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