmuch_database_needs_upgrade (notmuch_database_t *notmuch)
{
    unsigned int version;

    if (_notmuch_database_mode (notmuch) != NOTMUCH_DATABASE_MODE_READ_WRITE)
	return FALSE;

    if (NOTMUCH_FEATURES_CURRENT & ~notmuch->features)
	return TRUE;

    version = notmuch_database_get_version (notmuch);

    return (version > 0 && version < NOTMUCH_DATABASE_VERSION);
}

static volatile sig_atomic_t do_progress_notify = 0;

static void
handle_sigalrm (unused (int signal))
{
    do_progress_notify = 1;
}

/* Upgrade the current database.
 *
 * After opening a database in read-write mode, the client should
 * check if an upgrade is needed (notmuch_database_needs_upgrade) and
 * if so, upgrade with this function before making any modifications.
 *
 * The optional progress_notify callback can be used by the caller to
 * provide progress indication to the user. If non-NULL it will be
 * called periodically with 'count' as the number of messages upgraded
 * so far and 'total' the overall number of messages that will be
 * converted.
 */
notmuch_status_t
notmuch_database_upgrade (notmuch_database_t *notmuch,
			  void (*progress_notify)(void *closure,
						  double progress),
			  void *closure)
{
    void *local = talloc_new (NULL);
    Xapian::TermIterator t, t_end;
    Xapian::WritableDatabase *db;
    struct sigaction action;
    struct itimerval timerval;
    bool timer_is_active = false;
    enum _notmuch_features target_features, new_features;
    notmuch_status_t status;
    notmuch_private_status_t private_status;
    notmuch_query_t *query = NULL;
    unsigned int count = 0, total = 0;

    if (_notmuch_database_mode (notmuch) != NOTMUCH_DATABASE_MODE_READ_WRITE)
	return NOTMUCH_STATUS_READ_ONLY_DATABASE;

    db = notmuch->writable_xapian_db;

    target_features = notmuch->features | NOTMUCH_FEATURES_CURRENT;
    new_features = NOTMUCH_FEATURES_CURRENT & ~notmuch->features;

    if (! notmuch_database_needs_upgrade (notmuch))
	return NOTMUCH_STATUS_SUCCESS;

    if (progress_notify) {
	/* Set up our handler for SIGALRM */
	memset (&action, 0, sizeof (struct sigaction));
	action.sa_handler = handle_sigalrm;
	sigemptyset (&action.sa_mask);
	action.sa_flags = SA_RESTART;
	sigaction (SIGALRM, &action, NULL);

	/* Then start a timer to send SIGALRM once per second. */
	timerval.it_interval.tv_sec = 1;
	timerval.it_interval.tv_usec = 0;
	timerval.it_value.tv_sec = 1;
	timerval.it_value.tv_usec = 0;
	setitimer (ITIMER_REAL, &timerval, NULL);

	timer_is_active = true;
    }

    /* Figure out how much total work we need to do. */
    if (new_features &
	(NOTMUCH_FEATURE_FILE_TERMS | NOTMUCH_FEATURE_BOOL_FOLDER |
	 NOTMUCH_FEATURE_LAST_MOD)) {
	query = notmuch_query_create (notmuch, "");
	unsigned msg_count;

	status = notmuch_query_count_messages (query, &msg_count);
	if (status)
	    goto DONE;

	total += msg_count;
	notmuch_query_destroy (query);
	query = NULL;
    }
    if (new_features & NOTMUCH_FEATURE_DIRECTORY_DOCS) {
	t_end = db->allterms_end ("XTIMESTAMP");
	for (t = db->allterms_begin ("XTIMESTAMP"); t != t_end; t++)
	    ++total;
    }
    if (new_features & NOTMUCH_FEATURE_GHOSTS) {
	/* The ghost message upgrade converts all thread_id_*
	 * metadata values into ghost message documents. */
	t_end = db->metadata_keys_end ("thread_id_");
	for (t = db->metadata_keys_begin ("thread_id_"); t != t_end; ++t)
	    ++total;
    }

    /* Perform the upgrade in a transaction. */
    db->begin_transaction (true);

    /* Set the target features so we write out changes in the desired
     * format. */
    notmuch->features = target_features;

    /* Perform per-message upgrades. */
    if (new_features &
	(NOTMUCH_FEATURE_FILE_TERMS | NOTMUCH_FEATURE_BOOL_FOLDER |
	 NOTMUCH_FEATURE_LAST_MOD)) {
	notmuch_messages_t *messages;
	notmuch_message_t *message;
	char *filename;

	query = notmuch_query_create (notmuch, "");

	status = notmuch_query_search_messages (query, &messages);
	if (status)
	    goto DONE;
	for (;
	     notmuch_messages_valid (messages);
	     notmuch_messages_move_to_next (messages)) {
	    if (do_progress_notify) {
		progress_notify (closure, (double) count / total);
		do_progress_notify = 0;
	    }

	    message = notmuch_messages_get (messages);

	    /* Before version 1, each message document had its
	     * filename in the data field. Copy that into the new
	     * format by calling notmuch_message_add_filename.
	     */
	    if (new_features & NOTMUCH_FEATURE_FILE_TERMS) {
		filename = _notmuch_message_talloc_copy_data (message);
		if (filename && *filename != '\0') {
		    _notmuch_message_add_filename (message, filename);
		    _notmuch_message_clear_data (message);
		}
		talloc_free (filename);
	    }

	    /* Prior to version 2, the "folder:" prefix was
	     * probabilistic and stemmed. Change it to the current
	     * boolean prefix. Add "path:" prefixes while at it.
	     */
	    if (new_features & NOTMUCH_FEATURE_BOOL_FOLDER)
		_notmuch_message_upgrade_folder (message);

	    /* Prior to NOTMUCH_FEATURE_LAST_MOD, messages did not
	     * track modification revisions.  Give all messages the
	     * next available revision; since we just started tracking
	     * revisions for this database, that will be 1.
	     */
	    if (new_features & NOTMUCH_FEATURE_LAST_MOD)
		_notmuch_message_upgrade_last_mod (message);

	    _notmuch_message_sync (message);

	    notmuch_message_destroy (message);

	    count++;
	}

	notmuch_query_destroy (query);
	query = NULL;
    }

    /* Perform per-directory upgrades. */

    /* Before version 1 we stored directory timestamps in
     * XTIMESTAMP documents instead of the current XDIRECTORY
     * documents. So copy those as well. */
    if (new_features & NOTMUCH_FEATURE_DIRECTORY_DOCS) {
	t_end = notmuch->xapian_db->allterms_end ("XTIMESTAMP");

	for (t = notmuch->xapian_db->allterms_begin ("XTIMESTAMP");
	     t != t_end;
	     t++) {
	    Xapian::PostingIterator p, p_end;
	    std::string term = *t;

	    p_end = notmuch->xapian_db->postlist_end (term);

	    for (p = notmuch->xapian_db->postlist_begin (term);
		 p != p_end;
		 p++) {
		Xapian::Document document;
		time_t mtime;
		notmuch_directory_t *directory;

		if (do_progress_notify) {
		    progress_notify (closure, (double) count / total);
		    do_progress_notify = 0;
		}

		document = find_document_for_doc_id (notmuch, *p);
		mtime = Xapian::sortable_unserialise (
		    document.get_value (NOTMUCH_VALUE_TIMESTAMP));

		directory = _notmuch_directory_find_or_create (notmuch, term.c_str () + 10,
							       NOTMUCH_FIND_CREATE, &status);
		notmuch_directory_set_mtime (directory, mtime);
		notmuch_directory_destroy (directory);

		db->delete_document (*p);
	    }

	    ++count;
	}
    }

    /* Perform metadata upgrades. */

    /* Prior to NOTMUCH_FEATURE_GHOSTS, thread IDs for missing
     * messages were stored as database metadata. Change these to
     * ghost messages.
     */
    if (new_features & NOTMUCH_FEATURE_GHOSTS) {
	notmuch_message_t *message;
	std::string message_id, thread_id;

	t_end = db->metadata_keys_end (NOTMUCH_METADATA_THREAD_ID_PREFIX);
	for (t = db->metadata_keys_begin (NOTMUCH_METADATA_THREAD_ID_PREFIX);
	     t != t_end; ++t) {
	    if (do_progress_notify) {
		progress_notify (closure, (double) count / total);
		do_progress_notify = 0;
	    }

	    message_id = (*t).substr (
		strlen (NOTMUCH_METADATA_THREAD_ID_PREFIX));
	    thread_id = db->get_metadata (*t);

	    /* Create ghost message */
	    message = _notmuch_message_create_for_message_id (
		notmuch, message_id.c_str (), &private_status);
	    if (private_status == NOTMUCH_PRIVATE_STATUS_SUCCESS) {
		/* Document already exists; ignore the stored thread ID */
	    } else if (private_status ==
		       NOTMUCH_PRIVATE_STATUS_NO_DOCUMENT_FOUND) {
		private_status = _notmuch_message_initialize_ghost (
		    message, thread_id.c_str ());
		if (! private_status)
		    _notmuch_message_sync (message);
	    }

	    if (private_status) {
		_notmuch_database_log (notmuch,
				       "Upgrade failed while creating ghost messages.\n");
		status = COERCE_STATUS (private_status,
					"Unexpected status from _notmuch_message_initialize_ghost");
		goto DONE;
	    }

	    /* Clear saved metadata thread ID */
	    db->set_metadata (*t, "");

	    ++count;
	}
    }

    status = NOTMUCH_STATUS_SUCCESS;
    db->set_metadata ("features", _notmuch_database_print_features (local, notmuch->features));
    db->set_metadata ("version", STRINGIFY (NOTMUCH_DATABASE_VERSION));

  DONE:
    if (status == NOTMUCH_STATUS_SUCCESS)
	db->commit_transaction ();
    else
	db->cancel_transaction ();

    if (timer_is_active) {
	/* Now stop the timer. */
	timerval.it_interval.tv_sec = 0;
	timerval.it_interval.tv_usec = 0;
	timerval.it_value.tv_sec = 0;
	timerval.it_value.tv_usec = 0;
	setitimer (ITIMER_REAL, &timerval, NULL);

	/* And disable the signal handler. */
	action.sa_handler = SIG_IGN;
	sigaction (SIGALRM, &action, NULL);
    }

    if (query)
	notmuch_query_destroy (query);

    talloc_free (local);
    return status;
}

notmuch_status_t
notmuch_database_begin_atomic (notmuch_database_t *notmuch)
{
    if (_notmuch_database_mode (notmuch) == NOTMUCH_DATABASE_MODE_READ_ONLY ||
	notmuch->atomic_nesting > 0)
	goto DONE;

    if (notmuch_database_needs_upgrade (notmuch))
	return NOTMUCH_STATUS_UPGRADE_REQUIRED;

    try {
	notmuch->writable_xapian_db->begin_transaction (false);
    } catch (const Xapian::Error &error) {
	_notmuch_database_log (notmuch, "A Xapian exception occurred beginning transaction: %s.\n",
			       error.get_msg ().c_str ());
	notmuch->exception_reported = true;
	return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
    }

  DONE:
    notmuch->atomic_nesting++;
    return NOTMUCH_STATUS_SUCCESS;
}

notmuch_status_t
notmuch_database_end_atomic (notmuch_database_t *notmuch)
{
    Xapian::WritableDatabase *db;

    if (notmuch->atomic_nesting == 0)
	return NOTMUCH_STATUS_UNBALANCED_ATOMIC;

    if (_notmuch_database_mode (notmuch) == NOTMUCH_DATABASE_MODE_READ_ONLY ||
	notmuch->atomic_nesting > 1)
	goto DONE;

    db = notmuch->writable_xapian_db;
    try {
	db->commit_transaction ();
	notmuch->transaction_count++;

	/* Xapian never flushes on a non-flushed commit, even if the
	 * flush threshold is 1.  However, we rely on flushing to test
	 * atomicity. On the other hand, we can't straight replace
	 * XAPIAN_FLUSH_THRESHOLD with our autocommit counter, because
	 * the former also applies outside notmuch atomic
	 * commits. Hence the follow complicated  test */
	const char *thresh = getenv ("XAPIAN_FLUSH_THRESHOLD");
	if ((notmuch->transaction_threshold > 0 &&
	     notmuch->transaction_count >= notmuch->transaction_threshold) ||
	    (thresh && atoi (thresh) == 1)) {
	    db->commit ();
	    notmuch->transaction_count = 0;
	}
    } catch (const Xapian::Error &error) {
	_notmuch_database_log (notmuch, "A Xapian exception occurred committing transaction: %s.\n",
			       error.get_msg ().c_str ());
	notmuch->exception_reported = true;
	return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
    }

    if (notmuch->atomic_dirty) {
	++notmuch->revision;
	notmuch->atomic_dirty = false;
    }

  DONE:
    notmuch->atomic_nesting--;
    return NOTMUCH_STATUS_SUCCESS;
}

unsigned long
notmuch_database_get_revision (notmuch_database_t *notmuch,
			       const char **uuid)
{
    if (uuid)
	*uuid = notmuch->uuid;
    return notmuch->revision;
}

/* We allow the user to use arbitrarily long paths for directories. But
 * we have a term-length limit. So if we exceed that, we'll use the
 * SHA-1 of the path for the database term.
 *
 * Note: This function may return the original value of 'path'. If it
 * does not, then the caller is responsible to free() the returned
 * value.
 */
const char *
_notmuch_database_get_directory_db_path (const char *path)
{
    int term_len = strlen (_find_prefix ("directory")) + strlen (path);

    if (term_len > NOTMUCH_TERM_MAX)
	return _notmuch_sha1_of_string (path);
    else
	return path;
}

/* Given a path, split it into two parts: the directory part is all
 * components except for the last, and the basename is that last
 * component. Getting the return-value for either part is optional
 * (the caller can pass NULL).
 *
 * The original 'path' can represent either a regular file or a
 * directory---the splitting will be carried out in the same way in
 * either case. Trailing slashes on 'path' will be ignored, and any
 * cases of multiple '/' characters appearing in series will be
 * treated as a single '/'.
 *
 * Allocation (if any) will have 'ctx' as the talloc owner. But
 * pointers will be returned within the original path string whenever
 * possible.
 *
 * Note: If 'path' is non-empty and contains no non-trailing slash,
 * (that is, consists of a filename with no parent directory), then
 * the directory returned will be an empty string. However, if 'path'
 * is an empty string, then both directory and basename will be
 * returned as NULL.
 */
notmuch_status_t
_notmuch_database_split_path (void *ctx,
			      const char *path,
			      const char **directory,
			      const char **basename)
{
    const char *slash;

    if (path == NULL || *path == '\0') {
	if (directory)
	    *directory = NULL;
	if (basename)
	    *basename = NULL;
	return NOTMUCH_STATUS_SUCCESS;
    }

    /* Find the last slash (not counting a trailing slash), if any. */

    slash = path + strlen (path) - 1;

    /* First, skip trailing slashes. */
    while (slash != path && *slash == '/')
	--slash;

    /* Then, find a slash. */
    while (slash != path && *slash != '/') {
	if (basename)
	    *basename = slash;

	--slash;
    }

    /* Finally, skip multiple slashes. */
    while (slash != path && *(slash - 1) == '/')
	--slash;

    if (slash == path) {
	if (directory)
	    *directory = talloc_strdup (ctx, "");
	if (basename)
	    *basename = path;
    } else {
	if (directory)
	    *directory = talloc_strndup (ctx, path, slash - path);
    }

    return NOTMUCH_STATUS_SUCCESS;
}

/* Find the document ID of the specified directory.
 *
 * If (flags & NOTMUCH_FIND_CREATE), a new directory document will be
 * created if one does not exist for 'path'.  Otherwise, if the
 * directory document does not exist, this sets *directory_id to
 * ((unsigned int)-1) and returns NOTMUCH_STATUS_SUCCESS.
 */
notmuch_status_t
_notmuch_database_find_directory_id (notmuch_database_t *notmuch,
				     const char *path,
				     notmuch_find_flags_t flags,
				     unsigned int *directory_id)
{
    notmuch_directory_t *directory;
    notmuch_status_t status;

    if (path == NULL) {
	*directory_id = 0;
	return NOTMUCH_STATUS_SUCCESS;
    }

    directory = _notmuch_directory_find_or_create (notmuch, path, flags, &status);
    if (status || ! directory) {
	*directory_id = -1;
	return status;
    }

    *directory_id = _notmuch_directory_get_document_id (directory);

    notmuch_directory_destroy (directory);

    return NOTMUCH_STATUS_SUCCESS;
}

const char *
_notmuch_database_get_directory_path (void *ctx,
				      notmuch_database_t *notmuch,
				      unsigned int doc_id)
{
    Xapian::Document document;

    document = find_document_for_doc_id (notmuch, doc_id);

    return talloc_strdup (ctx, document.get_data ().c_str ());
}

/* Given a legal 'filename' for the database, (either relative to
 * database path or absolute with initial components identical to
 * database path), return a new string (with 'ctx' as the talloc
 * owner) suitable for use as a direntry term value.
 *
 * If (flags & NOTMUCH_FIND_CREATE), the necessary directory documents
 * will be created in the database as needed.  Otherwise, if the
 * necessary directory documents do not exist, this sets
 * *direntry to NULL and returns NOTMUCH_STATUS_SUCCESS.
 */
notmuch_status_t
_notmuch_database_filename_to_direntry (void *ctx,
					notmuch_database_t *notmuch,
					const char *filename,
					notmuch_find_flags_t flags,
					char **direntry)
{
    const char *relative, *directory, *basename;
    Xapian::docid directory_id;
    notmuch_status_t status;

    relative = _notmuch_database_relative_path (notmuch, filename);

    status = _notmuch_database_split_path (ctx, relative,
					   &directory, &basename);
    if (status)
	return status;

    status = _notmuch_database_find_directory_id (notmuch, directory, flags,
						  &directory_id);
    if (status || directory_id == (unsigned int) -1) {
	*direntry = NULL;
	return status;
    }

    *direntry = talloc_asprintf (ctx, "%u:%s", directory_id, basename);

    return NOTMUCH_STATUS_SUCCESS;
}

/* Given a legal 'path' for the database, return the relative path.
 *
 * The return value will be a pointer to the original path contents,
 * and will be either the original string (if 'path' was relative) or
 * a portion of the string (if path was absolute and begins with the
 * database path).
 */
const char *
_notmuch_database_relative_path (notmuch_database_t *notmuch,
				 const char *path)
{
    const char *db_path, *relative;
    unsigned int db_path_len;

    db_path = notmuch_config_get (notmuch, NOTMUCH_CONFIG_MAIL_ROOT);
    db_path_len = strlen (db_path);

    relative = path;

    if (*relative == '/') {
	while (*relative == '/' && *(relative + 1) == '/')
	    relative++;

	if (strncmp (relative, db_path, db_path_len) == 0) {
	    relative += db_path_len;
	    while (*relative == '/')
		relative++;
	}
    }

    return relative;
}

notmuch_status_t
notmuch_database_get_directory (notmuch_database_t *notmuch,
				const char *path,
				notmuch_directory_t **directory)
{
    notmuch_status_t status;

    if (directory == NULL)
	return NOTMUCH_STATUS_NULL_POINTER;
    *directory = NULL;

    try {
	*directory = _notmuch_directory_find_or_create (notmuch, path,
							NOTMUCH_FIND_LOOKUP, &status);
    } catch (const Xapian::Error &error) {
	_notmuch_database_log (notmuch, "A Xapian exception occurred getting directory: %s.\n",
			       error.get_msg ().c_str ());
	notmuch->exception_reported = true;
	status = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
    }
    return status;
}

/* Allocate a document ID that satisfies the following criteria:
 *
 * 1. The ID does not exist for any document in the Xapian database
 *
 * 2. The ID was not previously returned from this function
 *
 * 3. The ID is the smallest integer satisfying (1) and (2)
 *
 * This function will trigger an internal error if these constraints
 * cannot all be satisfied, (that is, the pool of available document
 * IDs has been exhausted).
 */
unsigned int
_notmuch_database_generate_doc_id (notmuch_database_t *notmuch)
{
    assert (notmuch->last_doc_id >= notmuch->xapian_db->get_lastdocid ());

    notmuch->last_doc_id++;

    if (notmuch->last_doc_id == 0)
	INTERNAL_ERROR ("Xapian document IDs are exhausted.\n");

    return notmuch->last_doc_id;
}

notmuch_status_t
notmuch_database_remove_message (notmuch_database_t *notmuch,
				 const char *filename)
{
    notmuch_status_t status;
    notmuch_message_t *message;

    status = notmuch_database_find_message_by_filename (notmuch, filename,
							&message);

    if (status == NOTMUCH_STATUS_SUCCESS && message) {
	status = _notmuch_message_remove_filename (message, filename);
	if (status == NOTMUCH_STATUS_SUCCESS)
	    status = _notmuch_message_delete (message);
	else if (status == NOTMUCH_STATUS_DUPLICATE_MESSAGE_ID)
	    _notmuch_message_sync (message);

	notmuch_message_destroy (message);
    }

    return status;
}

notmuch_status_t
notmuch_database_find_message_by_filename (notmuch_database_t *notmuch,
					   const char *filename,
					   notmuch_message_t **message_ret)
{
    void *local;
    const char *prefix = _find_prefix ("file-direntry");
    char *direntry, *term;
    Xapian::PostingIterator i, end;
    notmuch_status_t status;

    if (message_ret == NULL)
	return NOTMUCH_STATUS_NULL_POINTER;

    if (! (notmuch->features & NOTMUCH_FEATURE_FILE_TERMS))
	return NOTMUCH_STATUS_UPGRADE_REQUIRED;

    /* return NULL on any failure */
    *message_ret = NULL;

    local = talloc_new (notmuch);

    try {
	status = _notmuch_database_filename_to_direntry (
	    local, notmuch, filename, NOTMUCH_FIND_LOOKUP, &direntry);
	if (status || ! direntry)
	    goto DONE;

	term = talloc_asprintf (local, "%s%s", prefix, direntry);

	find_doc_ids_for_term (notmuch, term, &i, &end);

	if (i != end) {
	    notmuch_private_status_t private_status;

	    *message_ret = _notmuch_message_create (notmuch, notmuch, *i,
						    &private_status);
	    if (*message_ret == NULL)
		status = NOTMUCH_STATUS_OUT_OF_MEMORY;
	}
    } catch (const Xapian::Error &error) {
	_notmuch_database_log (notmuch,
			       "Error: A Xapian exception occurred finding message by filename: %s\n",
			       error.get_msg ().c_str ());
	notmuch->exception_reported = true;
	status = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
    }

  DONE:
    talloc_free (local);

    if (status && *message_ret) {
	notmuch_message_destroy (*message_ret);
	*message_ret = NULL;
    }
    return status;
}

notmuch_string_list_t *
_notmuch_database_get_terms_with_prefix (void *ctx, Xapian::TermIterator &i,
					 Xapian::TermIterator &end,
					 const char *prefix)
{
    int prefix_len = strlen (prefix);
    notmuch_string_list_t *list;

    list = _notmuch_string_list_create (ctx);
    if (unlikely (list == NULL))
	return NULL;

    for (i.skip_to (prefix); i != end; i++) {
	/* Terminate loop at first term without desired prefix. */
	if (strncmp ((*i).c_str (), prefix, prefix_len))
	    break;

	_notmuch_string_list_append (list, (*i).c_str () + prefix_len);
    }

    return list;
}

notmuch_tags_t *
notmuch_database_get_all_tags (notmuch_database_t *db)
{
    Xapian::TermIterator i, end;
    notmuch_string_list_t *tags;

    try {
	i = db->xapian_db->allterms_begin ();
	end = db->xapian_db->allterms_end ();
	tags = _notmuch_database_get_terms_with_prefix (db, i, end,
							_find_prefix ("tag"));
	_notmuch_string_list_sort (tags);
	return _notmuch_tags_create (db, tags);
    } catch (const Xapian::Error &error) {
	_notmuch_database_log (db, "A Xapian exception occurred getting tags: %s.\n",
			       error.get_msg ().c_str ());
	db->exception_reported = true;
	return NULL;
    }
}

const char *
notmuch_database_status_string (const notmuch_database_t *notmuch)
{
    return notmuch->status_string;
}

bool
_notmuch_database_indexable_as_text (notmuch_database_t *notmuch, const char *mime_string)
{
    for (size_t i = 0; i < notmuch->index_as_text_length; i++) {
	if (regexec (&notmuch->index_as_text[i], mime_string, 0, NULL, 0) == 0) {
	    return true;
	}
    }

    return false;
}

debug log:

solving 6987e2f4 ...
found 6987e2f4 in https://yhetil.org/notmuch.git/

(*) Git path names are given by the tree(s) the blob belongs to.
    Blobs themselves have no identifier aside from the hash of its contents.^

Code repositories for project(s) associated with this public inbox

	https://yhetil.org/notmuch.git/

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).