summaryrefslogtreecommitdiff
path: root/includes/Export.php
blob: 98de4c001b6f5536de3ee4c7cd01db3259890054 (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
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
<?php
/**
 * Base classes for dumps and export
 *
 * Copyright © 2003, 2005, 2006 Brion Vibber <brion@pobox.com>
 * http://www.mediawiki.org/
 *
 * 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 2 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

/**
 * @defgroup Dump Dump
 */

/**
 * @ingroup SpecialPage Dump
 */
class WikiExporter {
	var $list_authors = false; # Return distinct author list (when not returning full history)
	var $author_list = "";

	var $dumpUploads = false;
	var $dumpUploadFileContents = false;

	const FULL = 1;
	const CURRENT = 2;
	const STABLE = 4; // extension defined
	const LOGS = 8;
	const RANGE = 16;

	const BUFFER = 0;
	const STREAM = 1;

	const TEXT = 0;
	const STUB = 1;

	var $buffer;

	var $text;

	/**
	 * @var DumpOutput
	 */
	var $sink;

	/**
	 * Returns the export schema version.
	 * @return string
	 */
	public static function schemaVersion() {
		return "0.8";
	}

	/**
	 * If using WikiExporter::STREAM to stream a large amount of data,
	 * provide a database connection which is not managed by
	 * LoadBalancer to read from: some history blob types will
	 * make additional queries to pull source data while the
	 * main query is still running.
	 *
	 * @param $db DatabaseBase
	 * @param $history Mixed: one of WikiExporter::FULL, WikiExporter::CURRENT,
	 *                 WikiExporter::RANGE or WikiExporter::STABLE,
	 *                 or an associative array:
	 *                   offset: non-inclusive offset at which to start the query
	 *                   limit: maximum number of rows to return
	 *                   dir: "asc" or "desc" timestamp order
	 * @param int $buffer one of WikiExporter::BUFFER or WikiExporter::STREAM
	 * @param int $text one of WikiExporter::TEXT or WikiExporter::STUB
	 */
	function __construct( $db, $history = WikiExporter::CURRENT,
			$buffer = WikiExporter::BUFFER, $text = WikiExporter::TEXT ) {
		$this->db = $db;
		$this->history = $history;
		$this->buffer = $buffer;
		$this->writer = new XmlDumpWriter();
		$this->sink = new DumpOutput();
		$this->text = $text;
	}

	/**
	 * Set the DumpOutput or DumpFilter object which will receive
	 * various row objects and XML output for filtering. Filters
	 * can be chained or used as callbacks.
	 *
	 * @param $sink mixed
	 */
	public function setOutputSink( &$sink ) {
		$this->sink =& $sink;
	}

	public function openStream() {
		$output = $this->writer->openStream();
		$this->sink->writeOpenStream( $output );
	}

	public function closeStream() {
		$output = $this->writer->closeStream();
		$this->sink->writeCloseStream( $output );
	}

	/**
	 * Dumps a series of page and revision records for all pages
	 * in the database, either including complete history or only
	 * the most recent version.
	 */
	public function allPages() {
		$this->dumpFrom( '' );
	}

	/**
	 * Dumps a series of page and revision records for those pages
	 * in the database falling within the page_id range given.
	 * @param int $start inclusive lower limit (this id is included)
	 * @param $end   Int: Exclusive upper limit (this id is not included)
	 *                   If 0, no upper limit.
	 */
	public function pagesByRange( $start, $end ) {
		$condition = 'page_id >= ' . intval( $start );
		if ( $end ) {
			$condition .= ' AND page_id < ' . intval( $end );
		}
		$this->dumpFrom( $condition );
	}

	/**
	 * Dumps a series of page and revision records for those pages
	 * in the database with revisions falling within the rev_id range given.
	 * @param int $start inclusive lower limit (this id is included)
	 * @param $end   Int: Exclusive upper limit (this id is not included)
	 *                   If 0, no upper limit.
	 */
	public function revsByRange( $start, $end ) {
		$condition = 'rev_id >= ' . intval( $start );
		if ( $end ) {
			$condition .= ' AND rev_id < ' . intval( $end );
		}
		$this->dumpFrom( $condition );
	}

	/**
	 * @param $title Title
	 */
	public function pageByTitle( $title ) {
		$this->dumpFrom(
			'page_namespace=' . $title->getNamespace() .
			' AND page_title=' . $this->db->addQuotes( $title->getDBkey() ) );
	}

	/**
	 * @param $name string
	 * @throws MWException
	 */
	public function pageByName( $name ) {
		$title = Title::newFromText( $name );
		if ( is_null( $title ) ) {
			throw new MWException( "Can't export invalid title" );
		} else {
			$this->pageByTitle( $title );
		}
	}

	/**
	 * @param $names array
	 */
	public function pagesByName( $names ) {
		foreach ( $names as $name ) {
			$this->pageByName( $name );
		}
	}

	public function allLogs() {
		$this->dumpFrom( '' );
	}

	/**
	 * @param $start int
	 * @param $end int
	 */
	public function logsByRange( $start, $end ) {
		$condition = 'log_id >= ' . intval( $start );
		if ( $end ) {
			$condition .= ' AND log_id < ' . intval( $end );
		}
		$this->dumpFrom( $condition );
	}

	/**
	 * Generates the distinct list of authors of an article
	 * Not called by default (depends on $this->list_authors)
	 * Can be set by Special:Export when not exporting whole history
	 *
	 * @param $cond
	 */
	protected function do_list_authors( $cond ) {
		wfProfileIn( __METHOD__ );
		$this->author_list = "<contributors>";
		// rev_deleted

		$res = $this->db->select(
			array( 'page', 'revision' ),
			array( 'DISTINCT rev_user_text', 'rev_user' ),
			array(
				$this->db->bitAnd( 'rev_deleted', Revision::DELETED_USER ) . ' = 0',
				$cond,
				'page_id = rev_id',
			),
			__METHOD__
		);

		foreach ( $res as $row ) {
			$this->author_list .= "<contributor>" .
				"<username>" .
				htmlentities( $row->rev_user_text ) .
				"</username>" .
				"<id>" .
				$row->rev_user .
				"</id>" .
				"</contributor>";
		}
		$this->author_list .= "</contributors>";
		wfProfileOut( __METHOD__ );
	}

	/**
	 * @param $cond string
	 * @throws MWException
	 * @throws Exception
	 */
	protected function dumpFrom( $cond = '' ) {
		wfProfileIn( __METHOD__ );
		# For logging dumps...
		if ( $this->history & self::LOGS ) {
			$where = array( 'user_id = log_user' );
			# Hide private logs
			$hideLogs = LogEventsList::getExcludeClause( $this->db );
			if ( $hideLogs ) {
				$where[] = $hideLogs;
			}
			# Add on any caller specified conditions
			if ( $cond ) {
				$where[] = $cond;
			}
			# Get logging table name for logging.* clause
			$logging = $this->db->tableName( 'logging' );

			if ( $this->buffer == WikiExporter::STREAM ) {
				$prev = $this->db->bufferResults( false );
			}
			$wrapper = null; // Assuring $wrapper is not undefined, if exception occurs early
			try {
				$result = $this->db->select( array( 'logging', 'user' ),
					array( "{$logging}.*", 'user_name' ), // grab the user name
					$where,
					__METHOD__,
					array( 'ORDER BY' => 'log_id', 'USE INDEX' => array( 'logging' => 'PRIMARY' ) )
				);
				$wrapper = $this->db->resultObject( $result );
				$this->outputLogStream( $wrapper );
				if ( $this->buffer == WikiExporter::STREAM ) {
					$this->db->bufferResults( $prev );
				}
			} catch ( Exception $e ) {
				// Throwing the exception does not reliably free the resultset, and
				// would also leave the connection in unbuffered mode.

				// Freeing result
				try {
					if ( $wrapper ) {
						$wrapper->free();
					}
				} catch ( Exception $e2 ) {
					// Already in panic mode -> ignoring $e2 as $e has
					// higher priority
				}

				// Putting database back in previous buffer mode
				try {
					if ( $this->buffer == WikiExporter::STREAM ) {
						$this->db->bufferResults( $prev );
					}
				} catch ( Exception $e2 ) {
					// Already in panic mode -> ignoring $e2 as $e has
					// higher priority
				}

				// Inform caller about problem
				wfProfileOut( __METHOD__ );
				throw $e;
			}
		# For page dumps...
		} else {
			$tables = array( 'page', 'revision' );
			$opts = array( 'ORDER BY' => 'page_id ASC' );
			$opts['USE INDEX'] = array();
			$join = array();
			if ( is_array( $this->history ) ) {
				# Time offset/limit for all pages/history...
				$revJoin = 'page_id=rev_page';
				# Set time order
				if ( $this->history['dir'] == 'asc' ) {
					$op = '>';
					$opts['ORDER BY'] = 'rev_timestamp ASC';
				} else {
					$op = '<';
					$opts['ORDER BY'] = 'rev_timestamp DESC';
				}
				# Set offset
				if ( !empty( $this->history['offset'] ) ) {
					$revJoin .= " AND rev_timestamp $op " .
						$this->db->addQuotes( $this->db->timestamp( $this->history['offset'] ) );
				}
				$join['revision'] = array( 'INNER JOIN', $revJoin );
				# Set query limit
				if ( !empty( $this->history['limit'] ) ) {
					$opts['LIMIT'] = intval( $this->history['limit'] );
				}
			} elseif ( $this->history & WikiExporter::FULL ) {
				# Full history dumps...
				$join['revision'] = array( 'INNER JOIN', 'page_id=rev_page' );
			} elseif ( $this->history & WikiExporter::CURRENT ) {
				# Latest revision dumps...
				if ( $this->list_authors && $cond != '' ) { // List authors, if so desired
					$this->do_list_authors( $cond );
				}
				$join['revision'] = array( 'INNER JOIN', 'page_id=rev_page AND page_latest=rev_id' );
			} elseif ( $this->history & WikiExporter::STABLE ) {
				# "Stable" revision dumps...
				# Default JOIN, to be overridden...
				$join['revision'] = array( 'INNER JOIN', 'page_id=rev_page AND page_latest=rev_id' );
				# One, and only one hook should set this, and return false
				if ( wfRunHooks( 'WikiExporter::dumpStableQuery', array( &$tables, &$opts, &$join ) ) ) {
					wfProfileOut( __METHOD__ );
					throw new MWException( __METHOD__ . " given invalid history dump type." );
				}
			} elseif ( $this->history & WikiExporter::RANGE ) {
				# Dump of revisions within a specified range
				$join['revision'] = array( 'INNER JOIN', 'page_id=rev_page' );
				$opts['ORDER BY'] = array( 'rev_page ASC', 'rev_id ASC' );
			} else {
				# Unknown history specification parameter?
				wfProfileOut( __METHOD__ );
				throw new MWException( __METHOD__ . " given invalid history dump type." );
			}
			# Query optimization hacks
			if ( $cond == '' ) {
				$opts[] = 'STRAIGHT_JOIN';
				$opts['USE INDEX']['page'] = 'PRIMARY';
			}
			# Build text join options
			if ( $this->text != WikiExporter::STUB ) { // 1-pass
				$tables[] = 'text';
				$join['text'] = array( 'INNER JOIN', 'rev_text_id=old_id' );
			}

			if ( $this->buffer == WikiExporter::STREAM ) {
				$prev = $this->db->bufferResults( false );
			}

			$wrapper = null; // Assuring $wrapper is not undefined, if exception occurs early
			try {
				wfRunHooks( 'ModifyExportQuery',
						array( $this->db, &$tables, &$cond, &$opts, &$join ) );

				# Do the query!
				$result = $this->db->select( $tables, '*', $cond, __METHOD__, $opts, $join );
				$wrapper = $this->db->resultObject( $result );
				# Output dump results
				$this->outputPageStream( $wrapper );

				if ( $this->buffer == WikiExporter::STREAM ) {
					$this->db->bufferResults( $prev );
				}
			} catch ( Exception $e ) {
				// Throwing the exception does not reliably free the resultset, and
				// would also leave the connection in unbuffered mode.

				// Freeing result
				try {
					if ( $wrapper ) {
						$wrapper->free();
					}
				} catch ( Exception $e2 ) {
					// Already in panic mode -> ignoring $e2 as $e has
					// higher priority
				}

				// Putting database back in previous buffer mode
				try {
					if ( $this->buffer == WikiExporter::STREAM ) {
						$this->db->bufferResults( $prev );
					}
				} catch ( Exception $e2 ) {
					// Already in panic mode -> ignoring $e2 as $e has
					// higher priority
				}

				// Inform caller about problem
				throw $e;
			}
		}
		wfProfileOut( __METHOD__ );
	}

	/**
	 * Runs through a query result set dumping page and revision records.
	 * The result set should be sorted/grouped by page to avoid duplicate
	 * page records in the output.
	 *
	 * Should be safe for
	 * streaming (non-buffered) queries, as long as it was made on a
	 * separate database connection not managed by LoadBalancer; some
	 * blob storage types will make queries to pull source data.
	 *
	 * @param $resultset ResultWrapper
	 */
	protected function outputPageStream( $resultset ) {
		$last = null;
		foreach ( $resultset as $row ) {
			if ( $last === null ||
				$last->page_namespace != $row->page_namespace ||
				$last->page_title != $row->page_title ) {
				if ( $last !== null ) {
					$output = '';
					if ( $this->dumpUploads ) {
						$output .= $this->writer->writeUploads( $last, $this->dumpUploadFileContents );
					}
					$output .= $this->writer->closePage();
					$this->sink->writeClosePage( $output );
				}
				$output = $this->writer->openPage( $row );
				$this->sink->writeOpenPage( $row, $output );
				$last = $row;
			}
			$output = $this->writer->writeRevision( $row );
			$this->sink->writeRevision( $row, $output );
		}
		if ( $last !== null ) {
			$output = '';
			if ( $this->dumpUploads ) {
				$output .= $this->writer->writeUploads( $last, $this->dumpUploadFileContents );
			}
			$output .= $this->author_list;
			$output .= $this->writer->closePage();
			$this->sink->writeClosePage( $output );
		}
	}

	/**
	 * @param $resultset array
	 */
	protected function outputLogStream( $resultset ) {
		foreach ( $resultset as $row ) {
			$output = $this->writer->writeLogItem( $row );
			$this->sink->writeLogItem( $row, $output );
		}
	}
}

/**
 * @ingroup Dump
 */
class XmlDumpWriter {
	/**
	 * Returns the export schema version.
	 * @deprecated in 1.20; use WikiExporter::schemaVersion() instead
	 * @return string
	 */
	function schemaVersion() {
		wfDeprecated( __METHOD__, '1.20' );
		return WikiExporter::schemaVersion();
	}

	/**
	 * Opens the XML output stream's root "<mediawiki>" element.
	 * This does not include an xml directive, so is safe to include
	 * as a subelement in a larger XML stream. Namespace and XML Schema
	 * references are included.
	 *
	 * Output will be encoded in UTF-8.
	 *
	 * @return string
	 */
	function openStream() {
		global $wgLanguageCode;
		$ver = WikiExporter::schemaVersion();
		return Xml::element( 'mediawiki', array(
			'xmlns'              => "http://www.mediawiki.org/xml/export-$ver/",
			'xmlns:xsi'          => "http://www.w3.org/2001/XMLSchema-instance",
			'xsi:schemaLocation' => "http://www.mediawiki.org/xml/export-$ver/ " .
			                        "http://www.mediawiki.org/xml/export-$ver.xsd", #TODO: how do we get a new version up there?
			'version'            => $ver,
			'xml:lang'           => $wgLanguageCode ),
			null ) .
			"\n" .
			$this->siteInfo();
	}

	/**
	 * @return string
	 */
	function siteInfo() {
		$info = array(
			$this->sitename(),
			$this->homelink(),
			$this->generator(),
			$this->caseSetting(),
			$this->namespaces() );
		return "  <siteinfo>\n    " .
			implode( "\n    ", $info ) .
			"\n  </siteinfo>\n";
	}

	/**
	 * @return string
	 */
	function sitename() {
		global $wgSitename;
		return Xml::element( 'sitename', array(), $wgSitename );
	}

	/**
	 * @return string
	 */
	function generator() {
		global $wgVersion;
		return Xml::element( 'generator', array(), "MediaWiki $wgVersion" );
	}

	/**
	 * @return string
	 */
	function homelink() {
		return Xml::element( 'base', array(), Title::newMainPage()->getCanonicalURL() );
	}

	/**
	 * @return string
	 */
	function caseSetting() {
		global $wgCapitalLinks;
		// "case-insensitive" option is reserved for future
		$sensitivity = $wgCapitalLinks ? 'first-letter' : 'case-sensitive';
		return Xml::element( 'case', array(), $sensitivity );
	}

	/**
	 * @return string
	 */
	function namespaces() {
		global $wgContLang;
		$spaces = "<namespaces>\n";
		foreach ( $wgContLang->getFormattedNamespaces() as $ns => $title ) {
			$spaces .= '      ' .
				Xml::element( 'namespace',
					array(
						'key' => $ns,
						'case' => MWNamespace::isCapitalized( $ns ) ? 'first-letter' : 'case-sensitive',
					), $title ) . "\n";
		}
		$spaces .= "    </namespaces>";
		return $spaces;
	}

	/**
	 * Closes the output stream with the closing root element.
	 * Call when finished dumping things.
	 *
	 * @return string
	 */
	function closeStream() {
		return "</mediawiki>\n";
	}

	/**
	 * Opens a "<page>" section on the output stream, with data
	 * from the given database row.
	 *
	 * @param $row object
	 * @return string
	 * @access private
	 */
	function openPage( $row ) {
		$out = "  <page>\n";
		$title = Title::makeTitle( $row->page_namespace, $row->page_title );
		$out .= '    ' . Xml::elementClean( 'title', array(), self::canonicalTitle( $title ) ) . "\n";
		$out .= '    ' . Xml::element( 'ns', array(), strval( $row->page_namespace ) ) . "\n";
		$out .= '    ' . Xml::element( 'id', array(), strval( $row->page_id ) ) . "\n";
		if ( $row->page_is_redirect ) {
			$page = WikiPage::factory( $title );
			$redirect = $page->getRedirectTarget();
			if ( $redirect instanceOf Title && $redirect->isValidRedirectTarget() ) {
				$out .= '    ' . Xml::element( 'redirect', array( 'title' => self::canonicalTitle( $redirect ) ) ) . "\n";
			}
		}

		if ( $row->page_restrictions != '' ) {
			$out .= '    ' . Xml::element( 'restrictions', array(),
				strval( $row->page_restrictions ) ) . "\n";
		}

		wfRunHooks( 'XmlDumpWriterOpenPage', array( $this, &$out, $row, $title ) );

		return $out;
	}

	/**
	 * Closes a "<page>" section on the output stream.
	 *
	 * @access private
	 * @return string
	 */
	function closePage() {
		return "  </page>\n";
	}

	/**
	 * Dumps a "<revision>" section on the output stream, with
	 * data filled in from the given database row.
	 *
	 * @param $row object
	 * @return string
	 * @access private
	 */
	function writeRevision( $row ) {
		wfProfileIn( __METHOD__ );

		$out = "    <revision>\n";
		$out .= "      " . Xml::element( 'id', null, strval( $row->rev_id ) ) . "\n";
		if ( isset( $row->rev_parent_id ) && $row->rev_parent_id ) {
			$out .= "      " . Xml::element( 'parentid', null, strval( $row->rev_parent_id ) ) . "\n";
		}

		$out .= $this->writeTimestamp( $row->rev_timestamp );

		if ( isset( $row->rev_deleted ) && ( $row->rev_deleted & Revision::DELETED_USER ) ) {
			$out .= "      " . Xml::element( 'contributor', array( 'deleted' => 'deleted' ) ) . "\n";
		} else {
			$out .= $this->writeContributor( $row->rev_user, $row->rev_user_text );
		}

		if ( isset( $row->rev_minor_edit ) && $row->rev_minor_edit ) {
			$out .= "      <minor/>\n";
		}
		if ( isset( $row->rev_deleted ) && ( $row->rev_deleted & Revision::DELETED_COMMENT ) ) {
			$out .= "      " . Xml::element( 'comment', array( 'deleted' => 'deleted' ) ) . "\n";
		} elseif ( $row->rev_comment != '' ) {
			$out .= "      " . Xml::elementClean( 'comment', array(), strval( $row->rev_comment ) ) . "\n";
		}

		$text = '';
		if ( isset( $row->rev_deleted ) && ( $row->rev_deleted & Revision::DELETED_TEXT ) ) {
			$out .= "      " . Xml::element( 'text', array( 'deleted' => 'deleted' ) ) . "\n";
		} elseif ( isset( $row->old_text ) ) {
			// Raw text from the database may have invalid chars
			$text = strval( Revision::getRevisionText( $row ) );
			$out .= "      " . Xml::elementClean( 'text',
				array( 'xml:space' => 'preserve', 'bytes' => intval( $row->rev_len ) ),
				strval( $text ) ) . "\n";
		} else {
			// Stub output
			$out .= "      " . Xml::element( 'text',
				array( 'id' => $row->rev_text_id, 'bytes' => intval( $row->rev_len ) ),
				"" ) . "\n";
		}

		if ( isset( $row->rev_sha1 ) && $row->rev_sha1 && !( $row->rev_deleted & Revision::DELETED_TEXT ) ) {
			$out .= "      " . Xml::element( 'sha1', null, strval( $row->rev_sha1 ) ) . "\n";
		} else {
			$out .= "      <sha1/>\n";
		}

		if ( isset( $row->rev_content_model ) && !is_null( $row->rev_content_model ) ) {
			$content_model = strval( $row->rev_content_model );
		} else {
			// probably using $wgContentHandlerUseDB = false;
			// @todo test!
			$title = Title::makeTitle( $row->page_namespace, $row->page_title );
			$content_model = ContentHandler::getDefaultModelFor( $title );
		}

		$out .= "      " . Xml::element( 'model', null, strval( $content_model ) ) . "\n";

		if ( isset( $row->rev_content_format ) && !is_null( $row->rev_content_format ) ) {
			$content_format = strval( $row->rev_content_format );
		} else {
			// probably using $wgContentHandlerUseDB = false;
			// @todo test!
			$content_handler = ContentHandler::getForModelID( $content_model );
			$content_format = $content_handler->getDefaultFormat();
		}

		$out .= "      " . Xml::element( 'format', null, strval( $content_format ) ) . "\n";

		wfRunHooks( 'XmlDumpWriterWriteRevision', array( &$this, &$out, $row, $text ) );

		$out .= "    </revision>\n";

		wfProfileOut( __METHOD__ );
		return $out;
	}

	/**
	 * Dumps a "<logitem>" section on the output stream, with
	 * data filled in from the given database row.
	 *
	 * @param $row object
	 * @return string
	 * @access private
	 */
	function writeLogItem( $row ) {
		wfProfileIn( __METHOD__ );

		$out = "  <logitem>\n";
		$out .= "    " . Xml::element( 'id', null, strval( $row->log_id ) ) . "\n";

		$out .= $this->writeTimestamp( $row->log_timestamp, "    " );

		if ( $row->log_deleted & LogPage::DELETED_USER ) {
			$out .= "    " . Xml::element( 'contributor', array( 'deleted' => 'deleted' ) ) . "\n";
		} else {
			$out .= $this->writeContributor( $row->log_user, $row->user_name, "    " );
		}

		if ( $row->log_deleted & LogPage::DELETED_COMMENT ) {
			$out .= "    " . Xml::element( 'comment', array( 'deleted' => 'deleted' ) ) . "\n";
		} elseif ( $row->log_comment != '' ) {
			$out .= "    " . Xml::elementClean( 'comment', null, strval( $row->log_comment ) ) . "\n";
		}

		$out .= "    " . Xml::element( 'type', null, strval( $row->log_type ) ) . "\n";
		$out .= "    " . Xml::element( 'action', null, strval( $row->log_action ) ) . "\n";

		if ( $row->log_deleted & LogPage::DELETED_ACTION ) {
			$out .= "    " . Xml::element( 'text', array( 'deleted' => 'deleted' ) ) . "\n";
		} else {
			$title = Title::makeTitle( $row->log_namespace, $row->log_title );
			$out .= "    " . Xml::elementClean( 'logtitle', null, self::canonicalTitle( $title ) ) . "\n";
			$out .= "    " . Xml::elementClean( 'params',
				array( 'xml:space' => 'preserve' ),
				strval( $row->log_params ) ) . "\n";
		}

		$out .= "  </logitem>\n";

		wfProfileOut( __METHOD__ );
		return $out;
	}

	/**
	 * @param $timestamp string
	 * @param string $indent Default to six spaces
	 * @return string
	 */
	function writeTimestamp( $timestamp, $indent = "      " ) {
		$ts = wfTimestamp( TS_ISO_8601, $timestamp );
		return $indent . Xml::element( 'timestamp', null, $ts ) . "\n";
	}

	/**
	 * @param $id
	 * @param $text string
	 * @param string $indent Default to six spaces
	 * @return string
	 */
	function writeContributor( $id, $text, $indent = "      " ) {
		$out = $indent . "<contributor>\n";
		if ( $id || !IP::isValid( $text ) ) {
			$out .= $indent . "  " . Xml::elementClean( 'username', null, strval( $text ) ) . "\n";
			$out .= $indent . "  " . Xml::element( 'id', null, strval( $id ) ) . "\n";
		} else {
			$out .= $indent . "  " . Xml::elementClean( 'ip', null, strval( $text ) ) . "\n";
		}
		$out .= $indent . "</contributor>\n";
		return $out;
	}

	/**
	 * Warning! This data is potentially inconsistent. :(
	 * @param $row
	 * @param $dumpContents bool
	 * @return string
	 */
	function writeUploads( $row, $dumpContents = false ) {
		if ( $row->page_namespace == NS_FILE ) {
			$img = wfLocalFile( $row->page_title );
			if ( $img && $img->exists() ) {
				$out = '';
				foreach ( array_reverse( $img->getHistory() ) as $ver ) {
					$out .= $this->writeUpload( $ver, $dumpContents );
				}
				$out .= $this->writeUpload( $img, $dumpContents );
				return $out;
			}
		}
		return '';
	}

	/**
	 * @param $file File
	 * @param $dumpContents bool
	 * @return string
	 */
	function writeUpload( $file, $dumpContents = false ) {
		if ( $file->isOld() ) {
			$archiveName = "      " .
				Xml::element( 'archivename', null, $file->getArchiveName() ) . "\n";
		} else {
			$archiveName = '';
		}
		if ( $dumpContents ) {
			$be = $file->getRepo()->getBackend();
			# Dump file as base64
			# Uses only XML-safe characters, so does not need escaping
			# @TODO: too bad this loads the contents into memory (script might swap)
			$contents = '      <contents encoding="base64">' .
				chunk_split( base64_encode(
					$be->getFileContents( array( 'src' => $file->getPath() ) ) ) ) .
				"      </contents>\n";
		} else {
			$contents = '';
		}
		if ( $file->isDeleted( File::DELETED_COMMENT ) ) {
			$comment = Xml::element( 'comment', array( 'deleted' => 'deleted' ) );
		} else {
			$comment = Xml::elementClean( 'comment', null, $file->getDescription() );
		}
		return "    <upload>\n" .
			$this->writeTimestamp( $file->getTimestamp() ) .
			$this->writeContributor( $file->getUser( 'id' ), $file->getUser( 'text' ) ) .
			"      " . $comment . "\n" .
			"      " . Xml::element( 'filename', null, $file->getName() ) . "\n" .
			$archiveName .
			"      " . Xml::element( 'src', null, $file->getCanonicalURL() ) . "\n" .
			"      " . Xml::element( 'size', null, $file->getSize() ) . "\n" .
			"      " . Xml::element( 'sha1base36', null, $file->getSha1() ) . "\n" .
			"      " . Xml::element( 'rel', null, $file->getRel() ) . "\n" .
			$contents .
			"    </upload>\n";
	}

	/**
	 * Return prefixed text form of title, but using the content language's
	 * canonical namespace. This skips any special-casing such as gendered
	 * user namespaces -- which while useful, are not yet listed in the
	 * XML "<siteinfo>" data so are unsafe in export.
	 *
	 * @param Title $title
	 * @return string
	 * @since 1.18
	 */
	public static function canonicalTitle( Title $title ) {
		if ( $title->getInterwiki() ) {
			return $title->getPrefixedText();
		}

		global $wgContLang;
		$prefix = str_replace( '_', ' ', $wgContLang->getNsText( $title->getNamespace() ) );

		if ( $prefix !== '' ) {
			$prefix .= ':';
		}

		return $prefix . $title->getText();
	}
}

/**
 * Base class for output stream; prints to stdout or buffer or wherever.
 * @ingroup Dump
 */
class DumpOutput {

	/**
	 * @param $string string
	 */
	function writeOpenStream( $string ) {
		$this->write( $string );
	}

	/**
	 * @param $string string
	 */
	function writeCloseStream( $string ) {
		$this->write( $string );
	}

	/**
	 * @param $page
	 * @param $string string
	 */
	function writeOpenPage( $page, $string ) {
		$this->write( $string );
	}

	/**
	 * @param $string string
	 */
	function writeClosePage( $string ) {
		$this->write( $string );
	}

	/**
	 * @param $rev
	 * @param $string string
	 */
	function writeRevision( $rev, $string ) {
		$this->write( $string );
	}

	/**
	 * @param $rev
	 * @param $string string
	 */
	function writeLogItem( $rev, $string ) {
		$this->write( $string );
	}

	/**
	 * Override to write to a different stream type.
	 * @param $string string
	 * @return bool
	 */
	function write( $string ) {
		print $string;
	}

	/**
	 * Close the old file, move it to a specified name,
	 * and reopen new file with the old name. Use this
	 * for writing out a file in multiple pieces
	 * at specified checkpoints (e.g. every n hours).
	 * @param $newname mixed File name. May be a string or an array with one element
	 */
	function closeRenameAndReopen( $newname ) {
	}

	/**
	 * Close the old file, and move it to a specified name.
	 * Use this for the last piece of a file written out
	 * at specified checkpoints (e.g. every n hours).
	 * @param $newname mixed File name. May be a string or an array with one element
	 * @param bool $open If true, a new file with the old filename will be opened again for writing (default: false)
	 */
	function closeAndRename( $newname, $open = false ) {
	}

	/**
	 * Returns the name of the file or files which are
	 * being written to, if there are any.
	 * @return null
	 */
	function getFilenames() {
		return null;
	}
}

/**
 * Stream outputter to send data to a file.
 * @ingroup Dump
 */
class DumpFileOutput extends DumpOutput {
	protected $handle = false, $filename;

	/**
	 * @param $file
	 */
	function __construct( $file ) {
		$this->handle = fopen( $file, "wt" );
		$this->filename = $file;
	}

	/**
	 * @param $string string
	 */
	function writeCloseStream( $string ) {
		parent::writeCloseStream( $string );
		if ( $this->handle ) {
			fclose( $this->handle );
			$this->handle = false;
		}
	}

	/**
	 * @param $string string
	 */
	function write( $string ) {
		fputs( $this->handle, $string );
	}

	/**
	 * @param $newname
	 */
	function closeRenameAndReopen( $newname ) {
		$this->closeAndRename( $newname, true );
	}

	/**
	 * @param $newname
	 * @throws MWException
	 */
	function renameOrException( $newname ) {
			if ( !rename( $this->filename, $newname ) ) {
				throw new MWException( __METHOD__ . ": rename of file {$this->filename} to $newname failed\n" );
			}
	}

	/**
	 * @param $newname array
	 * @return mixed
	 * @throws MWException
	 */
	function checkRenameArgCount( $newname ) {
		if ( is_array( $newname ) ) {
			if ( count( $newname ) > 1 ) {
				throw new MWException( __METHOD__ . ": passed multiple arguments for rename of single file\n" );
			} else {
				$newname = $newname[0];
			}
		}
		return $newname;
	}

	/**
	 * @param $newname mixed
	 * @param $open bool
	 */
	function closeAndRename( $newname, $open = false ) {
		$newname = $this->checkRenameArgCount( $newname );
		if ( $newname ) {
			if ( $this->handle ) {
				fclose( $this->handle );
				$this->handle = false;
			}
			$this->renameOrException( $newname );
			if ( $open ) {
				$this->handle = fopen( $this->filename, "wt" );
			}
		}
	}

	/**
	 * @return string|null
	 */
	function getFilenames() {
		return $this->filename;
	}
}

/**
 * Stream outputter to send data to a file via some filter program.
 * Even if compression is available in a library, using a separate
 * program can allow us to make use of a multi-processor system.
 * @ingroup Dump
 */
class DumpPipeOutput extends DumpFileOutput {
	protected $command, $filename;
	protected $procOpenResource = false;

	/**
	 * @param $command
	 * @param $file null
	 */
	function __construct( $command, $file = null ) {
		if ( !is_null( $file ) ) {
			$command .= " > " . wfEscapeShellArg( $file );
		}

		$this->startCommand( $command );
		$this->command = $command;
		$this->filename = $file;
	}

	/**
	 * @param $string string
	 */
	function writeCloseStream( $string ) {
		parent::writeCloseStream( $string );
		if ( $this->procOpenResource ) {
			proc_close( $this->procOpenResource );
			$this->procOpenResource = false;
		}
	}

	/**
	 * @param $command
	 */
	function startCommand( $command ) {
		$spec = array(
			0 => array( "pipe", "r" ),
		);
		$pipes = array();
		$this->procOpenResource = proc_open( $command, $spec, $pipes );
		$this->handle = $pipes[0];
	}

	/**
	 * @param mixed $newname
	 */
	function closeRenameAndReopen( $newname ) {
		$this->closeAndRename( $newname, true );
	}

	/**
	 * @param $newname mixed
	 * @param $open bool
	 */
	function closeAndRename( $newname, $open = false ) {
		$newname = $this->checkRenameArgCount( $newname );
		if ( $newname ) {
			if ( $this->handle ) {
				fclose( $this->handle );
				$this->handle = false;
			}
			if ( $this->procOpenResource ) {
				proc_close( $this->procOpenResource );
				$this->procOpenResource = false;
			}
			$this->renameOrException( $newname );
			if ( $open ) {
				$command = $this->command;
				$command .= " > " . wfEscapeShellArg( $this->filename );
				$this->startCommand( $command );
			}
		}
	}

}

/**
 * Sends dump output via the gzip compressor.
 * @ingroup Dump
 */
class DumpGZipOutput extends DumpPipeOutput {

	/**
	 * @param $file string
	 */
	function __construct( $file ) {
		parent::__construct( "gzip", $file );
	}
}

/**
 * Sends dump output via the bgzip2 compressor.
 * @ingroup Dump
 */
class DumpBZip2Output extends DumpPipeOutput {

	/**
	 * @param $file string
	 */
	function __construct( $file ) {
		parent::__construct( "bzip2", $file );
	}
}

/**
 * Sends dump output via the p7zip compressor.
 * @ingroup Dump
 */
class Dump7ZipOutput extends DumpPipeOutput {

	/**
	 * @param $file string
	 */
	function __construct( $file ) {
		$command = $this->setup7zCommand( $file );
		parent::__construct( $command );
		$this->filename = $file;
	}

	/**
	 * @param $file string
	 * @return string
	 */
	function setup7zCommand( $file ) {
		$command = "7za a -bd -si " . wfEscapeShellArg( $file );
		// Suppress annoying useless crap from p7zip
		// Unfortunately this could suppress real error messages too
		$command .= ' >' . wfGetNull() . ' 2>&1';
		return $command;
	}

	/**
	 * @param $newname string
	 * @param $open bool
	 */
	function closeAndRename( $newname, $open = false ) {
		$newname = $this->checkRenameArgCount( $newname );
		if ( $newname ) {
			fclose( $this->handle );
			proc_close( $this->procOpenResource );
			$this->renameOrException( $newname );
			if ( $open ) {
				$command = $this->setup7zCommand( $this->filename );
				$this->startCommand( $command );
			}
		}
	}
}

/**
 * Dump output filter class.
 * This just does output filtering and streaming; XML formatting is done
 * higher up, so be careful in what you do.
 * @ingroup Dump
 */
class DumpFilter {

	/**
	 * @var DumpOutput
	 * FIXME will need to be made protected whenever legacy code
	 * is updated.
	 */
	public $sink;

	/**
	 * @var bool
	 */
	protected $sendingThisPage;

	/**
	 * @param $sink DumpOutput
	 */
	function __construct( &$sink ) {
		$this->sink =& $sink;
	}

	/**
	 * @param $string string
	 */
	function writeOpenStream( $string ) {
		$this->sink->writeOpenStream( $string );
	}

	/**
	 * @param $string string
	 */
	function writeCloseStream( $string ) {
		$this->sink->writeCloseStream( $string );
	}

	/**
	 * @param $page
	 * @param $string string
	 */
	function writeOpenPage( $page, $string ) {
		$this->sendingThisPage = $this->pass( $page, $string );
		if ( $this->sendingThisPage ) {
			$this->sink->writeOpenPage( $page, $string );
		}
	}

	/**
	 * @param $string string
	 */
	function writeClosePage( $string ) {
		if ( $this->sendingThisPage ) {
			$this->sink->writeClosePage( $string );
			$this->sendingThisPage = false;
		}
	}

	/**
	 * @param $rev
	 * @param $string string
	 */
	function writeRevision( $rev, $string ) {
		if ( $this->sendingThisPage ) {
			$this->sink->writeRevision( $rev, $string );
		}
	}

	/**
	 * @param $rev
	 * @param $string string
	 */
	function writeLogItem( $rev, $string ) {
		$this->sink->writeRevision( $rev, $string );
	}

	/**
	 * @param $newname string
	 */
	function closeRenameAndReopen( $newname ) {
		$this->sink->closeRenameAndReopen( $newname );
	}

	/**
	 * @param $newname string
	 * @param $open bool
	 */
	function closeAndRename( $newname, $open = false ) {
		$this->sink->closeAndRename( $newname, $open );
	}

	/**
	 * @return array
	 */
	function getFilenames() {
		return $this->sink->getFilenames();
	}

	/**
	 * Override for page-based filter types.
	 * @param $page
	 * @return bool
	 */
	function pass( $page ) {
		return true;
	}
}

/**
 * Simple dump output filter to exclude all talk pages.
 * @ingroup Dump
 */
class DumpNotalkFilter extends DumpFilter {

	/**
	 * @param $page
	 * @return bool
	 */
	function pass( $page ) {
		return !MWNamespace::isTalk( $page->page_namespace );
	}
}

/**
 * Dump output filter to include or exclude pages in a given set of namespaces.
 * @ingroup Dump
 */
class DumpNamespaceFilter extends DumpFilter {
	var $invert = false;
	var $namespaces = array();

	/**
	 * @param $sink DumpOutput
	 * @param $param
	 * @throws MWException
	 */
	function __construct( &$sink, $param ) {
		parent::__construct( $sink );

		$constants = array(
			"NS_MAIN"           => NS_MAIN,
			"NS_TALK"           => NS_TALK,
			"NS_USER"           => NS_USER,
			"NS_USER_TALK"      => NS_USER_TALK,
			"NS_PROJECT"        => NS_PROJECT,
			"NS_PROJECT_TALK"   => NS_PROJECT_TALK,
			"NS_FILE"           => NS_FILE,
			"NS_FILE_TALK"      => NS_FILE_TALK,
			"NS_IMAGE"          => NS_IMAGE, // NS_IMAGE is an alias for NS_FILE
			"NS_IMAGE_TALK"     => NS_IMAGE_TALK,
			"NS_MEDIAWIKI"      => NS_MEDIAWIKI,
			"NS_MEDIAWIKI_TALK" => NS_MEDIAWIKI_TALK,
			"NS_TEMPLATE"       => NS_TEMPLATE,
			"NS_TEMPLATE_TALK"  => NS_TEMPLATE_TALK,
			"NS_HELP"           => NS_HELP,
			"NS_HELP_TALK"      => NS_HELP_TALK,
			"NS_CATEGORY"       => NS_CATEGORY,
			"NS_CATEGORY_TALK"  => NS_CATEGORY_TALK );

		if ( $param { 0 } == '!' ) {
			$this->invert = true;
			$param = substr( $param, 1 );
		}

		foreach ( explode( ',', $param ) as $key ) {
			$key = trim( $key );
			if ( isset( $constants[$key] ) ) {
				$ns = $constants[$key];
				$this->namespaces[$ns] = true;
			} elseif ( is_numeric( $key ) ) {
				$ns = intval( $key );
				$this->namespaces[$ns] = true;
			} else {
				throw new MWException( "Unrecognized namespace key '$key'\n" );
			}
		}
	}

	/**
	 * @param $page
	 * @return bool
	 */
	function pass( $page ) {
		$match = isset( $this->namespaces[$page->page_namespace] );
		return $this->invert xor $match;
	}
}

/**
 * Dump output filter to include only the last revision in each page sequence.
 * @ingroup Dump
 */
class DumpLatestFilter extends DumpFilter {
	var $page, $pageString, $rev, $revString;

	/**
	 * @param $page
	 * @param $string string
	 */
	function writeOpenPage( $page, $string ) {
		$this->page = $page;
		$this->pageString = $string;
	}

	/**
	 * @param $string string
	 */
	function writeClosePage( $string ) {
		if ( $this->rev ) {
			$this->sink->writeOpenPage( $this->page, $this->pageString );
			$this->sink->writeRevision( $this->rev, $this->revString );
			$this->sink->writeClosePage( $string );
		}
		$this->rev = null;
		$this->revString = null;
		$this->page = null;
		$this->pageString = null;
	}

	/**
	 * @param $rev
	 * @param $string string
	 */
	function writeRevision( $rev, $string ) {
		if ( $rev->rev_id == $this->page->page_latest ) {
			$this->rev = $rev;
			$this->revString = $string;
		}
	}
}

/**
 * Base class for output stream; prints to stdout or buffer or wherever.
 * @ingroup Dump
 */
class DumpMultiWriter {

	/**
	 * @param $sinks
	 */
	function __construct( $sinks ) {
		$this->sinks = $sinks;
		$this->count = count( $sinks );
	}

	/**
	 * @param $string string
	 */
	function writeOpenStream( $string ) {
		for ( $i = 0; $i < $this->count; $i++ ) {
			$this->sinks[$i]->writeOpenStream( $string );
		}
	}

	/**
	 * @param $string string
	 */
	function writeCloseStream( $string ) {
		for ( $i = 0; $i < $this->count; $i++ ) {
			$this->sinks[$i]->writeCloseStream( $string );
		}
	}

	/**
	 * @param $page
	 * @param $string string
	 */
	function writeOpenPage( $page, $string ) {
		for ( $i = 0; $i < $this->count; $i++ ) {
			$this->sinks[$i]->writeOpenPage( $page, $string );
		}
	}

	/**
	 * @param $string
	 */
	function writeClosePage( $string ) {
		for ( $i = 0; $i < $this->count; $i++ ) {
			$this->sinks[$i]->writeClosePage( $string );
		}
	}

	/**
	 * @param $rev
	 * @param $string
	 */
	function writeRevision( $rev, $string ) {
		for ( $i = 0; $i < $this->count; $i++ ) {
			$this->sinks[$i]->writeRevision( $rev, $string );
		}
	}

	/**
	 * @param $newnames
	 */
	function closeRenameAndReopen( $newnames ) {
		$this->closeAndRename( $newnames, true );
	}

	/**
	 * @param $newnames array
	 * @param bool $open
	 */
	function closeAndRename( $newnames, $open = false ) {
		for ( $i = 0; $i < $this->count; $i++ ) {
			$this->sinks[$i]->closeAndRename( $newnames[$i], $open );
		}
	}

	/**
	 * @return array
	 */
	function getFilenames() {
		$filenames = array();
		for ( $i = 0; $i < $this->count; $i++ ) {
			$filenames[] = $this->sinks[$i]->getFilenames();
		}
		return $filenames;
	}

}

/**
 * @param $string string
 * @return string
 */
function xmlsafe( $string ) {
	wfProfileIn( __FUNCTION__ );

	/**
	 * The page may contain old data which has not been properly normalized.
	 * Invalid UTF-8 sequences or forbidden control characters will make our
	 * XML output invalid, so be sure to strip them out.
	 */
	$string = UtfNormal::cleanUp( $string );

	$string = htmlspecialchars( $string );
	wfProfileOut( __FUNCTION__ );
	return $string;
}