maintenance/backupTextPass.inc

   1 <?php
   2 /**
   3  * BackupDumper that postprocesses XML dumps from dumpBackup.php to add page text
   4  *
   5  * Copyright (C) 2005 Brion Vibber <brion@pobox.com>
   6  * http://www.mediawiki.org/
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; if not, write to the Free Software Foundation, Inc.,
  20  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  21  * http://www.gnu.org/copyleft/gpl.html
  22  *
  23  * @file
  24  * @ingroup Maintenance
  25  */
  26
  27
  28 /**
  29  * @ingroup Maintenance
  30  */
  31 class TextPassDumper extends BackupDumper {
  32         var $prefetch = null;
  33         var $input = "php://stdin";
  34         var $history = WikiExporter::FULL;
  35         var $fetchCount = 0;
  36         var $prefetchCount = 0;
  37         var $prefetchCountLast = 0;
  38         var $fetchCountLast = 0;
  39
  40         var $maxFailures = 5;
  41         var $maxConsecutiveFailedTextRetrievals = 200;
  42         var $failureTimeout = 5; // Seconds to sleep after db failure
  43
  44         var $php = "php";
  45         var $spawn = false;
  46         var $spawnProc = false;
  47         var $spawnWrite = false;
  48         var $spawnRead = false;
  49         var $spawnErr = false;
  50
  51         var $xmlwriterobj = false;
  52
  53         // when we spend more than maxTimeAllowed seconds on this run, we continue
  54         // processing until we write out the next complete page, then save output file(s),
  55         // rename it/them and open new one(s)
  56         var $maxTimeAllowed = 0;  // 0 = no limit
  57         var $timeExceeded = false;
  58         var $firstPageWritten = false;
  59         var $lastPageWritten = false;
  60         var $checkpointJustWritten = false;
  61         var $checkpointFiles = array();
  62
  63         /**
  64          * @var DatabaseBase
  65          */
  66         protected $db;
  67
  68
  69         /**
  70          * Drop the database connection $this->db and try to get a new one.
  71          *
  72          * This function tries to get a /different/ connection if this is
  73          * possible. Hence, (if this is possible) it switches to a different
  74          * failover upon each call.
  75          *
  76          * This function resets $this->lb and closes all connections on it.
  77          *
  78          * @throws MWException
  79          */
  80         function rotateDb() {
  81                 // Cleaning up old connections
  82                 if ( isset( $this->lb ) ) {
  83                         $this->lb->closeAll();
  84                         unset( $this->lb );
  85                 }
  86
  87                 if ( $this->forcedDb !== null ) {
  88                         $this->db = $this->forcedDb;
  89                         return;
  90                 }
  91
  92                 if ( isset( $this->db ) && $this->db->isOpen() ) {
  93                         throw new MWException( 'DB is set and has not been closed by the Load Balancer' );
  94                 }
  95
  96                 unset( $this->db );
  97
  98                 // Trying to set up new connection.
  99                 // We do /not/ retry upon failure, but delegate to encapsulating logic, to avoid
 100                 // individually retrying at different layers of code.
 101
 102                 // 1. The LoadBalancer.
 103                 try {
 104                         $this->lb = wfGetLBFactory()->newMainLB();
 105                 } catch ( Exception $e ) {
 106                         throw new MWException( __METHOD__ . " rotating DB failed to obtain new load balancer (" . $e->getMessage() . ")" );
 107                 }
 108
 109
 110                 // 2. The Connection, through the load balancer.
 111                 try {
 112                         $this->db = $this->lb->getConnection( DB_SLAVE, 'backup' );
 113                 } catch ( Exception $e ) {
 114                         throw new MWException( __METHOD__ . " rotating DB failed to obtain new database (" . $e->getMessage() . ")" );
 115                 }
 116         }
 117
 118
 119         function initProgress( $history = WikiExporter::FULL ) {
 120                 parent::initProgress();
 121                 $this->timeOfCheckpoint = $this->startTime;
 122         }
 123
 124         function dump( $history, $text = WikiExporter::TEXT ) {
 125                 // Notice messages will foul up your XML output even if they're
 126                 // relatively harmless.
 127                 if ( ini_get( 'display_errors' ) )
 128                         ini_set( 'display_errors', 'stderr' );
 129
 130                 $this->initProgress( $this->history );
 131
 132                 // We are trying to get an initial database connection to avoid that the
 133                 // first try of this request's first call to getText fails. However, if
 134                 // obtaining a good DB connection fails it's not a serious issue, as
 135                 // getText does retry upon failure and can start without having a working
 136                 // DB connection.
 137                 try {
 138                         $this->rotateDb();
 139                 } catch ( Exception $e ) {
 140                         // We do not even count this as failure. Just let eventual
 141                         // watchdogs know.
 142                         $this->progress( "Getting initial DB connection failed (" .
 143                                 $e->getMessage() . ")" );
 144                 }
 145
 146                 $this->egress = new ExportProgressFilter( $this->sink, $this );
 147
 148                 // it would be nice to do it in the constructor, oh well. need egress set
 149                 $this->finalOptionCheck();
 150
 151                 // we only want this so we know how to close a stream :-P
 152                 $this->xmlwriterobj = new XmlDumpWriter();
 153
 154                 $input = fopen( $this->input, "rt" );
 155                 $result = $this->readDump( $input );
 156
 157                 if ( WikiError::isError( $result ) ) {
 158                         throw new MWException( $result->getMessage() );
 159                 }
 160
 161                 if ( $this->spawnProc ) {
 162                         $this->closeSpawn();
 163                 }
 164
 165                 $this->report( true );
 166         }
 167
 168         function processOption( $opt, $val, $param ) {
 169                 global $IP;
 170                 $url = $this->processFileOpt( $val, $param );
 171
 172                 switch( $opt ) {
 173                 case 'prefetch':
 174                         require_once "$IP/maintenance/backupPrefetch.inc";
 175                         $this->prefetch = new BaseDump( $url );
 176                         break;
 177                 case 'stub':
 178                         $this->input = $url;
 179                         break;
 180                 case 'maxtime':
 181                         $this->maxTimeAllowed = intval( $val ) * 60;
 182                         break;
 183                 case 'checkpointfile':
 184                         $this->checkpointFiles[] = $val;
 185                         break;
 186                 case 'current':
 187                         $this->history = WikiExporter::CURRENT;
 188                         break;
 189                 case 'full':
 190                         $this->history = WikiExporter::FULL;
 191                         break;
 192                 case 'spawn':
 193                         $this->spawn = true;
 194                         if ( $val ) {
 195                                 $this->php = $val;
 196                         }
 197                         break;
 198                 }
 199         }
 200
 201         function processFileOpt( $val, $param ) {
 202                 $fileURIs = explode( ';', $param );
 203                 foreach ( $fileURIs as $URI ) {
 204                         switch( $val ) {
 205                                 case "file":
 206                                         $newURI = $URI;
 207                                         break;
 208                                 case "gzip":
 209                                         $newURI = "compress.zlib://$URI";
 210                                         break;
 211                                 case "bzip2":
 212                                         $newURI = "compress.bzip2://$URI";
 213                                         break;
 214                                 case "7zip":
 215                                         $newURI = "mediawiki.compress.7z://$URI";
 216                                         break;
 217                                 default:
 218                                         $newURI = $URI;
 219                         }
 220                         $newFileURIs[] = $newURI;
 221                 }
 222                 $val = implode( ';', $newFileURIs );
 223                 return $val;
 224         }
 225
 226         /**
 227          * Overridden to include prefetch ratio if enabled.
 228          */
 229         function showReport() {
 230                 if ( !$this->prefetch ) {
 231                         parent::showReport();
 232                         return;
 233                 }
 234
 235                 if ( $this->reporting ) {
 236                         $now = wfTimestamp( TS_DB );
 237                         $nowts = wfTime();
 238                         $deltaAll = wfTime() - $this->startTime;
 239                         $deltaPart = wfTime() - $this->lastTime;
 240                         $this->pageCountPart = $this->pageCount - $this->pageCountLast;
 241                         $this->revCountPart = $this->revCount - $this->revCountLast;
 242
 243                         if ( $deltaAll ) {
 244                                 $portion = $this->revCount / $this->maxCount;
 245                                 $eta = $this->startTime + $deltaAll / $portion;
 246                                 $etats = wfTimestamp( TS_DB, intval( $eta ) );
 247                                 if ( $this->fetchCount ) {
 248                                         $fetchRate = 100.0 * $this->prefetchCount / $this->fetchCount;
 249                                 } else {
 250                                         $fetchRate = '-';
 251                                 }
 252                                 $pageRate = $this->pageCount / $deltaAll;
 253                                 $revRate = $this->revCount / $deltaAll;
 254                         } else {
 255                                 $pageRate = '-';
 256                                 $revRate = '-';
 257                                 $etats = '-';
 258                                 $fetchRate = '-';
 259                         }
 260                         if ( $deltaPart ) {
 261                                 if ( $this->fetchCountLast ) {
 262                                         $fetchRatePart = 100.0 * $this->prefetchCountLast / $this->fetchCountLast;
 263                                 } else {
 264                                         $fetchRatePart = '-';
 265                                 }
 266                                 $pageRatePart = $this->pageCountPart / $deltaPart;
 267                                 $revRatePart = $this->revCountPart / $deltaPart;
 268
 269                         } else {
 270                                 $fetchRatePart = '-';
 271                                 $pageRatePart = '-';
 272                                 $revRatePart = '-';
 273                         }
 274                         $this->progress( sprintf( "%s: %s (ID %d) %d pages (%0.1f|%0.1f/sec all|curr), %d revs (%0.1f|%0.1f/sec all|curr), %0.1f%%|%0.1f%% prefetched (all|curr), ETA %s [max %d]",
 275                                         $now, wfWikiID(), $this->ID, $this->pageCount, $pageRate, $pageRatePart, $this->revCount, $revRate, $revRatePart, $fetchRate, $fetchRatePart, $etats, $this->maxCount ) );
 276                         $this->lastTime = $nowts;
 277                         $this->revCountLast = $this->revCount;
 278                         $this->prefetchCountLast = $this->prefetchCount;
 279                         $this->fetchCountLast = $this->fetchCount;
 280                 }
 281         }
 282
 283         function setTimeExceeded() {
 284                 $this->timeExceeded = True;
 285         }
 286
 287         function checkIfTimeExceeded() {
 288                 if ( $this->maxTimeAllowed &&  ( $this->lastTime - $this->timeOfCheckpoint  > $this->maxTimeAllowed ) ) {
 289                         return true;
 290                 }
 291                 return false;
 292         }
 293
 294         function finalOptionCheck() {
 295                 if ( ( $this->checkpointFiles && ! $this->maxTimeAllowed ) ||
 296                         ( $this->maxTimeAllowed && !$this->checkpointFiles ) ) {
 297                         throw new MWException( "Options checkpointfile and maxtime must be specified together.\n" );
 298                 }
 299                 foreach ( $this->checkpointFiles as $checkpointFile ) {
 300                         $count = substr_count ( $checkpointFile, "%s" );
 301                         if ( $count != 2 ) {
 302                                 throw new MWException( "Option checkpointfile must contain two '%s' for substitution of first and last pageids, count is $count instead, file is $checkpointFile.\n" );
 303                         }
 304                 }
 305
 306                 if ( $this->checkpointFiles ) {
 307                         $filenameList = (array)$this->egress->getFilenames();
 308                         if ( count( $filenameList ) != count( $this->checkpointFiles ) ) {
 309                                 throw new MWException( "One checkpointfile must be specified for each output option, if maxtime is used.\n" );
 310                         }
 311                 }
 312         }
 313
 314         function readDump( $input ) {
 315                 $this->buffer = "";
 316                 $this->openElement = false;
 317                 $this->atStart = true;
 318                 $this->state = "";
 319                 $this->lastName = "";
 320                 $this->thisPage = 0;
 321                 $this->thisRev = 0;
 322
 323                 $parser = xml_parser_create( "UTF-8" );
 324                 xml_parser_set_option( $parser, XML_OPTION_CASE_FOLDING, false );
 325
 326                 xml_set_element_handler( $parser, array( &$this, 'startElement' ), array( &$this, 'endElement' ) );
 327                 xml_set_character_data_handler( $parser, array( &$this, 'characterData' ) );
 328
 329                 $offset = 0; // for context extraction on error reporting
 330                 $bufferSize = 512 * 1024;
 331                 do {
 332                         if ( $this->checkIfTimeExceeded() ) {
 333                                 $this->setTimeExceeded();
 334                         }
 335                         $chunk = fread( $input, $bufferSize );
 336                         if ( !xml_parse( $parser, $chunk, feof( $input ) ) ) {
 337                                 wfDebug( "TextDumpPass::readDump encountered XML parsing error\n" );
 338                                 return new WikiXmlError( $parser, 'XML import parse failure', $chunk, $offset );
 339                         }
 340                         $offset += strlen( $chunk );
 341                 } while ( $chunk !== false && !feof( $input ) );
 342                 if ( $this->maxTimeAllowed ) {
 343                         $filenameList = (array)$this->egress->getFilenames();
 344                         // we wrote some stuff after last checkpoint that needs renamed
 345                         if ( file_exists( $filenameList[0] ) ) {
 346                                 $newFilenames = array();
 347                                 # we might have just written the header and footer and had no
 348                                 # pages or revisions written... perhaps they were all deleted
 349                                 # there's no pageID 0 so we use that. the caller is responsible
 350                                 # for deciding what to do with a file containing only the
 351                                 # siteinfo information and the mw tags.
 352                                 if ( ! $this->firstPageWritten ) {
 353                                         $firstPageID = str_pad( 0, 9, "0", STR_PAD_LEFT );
 354                                         $lastPageID = str_pad( 0, 9, "0", STR_PAD_LEFT );
 355                                 }
 356                                 else {
 357                                         $firstPageID = str_pad( $this->firstPageWritten, 9, "0", STR_PAD_LEFT );
 358                                         $lastPageID = str_pad( $this->lastPageWritten, 9, "0", STR_PAD_LEFT );
 359                                 }
 360                                 for ( $i = 0; $i < count( $filenameList ); $i++ ) {
 361                                         $checkpointNameFilledIn = sprintf( $this->checkpointFiles[$i], $firstPageID, $lastPageID );
 362                                         $fileinfo = pathinfo( $filenameList[$i] );
 363                                         $newFilenames[] = $fileinfo['dirname'] . '/' . $checkpointNameFilledIn;
 364                                 }
 365                                 $this->egress->closeAndRename( $newFilenames );
 366                         }
 367                 }
 368                 xml_parser_free( $parser );
 369
 370                 return true;
 371         }
 372
 373         /**
 374          * Tries to get the revision text for a revision id.
 375          *
 376          * Upon errors, retries (Up to $this->maxFailures tries each call).
 377          * If still no good revision get could be found even after this retrying, "" is returned.
 378          * If no good revision text could be returned for
 379          * $this->maxConsecutiveFailedTextRetrievals consecutive calls to getText, MWException
 380          * is thrown.
 381          *
 382          * @param $id string The revision id to get the text for
 383          *
 384          * @return string The revision text for $id, or ""
 385          * @throws MWException
 386          */
 387         function getText( $id ) {
 388                 $prefetchNotTried = true; // Whether or not we already tried to get the text via prefetch.
 389                 $text = false; // The candidate for a good text. false if no proper value.
 390                 $failures = 0; // The number of times, this invocation of getText already failed.
 391
 392                 static $consecutiveFailedTextRetrievals = 0; // The number of times getText failed without
 393                                                              // yielding a good text in between.
 394
 395                 $this->fetchCount++;
 396
 397                 // To allow to simply return on success and do not have to worry about book keeping,
 398                 // we assume, this fetch works (possible after some retries). Nevertheless, we koop
 399                 // the old value, so we can restore it, if problems occur (See after the while loop).
 400                 $oldConsecutiveFailedTextRetrievals = $consecutiveFailedTextRetrievals;
 401                 $consecutiveFailedTextRetrievals = 0;
 402
 403                 while ( $failures < $this->maxFailures ) {
 404
 405                         // As soon as we found a good text for the $id, we will return immediately.
 406                         // Hence, if we make it past the try catch block, we know that we did not
 407                         // find a good text.
 408
 409                         try {
 410                                 // Step 1: Get some text (or reuse from previous iteratuon if checking
 411                                 //         for plausibility failed)
 412
 413                                 // Trying to get prefetch, if it has not been tried before
 414                                 if ( $text === false && isset( $this->prefetch ) && $prefetchNotTried ) {
 415                                         $prefetchNotTried = false;
 416                                         $tryIsPrefetch = true;
 417                                         $text = $this->prefetch->prefetch( $this->thisPage, $this->thisRev );
 418                                         if ( $text === null ) {
 419                                                 $text = false;
 420                                         }
 421                                 }
 422
 423                                 if ( $text === false ) {
 424                                         // Fallback to asking the database
 425                                         $tryIsPrefetch = false;
 426                                         if ( $this->spawn ) {
 427                                                 $text = $this->getTextSpawned( $id );
 428                                         } else {
 429                                                 $text = $this->getTextDb( $id );
 430                                         }
 431                                 }
 432
 433                                 if ( $text === false ) {
 434                                         throw new MWException( "Generic error while obtaining text for id " . $id );
 435                                 }
 436
 437                                 // We received a good candidate for the text of $id via some method
 438
 439                                 // Step 2: Checking for plausibility and return the text if it is
 440                                 //         plausible
 441                                 $revID = intval( $this->thisRev );
 442                                 if ( ! isset( $this->db ) ) {
 443                                         throw new MWException( "No database available" );
 444                                 }
 445                                 $revLength = $this->db->selectField( 'revision', 'rev_len', array( 'rev_id' => $revID ) );
 446                                 if ( strlen( $text ) == $revLength ) {
 447                                         if ( $tryIsPrefetch ) {
 448                                                 $this->prefetchCount++;
 449                                         }
 450                                         return $text;
 451                                 }
 452
 453                                 $text = false;
 454                                 throw new MWException( "Received text is unplausible for id " . $id );
 455
 456                         } catch ( Exception $e ) {
 457                                 $msg = "getting/checking text " . $id . " failed (" . $e->getMessage() . ")";
 458                                 if ( $failures + 1 < $this->maxFailures ) {
 459                                         $msg .= " (Will retry " . ( $this->maxFailures - $failures - 1 ) . " more times)";
 460                                 }
 461                                 $this->progress( $msg );
 462                         }
 463
 464                         // Something went wrong; we did not a text that was plausible :(
 465                         $failures++;
 466
 467
 468                         // After backing off for some time, we try to reboot the whole process as
 469                         // much as possible to not carry over failures from one part to the other
 470                         // parts
 471                         sleep( $this->failureTimeout );
 472                         try {
 473                                 $this->rotateDb();
 474                                 if ( $this->spawn ) {
 475                                         $this->closeSpawn();
 476                                         $this->openSpawn();
 477                                 }
 478                         } catch ( Exception $e ) {
 479                                 $this->progress( "Rebooting getText infrastructure failed (" . $e->getMessage() . ")" .
 480                                         " Trying to continue anyways" );
 481                         }
 482                 }
 483
 484                 // Retirieving a good text for $id failed (at least) maxFailures times.
 485                 // We abort for this $id.
 486
 487                 // Restoring the consecutive failures, and maybe aborting, if the dump
 488                 // is too broken.
 489                 $consecutiveFailedTextRetrievals = $oldConsecutiveFailedTextRetrievals + 1;
 490                 if ( $consecutiveFailedTextRetrievals > $this->maxConsecutiveFailedTextRetrievals ) {
 491                         throw new MWException( "Graceful storage failure" );
 492                 }
 493
 494                 return "";
 495         }
 496
 497
 498         /**
 499          * May throw a database error if, say, the server dies during query.
 500          * @param $id
 501          * @return bool|string
 502          * @throws MWException
 503          */
 504         private function getTextDb( $id ) {
 505                 global $wgContLang;
 506                 if ( ! isset( $this->db ) ) {
 507                         throw new MWException( __METHOD__ . "No database available" );
 508                 }
 509                 $row = $this->db->selectRow( 'text',
 510                         array( 'old_text', 'old_flags' ),
 511                         array( 'old_id' => $id ),
 512                         __METHOD__ );
 513                 $text = Revision::getRevisionText( $row );
 514                 if ( $text === false ) {
 515                         return false;
 516                 }
 517                 $stripped = str_replace( "\r", "", $text );
 518                 $normalized = $wgContLang->normalize( $stripped );
 519                 return $normalized;
 520         }
 521
 522         private function getTextSpawned( $id ) {
 523                 wfSuppressWarnings();
 524                 if ( !$this->spawnProc ) {
 525                         // First time?
 526                         $this->openSpawn();
 527                 }
 528                 $text = $this->getTextSpawnedOnce( $id );
 529                 wfRestoreWarnings();
 530                 return $text;
 531         }
 532
 533         function openSpawn() {
 534                 global $IP;
 535
 536                 if ( file_exists( "$IP/../multiversion/MWScript.php" ) ) {
 537                         $cmd = implode( " ",
 538                                 array_map( 'wfEscapeShellArg',
 539                                         array(
 540                                                 $this->php,
 541                                                 "$IP/../multiversion/MWScript.php",
 542                                                 "fetchText.php",
 543                                                 '--wiki', wfWikiID() ) ) );
 544                 }
 545                 else {
 546                         $cmd = implode( " ",
 547                                 array_map( 'wfEscapeShellArg',
 548                                         array(
 549                                                 $this->php,
 550                                                 "$IP/maintenance/fetchText.php",
 551                                                 '--wiki', wfWikiID() ) ) );
 552                 }
 553                 $spec = array(
 554                         0 => array( "pipe", "r" ),
 555                         1 => array( "pipe", "w" ),
 556                         2 => array( "file", "/dev/null", "a" ) );
 557                 $pipes = array();
 558
 559                 $this->progress( "Spawning database subprocess: $cmd" );
 560                 $this->spawnProc = proc_open( $cmd, $spec, $pipes );
 561                 if ( !$this->spawnProc ) {
 562                         // shit
 563                         $this->progress( "Subprocess spawn failed." );
 564                         return false;
 565                 }
 566                 list(
 567                         $this->spawnWrite, // -> stdin
 568                         $this->spawnRead,  // <- stdout
 569                 ) = $pipes;
 570
 571                 return true;
 572         }
 573
 574         private function closeSpawn() {
 575                 wfSuppressWarnings();
 576                 if ( $this->spawnRead )
 577                         fclose( $this->spawnRead );
 578                 $this->spawnRead = false;
 579                 if ( $this->spawnWrite )
 580                         fclose( $this->spawnWrite );
 581                 $this->spawnWrite = false;
 582                 if ( $this->spawnErr )
 583                         fclose( $this->spawnErr );
 584                 $this->spawnErr = false;
 585                 if ( $this->spawnProc )
 586                         pclose( $this->spawnProc );
 587                 $this->spawnProc = false;
 588                 wfRestoreWarnings();
 589         }
 590
 591         private function getTextSpawnedOnce( $id ) {
 592                 global $wgContLang;
 593
 594                 $ok = fwrite( $this->spawnWrite, "$id\n" );
 595                 // $this->progress( ">> $id" );
 596                 if ( !$ok ) return false;
 597
 598                 $ok = fflush( $this->spawnWrite );
 599                 // $this->progress( ">> [flush]" );
 600                 if ( !$ok ) return false;
 601
 602                 // check that the text id they are sending is the one we asked for
 603                 // this avoids out of sync revision text errors we have encountered in the past
 604                 $newId = fgets( $this->spawnRead );
 605                 if ( $newId === false ) {
 606                         return false;
 607                 }
 608                 if ( $id != intval( $newId ) ) {
 609                         return false;
 610                 }
 611
 612                 $len = fgets( $this->spawnRead );
 613                 // $this->progress( "<< " . trim( $len ) );
 614                 if ( $len === false ) return false;
 615
 616                 $nbytes = intval( $len );
 617                 // actual error, not zero-length text
 618                 if ( $nbytes < 0 ) return false;
 619
 620                 $text = "";
 621
 622                 // Subprocess may not send everything at once, we have to loop.
 623                 while ( $nbytes > strlen( $text ) ) {
 624                         $buffer = fread( $this->spawnRead, $nbytes - strlen( $text ) );
 625                         if ( $buffer === false ) break;
 626                         $text .= $buffer;
 627                 }
 628
 629                 $gotbytes = strlen( $text );
 630                 if ( $gotbytes != $nbytes ) {
 631                         $this->progress( "Expected $nbytes bytes from database subprocess, got $gotbytes " );
 632                         return false;
 633                 }
 634
 635                 // Do normalization in the dump thread...
 636                 $stripped = str_replace( "\r", "", $text );
 637                 $normalized = $wgContLang->normalize( $stripped );
 638                 return $normalized;
 639         }
 640
 641         function startElement( $parser, $name, $attribs ) {
 642                 $this->checkpointJustWritten = false;
 643
 644                 $this->clearOpenElement( null );
 645                 $this->lastName = $name;
 646
 647                 if ( $name == 'revision' ) {
 648                         $this->state = $name;
 649                         $this->egress->writeOpenPage( null, $this->buffer );
 650                         $this->buffer = "";
 651                 } elseif ( $name == 'page' ) {
 652                         $this->state = $name;
 653                         if ( $this->atStart ) {
 654                                 $this->egress->writeOpenStream( $this->buffer );
 655                                 $this->buffer = "";
 656                                 $this->atStart = false;
 657                         }
 658                 }
 659
 660                 if ( $name == "text" && isset( $attribs['id'] ) ) {
 661                         $text = $this->getText( $attribs['id'] );
 662                         $this->openElement = array( $name, array( 'xml:space' => 'preserve' ) );
 663                         if ( strlen( $text ) > 0 ) {
 664                                 $this->characterData( $parser, $text );
 665                         }
 666                 } else {
 667                         $this->openElement = array( $name, $attribs );
 668                 }
 669         }
 670
 671         function endElement( $parser, $name ) {
 672                 $this->checkpointJustWritten = false;
 673
 674                 if ( $this->openElement ) {
 675                         $this->clearOpenElement( "" );
 676                 } else {
 677                         $this->buffer .= "</$name>";
 678                 }
 679
 680                 if ( $name == 'revision' ) {
 681                         $this->egress->writeRevision( null, $this->buffer );
 682                         $this->buffer = "";
 683                         $this->thisRev = "";
 684                 } elseif ( $name == 'page' ) {
 685                         if ( ! $this->firstPageWritten ) {
 686                                 $this->firstPageWritten = trim( $this->thisPage );
 687                         }
 688                         $this->lastPageWritten = trim( $this->thisPage );
 689                         if ( $this->timeExceeded ) {
 690                                 $this->egress->writeClosePage( $this->buffer );
 691                                 // nasty hack, we can't just write the chardata after the
 692                                 // page tag, it will include leading blanks from the next line
 693                                 $this->egress->sink->write( "\n" );
 694
 695                                 $this->buffer = $this->xmlwriterobj->closeStream();
 696                                 $this->egress->writeCloseStream( $this->buffer );
 697
 698                                 $this->buffer = "";
 699                                 $this->thisPage = "";
 700                                 // this could be more than one file if we had more than one output arg
 701
 702                                 $filenameList = (array)$this->egress->getFilenames();
 703                                 $newFilenames = array();
 704                                 $firstPageID = str_pad( $this->firstPageWritten, 9, "0", STR_PAD_LEFT );
 705                                 $lastPageID = str_pad( $this->lastPageWritten, 9, "0", STR_PAD_LEFT );
 706                                 for ( $i = 0; $i < count( $filenameList ); $i++ ) {
 707                                         $checkpointNameFilledIn = sprintf( $this->checkpointFiles[$i], $firstPageID, $lastPageID );
 708                                         $fileinfo = pathinfo( $filenameList[$i] );
 709                                         $newFilenames[] = $fileinfo['dirname'] . '/' . $checkpointNameFilledIn;
 710                                 }
 711                                 $this->egress->closeRenameAndReopen( $newFilenames );
 712                                 $this->buffer = $this->xmlwriterobj->openStream();
 713                                 $this->timeExceeded = false;
 714                                 $this->timeOfCheckpoint = $this->lastTime;
 715                                 $this->firstPageWritten = false;
 716                                 $this->checkpointJustWritten = true;
 717                         }
 718                         else {
 719                                 $this->egress->writeClosePage( $this->buffer );
 720                                 $this->buffer = "";
 721                                 $this->thisPage = "";
 722                         }
 723
 724                 } elseif ( $name == 'mediawiki' ) {
 725                         $this->egress->writeCloseStream( $this->buffer );
 726                         $this->buffer = "";
 727                 }
 728         }
 729
 730         function characterData( $parser, $data ) {
 731                 $this->clearOpenElement( null );
 732                 if ( $this->lastName == "id" ) {
 733                         if ( $this->state == "revision" ) {
 734                                 $this->thisRev .= $data;
 735                         } elseif ( $this->state == "page" ) {
 736                                 $this->thisPage .= $data;
 737                         }
 738                 }
 739                 // have to skip the newline left over from closepagetag line of
 740                 // end of checkpoint files. nasty hack!!
 741                 if ( $this->checkpointJustWritten ) {
 742                         if ( $data[0] == "\n" ) {
 743                                 $data = substr( $data, 1 );
 744                         }
 745                         $this->checkpointJustWritten = false;
 746                 }
 747                 $this->buffer .= htmlspecialchars( $data );
 748         }
 749
 750         function clearOpenElement( $style ) {
 751                 if ( $this->openElement ) {
 752                         $this->buffer .= Xml::element( $this->openElement[0], $this->openElement[1], $style );
 753                         $this->openElement = false;
 754                 }
 755         }
 756 }