summaryrefslogtreecommitdiff
path: root/maintenance/storage/compressOld.php
blob: 3cb4a2ba963d80b0d588c3d5367980516bf18d26 (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
<?php
/**
 * Compress the text of a wiki.
 *
 * Usage:
 *
 * Non-wikimedia
 * php compressOld.php [options...]
 *
 * Wikimedia
 * php compressOld.php <database> [options...]
 *
 * Options are:
 *  -t <type>           set compression type to either:
 *                          gzip: compress revisions independently
 *                          concat: concatenate revisions and compress in chunks (default)
 *  -c <chunk-size>     maximum number of revisions in a concat chunk
 *  -b <begin-date>     earliest date to check for uncompressed revisions
 *  -e <end-date>       latest revision date to compress
 *  -s <startid>        the id to start from (referring to the text table for
 *                      type gzip, and to the page table for type concat)
 *  -n <endid>          the page_id to stop at (only when using concat compression type)
 *  --extdb <cluster>   store specified revisions in an external cluster (untested)
 *
 * 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
 * @ingroup Maintenance ExternalStorage
 */

require_once __DIR__ . '/../Maintenance.php';

/**
 * Maintenance script that compress the text of a wiki.
 *
 * @ingroup Maintenance ExternalStorage
 */
class CompressOld extends Maintenance {
	/**
	 * Option to load each revision individually.
	 *
	 */
	const LS_INDIVIDUAL = 0;

	/**
	 * Option to load revisions in chunks.
	 *
	 */
	const LS_CHUNKED = 1;

	public function __construct() {
		parent::__construct();
		$this->mDescription = 'Compress the text of a wiki';
		$this->addOption( 'type', 'Set compression type to either: gzip|concat', false, true, 't' );
		$this->addOption(
			'chunksize',
			'Maximum number of revisions in a concat chunk',
			false,
			true,
			'c'
		);
		$this->addOption(
			'begin-date',
			'Earliest date to check for uncompressed revisions',
			false,
			true,
			'b'
		);
		$this->addOption( 'end-date', 'Latest revision date to compress', false, true, 'e' );
		$this->addOption(
			'startid',
			'The id to start from (gzip -> text table, concat -> page table)',
			false,
			true,
			's'
		);
		$this->addOption(
			'extdb',
			'Store specified revisions in an external cluster (untested)',
			false,
			true
		);
		$this->addOption(
			'endid',
			'The page_id to stop at (only when using concat compression type)',
			false,
			true,
			'n'
		);
	}

	public function execute() {
		global $wgDBname;
		if ( !function_exists( "gzdeflate" ) ) {
			$this->error( "You must enable zlib support in PHP to compress old revisions!\n" .
				"Please see http://www.php.net/manual/en/ref.zlib.php\n", true );
		}

		$type = $this->getOption( 'type', 'concat' );
		$chunkSize = $this->getOption( 'chunksize', 20 );
		$startId = $this->getOption( 'startid', 0 );
		$beginDate = $this->getOption( 'begin-date', '' );
		$endDate = $this->getOption( 'end-date', '' );
		$extDB = $this->getOption( 'extdb', '' );
		$endId = $this->getOption( 'endid', false );

		if ( $type != 'concat' && $type != 'gzip' ) {
			$this->error( "Type \"{$type}\" not supported" );
		}

		if ( $extDB != '' ) {
			$this->output( "Compressing database {$wgDBname} to external cluster {$extDB}\n"
				. str_repeat( '-', 76 ) . "\n\n" );
		} else {
			$this->output( "Compressing database {$wgDBname}\n"
				. str_repeat( '-', 76 ) . "\n\n" );
		}

		$success = true;
		if ( $type == 'concat' ) {
			$success = $this->compressWithConcat( $startId, $chunkSize, $beginDate,
				$endDate, $extDB, $endId );
		} else {
			$this->compressOldPages( $startId, $extDB );
		}

		if ( $success ) {
			$this->output( "Done.\n" );
		}
	}

	/**
	 * Fetch the text row-by-row to 'compressPage' function for compression.
	 *
	 * @param int $start
	 * @param string $extdb
	 */
	private function compressOldPages( $start = 0, $extdb = '' ) {
		$chunksize = 50;
		$this->output( "Starting from old_id $start...\n" );
		$dbw = wfGetDB( DB_MASTER );
		do {
			$res = $dbw->select(
				'text',
				array( 'old_id', 'old_flags', 'old_text' ),
				"old_id>=$start",
				__METHOD__,
				array( 'ORDER BY' => 'old_id', 'LIMIT' => $chunksize, 'FOR UPDATE' )
			);

			if ( $res->numRows() == 0 ) {
				break;
			}

			$last = $start;

			foreach ( $res as $row ) {
				# print "  {$row->old_id} - {$row->old_namespace}:{$row->old_title}\n";
				$this->compressPage( $row, $extdb );
				$last = $row->old_id;
			}

			$start = $last + 1; # Deletion may leave long empty stretches
			$this->output( "$start...\n" );
		} while ( true );
	}

	/**
	 * Compress the text in gzip format.
	 *
	 * @param stdClass $row
	 * @param string $extdb
	 * @return bool
	 */
	private function compressPage( $row, $extdb ) {
		if ( false !== strpos( $row->old_flags, 'gzip' )
			|| false !== strpos( $row->old_flags, 'object' )
		) {
			#print "Already compressed row {$row->old_id}\n";
			return false;
		}
		$dbw = wfGetDB( DB_MASTER );
		$flags = $row->old_flags ? "{$row->old_flags},gzip" : "gzip";
		$compress = gzdeflate( $row->old_text );

		# Store in external storage if required
		if ( $extdb !== '' ) {
			$storeObj = new ExternalStoreDB;
			$compress = $storeObj->store( $extdb, $compress );
			if ( $compress === false ) {
				$this->error( "Unable to store object" );

				return false;
			}
		}

		# Update text row
		$dbw->update( 'text',
			array( /* SET */
				'old_flags' => $flags,
				'old_text' => $compress
			), array( /* WHERE */
				'old_id' => $row->old_id
			), __METHOD__,
			array( 'LIMIT' => 1 )
		);

		return true;
	}

	/**
	 * Compress the text in chunks after concatenating the revisions.
	 *
	 * @param int $startId
	 * @param int $maxChunkSize
	 * @param string $beginDate
	 * @param string $endDate
	 * @param string $extdb
	 * @param bool|int $maxPageId
	 * @return bool
	 */
	private function compressWithConcat( $startId, $maxChunkSize, $beginDate,
		$endDate, $extdb = "", $maxPageId = false
	) {
		$loadStyle = self::LS_CHUNKED;

		$dbr = wfGetDB( DB_SLAVE );
		$dbw = wfGetDB( DB_MASTER );

		# Set up external storage
		if ( $extdb != '' ) {
			$storeObj = new ExternalStoreDB;
		}

		# Get all articles by page_id
		if ( !$maxPageId ) {
			$maxPageId = $dbr->selectField( 'page', 'max(page_id)', '', __METHOD__ );
		}
		$this->output( "Starting from $startId of $maxPageId\n" );
		$pageConds = array();

		/*
		if ( $exclude_ns0 ) {
			print "Excluding main namespace\n";
			$pageConds[] = 'page_namespace<>0';
		}
		if ( $queryExtra ) {
					$pageConds[] = $queryExtra;
		}
		 */

		# For each article, get a list of revisions which fit the criteria

		# No recompression, use a condition on old_flags
		# Don't compress object type entities, because that might produce data loss when
		# overwriting bulk storage concat rows. Don't compress external references, because
		# the script doesn't yet delete rows from external storage.
		$conds = array(
			'old_flags NOT ' . $dbr->buildLike( $dbr->anyString(), 'object', $dbr->anyString() )
			. ' AND old_flags NOT '
			. $dbr->buildLike( $dbr->anyString(), 'external', $dbr->anyString() )
		);

		if ( $beginDate ) {
			if ( !preg_match( '/^\d{14}$/', $beginDate ) ) {
				$this->error( "Invalid begin date \"$beginDate\"\n" );

				return false;
			}
			$conds[] = "rev_timestamp>'" . $beginDate . "'";
		}
		if ( $endDate ) {
			if ( !preg_match( '/^\d{14}$/', $endDate ) ) {
				$this->error( "Invalid end date \"$endDate\"\n" );

				return false;
			}
			$conds[] = "rev_timestamp<'" . $endDate . "'";
		}
		if ( $loadStyle == self::LS_CHUNKED ) {
			$tables = array( 'revision', 'text' );
			$fields = array( 'rev_id', 'rev_text_id', 'old_flags', 'old_text' );
			$conds[] = 'rev_text_id=old_id';
			$revLoadOptions = 'FOR UPDATE';
		} else {
			$tables = array( 'revision' );
			$fields = array( 'rev_id', 'rev_text_id' );
			$revLoadOptions = array();
		}

		# Don't work with current revisions
		# Don't lock the page table for update either -- TS 2006-04-04
		#$tables[] = 'page';
		#$conds[] = 'page_id=rev_page AND rev_id != page_latest';

		for ( $pageId = $startId; $pageId <= $maxPageId; $pageId++ ) {
			wfWaitForSlaves();

			# Wake up
			$dbr->ping();

			# Get the page row
			$pageRes = $dbr->select( 'page',
				array( 'page_id', 'page_namespace', 'page_title', 'page_latest' ),
				$pageConds + array( 'page_id' => $pageId ), __METHOD__ );
			if ( $pageRes->numRows() == 0 ) {
				continue;
			}
			$pageRow = $dbr->fetchObject( $pageRes );

			# Display progress
			$titleObj = Title::makeTitle( $pageRow->page_namespace, $pageRow->page_title );
			$this->output( "$pageId\t" . $titleObj->getPrefixedDBkey() . " " );

			# Load revisions
			$revRes = $dbw->select( $tables, $fields,
				array_merge( array(
					'rev_page' => $pageRow->page_id,
					# Don't operate on the current revision
					# Use < instead of <> in case the current revision has changed
					# since the page select, which wasn't locking
					'rev_id < ' . $pageRow->page_latest
				), $conds ),
				__METHOD__,
				$revLoadOptions
			);
			$revs = array();
			foreach ( $revRes as $revRow ) {
				$revs[] = $revRow;
			}

			if ( count( $revs ) < 2 ) {
				# No revisions matching, no further processing
				$this->output( "\n" );
				continue;
			}

			# For each chunk
			$i = 0;
			while ( $i < count( $revs ) ) {
				if ( $i < count( $revs ) - $maxChunkSize ) {
					$thisChunkSize = $maxChunkSize;
				} else {
					$thisChunkSize = count( $revs ) - $i;
				}

				$chunk = new ConcatenatedGzipHistoryBlob();
				$stubs = array();
				$dbw->begin( __METHOD__ );
				$usedChunk = false;
				$primaryOldid = $revs[$i]->rev_text_id;

				// @codingStandardsIgnoreStart Ignore avoid function calls in a FOR loop test part warning
				# Get the text of each revision and add it to the object
				for ( $j = 0; $j < $thisChunkSize && $chunk->isHappy(); $j++ ) {
					// @codingStandardsIgnoreEnd
					$oldid = $revs[$i + $j]->rev_text_id;

					# Get text
					if ( $loadStyle == self::LS_INDIVIDUAL ) {
						$textRow = $dbw->selectRow( 'text',
							array( 'old_flags', 'old_text' ),
							array( 'old_id' => $oldid ),
							__METHOD__,
							'FOR UPDATE'
						);
						$text = Revision::getRevisionText( $textRow );
					} else {
						$text = Revision::getRevisionText( $revs[$i + $j] );
					}

					if ( $text === false ) {
						$this->error( "\nError, unable to get text in old_id $oldid" );
						#$dbw->delete( 'old', array( 'old_id' => $oldid ) );
					}

					if ( $extdb == "" && $j == 0 ) {
						$chunk->setText( $text );
						$this->output( '.' );
					} else {
						# Don't make a stub if it's going to be longer than the article
						# Stubs are typically about 100 bytes
						if ( strlen( $text ) < 120 ) {
							$stub = false;
							$this->output( 'x' );
						} else {
							$stub = new HistoryBlobStub( $chunk->addItem( $text ) );
							$stub->setLocation( $primaryOldid );
							$stub->setReferrer( $oldid );
							$this->output( '.' );
							$usedChunk = true;
						}
						$stubs[$j] = $stub;
					}
				}
				$thisChunkSize = $j;

				# If we couldn't actually use any stubs because the pages were too small, do nothing
				if ( $usedChunk ) {
					if ( $extdb != "" ) {
						# Move blob objects to External Storage
						$stored = $storeObj->store( $extdb, serialize( $chunk ) );
						if ( $stored === false ) {
							$this->error( "Unable to store object" );

							return false;
						}
						# Store External Storage URLs instead of Stub placeholders
						foreach ( $stubs as $stub ) {
							if ( $stub === false ) {
								continue;
							}
							# $stored should provide base path to a BLOB
							$url = $stored . "/" . $stub->getHash();
							$dbw->update( 'text',
								array( /* SET */
									'old_text' => $url,
									'old_flags' => 'external,utf-8',
								), array( /* WHERE */
									'old_id' => $stub->getReferrer(),
								)
							);
						}
					} else {
						# Store the main object locally
						$dbw->update( 'text',
							array( /* SET */
								'old_text' => serialize( $chunk ),
								'old_flags' => 'object,utf-8',
							), array( /* WHERE */
								'old_id' => $primaryOldid
							)
						);

						# Store the stub objects
						for ( $j = 1; $j < $thisChunkSize; $j++ ) {
							# Skip if not compressing and don't overwrite the first revision
							if ( $stubs[$j] !== false && $revs[$i + $j]->rev_text_id != $primaryOldid ) {
								$dbw->update( 'text',
									array( /* SET */
										'old_text' => serialize( $stubs[$j] ),
										'old_flags' => 'object,utf-8',
									), array( /* WHERE */
										'old_id' => $revs[$i + $j]->rev_text_id
									)
								);
							}
						}
					}
				}
				# Done, next
				$this->output( "/" );
				$dbw->commit( __METHOD__ );
				$i += $thisChunkSize;
				wfWaitForSlaves();
			}
			$this->output( "\n" );
		}

		return true;
	}
}

$maintClass = 'CompressOld';
require_once RUN_MAINTENANCE_IF_MAIN;