includes/db/DatabaseMysql.php

   1 <?php
   2 /**
   3  * This is the MySQL database abstraction layer.
   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 Database
  22  */
  23
  24 /**
  25  * Database abstraction object for mySQL
  26  * Inherit all methods and properties of Database::Database()
  27  *
  28  * @ingroup Database
  29  * @see Database
  30  */
  31 class DatabaseMysql extends DatabaseBase {
  32
  33         /**
  34          * @return string
  35          */
  36         function getType() {
  37                 return 'mysql';
  38         }
  39
  40         /**
  41          * @param $sql string
  42          * @return resource
  43          */
  44         protected function doQuery( $sql ) {
  45                 if( $this->bufferResults() ) {
  46                         $ret = mysql_query( $sql, $this->mConn );
  47                 } else {
  48                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
  49                 }
  50                 return $ret;
  51         }
  52
  53         /**
  54          * @param $server string
  55          * @param $user string
  56          * @param $password string
  57          * @param $dbName string
  58          * @return bool
  59          * @throws DBConnectionError
  60          */
  61         function open( $server, $user, $password, $dbName ) {
  62                 global $wgAllDBsAreLocalhost, $wgDBmysql5, $wgSQLMode;
  63                 wfProfileIn( __METHOD__ );
  64
  65                 # Load mysql.so if we don't have it
  66                 wfDl( 'mysql' );
  67
  68                 # Fail now
  69                 # Otherwise we get a suppressed fatal error, which is very hard to track down
  70                 if ( !function_exists( 'mysql_connect' ) ) {
  71                         throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
  72                 }
  73
  74                 # Debugging hack -- fake cluster
  75                 if ( $wgAllDBsAreLocalhost ) {
  76                         $realServer = 'localhost';
  77                 } else {
  78                         $realServer = $server;
  79                 }
  80                 $this->close();
  81                 $this->mServer = $server;
  82                 $this->mUser = $user;
  83                 $this->mPassword = $password;
  84                 $this->mDBname = $dbName;
  85
  86                 $connFlags = 0;
  87                 if ( $this->mFlags & DBO_SSL ) {
  88                         $connFlags |= MYSQL_CLIENT_SSL;
  89                 }
  90                 if ( $this->mFlags & DBO_COMPRESS ) {
  91                         $connFlags |= MYSQL_CLIENT_COMPRESS;
  92                 }
  93
  94                 wfProfileIn( "dbconnect-$server" );
  95
  96                 # The kernel's default SYN retransmission period is far too slow for us,
  97                 # so we use a short timeout plus a manual retry. Retrying means that a small
  98                 # but finite rate of SYN packet loss won't cause user-visible errors.
  99                 $this->mConn = false;
 100                 if ( ini_get( 'mysql.connect_timeout' ) <= 3 ) {
 101                         $numAttempts = 2;
 102                 } else {
 103                         $numAttempts = 1;
 104                 }
 105                 $this->installErrorHandler();
 106                 for ( $i = 0; $i < $numAttempts && !$this->mConn; $i++ ) {
 107                         if ( $i > 1 ) {
 108                                 usleep( 1000 );
 109                         }
 110                         if ( $this->mFlags & DBO_PERSISTENT ) {
 111                                 $this->mConn = mysql_pconnect( $realServer, $user, $password, $connFlags );
 112                         } else {
 113                                 # Create a new connection...
 114                                 $this->mConn = mysql_connect( $realServer, $user, $password, true, $connFlags );
 115                         }
 116                         #if ( $this->mConn === false ) {
 117                                 #$iplus = $i + 1;
 118                                 #wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
 119                         #}
 120                 }
 121                 $error = $this->restoreErrorHandler();
 122
 123                 wfProfileOut( "dbconnect-$server" );
 124
 125                 # Always log connection errors
 126                 if ( !$this->mConn ) {
 127                         if ( !$error ) {
 128                                 $error = $this->lastError();
 129                         }
 130                         wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
 131                         wfDebug( "DB connection error\n" .
 132                                 "Server: $server, User: $user, Password: " .
 133                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 134
 135                         wfProfileOut( __METHOD__ );
 136                         $this->reportConnectionError( $error );
 137                 }
 138
 139                 if ( $dbName != '' ) {
 140                         wfSuppressWarnings();
 141                         $success = mysql_select_db( $dbName, $this->mConn );
 142                         wfRestoreWarnings();
 143                         if ( !$success ) {
 144                                 wfLogDBError( "Error selecting database $dbName on server {$this->mServer}\n" );
 145                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 146                                         "from client host " . wfHostname() . "\n" );
 147
 148                                 wfProfileOut( __METHOD__ );
 149                                 $this->reportConnectionError( "Error selecting database $dbName" );
 150                         }
 151                 }
 152
 153                 // Tell the server we're communicating with it in UTF-8.
 154                 // This may engage various charset conversions.
 155                 if( $wgDBmysql5 ) {
 156                         $this->query( 'SET NAMES utf8', __METHOD__ );
 157                 } else {
 158                         $this->query( 'SET NAMES binary', __METHOD__ );
 159                 }
 160                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 161                 if ( is_string( $wgSQLMode ) ) {
 162                         $mode = $this->addQuotes( $wgSQLMode );
 163                         $this->query( "SET sql_mode = $mode", __METHOD__ );
 164                 }
 165
 166                 $this->mOpened = true;
 167                 wfProfileOut( __METHOD__ );
 168                 return true;
 169         }
 170
 171         /**
 172          * @return bool
 173          */
 174         protected function closeConnection() {
 175                 return mysql_close( $this->mConn );
 176         }
 177
 178         /**
 179          * @param $res ResultWrapper
 180          * @throws DBUnexpectedError
 181          */
 182         function freeResult( $res ) {
 183                 if ( $res instanceof ResultWrapper ) {
 184                         $res = $res->result;
 185                 }
 186                 wfSuppressWarnings();
 187                 $ok = mysql_free_result( $res );
 188                 wfRestoreWarnings();
 189                 if ( !$ok ) {
 190                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 191                 }
 192         }
 193
 194         /**
 195          * @param $res ResultWrapper
 196          * @return object|stdClass
 197          * @throws DBUnexpectedError
 198          */
 199         function fetchObject( $res ) {
 200                 if ( $res instanceof ResultWrapper ) {
 201                         $res = $res->result;
 202                 }
 203                 wfSuppressWarnings();
 204                 $row = mysql_fetch_object( $res );
 205                 wfRestoreWarnings();
 206                 if( $this->lastErrno() ) {
 207                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 208                 }
 209                 return $row;
 210         }
 211
 212         /**
 213          * @param $res ResultWrapper
 214          * @return array
 215          * @throws DBUnexpectedError
 216          */
 217         function fetchRow( $res ) {
 218                 if ( $res instanceof ResultWrapper ) {
 219                         $res = $res->result;
 220                 }
 221                 wfSuppressWarnings();
 222                 $row = mysql_fetch_array( $res );
 223                 wfRestoreWarnings();
 224                 if ( $this->lastErrno() ) {
 225                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 226                 }
 227                 return $row;
 228         }
 229
 230         /**
 231          * @throws DBUnexpectedError
 232          * @param $res ResultWrapper
 233          * @return int
 234          */
 235         function numRows( $res ) {
 236                 if ( $res instanceof ResultWrapper ) {
 237                         $res = $res->result;
 238                 }
 239                 wfSuppressWarnings();
 240                 $n = mysql_num_rows( $res );
 241                 wfRestoreWarnings();
 242                 if( $this->lastErrno() ) {
 243                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 244                 }
 245                 return $n;
 246         }
 247
 248         /**
 249          * @param $res ResultWrapper
 250          * @return int
 251          */
 252         function numFields( $res ) {
 253                 if ( $res instanceof ResultWrapper ) {
 254                         $res = $res->result;
 255                 }
 256                 return mysql_num_fields( $res );
 257         }
 258
 259         /**
 260          * @param $res ResultWrapper
 261          * @param $n string
 262          * @return string
 263          */
 264         function fieldName( $res, $n ) {
 265                 if ( $res instanceof ResultWrapper ) {
 266                         $res = $res->result;
 267                 }
 268                 return mysql_field_name( $res, $n );
 269         }
 270
 271         /**
 272          * @return int
 273          */
 274         function insertId() {
 275                 return mysql_insert_id( $this->mConn );
 276         }
 277
 278         /**
 279          * @param $res ResultWrapper
 280          * @param $row
 281          * @return bool
 282          */
 283         function dataSeek( $res, $row ) {
 284                 if ( $res instanceof ResultWrapper ) {
 285                         $res = $res->result;
 286                 }
 287                 return mysql_data_seek( $res, $row );
 288         }
 289
 290         /**
 291          * @return int
 292          */
 293         function lastErrno() {
 294                 if ( $this->mConn ) {
 295                         return mysql_errno( $this->mConn );
 296                 } else {
 297                         return mysql_errno();
 298                 }
 299         }
 300
 301         /**
 302          * @return string
 303          */
 304         function lastError() {
 305                 if ( $this->mConn ) {
 306                         # Even if it's non-zero, it can still be invalid
 307                         wfSuppressWarnings();
 308                         $error = mysql_error( $this->mConn );
 309                         if ( !$error ) {
 310                                 $error = mysql_error();
 311                         }
 312                         wfRestoreWarnings();
 313                 } else {
 314                         $error = mysql_error();
 315                 }
 316                 if( $error ) {
 317                         $error .= ' (' . $this->mServer . ')';
 318                 }
 319                 return $error;
 320         }
 321
 322         /**
 323          * @return int
 324          */
 325         function affectedRows() {
 326                 return mysql_affected_rows( $this->mConn );
 327         }
 328
 329         /**
 330          * @param $table string
 331          * @param $uniqueIndexes
 332          * @param $rows array
 333          * @param $fname string
 334          * @return ResultWrapper
 335          */
 336         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseMysql::replace' ) {
 337                 return $this->nativeReplace( $table, $rows, $fname );
 338         }
 339
 340         /**
 341          * Estimate rows in dataset
 342          * Returns estimated count, based on EXPLAIN output
 343          * Takes same arguments as Database::select()
 344          *
 345          * @param $table string|array
 346          * @param $vars string|array
 347          * @param $conds string|array
 348          * @param $fname string
 349          * @param $options string|array
 350          * @return int
 351          */
 352         public function estimateRowCount( $table, $vars='*', $conds='', $fname = 'DatabaseMysql::estimateRowCount', $options = array() ) {
 353                 $options['EXPLAIN'] = true;
 354                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 355                 if ( $res === false ) {
 356                         return false;
 357                 }
 358                 if ( !$this->numRows( $res ) ) {
 359                         return 0;
 360                 }
 361
 362                 $rows = 1;
 363                 foreach ( $res as $plan ) {
 364                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 365                 }
 366                 return $rows;
 367         }
 368
 369         /**
 370          * @param $table string
 371          * @param $field string
 372          * @return bool|MySQLField
 373          */
 374         function fieldInfo( $table, $field ) {
 375                 $table = $this->tableName( $table );
 376                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 377                 if ( !$res ) {
 378                         return false;
 379                 }
 380                 $n = mysql_num_fields( $res->result );
 381                 for( $i = 0; $i < $n; $i++ ) {
 382                         $meta = mysql_fetch_field( $res->result, $i );
 383                         if( $field == $meta->name ) {
 384                                 return new MySQLField($meta);
 385                         }
 386                 }
 387                 return false;
 388         }
 389
 390         /**
 391          * Get information about an index into an object
 392          * Returns false if the index does not exist
 393          *
 394          * @param $table string
 395          * @param $index string
 396          * @param $fname string
 397          * @return bool|array|null False or null on failure
 398          */
 399         function indexInfo( $table, $index, $fname = 'DatabaseMysql::indexInfo' ) {
 400                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 401                 # SHOW INDEX should work for 3.x and up:
 402                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 403                 $table = $this->tableName( $table );
 404                 $index = $this->indexName( $index );
 405                 $sql = 'SHOW INDEX FROM ' . $table;
 406                 $res = $this->query( $sql, $fname );
 407
 408                 if ( !$res ) {
 409                         return null;
 410                 }
 411
 412                 $result = array();
 413
 414                 foreach ( $res as $row ) {
 415                         if ( $row->Key_name == $index ) {
 416                                 $result[] = $row;
 417                         }
 418                 }
 419
 420                 return empty( $result ) ? false : $result;
 421         }
 422
 423         /**
 424          * @param $db
 425          * @return bool
 426          */
 427         function selectDB( $db ) {
 428                 $this->mDBname = $db;
 429                 return mysql_select_db( $db, $this->mConn );
 430         }
 431
 432         /**
 433          * @param $s string
 434          *
 435          * @return string
 436          */
 437         function strencode( $s ) {
 438                 $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 439
 440                 if($sQuoted === false) {
 441                         $this->ping();
 442                         $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 443                 }
 444                 return $sQuoted;
 445         }
 446
 447         /**
 448          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 449          *
 450          * @param $s string
 451          *
 452          * @return string
 453          */
 454         public function addIdentifierQuotes( $s ) {
 455                 return "`" . $this->strencode( $s ) . "`";
 456         }
 457
 458         /**
 459          * @param $name string
 460          * @return bool
 461          */
 462         public function isQuotedIdentifier( $name ) {
 463                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 464         }
 465
 466         /**
 467          * @return bool
 468          */
 469         function ping() {
 470                 $ping = mysql_ping( $this->mConn );
 471                 if ( $ping ) {
 472                         return true;
 473                 }
 474
 475                 mysql_close( $this->mConn );
 476                 $this->mOpened = false;
 477                 $this->mConn = false;
 478                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 479                 return true;
 480         }
 481
 482         /**
 483          * Returns slave lag.
 484          *
 485          * This will do a SHOW SLAVE STATUS
 486          *
 487          * @return int
 488          */
 489         function getLag() {
 490                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 491                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 492                         return $this->mFakeSlaveLag;
 493                 }
 494
 495                 return $this->getLagFromSlaveStatus();
 496         }
 497
 498         /**
 499          * @return bool|int
 500          */
 501         function getLagFromSlaveStatus() {
 502                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 503                 if ( !$res ) {
 504                         return false;
 505                 }
 506                 $row = $res->fetchObject();
 507                 if ( !$row ) {
 508                         return false;
 509                 }
 510                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 511                         return false;
 512                 } else {
 513                         return intval( $row->Seconds_Behind_Master );
 514                 }
 515         }
 516
 517         /**
 518          * @deprecated in 1.19, use getLagFromSlaveStatus
 519          *
 520          * @return bool|int
 521          */
 522         function getLagFromProcesslist() {
 523                 wfDeprecated( __METHOD__, '1.19' );
 524                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 525                 if( !$res ) {
 526                         return false;
 527                 }
 528                 # Find slave SQL thread
 529                 foreach( $res as $row ) {
 530                         /* This should work for most situations - when default db
 531                          * for thread is not specified, it had no events executed,
 532                          * and therefore it doesn't know yet how lagged it is.
 533                          *
 534                          * Relay log I/O thread does not select databases.
 535                          */
 536                         if ( $row->User == 'system user' &&
 537                                 $row->State != 'Waiting for master to send event' &&
 538                                 $row->State != 'Connecting to master' &&
 539                                 $row->State != 'Queueing master event to the relay log' &&
 540                                 $row->State != 'Waiting for master update' &&
 541                                 $row->State != 'Requesting binlog dump' &&
 542                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 543                                 $row->State != 'Reconnecting after a failed master event read' &&
 544                                 $row->State != 'Registering slave on master'
 545                                 ) {
 546                                 # This is it, return the time (except -ve)
 547                                 if ( $row->Time > 0x7fffffff ) {
 548                                         return false;
 549                                 } else {
 550                                         return $row->Time;
 551                                 }
 552                         }
 553                 }
 554                 return false;
 555         }
 556
 557         /**
 558          * Wait for the slave to catch up to a given master position.
 559          *
 560          * @param $pos DBMasterPos object
 561          * @param $timeout Integer: the maximum number of seconds to wait for synchronisation
 562          * @return bool|string
 563          */
 564         function masterPosWait( DBMasterPos $pos, $timeout ) {
 565                 $fname = 'DatabaseBase::masterPosWait';
 566                 wfProfileIn( $fname );
 567
 568                 # Commit any open transactions
 569                 if ( $this->mTrxLevel ) {
 570                         $this->commit( __METHOD__ );
 571                 }
 572
 573                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 574                         $status = parent::masterPosWait( $pos, $timeout );
 575                         wfProfileOut( $fname );
 576                         return $status;
 577                 }
 578
 579                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 580                 $encFile = $this->addQuotes( $pos->file );
 581                 $encPos = intval( $pos->pos );
 582                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 583                 $res = $this->doQuery( $sql );
 584
 585                 if ( $res && $row = $this->fetchRow( $res ) ) {
 586                         wfProfileOut( $fname );
 587                         return $row[0];
 588                 } else {
 589                         wfProfileOut( $fname );
 590                         return false;
 591                 }
 592         }
 593
 594         /**
 595          * Get the position of the master from SHOW SLAVE STATUS
 596          *
 597          * @return MySQLMasterPos|bool
 598          */
 599         function getSlavePos() {
 600                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 601                         return parent::getSlavePos();
 602                 }
 603
 604                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 605                 $row = $this->fetchObject( $res );
 606
 607                 if ( $row ) {
 608                         $pos = isset( $row->Exec_master_log_pos ) ? $row->Exec_master_log_pos : $row->Exec_Master_Log_Pos;
 609                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 610                 } else {
 611                         return false;
 612                 }
 613         }
 614
 615         /**
 616          * Get the position of the master from SHOW MASTER STATUS
 617          *
 618          * @return MySQLMasterPos|bool
 619          */
 620         function getMasterPos() {
 621                 if ( $this->mFakeMaster ) {
 622                         return parent::getMasterPos();
 623                 }
 624
 625                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 626                 $row = $this->fetchObject( $res );
 627
 628                 if ( $row ) {
 629                         return new MySQLMasterPos( $row->File, $row->Position );
 630                 } else {
 631                         return false;
 632                 }
 633         }
 634
 635         /**
 636          * @return string
 637          */
 638         function getServerVersion() {
 639                 return mysql_get_server_info( $this->mConn );
 640         }
 641
 642         /**
 643          * @param $index
 644          * @return string
 645          */
 646         function useIndexClause( $index ) {
 647                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 648         }
 649
 650         /**
 651          * @return string
 652          */
 653         function lowPriorityOption() {
 654                 return 'LOW_PRIORITY';
 655         }
 656
 657         /**
 658          * @return string
 659          */
 660         public static function getSoftwareLink() {
 661                 return '[http://www.mysql.com/ MySQL]';
 662         }
 663
 664         /**
 665          * @param $options array
 666          */
 667         public function setSessionOptions( array $options ) {
 668                 if ( isset( $options['connTimeout'] ) ) {
 669                         $timeout = (int)$options['connTimeout'];
 670                         $this->query( "SET net_read_timeout=$timeout" );
 671                         $this->query( "SET net_write_timeout=$timeout" );
 672                 }
 673         }
 674
 675         public function streamStatementEnd( &$sql, &$newLine ) {
 676                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 677                         preg_match( '/^DELIMITER\s+(\S+)/' , $newLine, $m );
 678                         $this->delimiter = $m[1];
 679                         $newLine = '';
 680                 }
 681                 return parent::streamStatementEnd( $sql, $newLine );
 682         }
 683
 684         /**
 685          * Check to see if a named lock is available. This is non-blocking.
 686          *
 687          * @param $lockName String: name of lock to poll
 688          * @param $method String: name of method calling us
 689          * @return Boolean
 690          * @since 1.20
 691          */
 692         public function lockIsFree( $lockName, $method ) {
 693                 $lockName = $this->addQuotes( $lockName );
 694                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 695                 $row = $this->fetchObject( $result );
 696                 return ( $row->lockstatus == 1 );
 697         }
 698
 699         /**
 700          * @param $lockName string
 701          * @param $method string
 702          * @param $timeout int
 703          * @return bool
 704          */
 705         public function lock( $lockName, $method, $timeout = 5 ) {
 706                 $lockName = $this->addQuotes( $lockName );
 707                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 708                 $row = $this->fetchObject( $result );
 709
 710                 if( $row->lockstatus == 1 ) {
 711                         return true;
 712                 } else {
 713                         wfDebug( __METHOD__." failed to acquire lock\n" );
 714                         return false;
 715                 }
 716         }
 717
 718         /**
 719          * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 720          * @param $lockName string
 721          * @param $method string
 722          * @return bool
 723          */
 724         public function unlock( $lockName, $method ) {
 725                 $lockName = $this->addQuotes( $lockName );
 726                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 727                 $row = $this->fetchObject( $result );
 728                 return ( $row->lockstatus == 1 );
 729         }
 730
 731         /**
 732          * @param $read array
 733          * @param $write array
 734          * @param $method string
 735          * @param $lowPriority bool
 736          */
 737         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 738                 $items = array();
 739
 740                 foreach( $write as $table ) {
 741                         $tbl = $this->tableName( $table ) .
 742                                         ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 743                                         ' WRITE';
 744                         $items[] = $tbl;
 745                 }
 746                 foreach( $read as $table ) {
 747                         $items[] = $this->tableName( $table ) . ' READ';
 748                 }
 749                 $sql = "LOCK TABLES " . implode( ',', $items );
 750                 $this->query( $sql, $method );
 751         }
 752
 753         /**
 754          * @param $method string
 755          */
 756         public function unlockTables( $method ) {
 757                 $this->query( "UNLOCK TABLES", $method );
 758         }
 759
 760         /**
 761          * Get search engine class. All subclasses of this
 762          * need to implement this if they wish to use searching.
 763          *
 764          * @return String
 765          */
 766         public function getSearchEngine() {
 767                 return 'SearchMySQL';
 768         }
 769
 770         /**
 771          * @param bool $value
 772          * @return mixed
 773          */
 774         public function setBigSelects( $value = true ) {
 775                 if ( $value === 'default' ) {
 776                         if ( $this->mDefaultBigSelects === null ) {
 777                                 # Function hasn't been called before so it must already be set to the default
 778                                 return;
 779                         } else {
 780                                 $value = $this->mDefaultBigSelects;
 781                         }
 782                 } elseif ( $this->mDefaultBigSelects === null ) {
 783                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 784                 }
 785                 $encValue = $value ? '1' : '0';
 786                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 787         }
 788
 789         /**
 790          * DELETE where the condition is a join. MySql uses multi-table deletes.
 791          * @param $delTable string
 792          * @param $joinTable string
 793          * @param $delVar string
 794          * @param $joinVar string
 795          * @param $conds array|string
 796          * @param $fname bool
 797          * @return bool|ResultWrapper
 798          */
 799         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'DatabaseBase::deleteJoin' ) {
 800                 if ( !$conds ) {
 801                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 802                 }
 803
 804                 $delTable = $this->tableName( $delTable );
 805                 $joinTable = $this->tableName( $joinTable );
 806                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 807
 808                 if ( $conds != '*' ) {
 809                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 810                 }
 811
 812                 return $this->query( $sql, $fname );
 813         }
 814
 815         /**
 816          * Determines how long the server has been up
 817          *
 818          * @return int
 819          */
 820         function getServerUptime() {
 821                 $vars = $this->getMysqlStatus( 'Uptime' );
 822                 return (int)$vars['Uptime'];
 823         }
 824
 825         /**
 826          * Determines if the last failure was due to a deadlock
 827          *
 828          * @return bool
 829          */
 830         function wasDeadlock() {
 831                 return $this->lastErrno() == 1213;
 832         }
 833
 834         /**
 835          * Determines if the last failure was due to a lock timeout
 836          *
 837          * @return bool
 838          */
 839         function wasLockTimeout() {
 840                 return $this->lastErrno() == 1205;
 841         }
 842
 843         /**
 844          * Determines if the last query error was something that should be dealt
 845          * with by pinging the connection and reissuing the query
 846          *
 847          * @return bool
 848          */
 849         function wasErrorReissuable() {
 850                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
 851         }
 852
 853         /**
 854          * Determines if the last failure was due to the database being read-only.
 855          *
 856          * @return bool
 857          */
 858         function wasReadOnlyError() {
 859                 return $this->lastErrno() == 1223 ||
 860                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
 861         }
 862
 863         /**
 864          * @param $oldName
 865          * @param $newName
 866          * @param $temporary bool
 867          * @param $fname string
 868          */
 869         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseMysql::duplicateTableStructure' ) {
 870                 $tmp = $temporary ? 'TEMPORARY ' : '';
 871                 $newName = $this->addIdentifierQuotes( $newName );
 872                 $oldName = $this->addIdentifierQuotes( $oldName );
 873                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
 874                 $this->query( $query, $fname );
 875         }
 876
 877         /**
 878          * List all tables on the database
 879          *
 880          * @param $prefix string Only show tables with this prefix, e.g. mw_
 881          * @param $fname String: calling function name
 882          * @return array
 883          */
 884         function listTables( $prefix = null, $fname = 'DatabaseMysql::listTables' ) {
 885                 $result = $this->query( "SHOW TABLES", $fname);
 886
 887                 $endArray = array();
 888
 889                 foreach( $result as $table ) {
 890                         $vars = get_object_vars($table);
 891                         $table = array_pop( $vars );
 892
 893                         if( !$prefix || strpos( $table, $prefix ) === 0 ) {
 894                                 $endArray[] = $table;
 895                         }
 896                 }
 897
 898                 return $endArray;
 899         }
 900
 901         /**
 902          * @param $tableName
 903          * @param $fName string
 904          * @return bool|ResultWrapper
 905          */
 906         public function dropTable( $tableName, $fName = 'DatabaseMysql::dropTable' ) {
 907                 if( !$this->tableExists( $tableName, $fName ) ) {
 908                         return false;
 909                 }
 910                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
 911         }
 912
 913         /**
 914          * @return array
 915          */
 916         protected function getDefaultSchemaVars() {
 917                 $vars = parent::getDefaultSchemaVars();
 918                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
 919                 $vars['wgDBTableOptions'] = str_replace( 'CHARSET=mysql4', 'CHARSET=binary', $vars['wgDBTableOptions'] );
 920                 return $vars;
 921         }
 922
 923         /**
 924          * Get status information from SHOW STATUS in an associative array
 925          *
 926          * @param $which string
 927          * @return array
 928          */
 929         function getMysqlStatus( $which = "%" ) {
 930                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
 931                 $status = array();
 932
 933                 foreach ( $res as $row ) {
 934                         $status[$row->Variable_name] = $row->Value;
 935                 }
 936
 937                 return $status;
 938         }
 939
 940 }
 941
 942 /**
 943  * Legacy support: Database == DatabaseMysql
 944  *
 945  * @deprecated in 1.16
 946  */
 947 class Database extends DatabaseMysql {}
 948
 949 /**
 950  * Utility class.
 951  * @ingroup Database
 952  */
 953 class MySQLField implements Field {
 954         private $name, $tablename, $default, $max_length, $nullable,
 955                 $is_pk, $is_unique, $is_multiple, $is_key, $type;
 956
 957         function __construct ( $info ) {
 958                 $this->name = $info->name;
 959                 $this->tablename = $info->table;
 960                 $this->default = $info->def;
 961                 $this->max_length = $info->max_length;
 962                 $this->nullable = !$info->not_null;
 963                 $this->is_pk = $info->primary_key;
 964                 $this->is_unique = $info->unique_key;
 965                 $this->is_multiple = $info->multiple_key;
 966                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
 967                 $this->type = $info->type;
 968         }
 969
 970         /**
 971          * @return string
 972          */
 973         function name() {
 974                 return $this->name;
 975         }
 976
 977         /**
 978          * @return string
 979          */
 980         function tableName() {
 981                 return $this->tableName;
 982         }
 983
 984         /**
 985          * @return string
 986          */
 987         function type() {
 988                 return $this->type;
 989         }
 990
 991         /**
 992          * @return bool
 993          */
 994         function isNullable() {
 995                 return $this->nullable;
 996         }
 997
 998         function defaultValue() {
 999                 return $this->default;
1000         }
1001
1002         /**
1003          * @return bool
1004          */
1005         function isKey() {
1006                 return $this->is_key;
1007         }
1008
1009         /**
1010          * @return bool
1011          */
1012         function isMultipleKey() {
1013                 return $this->is_multiple;
1014         }
1015 }
1016
1017 class MySQLMasterPos implements DBMasterPos {
1018         var $file, $pos;
1019
1020         function __construct( $file, $pos ) {
1021                 $this->file = $file;
1022                 $this->pos = $pos;
1023         }
1024
1025         function __toString() {
1026                 return "{$this->file}/{$this->pos}";
1027         }
1028 }