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compressOld.php
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1 <?php
44 require_once __DIR__ . '/../Maintenance.php';
45 
51 class CompressOld extends Maintenance {
55  const LS_INDIVIDUAL = 0;
56 
60  const LS_CHUNKED = 1;
61 
62  public function __construct() {
63  parent::__construct();
64  $this->addDescription( 'Compress the text of a wiki' );
65  $this->addOption( 'type', 'Set compression type to either: gzip|concat', false, true, 't' );
66  $this->addOption(
67  'chunksize',
68  'Maximum number of revisions in a concat chunk',
69  false,
70  true,
71  'c'
72  );
73  $this->addOption(
74  'begin-date',
75  'Earliest date to check for uncompressed revisions',
76  false,
77  true,
78  'b'
79  );
80  $this->addOption( 'end-date', 'Latest revision date to compress', false, true, 'e' );
81  $this->addOption(
82  'startid',
83  'The id to start from (gzip -> text table, concat -> page table)',
84  false,
85  true,
86  's'
87  );
88  $this->addOption(
89  'extdb',
90  'Store specified revisions in an external cluster (untested)',
91  false,
92  true
93  );
94  $this->addOption(
95  'endid',
96  'The page_id to stop at (only when using concat compression type)',
97  false,
98  true,
99  'n'
100  );
101  }
102 
103  public function execute() {
104  global $wgDBname;
105  if ( !function_exists( "gzdeflate" ) ) {
106  $this->fatalError( "You must enable zlib support in PHP to compress old revisions!\n" .
107  "Please see https://www.php.net/manual/en/ref.zlib.php\n" );
108  }
109 
110  $type = $this->getOption( 'type', 'concat' );
111  $chunkSize = $this->getOption( 'chunksize', 20 );
112  $startId = $this->getOption( 'startid', 0 );
113  $beginDate = $this->getOption( 'begin-date', '' );
114  $endDate = $this->getOption( 'end-date', '' );
115  $extDB = $this->getOption( 'extdb', '' );
116  $endId = $this->getOption( 'endid', false );
117 
118  if ( $type != 'concat' && $type != 'gzip' ) {
119  $this->error( "Type \"{$type}\" not supported" );
120  }
121 
122  if ( $extDB != '' ) {
123  $this->output( "Compressing database {$wgDBname} to external cluster {$extDB}\n"
124  . str_repeat( '-', 76 ) . "\n\n" );
125  } else {
126  $this->output( "Compressing database {$wgDBname}\n"
127  . str_repeat( '-', 76 ) . "\n\n" );
128  }
129 
130  $success = true;
131  if ( $type == 'concat' ) {
132  $success = $this->compressWithConcat( $startId, $chunkSize, $beginDate,
133  $endDate, $extDB, $endId );
134  } else {
135  $this->compressOldPages( $startId, $extDB );
136  }
137 
138  if ( $success ) {
139  $this->output( "Done.\n" );
140  }
141  }
142 
149  private function compressOldPages( $start = 0, $extdb = '' ) {
150  $chunksize = 50;
151  $this->output( "Starting from old_id $start...\n" );
152  $dbw = $this->getDB( DB_MASTER );
153  do {
154  $res = $dbw->select(
155  'text',
156  [ 'old_id', 'old_flags', 'old_text' ],
157  "old_id>=$start",
158  __METHOD__,
159  [ 'ORDER BY' => 'old_id', 'LIMIT' => $chunksize, 'FOR UPDATE' ]
160  );
161 
162  if ( $res->numRows() == 0 ) {
163  break;
164  }
165 
166  $last = $start;
167 
168  foreach ( $res as $row ) {
169  # print " {$row->old_id} - {$row->old_namespace}:{$row->old_title}\n";
170  $this->compressPage( $row, $extdb );
171  $last = $row->old_id;
172  }
173 
174  $start = $last + 1; # Deletion may leave long empty stretches
175  $this->output( "$start...\n" );
176  } while ( true );
177  }
178 
186  private function compressPage( $row, $extdb ) {
187  if ( strpos( $row->old_flags, 'gzip' ) !== false
188  || strpos( $row->old_flags, 'object' ) !== false
189  ) {
190  # print "Already compressed row {$row->old_id}\n";
191  return false;
192  }
193  $dbw = $this->getDB( DB_MASTER );
194  $flags = $row->old_flags ? "{$row->old_flags},gzip" : "gzip";
195  $compress = gzdeflate( $row->old_text );
196 
197  # Store in external storage if required
198  if ( $extdb !== '' ) {
199  $storeObj = new ExternalStoreDB;
200  $compress = $storeObj->store( $extdb, $compress );
201  if ( $compress === false ) {
202  $this->error( "Unable to store object" );
203 
204  return false;
205  }
206  }
207 
208  # Update text row
209  $dbw->update( 'text',
210  [ /* SET */
211  'old_flags' => $flags,
212  'old_text' => $compress
213  ], [ /* WHERE */
214  'old_id' => $row->old_id
215  ], __METHOD__,
216  [ 'LIMIT' => 1 ]
217  );
218 
219  return true;
220  }
221 
233  private function compressWithConcat( $startId, $maxChunkSize, $beginDate,
234  $endDate, $extdb = "", $maxPageId = false
235  ) {
236  $loadStyle = self::LS_CHUNKED;
237 
238  $dbr = $this->getDB( DB_REPLICA );
239  $dbw = $this->getDB( DB_MASTER );
240 
241  # Set up external storage
242  if ( $extdb != '' ) {
243  $storeObj = new ExternalStoreDB;
244  }
245 
246  # Get all articles by page_id
247  if ( !$maxPageId ) {
248  $maxPageId = $dbr->selectField( 'page', 'max(page_id)', '', __METHOD__ );
249  }
250  $this->output( "Starting from $startId of $maxPageId\n" );
251  $pageConds = [];
252 
253  /*
254  if ( $exclude_ns0 ) {
255  print "Excluding main namespace\n";
256  $pageConds[] = 'page_namespace<>0';
257  }
258  if ( $queryExtra ) {
259  $pageConds[] = $queryExtra;
260  }
261  */
262 
263  # For each article, get a list of revisions which fit the criteria
264 
265  # No recompression, use a condition on old_flags
266  # Don't compress object type entities, because that might produce data loss when
267  # overwriting bulk storage concat rows. Don't compress external references, because
268  # the script doesn't yet delete rows from external storage.
269  $conds = [
270  'old_flags NOT ' . $dbr->buildLike( $dbr->anyString(), 'object', $dbr->anyString() )
271  . ' AND old_flags NOT '
272  . $dbr->buildLike( $dbr->anyString(), 'external', $dbr->anyString() )
273  ];
274 
275  if ( $beginDate ) {
276  if ( !preg_match( '/^\d{14}$/', $beginDate ) ) {
277  $this->error( "Invalid begin date \"$beginDate\"\n" );
278 
279  return false;
280  }
281  $conds[] = "rev_timestamp>'" . $beginDate . "'";
282  }
283  if ( $endDate ) {
284  if ( !preg_match( '/^\d{14}$/', $endDate ) ) {
285  $this->error( "Invalid end date \"$endDate\"\n" );
286 
287  return false;
288  }
289  $conds[] = "rev_timestamp<'" . $endDate . "'";
290  }
291  if ( $loadStyle == self::LS_CHUNKED ) {
292  $tables = [ 'revision', 'text' ];
293  $fields = [ 'rev_id', 'rev_text_id', 'old_flags', 'old_text' ];
294  $conds[] = 'rev_text_id=old_id';
295  $revLoadOptions = 'FOR UPDATE';
296  } else {
297  $tables = [ 'revision' ];
298  $fields = [ 'rev_id', 'rev_text_id' ];
299  $revLoadOptions = [];
300  }
301 
302  # Don't work with current revisions
303  # Don't lock the page table for update either -- TS 2006-04-04
304  # $tables[] = 'page';
305  # $conds[] = 'page_id=rev_page AND rev_id != page_latest';
306 
307  for ( $pageId = $startId; $pageId <= $maxPageId; $pageId++ ) {
308  wfWaitForSlaves();
309 
310  # Wake up
311  $dbr->ping();
312 
313  # Get the page row
314  $pageRes = $dbr->select( 'page',
315  [ 'page_id', 'page_namespace', 'page_title', 'page_latest' ],
316  $pageConds + [ 'page_id' => $pageId ], __METHOD__ );
317  if ( $pageRes->numRows() == 0 ) {
318  continue;
319  }
320  $pageRow = $dbr->fetchObject( $pageRes );
321 
322  # Display progress
323  $titleObj = Title::makeTitle( $pageRow->page_namespace, $pageRow->page_title );
324  $this->output( "$pageId\t" . $titleObj->getPrefixedDBkey() . " " );
325 
326  # Load revisions
327  $revRes = $dbw->select( $tables, $fields,
328  array_merge( [
329  'rev_page' => $pageRow->page_id,
330  # Don't operate on the current revision
331  # Use < instead of <> in case the current revision has changed
332  # since the page select, which wasn't locking
333  'rev_id < ' . $pageRow->page_latest
334  ], $conds ),
335  __METHOD__,
336  $revLoadOptions
337  );
338  $revs = [];
339  foreach ( $revRes as $revRow ) {
340  $revs[] = $revRow;
341  }
342 
343  if ( count( $revs ) < 2 ) {
344  # No revisions matching, no further processing
345  $this->output( "\n" );
346  continue;
347  }
348 
349  # For each chunk
350  $i = 0;
351  while ( $i < count( $revs ) ) {
352  if ( $i < count( $revs ) - $maxChunkSize ) {
353  $thisChunkSize = $maxChunkSize;
354  } else {
355  $thisChunkSize = count( $revs ) - $i;
356  }
357 
358  $chunk = new ConcatenatedGzipHistoryBlob();
359  $stubs = [];
360  $this->beginTransaction( $dbw, __METHOD__ );
361  $usedChunk = false;
362  $primaryOldid = $revs[$i]->rev_text_id;
363 
364  # Get the text of each revision and add it to the object
365  for ( $j = 0; $j < $thisChunkSize && $chunk->isHappy(); $j++ ) {
366  $oldid = $revs[$i + $j]->rev_text_id;
367 
368  # Get text
369  if ( $loadStyle == self::LS_INDIVIDUAL ) {
370  $textRow = $dbw->selectRow( 'text',
371  [ 'old_flags', 'old_text' ],
372  [ 'old_id' => $oldid ],
373  __METHOD__,
374  'FOR UPDATE'
375  );
376  $text = Revision::getRevisionText( $textRow );
377  } else {
378  $text = Revision::getRevisionText( $revs[$i + $j] );
379  }
380 
381  if ( $text === false ) {
382  $this->error( "\nError, unable to get text in old_id $oldid" );
383  # $dbw->delete( 'old', [ 'old_id' => $oldid ] );
384  }
385 
386  if ( $extdb == "" && $j == 0 ) {
387  $chunk->setText( $text );
388  $this->output( '.' );
389  } else {
390  # Don't make a stub if it's going to be longer than the article
391  # Stubs are typically about 100 bytes
392  if ( strlen( $text ) < 120 ) {
393  $stub = false;
394  $this->output( 'x' );
395  } else {
396  $stub = new HistoryBlobStub( $chunk->addItem( $text ) );
397  $stub->setLocation( $primaryOldid );
398  $stub->setReferrer( $oldid );
399  $this->output( '.' );
400  $usedChunk = true;
401  }
402  $stubs[$j] = $stub;
403  }
404  }
405  $thisChunkSize = $j;
406 
407  # If we couldn't actually use any stubs because the pages were too small, do nothing
408  if ( $usedChunk ) {
409  if ( $extdb != "" ) {
410  # Move blob objects to External Storage
411  $stored = $storeObj->store( $extdb, serialize( $chunk ) );
412  if ( $stored === false ) {
413  $this->error( "Unable to store object" );
414 
415  return false;
416  }
417  # Store External Storage URLs instead of Stub placeholders
418  foreach ( $stubs as $stub ) {
419  if ( $stub === false ) {
420  continue;
421  }
422  # $stored should provide base path to a BLOB
423  $url = $stored . "/" . $stub->getHash();
424  $dbw->update( 'text',
425  [ /* SET */
426  'old_text' => $url,
427  'old_flags' => 'external,utf-8',
428  ], [ /* WHERE */
429  'old_id' => $stub->getReferrer(),
430  ]
431  );
432  }
433  } else {
434  # Store the main object locally
435  $dbw->update( 'text',
436  [ /* SET */
437  'old_text' => serialize( $chunk ),
438  'old_flags' => 'object,utf-8',
439  ], [ /* WHERE */
440  'old_id' => $primaryOldid
441  ]
442  );
443 
444  # Store the stub objects
445  for ( $j = 1; $j < $thisChunkSize; $j++ ) {
446  # Skip if not compressing and don't overwrite the first revision
447  if ( $stubs[$j] !== false && $revs[$i + $j]->rev_text_id != $primaryOldid ) {
448  $dbw->update( 'text',
449  [ /* SET */
450  'old_text' => serialize( $stubs[$j] ),
451  'old_flags' => 'object,utf-8',
452  ], [ /* WHERE */
453  'old_id' => $revs[$i + $j]->rev_text_id
454  ]
455  );
456  }
457  }
458  }
459  }
460  # Done, next
461  $this->output( "/" );
462  $this->commitTransaction( $dbw, __METHOD__ );
463  $i += $thisChunkSize;
464  }
465  $this->output( "\n" );
466  }
467 
468  return true;
469  }
470 }
471 
473 require_once RUN_MAINTENANCE_IF_MAIN;
commitTransaction(IDatabase $dbw, $fname)
Commit the transcation on a DB handle and wait for replica DBs to catch up.
$success
$maintClass
error( $err, $die=0)
Throw an error to the user.
serialize()
getOption( $name, $default=null)
Get an option, or return the default.
const LS_CHUNKED
Option to load revisions in chunks.
Definition: compressOld.php:60
Abstract maintenance class for quickly writing and churning out maintenance scripts with minimal effo...
Definition: maintenance.txt:39
compressPage( $row, $extdb)
Compress the text in gzip format.
require_once RUN_MAINTENANCE_IF_MAIN
Definition: maintenance.txt:50
Pointer object for an item within a CGZ blob stored in the text table.
const DB_MASTER
Definition: defines.php:26
this hook is for auditing only RecentChangesLinked and Watchlist Do not use this to implement individual filters if they are compatible with the ChangesListFilter and ChangesListFilterGroup structure use sub classes of those in conjunction with the ChangesListSpecialPageStructuredFilters hook This hook can be used to implement filters that do not implement that or custom behavior that is not an individual filter e g Watchlist & $tables
Definition: hooks.txt:979
static getRevisionText( $row, $prefix='old_', $wiki=false)
Get revision text associated with an old or archive row.
Definition: Revision.php:1048
$last
const LS_INDIVIDUAL
Option to load each revision individually.
Definition: compressOld.php:55
setLocation( $id)
Sets the location (old_id) of the main object to which this object points.
compressWithConcat( $startId, $maxChunkSize, $beginDate, $endDate, $extdb="", $maxPageId=false)
Compress the text in chunks after concatenating the revisions.
Concatenated gzip (CGZ) storage Improves compression ratio by concatenating like objects before gzipp...
$res
Definition: database.txt:21
wfWaitForSlaves( $ifWritesSince=null, $wiki=false, $cluster=false, $timeout=null)
Waits for the replica DBs to catch up to the master position.
addDescription( $text)
Set the description text.
getDB( $db, $groups=[], $wiki=false)
Returns a database to be used by current maintenance script.
output( $out, $channel=null)
Throw some output to the user.
This document is intended to provide useful advice for parties seeking to redistribute MediaWiki to end users It s targeted particularly at maintainers for Linux since it s been observed that distribution packages of MediaWiki often break We ve consistently had to recommend that users seeking support use official tarballs instead of their distribution s and this often solves whatever problem the user is having It would be nice if this could such as
Definition: distributors.txt:9
static makeTitle( $ns, $title, $fragment='', $interwiki='')
Create a new Title from a namespace index and a DB key.
Definition: Title.php:589
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35
compressOldPages( $start=0, $extdb='')
Fetch the text row-by-row to &#39;compressPage&#39; function for compression.
you have access to all of the normal MediaWiki so you can get a DB use the etc For full docs on the Maintenance class
Definition: maintenance.txt:52
store( $location, $data)
controlled by the following MediaWiki still creates a BagOStuff but calls it to it are no ops If the cache daemon can t be it should also disable itself fairly $wgDBname
Definition: memcached.txt:93
Maintenance script that compress the text of a wiki.
Definition: compressOld.php:51
addOption( $name, $description, $required=false, $withArg=false, $shortName=false, $multiOccurrence=false)
Add a parameter to the script.
const DB_REPLICA
Definition: defines.php:25
fatalError( $msg, $exitCode=1)
Output a message and terminate the current script.
DB accessible external objects.
beginTransaction(IDatabase $dbw, $fname)
Begin a transcation on a DB.