includes/installer/DatabaseUpdater.php

   1 <?php
   2 /**
   3  * DBMS-specific updater helper.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Deployment
  22  */
  23
  24 require_once __DIR__ . '/../../maintenance/Maintenance.php';
  25
  26 /**
  27  * Class for handling database updates. Roughly based off of updaters.inc, with
  28  * a few improvements :)
  29  *
  30  * @ingroup Deployment
  31  * @since 1.17
  32  */
  33 abstract class DatabaseUpdater {
  34
  35         /**
  36          * Array of updates to perform on the database
  37          *
  38          * @var array
  39          */
  40         protected $updates = array();
  41
  42         /**
  43          * Array of updates that were skipped
  44          *
  45          * @var array
  46          */
  47         protected $updatesSkipped = array();
  48
  49         /**
  50          * List of extension-provided database updates
  51          * @var array
  52          */
  53         protected $extensionUpdates = array();
  54
  55         /**
  56          * Handle to the database subclass
  57          *
  58          * @var DatabaseBase
  59          */
  60         protected $db;
  61
  62         protected $shared = false;
  63
  64         /**
  65          * Scripts to run after database update
  66          * Should be a subclass of LoggedUpdateMaintenance
  67          */
  68         protected $postDatabaseUpdateMaintenance = array(
  69                 'DeleteDefaultMessages',
  70                 'PopulateRevisionLength',
  71                 'PopulateRevisionSha1',
  72                 'PopulateImageSha1',
  73                 'FixExtLinksProtocolRelative',
  74                 'PopulateFilearchiveSha1',
  75         );
  76
  77         /**
  78          * File handle for SQL output.
  79          *
  80          * @var Filehandle
  81          */
  82         protected $fileHandle = null;
  83
  84         /**
  85          * Flag specifying whether or not to skip schema (e.g. SQL-only) updates.
  86          *
  87          * @var bool
  88          */
  89         protected $skipSchema = false;
  90
  91         /**
  92          * Hold the value of $wgContentHandlerUseDB during the upgrade.
  93          */
  94         protected $holdContentHandlerUseDB = true;
  95
  96         /**
  97          * Constructor
  98          *
  99          * @param $db DatabaseBase object to perform updates on
 100          * @param bool $shared Whether to perform updates on shared tables
 101          * @param $maintenance Maintenance Maintenance object which created us
 102          */
 103         protected function __construct( DatabaseBase &$db, $shared, Maintenance $maintenance = null ) {
 104                 $this->db = $db;
 105                 $this->db->setFlag( DBO_DDLMODE ); // For Oracle's handling of schema files
 106                 $this->shared = $shared;
 107                 if ( $maintenance ) {
 108                         $this->maintenance = $maintenance;
 109                         $this->fileHandle = $maintenance->fileHandle;
 110                 } else {
 111                         $this->maintenance = new FakeMaintenance;
 112                 }
 113                 $this->maintenance->setDB( $db );
 114                 $this->initOldGlobals();
 115                 $this->loadExtensions();
 116                 wfRunHooks( 'LoadExtensionSchemaUpdates', array( $this ) );
 117         }
 118
 119         /**
 120          * Initialize all of the old globals. One day this should all become
 121          * something much nicer
 122          */
 123         private function initOldGlobals() {
 124                 global $wgExtNewTables, $wgExtNewFields, $wgExtPGNewFields,
 125                         $wgExtPGAlteredFields, $wgExtNewIndexes, $wgExtModifiedFields;
 126
 127                 # For extensions only, should be populated via hooks
 128                 # $wgDBtype should be checked to specifiy the proper file
 129                 $wgExtNewTables = array(); // table, dir
 130                 $wgExtNewFields = array(); // table, column, dir
 131                 $wgExtPGNewFields = array(); // table, column, column attributes; for PostgreSQL
 132                 $wgExtPGAlteredFields = array(); // table, column, new type, conversion method; for PostgreSQL
 133                 $wgExtNewIndexes = array(); // table, index, dir
 134                 $wgExtModifiedFields = array(); // table, index, dir
 135         }
 136
 137         /**
 138          * Loads LocalSettings.php, if needed, and initialises everything needed for
 139          * LoadExtensionSchemaUpdates hook.
 140          */
 141         private function loadExtensions() {
 142                 if ( !defined( 'MEDIAWIKI_INSTALL' ) ) {
 143                         return; // already loaded
 144                 }
 145                 $vars = Installer::getExistingLocalSettings();
 146                 if ( !$vars ) {
 147                         return; // no LocalSettings found
 148                 }
 149                 if ( !isset( $vars['wgHooks'] ) || !isset( $vars['wgHooks']['LoadExtensionSchemaUpdates'] ) ) {
 150                         return;
 151                 }
 152                 global $wgHooks, $wgAutoloadClasses;
 153                 $wgHooks['LoadExtensionSchemaUpdates'] = $vars['wgHooks']['LoadExtensionSchemaUpdates'];
 154                 $wgAutoloadClasses = $wgAutoloadClasses + $vars['wgAutoloadClasses'];
 155         }
 156
 157         /**
 158          * @throws MWException
 159          * @param DatabaseBase $db
 160          * @param bool $shared
 161          * @param null $maintenance
 162          * @return DatabaseUpdater
 163          */
 164         public static function newForDB( &$db, $shared = false, $maintenance = null ) {
 165                 $type = $db->getType();
 166                 if ( in_array( $type, Installer::getDBTypes() ) ) {
 167                         $class = ucfirst( $type ) . 'Updater';
 168
 169                         return new $class( $db, $shared, $maintenance );
 170                 } else {
 171                         throw new MWException( __METHOD__ . ' called for unsupported $wgDBtype' );
 172                 }
 173         }
 174
 175         /**
 176          * Get a database connection to run updates
 177          *
 178          * @return DatabaseBase
 179          */
 180         public function getDB() {
 181                 return $this->db;
 182         }
 183
 184         /**
 185          * Output some text. If we're running from web, escape the text first.
 186          *
 187          * @param string $str Text to output
 188          */
 189         public function output( $str ) {
 190                 if ( $this->maintenance->isQuiet() ) {
 191                         return;
 192                 }
 193                 global $wgCommandLineMode;
 194                 if ( !$wgCommandLineMode ) {
 195                         $str = htmlspecialchars( $str );
 196                 }
 197                 echo $str;
 198                 flush();
 199         }
 200
 201         /**
 202          * Add a new update coming from an extension. This should be called by
 203          * extensions while executing the LoadExtensionSchemaUpdates hook.
 204          *
 205          * @since 1.17
 206          *
 207          * @param array $update the update to run. Format is the following:
 208          *                first item is the callback function, it also can be a
 209          *                simple string with the name of a function in this class,
 210          *                following elements are parameters to the function.
 211          *                Note that callback functions will receive this object as
 212          *                first parameter.
 213          */
 214         public function addExtensionUpdate( array $update ) {
 215                 $this->extensionUpdates[] = $update;
 216         }
 217
 218         /**
 219          * Convenience wrapper for addExtensionUpdate() when adding a new table (which
 220          * is the most common usage of updaters in an extension)
 221          *
 222          * @since 1.18
 223          *
 224          * @param string $tableName Name of table to create
 225          * @param string $sqlPath Full path to the schema file
 226          */
 227         public function addExtensionTable( $tableName, $sqlPath ) {
 228                 $this->extensionUpdates[] = array( 'addTable', $tableName, $sqlPath, true );
 229         }
 230
 231         /**
 232          * @since 1.19
 233          *
 234          * @param $tableName string
 235          * @param $indexName string
 236          * @param $sqlPath string
 237          */
 238         public function addExtensionIndex( $tableName, $indexName, $sqlPath ) {
 239                 $this->extensionUpdates[] = array( 'addIndex', $tableName, $indexName, $sqlPath, true );
 240         }
 241
 242         /**
 243          *
 244          * @since 1.19
 245          *
 246          * @param $tableName string
 247          * @param $columnName string
 248          * @param $sqlPath string
 249          */
 250         public function addExtensionField( $tableName, $columnName, $sqlPath ) {
 251                 $this->extensionUpdates[] = array( 'addField', $tableName, $columnName, $sqlPath, true );
 252         }
 253
 254         /**
 255          *
 256          * @since 1.20
 257          *
 258          * @param $tableName string
 259          * @param $columnName string
 260          * @param $sqlPath string
 261          */
 262         public function dropExtensionField( $tableName, $columnName, $sqlPath ) {
 263                 $this->extensionUpdates[] = array( 'dropField', $tableName, $columnName, $sqlPath, true );
 264         }
 265
 266         /**
 267          * Drop an index from an extension table
 268          *
 269          * @since 1.21
 270          *
 271          * @param string $tableName The table name
 272          * @param string $indexName The index name
 273          * @param string $sqlPath The path to the SQL change path
 274          */
 275         public function dropExtensionIndex( $tableName, $indexName, $sqlPath ) {
 276                 $this->extensionUpdates[] = array( 'dropIndex', $tableName, $indexName, $sqlPath, true );
 277         }
 278
 279         /**
 280          *
 281          * @since 1.20
 282          *
 283          * @param $tableName string
 284          * @param $sqlPath string
 285          */
 286         public function dropExtensionTable( $tableName, $sqlPath ) {
 287                 $this->extensionUpdates[] = array( 'dropTable', $tableName, $sqlPath, true );
 288         }
 289
 290         /**
 291          * Rename an index on an extension table
 292          *
 293          * @since 1.21
 294          *
 295          * @param string $tableName The table name
 296          * @param string $oldIndexName The old index name
 297          * @param string $newIndexName The new index name
 298          * @param $skipBothIndexExistWarning Boolean: Whether to warn if both the old
 299          * and the new indexes exist. [facultative; by default, false]
 300          * @param string $sqlPath The path to the SQL change path
 301          */
 302         public function renameExtensionIndex( $tableName, $oldIndexName, $newIndexName,
 303                 $sqlPath, $skipBothIndexExistWarning = false
 304         ) {
 305                 $this->extensionUpdates[] = array(
 306                         'renameIndex',
 307                         $tableName,
 308                         $oldIndexName,
 309                         $newIndexName,
 310                         $skipBothIndexExistWarning,
 311                         $sqlPath,
 312                         true
 313                 );
 314         }
 315
 316         /**
 317          * @since 1.21
 318          *
 319          * @param string $tableName The table name
 320          * @param string $fieldName The field to be modified
 321          * @param string $sqlPath The path to the SQL change path
 322          */
 323         public function modifyExtensionField( $tableName, $fieldName, $sqlPath ) {
 324                 $this->extensionUpdates[] = array( 'modifyField', $tableName, $fieldName, $sqlPath, true );
 325         }
 326
 327         /**
 328          *
 329          * @since 1.20
 330          *
 331          * @param $tableName string
 332          * @return bool
 333          */
 334         public function tableExists( $tableName ) {
 335                 return ( $this->db->tableExists( $tableName, __METHOD__ ) );
 336         }
 337
 338         /**
 339          * Add a maintenance script to be run after the database updates are complete.
 340          *
 341          * Script should subclass LoggedUpdateMaintenance
 342          *
 343          * @since 1.19
 344          *
 345          * @param string $class Name of a Maintenance subclass
 346          */
 347         public function addPostDatabaseUpdateMaintenance( $class ) {
 348                 $this->postDatabaseUpdateMaintenance[] = $class;
 349         }
 350
 351         /**
 352          * Get the list of extension-defined updates
 353          *
 354          * @return Array
 355          */
 356         protected function getExtensionUpdates() {
 357                 return $this->extensionUpdates;
 358         }
 359
 360         /**
 361          * @since 1.17
 362          *
 363          * @return array
 364          */
 365         public function getPostDatabaseUpdateMaintenance() {
 366                 return $this->postDatabaseUpdateMaintenance;
 367         }
 368
 369         /**
 370          * @since 1.21
 371          *
 372          * Writes the schema updates desired to a file for the DB Admin to run.
 373          */
 374         private function writeSchemaUpdateFile( $schemaUpdate = array() ) {
 375                 $updates = $this->updatesSkipped;
 376                 $this->updatesSkipped = array();
 377
 378                 foreach ( $updates as $funcList ) {
 379                         $func = $funcList[0];
 380                         $arg = $funcList[1];
 381                         $origParams = $funcList[2];
 382                         call_user_func_array( $func, $arg );
 383                         flush();
 384                         $this->updatesSkipped[] = $origParams;
 385                 }
 386         }
 387
 388         /**
 389          * Do all the updates
 390          *
 391          * @param array $what what updates to perform
 392          */
 393         public function doUpdates( $what = array( 'core', 'extensions', 'stats' ) ) {
 394                 global $wgVersion;
 395
 396                 $this->db->begin( __METHOD__ );
 397                 $what = array_flip( $what );
 398                 $this->skipSchema = isset( $what['noschema'] ) || $this->fileHandle !== null;
 399                 if ( isset( $what['core'] ) ) {
 400                         $this->runUpdates( $this->getCoreUpdateList(), false );
 401                 }
 402                 if ( isset( $what['extensions'] ) ) {
 403                         $this->runUpdates( $this->getOldGlobalUpdates(), false );
 404                         $this->runUpdates( $this->getExtensionUpdates(), true );
 405                 }
 406
 407                 if ( isset( $what['stats'] ) ) {
 408                         $this->checkStats();
 409                 }
 410
 411                 $this->setAppliedUpdates( $wgVersion, $this->updates );
 412
 413                 if ( $this->fileHandle ) {
 414                         $this->skipSchema = false;
 415                         $this->writeSchemaUpdateFile();
 416                         $this->setAppliedUpdates( "$wgVersion-schema", $this->updatesSkipped );
 417                 }
 418
 419                 $this->db->commit( __METHOD__ );
 420         }
 421
 422         /**
 423          * Helper function for doUpdates()
 424          *
 425          * @param array $updates of updates to run
 426          * @param $passSelf Boolean: whether to pass this object we calling external
 427          *                  functions
 428          */
 429         private function runUpdates( array $updates, $passSelf ) {
 430                 $updatesDone = array();
 431                 $updatesSkipped = array();
 432                 foreach ( $updates as $params ) {
 433                         $origParams = $params;
 434                         $func = array_shift( $params );
 435                         if ( !is_array( $func ) && method_exists( $this, $func ) ) {
 436                                 $func = array( $this, $func );
 437                         } elseif ( $passSelf ) {
 438                                 array_unshift( $params, $this );
 439                         }
 440                         $ret = call_user_func_array( $func, $params );
 441                         flush();
 442                         if ( $ret !== false ) {
 443                                 $updatesDone[] = $origParams;
 444                         } else {
 445                                 $updatesSkipped[] = array( $func, $params, $origParams );
 446                         }
 447                 }
 448                 $this->updatesSkipped = array_merge( $this->updatesSkipped, $updatesSkipped );
 449                 $this->updates = array_merge( $this->updates, $updatesDone );
 450         }
 451
 452         /**
 453          * @param $version
 454          * @param $updates array
 455          */
 456         protected function setAppliedUpdates( $version, $updates = array() ) {
 457                 $this->db->clearFlag( DBO_DDLMODE );
 458                 if ( !$this->canUseNewUpdatelog() ) {
 459                         return;
 460                 }
 461                 $key = "updatelist-$version-" . time();
 462                 $this->db->insert( 'updatelog',
 463                         array( 'ul_key' => $key, 'ul_value' => serialize( $updates ) ),
 464                         __METHOD__ );
 465                 $this->db->setFlag( DBO_DDLMODE );
 466         }
 467
 468         /**
 469          * Helper function: check if the given key is present in the updatelog table.
 470          * Obviously, only use this for updates that occur after the updatelog table was
 471          * created!
 472          * @param string $key Name of the key to check for
 473          *
 474          * @return bool
 475          */
 476         public function updateRowExists( $key ) {
 477                 $row = $this->db->selectRow(
 478                         'updatelog',
 479                         '1',
 480                         array( 'ul_key' => $key ),
 481                         __METHOD__
 482                 );
 483
 484                 return (bool)$row;
 485         }
 486
 487         /**
 488          * Helper function: Add a key to the updatelog table
 489          * Obviously, only use this for updates that occur after the updatelog table was
 490          * created!
 491          * @param string $key Name of key to insert
 492          * @param string $val [optional] value to insert along with the key
 493          */
 494         public function insertUpdateRow( $key, $val = null ) {
 495                 $this->db->clearFlag( DBO_DDLMODE );
 496                 $values = array( 'ul_key' => $key );
 497                 if ( $val && $this->canUseNewUpdatelog() ) {
 498                         $values['ul_value'] = $val;
 499                 }
 500                 $this->db->insert( 'updatelog', $values, __METHOD__, 'IGNORE' );
 501                 $this->db->setFlag( DBO_DDLMODE );
 502         }
 503
 504         /**
 505          * Updatelog was changed in 1.17 to have a ul_value column so we can record
 506          * more information about what kind of updates we've done (that's what this
 507          * class does). Pre-1.17 wikis won't have this column, and really old wikis
 508          * might not even have updatelog at all
 509          *
 510          * @return boolean
 511          */
 512         protected function canUseNewUpdatelog() {
 513                 return $this->db->tableExists( 'updatelog', __METHOD__ ) &&
 514                         $this->db->fieldExists( 'updatelog', 'ul_value', __METHOD__ );
 515         }
 516
 517         /**
 518          * Returns whether updates should be executed on the database table $name.
 519          * Updates will be prevented if the table is a shared table and it is not
 520          * specified to run updates on shared tables.
 521          *
 522          * @param string $name table name
 523          * @return bool
 524          */
 525         protected function doTable( $name ) {
 526                 global $wgSharedDB, $wgSharedTables;
 527
 528                 // Don't bother to check $wgSharedTables if there isn't a shared database
 529                 // or the user actually also wants to do updates on the shared database.
 530                 if ( $wgSharedDB === null || $this->shared ) {
 531                         return true;
 532                 }
 533
 534                 return !in_array( $name, $wgSharedTables );
 535         }
 536
 537         /**
 538          * Before 1.17, we used to handle updates via stuff like
 539          * $wgExtNewTables/Fields/Indexes. This is nasty :) We refactored a lot
 540          * of this in 1.17 but we want to remain back-compatible for a while. So
 541          * load up these old global-based things into our update list.
 542          *
 543          * @return array
 544          */
 545         protected function getOldGlobalUpdates() {
 546                 global $wgExtNewFields, $wgExtNewTables, $wgExtModifiedFields,
 547                         $wgExtNewIndexes;
 548
 549                 $updates = array();
 550
 551                 foreach ( $wgExtNewTables as $tableRecord ) {
 552                         $updates[] = array(
 553                                 'addTable', $tableRecord[0], $tableRecord[1], true
 554                         );
 555                 }
 556
 557                 foreach ( $wgExtNewFields as $fieldRecord ) {
 558                         $updates[] = array(
 559                                 'addField', $fieldRecord[0], $fieldRecord[1],
 560                                 $fieldRecord[2], true
 561                         );
 562                 }
 563
 564                 foreach ( $wgExtNewIndexes as $fieldRecord ) {
 565                         $updates[] = array(
 566                                 'addIndex', $fieldRecord[0], $fieldRecord[1],
 567                                 $fieldRecord[2], true
 568                         );
 569                 }
 570
 571                 foreach ( $wgExtModifiedFields as $fieldRecord ) {
 572                         $updates[] = array(
 573                                 'modifyField', $fieldRecord[0], $fieldRecord[1],
 574                                 $fieldRecord[2], true
 575                         );
 576                 }
 577
 578                 return $updates;
 579         }
 580
 581         /**
 582          * Get an array of updates to perform on the database. Should return a
 583          * multi-dimensional array. The main key is the MediaWiki version (1.12,
 584          * 1.13...) with the values being arrays of updates, identical to how
 585          * updaters.inc did it (for now)
 586          *
 587          * @return Array
 588          */
 589         abstract protected function getCoreUpdateList();
 590
 591         /**
 592          * Append an SQL fragment to the open file handle.
 593          *
 594          * @param string $filename File name to open
 595          */
 596         public function copyFile( $filename ) {
 597                 $this->db->sourceFile( $filename, false, false, false,
 598                         array( $this, 'appendLine' )
 599                 );
 600         }
 601
 602         /**
 603          * Append a line to the open filehandle.  The line is assumed to
 604          * be a complete SQL statement.
 605          *
 606          * This is used as a callback for for sourceLine().
 607          *
 608          * @param string $line text to append to the file
 609          * @return Boolean false to skip actually executing the file
 610          * @throws MWException
 611          */
 612         public function appendLine( $line ) {
 613                 $line = rtrim( $line ) . ";\n";
 614                 if ( fwrite( $this->fileHandle, $line ) === false ) {
 615                         throw new MWException( "trouble writing file" );
 616                 }
 617
 618                 return false;
 619         }
 620
 621         /**
 622          * Applies a SQL patch
 623          *
 624          * @param string $path Path to the patch file
 625          * @param $isFullPath Boolean Whether to treat $path as a relative or not
 626          * @param string $msg Description of the patch
 627          * @return boolean false if patch is skipped.
 628          */
 629         protected function applyPatch( $path, $isFullPath = false, $msg = null ) {
 630                 if ( $msg === null ) {
 631                         $msg = "Applying $path patch";
 632                 }
 633                 if ( $this->skipSchema ) {
 634                         $this->output( "...skipping schema change ($msg).\n" );
 635
 636                         return false;
 637                 }
 638
 639                 $this->output( "$msg ..." );
 640
 641                 if ( !$isFullPath ) {
 642                         $path = $this->db->patchPath( $path );
 643                 }
 644                 if ( $this->fileHandle !== null ) {
 645                         $this->copyFile( $path );
 646                 } else {
 647                         $this->db->sourceFile( $path );
 648                 }
 649                 $this->output( "done.\n" );
 650
 651                 return true;
 652         }
 653
 654         /**
 655          * Add a new table to the database
 656          *
 657          * @param string $name Name of the new table
 658          * @param string $patch Path to the patch file
 659          * @param $fullpath Boolean Whether to treat $patch path as a relative or not
 660          * @return Boolean false if this was skipped because schema changes are skipped
 661          */
 662         protected function addTable( $name, $patch, $fullpath = false ) {
 663                 if ( !$this->doTable( $name ) ) {
 664                         return true;
 665                 }
 666
 667                 if ( $this->db->tableExists( $name, __METHOD__ ) ) {
 668                         $this->output( "...$name table already exists.\n" );
 669                 } else {
 670                         return $this->applyPatch( $patch, $fullpath, "Creating $name table" );
 671                 }
 672
 673                 return true;
 674         }
 675
 676         /**
 677          * Add a new field to an existing table
 678          *
 679          * @param string $table Name of the table to modify
 680          * @param string $field Name of the new field
 681          * @param string $patch Path to the patch file
 682          * @param $fullpath Boolean Whether to treat $patch path as a relative or not
 683          * @return Boolean false if this was skipped because schema changes are skipped
 684          */
 685         protected function addField( $table, $field, $patch, $fullpath = false ) {
 686                 if ( !$this->doTable( $table ) ) {
 687                         return true;
 688                 }
 689
 690                 if ( !$this->db->tableExists( $table, __METHOD__ ) ) {
 691                         $this->output( "...$table table does not exist, skipping new field patch.\n" );
 692                 } elseif ( $this->db->fieldExists( $table, $field, __METHOD__ ) ) {
 693                         $this->output( "...have $field field in $table table.\n" );
 694                 } else {
 695                         return $this->applyPatch( $patch, $fullpath, "Adding $field field to table $table" );
 696                 }
 697
 698                 return true;
 699         }
 700
 701         /**
 702          * Add a new index to an existing table
 703          *
 704          * @param string $table Name of the table to modify
 705          * @param string $index Name of the new index
 706          * @param string $patch Path to the patch file
 707          * @param $fullpath Boolean Whether to treat $patch path as a relative or not
 708          * @return Boolean false if this was skipped because schema changes are skipped
 709          */
 710         protected function addIndex( $table, $index, $patch, $fullpath = false ) {
 711                 if ( !$this->doTable( $table ) ) {
 712                         return true;
 713                 }
 714
 715                 if ( !$this->db->tableExists( $table, __METHOD__ ) ) {
 716                         $this->output( "...skipping: '$table' table doesn't exist yet.\n" );
 717                 } elseif ( $this->db->indexExists( $table, $index, __METHOD__ ) ) {
 718                         $this->output( "...index $index already set on $table table.\n" );
 719                 } else {
 720                         return $this->applyPatch( $patch, $fullpath, "Adding index $index to table $table" );
 721                 }
 722
 723                 return true;
 724         }
 725
 726         /**
 727          * Drop a field from an existing table
 728          *
 729          * @param string $table Name of the table to modify
 730          * @param string $field Name of the old field
 731          * @param string $patch Path to the patch file
 732          * @param $fullpath Boolean Whether to treat $patch path as a relative or not
 733          * @return Boolean false if this was skipped because schema changes are skipped
 734          */
 735         protected function dropField( $table, $field, $patch, $fullpath = false ) {
 736                 if ( !$this->doTable( $table ) ) {
 737                         return true;
 738                 }
 739
 740                 if ( $this->db->fieldExists( $table, $field, __METHOD__ ) ) {
 741                         return $this->applyPatch( $patch, $fullpath, "Table $table contains $field field. Dropping" );
 742                 } else {
 743                         $this->output( "...$table table does not contain $field field.\n" );
 744                 }
 745
 746                 return true;
 747         }
 748
 749         /**
 750          * Drop an index from an existing table
 751          *
 752          * @param string $table Name of the table to modify
 753          * @param string $index Name of the index
 754          * @param string $patch Path to the patch file
 755          * @param $fullpath Boolean: Whether to treat $patch path as a relative or not
 756          * @return Boolean false if this was skipped because schema changes are skipped
 757          */
 758         protected function dropIndex( $table, $index, $patch, $fullpath = false ) {
 759                 if ( !$this->doTable( $table ) ) {
 760                         return true;
 761                 }
 762
 763                 if ( $this->db->indexExists( $table, $index, __METHOD__ ) ) {
 764                         return $this->applyPatch( $patch, $fullpath, "Dropping $index index from table $table" );
 765                 } else {
 766                         $this->output( "...$index key doesn't exist.\n" );
 767                 }
 768
 769                 return true;
 770         }
 771
 772         /**
 773          * Rename an index from an existing table
 774          *
 775          * @param string $table Name of the table to modify
 776          * @param string $oldIndex Old name of the index
 777          * @param string $newIndex New name of the index
 778          * @param $skipBothIndexExistWarning Boolean: Whether to warn if both the
 779          * old and the new indexes exist.
 780          * @param string $patch Path to the patch file
 781          * @param $fullpath Boolean: Whether to treat $patch path as a relative or not
 782          * @return Boolean false if this was skipped because schema changes are skipped
 783          */
 784         protected function renameIndex( $table, $oldIndex, $newIndex,
 785                 $skipBothIndexExistWarning, $patch, $fullpath = false
 786         ) {
 787                 if ( !$this->doTable( $table ) ) {
 788                         return true;
 789                 }
 790
 791                 // First requirement: the table must exist
 792                 if ( !$this->db->tableExists( $table, __METHOD__ ) ) {
 793                         $this->output( "...skipping: '$table' table doesn't exist yet.\n" );
 794
 795                         return true;
 796                 }
 797
 798                 // Second requirement: the new index must be missing
 799                 if ( $this->db->indexExists( $table, $newIndex, __METHOD__ ) ) {
 800                         $this->output( "...index $newIndex already set on $table table.\n" );
 801                         if ( !$skipBothIndexExistWarning &&
 802                                 $this->db->indexExists( $table, $oldIndex, __METHOD__ )
 803                         ) {
 804                                 $this->output( "...WARNING: $oldIndex still exists, despite it has " .
 805                                         "been renamed into $newIndex (which also exists).\n" .
 806                                         "            $oldIndex should be manually removed if not needed anymore.\n" );
 807                         }
 808
 809                         return true;
 810                 }
 811
 812                 // Third requirement: the old index must exist
 813                 if ( !$this->db->indexExists( $table, $oldIndex, __METHOD__ ) ) {
 814                         $this->output( "...skipping: index $oldIndex doesn't exist.\n" );
 815
 816                         return true;
 817                 }
 818
 819                 // Requirements have been satisfied, patch can be applied
 820                 return $this->applyPatch(
 821                         $patch,
 822                         $fullpath,
 823                         "Renaming index $oldIndex into $newIndex to table $table"
 824                 );
 825         }
 826
 827         /**
 828          * If the specified table exists, drop it, or execute the
 829          * patch if one is provided.
 830          *
 831          * Public @since 1.20
 832          *
 833          * @param $table string
 834          * @param $patch string|false
 835          * @param $fullpath bool
 836          * @return Boolean false if this was skipped because schema changes are skipped
 837          */
 838         public function dropTable( $table, $patch = false, $fullpath = false ) {
 839                 if ( !$this->doTable( $table ) ) {
 840                         return true;
 841                 }
 842
 843                 if ( $this->db->tableExists( $table, __METHOD__ ) ) {
 844                         $msg = "Dropping table $table";
 845
 846                         if ( $patch === false ) {
 847                                 $this->output( "$msg ..." );
 848                                 $this->db->dropTable( $table, __METHOD__ );
 849                                 $this->output( "done.\n" );
 850                         } else {
 851                                 return $this->applyPatch( $patch, $fullpath, $msg );
 852                         }
 853                 } else {
 854                         $this->output( "...$table doesn't exist.\n" );
 855                 }
 856
 857                 return true;
 858         }
 859
 860         /**
 861          * Modify an existing field
 862          *
 863          * @param string $table name of the table to which the field belongs
 864          * @param string $field name of the field to modify
 865          * @param string $patch path to the patch file
 866          * @param $fullpath Boolean: whether to treat $patch path as a relative or not
 867          * @return Boolean false if this was skipped because schema changes are skipped
 868          */
 869         public function modifyField( $table, $field, $patch, $fullpath = false ) {
 870                 if ( !$this->doTable( $table ) ) {
 871                         return true;
 872                 }
 873
 874                 $updateKey = "$table-$field-$patch";
 875                 if ( !$this->db->tableExists( $table, __METHOD__ ) ) {
 876                         $this->output( "...$table table does not exist, skipping modify field patch.\n" );
 877                 } elseif ( !$this->db->fieldExists( $table, $field, __METHOD__ ) ) {
 878                         $this->output( "...$field field does not exist in $table table, " .
 879                                 "skipping modify field patch.\n" );
 880                 } elseif ( $this->updateRowExists( $updateKey ) ) {
 881                         $this->output( "...$field in table $table already modified by patch $patch.\n" );
 882                 } else {
 883                         $this->insertUpdateRow( $updateKey );
 884
 885                         return $this->applyPatch( $patch, $fullpath, "Modifying $field field of table $table" );
 886                 }
 887
 888                 return true;
 889         }
 890
 891         /**
 892          * Purge the objectcache table
 893          */
 894         public function purgeCache() {
 895                 global $wgLocalisationCacheConf;
 896                 # We can't guarantee that the user will be able to use TRUNCATE,
 897                 # but we know that DELETE is available to us
 898                 $this->output( "Purging caches..." );
 899                 $this->db->delete( 'objectcache', '*', __METHOD__ );
 900                 if ( $wgLocalisationCacheConf['manualRecache'] ) {
 901                         $this->rebuildLocalisationCache();
 902                 }
 903                 MessageBlobStore::clear();
 904                 $this->output( "done.\n" );
 905         }
 906
 907         /**
 908          * Check the site_stats table is not properly populated.
 909          */
 910         protected function checkStats() {
 911                 $this->output( "...site_stats is populated..." );
 912                 $row = $this->db->selectRow( 'site_stats', '*', array( 'ss_row_id' => 1 ), __METHOD__ );
 913                 if ( $row === false ) {
 914                         $this->output( "data is missing! rebuilding...\n" );
 915                 } elseif ( isset( $row->site_stats ) && $row->ss_total_pages == -1 ) {
 916                         $this->output( "missing ss_total_pages, rebuilding...\n" );
 917                 } else {
 918                         $this->output( "done.\n" );
 919
 920                         return;
 921                 }
 922                 SiteStatsInit::doAllAndCommit( $this->db );
 923         }
 924
 925         # Common updater functions
 926
 927         /**
 928          * Sets the number of active users in the site_stats table
 929          */
 930         protected function doActiveUsersInit() {
 931                 $activeUsers = $this->db->selectField( 'site_stats', 'ss_active_users', false, __METHOD__ );
 932                 if ( $activeUsers == -1 ) {
 933                         $activeUsers = $this->db->selectField( 'recentchanges',
 934                                 'COUNT( DISTINCT rc_user_text )',
 935                                 array( 'rc_user != 0', 'rc_bot' => 0, "rc_log_type != 'newusers'" ), __METHOD__
 936                         );
 937                         $this->db->update( 'site_stats',
 938                                 array( 'ss_active_users' => intval( $activeUsers ) ),
 939                                 array( 'ss_row_id' => 1 ), __METHOD__, array( 'LIMIT' => 1 )
 940                         );
 941                 }
 942                 $this->output( "...ss_active_users user count set...\n" );
 943         }
 944
 945         /**
 946          * Populates the log_user_text field in the logging table
 947          */
 948         protected function doLogUsertextPopulation() {
 949                 if ( !$this->updateRowExists( 'populate log_usertext' ) ) {
 950                         $this->output(
 951                                 "Populating log_user_text field, printing progress markers. For large\n" .
 952                                 "databases, you may want to hit Ctrl-C and do this manually with\n" .
 953                                 "maintenance/populateLogUsertext.php.\n"
 954                         );
 955
 956                         $task = $this->maintenance->runChild( 'PopulateLogUsertext' );
 957                         $task->execute();
 958                         $this->output( "done.\n" );
 959                 }
 960         }
 961
 962         /**
 963          * Migrate log params to new table and index for searching
 964          */
 965         protected function doLogSearchPopulation() {
 966                 if ( !$this->updateRowExists( 'populate log_search' ) ) {
 967                         $this->output(
 968                                 "Populating log_search table, printing progress markers. For large\n" .
 969                                 "databases, you may want to hit Ctrl-C and do this manually with\n" .
 970                                 "maintenance/populateLogSearch.php.\n" );
 971
 972                         $task = $this->maintenance->runChild( 'PopulateLogSearch' );
 973                         $task->execute();
 974                         $this->output( "done.\n" );
 975                 }
 976         }
 977
 978         /**
 979          * Updates the timestamps in the transcache table
 980          */
 981         protected function doUpdateTranscacheField() {
 982                 if ( $this->updateRowExists( 'convert transcache field' ) ) {
 983                         $this->output( "...transcache tc_time already converted.\n" );
 984
 985                         return true;
 986                 }
 987
 988                 return $this->applyPatch( 'patch-tc-timestamp.sql', false,
 989                         "Converting tc_time from UNIX epoch to MediaWiki timestamp" );
 990         }
 991
 992         /**
 993          * Update CategoryLinks collation
 994          */
 995         protected function doCollationUpdate() {
 996                 global $wgCategoryCollation;
 997                 if ( $this->db->fieldExists( 'categorylinks', 'cl_collation', __METHOD__ ) ) {
 998                         if ( $this->db->selectField(
 999                                 'categorylinks',
1000                                 'COUNT(*)',
1001                                 'cl_collation != ' . $this->db->addQuotes( $wgCategoryCollation ),
1002                                 __METHOD__
1003                                 ) == 0
1004                         ) {
1005                                 $this->output( "...collations up-to-date.\n" );
1006
1007                                 return;
1008                         }
1009
1010                         $this->output( "Updating category collations..." );
1011                         $task = $this->maintenance->runChild( 'UpdateCollation' );
1012                         $task->execute();
1013                         $this->output( "...done.\n" );
1014                 }
1015         }
1016
1017         /**
1018          * Migrates user options from the user table blob to user_properties
1019          */
1020         protected function doMigrateUserOptions() {
1021                 if ( $this->db->tableExists( 'user_properties' ) ) {
1022                         $cl = $this->maintenance->runChild( 'ConvertUserOptions', 'convertUserOptions.php' );
1023                         $cl->execute();
1024                         $this->output( "done.\n" );
1025                 }
1026         }
1027
1028         /**
1029          * Rebuilds the localisation cache
1030          */
1031         protected function rebuildLocalisationCache() {
1032                 /**
1033                  * @var $cl RebuildLocalisationCache
1034                  */
1035                 $cl = $this->maintenance->runChild( 'RebuildLocalisationCache', 'rebuildLocalisationCache.php' );
1036                 $this->output( "Rebuilding localisation cache...\n" );
1037                 $cl->setForce();
1038                 $cl->execute();
1039                 $this->output( "done.\n" );
1040         }
1041
1042         /**
1043          * Turns off content handler fields during parts of the upgrade
1044          * where they aren't available.
1045          */
1046         protected function disableContentHandlerUseDB() {
1047                 global $wgContentHandlerUseDB;
1048
1049                 if( $wgContentHandlerUseDB ) {
1050                         $this->output( "Turning off Content Handler DB fields for this part of upgrade.\n" );
1051                         $this->holdContentHandlerUseDB = $wgContentHandlerUseDB;
1052                         $wgContentHandlerUseDB = false;
1053                 }
1054         }
1055
1056         /**
1057          * Turns content handler fields back on.
1058          */
1059         protected function enableContentHandlerUseDB() {
1060                 global $wgContentHandlerUseDB;
1061
1062                 if( $this->holdContentHandlerUseDB ) {
1063                         $this->output( "Content Handler DB fields should be usable now.\n" );
1064                         $wgContentHandlerUseDB = $this->holdContentHandlerUseDB;
1065                 }
1066         }
1067 }