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