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                         wfProfileOut( __METHOD__ );
  72                         throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
  73                 }
  74
  75                 # Debugging hack -- fake cluster
  76                 if ( $wgAllDBsAreLocalhost ) {
  77                         $realServer = 'localhost';
  78                 } else {
  79                         $realServer = $server;
  80                 }
  81                 $this->close();
  82                 $this->mServer = $server;
  83                 $this->mUser = $user;
  84                 $this->mPassword = $password;
  85                 $this->mDBname = $dbName;
  86
  87                 $connFlags = 0;
  88                 if ( $this->mFlags & DBO_SSL ) {
  89                         $connFlags |= MYSQL_CLIENT_SSL;
  90                 }
  91                 if ( $this->mFlags & DBO_COMPRESS ) {
  92                         $connFlags |= MYSQL_CLIENT_COMPRESS;
  93                 }
  94
  95                 wfProfileIn( "dbconnect-$server" );
  96
  97                 # The kernel's default SYN retransmission period is far too slow for us,
  98                 # so we use a short timeout plus a manual retry. Retrying means that a small
  99                 # but finite rate of SYN packet loss won't cause user-visible errors.
 100                 $this->mConn = false;
 101                 if ( ini_get( 'mysql.connect_timeout' ) <= 3 ) {
 102                         $numAttempts = 2;
 103                 } else {
 104                         $numAttempts = 1;
 105                 }
 106                 $this->installErrorHandler();
 107                 for ( $i = 0; $i < $numAttempts && !$this->mConn; $i++ ) {
 108                         if ( $i > 1 ) {
 109                                 usleep( 1000 );
 110                         }
 111                         if ( $this->mFlags & DBO_PERSISTENT ) {
 112                                 $this->mConn = mysql_pconnect( $realServer, $user, $password, $connFlags );
 113                         } else {
 114                                 # Create a new connection...
 115                                 $this->mConn = mysql_connect( $realServer, $user, $password, true, $connFlags );
 116                         }
 117                         #if ( $this->mConn === false ) {
 118                                 #$iplus = $i + 1;
 119                                 #wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
 120                         #}
 121                 }
 122                 $error = $this->restoreErrorHandler();
 123
 124                 wfProfileOut( "dbconnect-$server" );
 125
 126                 # Always log connection errors
 127                 if ( !$this->mConn ) {
 128                         if ( !$error ) {
 129                                 $error = $this->lastError();
 130                         }
 131                         wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
 132                         wfDebug( "DB connection error\n" .
 133                                 "Server: $server, User: $user, Password: " .
 134                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 135
 136                         wfProfileOut( __METHOD__ );
 137                         return $this->reportConnectionError( $error );
 138                 }
 139
 140                 if ( $dbName != '' ) {
 141                         wfSuppressWarnings();
 142                         $success = mysql_select_db( $dbName, $this->mConn );
 143                         wfRestoreWarnings();
 144                         if ( !$success ) {
 145                                 wfLogDBError( "Error selecting database $dbName on server {$this->mServer}\n" );
 146                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 147                                         "from client host " . wfHostname() . "\n" );
 148
 149                                 wfProfileOut( __METHOD__ );
 150                                 return $this->reportConnectionError( "Error selecting database $dbName" );
 151                         }
 152                 }
 153
 154                 // Tell the server we're communicating with it in UTF-8.
 155                 // This may engage various charset conversions.
 156                 if( $wgDBmysql5 ) {
 157                         $this->query( 'SET NAMES utf8', __METHOD__ );
 158                 } else {
 159                         $this->query( 'SET NAMES binary', __METHOD__ );
 160                 }
 161                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 162                 if ( is_string( $wgSQLMode ) ) {
 163                         $mode = $this->addQuotes( $wgSQLMode );
 164                         $this->query( "SET sql_mode = $mode", __METHOD__ );
 165                 }
 166
 167                 $this->mOpened = true;
 168                 wfProfileOut( __METHOD__ );
 169                 return true;
 170         }
 171
 172         /**
 173          * @return bool
 174          */
 175         protected function closeConnection() {
 176                 return mysql_close( $this->mConn );
 177         }
 178
 179         /**
 180          * @param $res ResultWrapper
 181          * @throws DBUnexpectedError
 182          */
 183         function freeResult( $res ) {
 184                 if ( $res instanceof ResultWrapper ) {
 185                         $res = $res->result;
 186                 }
 187                 wfSuppressWarnings();
 188                 $ok = mysql_free_result( $res );
 189                 wfRestoreWarnings();
 190                 if ( !$ok ) {
 191                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 192                 }
 193         }
 194
 195         /**
 196          * @param $res ResultWrapper
 197          * @return object|bool
 198          * @throws DBUnexpectedError
 199          */
 200         function fetchObject( $res ) {
 201                 if ( $res instanceof ResultWrapper ) {
 202                         $res = $res->result;
 203                 }
 204                 wfSuppressWarnings();
 205                 $row = mysql_fetch_object( $res );
 206                 wfRestoreWarnings();
 207
 208                 $errno = $this->lastErrno();
 209                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 210                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 211                 // these are the only errors mysql_fetch_object can cause.
 212                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 213                 if( $errno == 2000 || $errno == 2013 ) {
 214                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 215                 }
 216                 return $row;
 217         }
 218
 219         /**
 220          * @param $res ResultWrapper
 221          * @return array|bool
 222          * @throws DBUnexpectedError
 223          */
 224         function fetchRow( $res ) {
 225                 if ( $res instanceof ResultWrapper ) {
 226                         $res = $res->result;
 227                 }
 228                 wfSuppressWarnings();
 229                 $row = mysql_fetch_array( $res );
 230                 wfRestoreWarnings();
 231
 232                 $errno = $this->lastErrno();
 233                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 234                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 235                 // these are the only errors mysql_fetch_object can cause.
 236                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 237                 if( $errno == 2000 || $errno == 2013 ) {
 238                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 239                 }
 240                 return $row;
 241         }
 242
 243         /**
 244          * @throws DBUnexpectedError
 245          * @param $res ResultWrapper
 246          * @return int
 247          */
 248         function numRows( $res ) {
 249                 if ( $res instanceof ResultWrapper ) {
 250                         $res = $res->result;
 251                 }
 252                 wfSuppressWarnings();
 253                 $n = mysql_num_rows( $res );
 254                 wfRestoreWarnings();
 255                 // Unfortunately, mysql_num_rows does not reset the last errno.
 256                 // We are not checking for any errors here, since
 257                 // these are no errors mysql_num_rows can cause.
 258                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 259                 // See https://bugzilla.wikimedia.org/42430
 260                 return $n;
 261         }
 262
 263         /**
 264          * @param $res ResultWrapper
 265          * @return int
 266          */
 267         function numFields( $res ) {
 268                 if ( $res instanceof ResultWrapper ) {
 269                         $res = $res->result;
 270                 }
 271                 return mysql_num_fields( $res );
 272         }
 273
 274         /**
 275          * @param $res ResultWrapper
 276          * @param $n string
 277          * @return string
 278          */
 279         function fieldName( $res, $n ) {
 280                 if ( $res instanceof ResultWrapper ) {
 281                         $res = $res->result;
 282                 }
 283                 return mysql_field_name( $res, $n );
 284         }
 285
 286         /**
 287          * @return int
 288          */
 289         function insertId() {
 290                 return mysql_insert_id( $this->mConn );
 291         }
 292
 293         /**
 294          * @param $res ResultWrapper
 295          * @param $row
 296          * @return bool
 297          */
 298         function dataSeek( $res, $row ) {
 299                 if ( $res instanceof ResultWrapper ) {
 300                         $res = $res->result;
 301                 }
 302                 return mysql_data_seek( $res, $row );
 303         }
 304
 305         /**
 306          * @return int
 307          */
 308         function lastErrno() {
 309                 if ( $this->mConn ) {
 310                         return mysql_errno( $this->mConn );
 311                 } else {
 312                         return mysql_errno();
 313                 }
 314         }
 315
 316         /**
 317          * @return string
 318          */
 319         function lastError() {
 320                 if ( $this->mConn ) {
 321                         # Even if it's non-zero, it can still be invalid
 322                         wfSuppressWarnings();
 323                         $error = mysql_error( $this->mConn );
 324                         if ( !$error ) {
 325                                 $error = mysql_error();
 326                         }
 327                         wfRestoreWarnings();
 328                 } else {
 329                         $error = mysql_error();
 330                 }
 331                 if( $error ) {
 332                         $error .= ' (' . $this->mServer . ')';
 333                 }
 334                 return $error;
 335         }
 336
 337         /**
 338          * @return int
 339          */
 340         function affectedRows() {
 341                 return mysql_affected_rows( $this->mConn );
 342         }
 343
 344         /**
 345          * @param $table string
 346          * @param $uniqueIndexes
 347          * @param $rows array
 348          * @param $fname string
 349          * @return ResultWrapper
 350          */
 351         function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseMysql::replace' ) {
 352                 return $this->nativeReplace( $table, $rows, $fname );
 353         }
 354
 355         /**
 356          * Estimate rows in dataset
 357          * Returns estimated count, based on EXPLAIN output
 358          * Takes same arguments as Database::select()
 359          *
 360          * @param $table string|array
 361          * @param $vars string|array
 362          * @param $conds string|array
 363          * @param $fname string
 364          * @param $options string|array
 365          * @return int
 366          */
 367         public function estimateRowCount( $table, $vars = '*', $conds = '', $fname = 'DatabaseMysql::estimateRowCount', $options = array() ) {
 368                 $options['EXPLAIN'] = true;
 369                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 370                 if ( $res === false ) {
 371                         return false;
 372                 }
 373                 if ( !$this->numRows( $res ) ) {
 374                         return 0;
 375                 }
 376
 377                 $rows = 1;
 378                 foreach ( $res as $plan ) {
 379                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 380                 }
 381                 return $rows;
 382         }
 383
 384         /**
 385          * @param $table string
 386          * @param $field string
 387          * @return bool|MySQLField
 388          */
 389         function fieldInfo( $table, $field ) {
 390                 $table = $this->tableName( $table );
 391                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 392                 if ( !$res ) {
 393                         return false;
 394                 }
 395                 $n = mysql_num_fields( $res->result );
 396                 for( $i = 0; $i < $n; $i++ ) {
 397                         $meta = mysql_fetch_field( $res->result, $i );
 398                         if( $field == $meta->name ) {
 399                                 return new MySQLField( $meta );
 400                         }
 401                 }
 402                 return false;
 403         }
 404
 405         /**
 406          * Get information about an index into an object
 407          * Returns false if the index does not exist
 408          *
 409          * @param $table string
 410          * @param $index string
 411          * @param $fname string
 412          * @return bool|array|null False or null on failure
 413          */
 414         function indexInfo( $table, $index, $fname = 'DatabaseMysql::indexInfo' ) {
 415                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 416                 # SHOW INDEX should work for 3.x and up:
 417                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 418                 $table = $this->tableName( $table );
 419                 $index = $this->indexName( $index );
 420
 421                 $sql = 'SHOW INDEX FROM ' . $table;
 422                 $res = $this->query( $sql, $fname );
 423
 424                 if ( !$res ) {
 425                         return null;
 426                 }
 427
 428                 $result = array();
 429
 430                 foreach ( $res as $row ) {
 431                         if ( $row->Key_name == $index ) {
 432                                 $result[] = $row;
 433                         }
 434                 }
 435                 return empty( $result ) ? false : $result;
 436         }
 437
 438         /**
 439          * @param $db
 440          * @return bool
 441          */
 442         function selectDB( $db ) {
 443                 $this->mDBname = $db;
 444                 return mysql_select_db( $db, $this->mConn );
 445         }
 446
 447         /**
 448          * @param $s string
 449          *
 450          * @return string
 451          */
 452         function strencode( $s ) {
 453                 $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 454
 455                 if( $sQuoted === false ) {
 456                         $this->ping();
 457                         $sQuoted = mysql_real_escape_string( $s, $this->mConn );
 458                 }
 459                 return $sQuoted;
 460         }
 461
 462         /**
 463          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 464          *
 465          * @param $s string
 466          *
 467          * @return string
 468          */
 469         public function addIdentifierQuotes( $s ) {
 470                 return "`" . $this->strencode( $s ) . "`";
 471         }
 472
 473         /**
 474          * @param $name string
 475          * @return bool
 476          */
 477         public function isQuotedIdentifier( $name ) {
 478                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 479         }
 480
 481         /**
 482          * @return bool
 483          */
 484         function ping() {
 485                 $ping = mysql_ping( $this->mConn );
 486                 if ( $ping ) {
 487                         return true;
 488                 }
 489
 490                 mysql_close( $this->mConn );
 491                 $this->mOpened = false;
 492                 $this->mConn = false;
 493                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 494                 return true;
 495         }
 496
 497         /**
 498          * Returns slave lag.
 499          *
 500          * This will do a SHOW SLAVE STATUS
 501          *
 502          * @return int
 503          */
 504         function getLag() {
 505                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 506                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 507                         return $this->mFakeSlaveLag;
 508                 }
 509
 510                 return $this->getLagFromSlaveStatus();
 511         }
 512
 513         /**
 514          * @return bool|int
 515          */
 516         function getLagFromSlaveStatus() {
 517                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 518                 if ( !$res ) {
 519                         return false;
 520                 }
 521                 $row = $res->fetchObject();
 522                 if ( !$row ) {
 523                         return false;
 524                 }
 525                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 526                         return false;
 527                 } else {
 528                         return intval( $row->Seconds_Behind_Master );
 529                 }
 530         }
 531
 532         /**
 533          * @deprecated in 1.19, use getLagFromSlaveStatus
 534          *
 535          * @return bool|int
 536          */
 537         function getLagFromProcesslist() {
 538                 wfDeprecated( __METHOD__, '1.19' );
 539                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 540                 if( !$res ) {
 541                         return false;
 542                 }
 543                 # Find slave SQL thread
 544                 foreach( $res as $row ) {
 545                         /* This should work for most situations - when default db
 546                          * for thread is not specified, it had no events executed,
 547                          * and therefore it doesn't know yet how lagged it is.
 548                          *
 549                          * Relay log I/O thread does not select databases.
 550                          */
 551                         if ( $row->User == 'system user' &&
 552                                 $row->State != 'Waiting for master to send event' &&
 553                                 $row->State != 'Connecting to master' &&
 554                                 $row->State != 'Queueing master event to the relay log' &&
 555                                 $row->State != 'Waiting for master update' &&
 556                                 $row->State != 'Requesting binlog dump' &&
 557                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 558                                 $row->State != 'Reconnecting after a failed master event read' &&
 559                                 $row->State != 'Registering slave on master'
 560                                 ) {
 561                                 # This is it, return the time (except -ve)
 562                                 if ( $row->Time > 0x7fffffff ) {
 563                                         return false;
 564                                 } else {
 565                                         return $row->Time;
 566                                 }
 567                         }
 568                 }
 569                 return false;
 570         }
 571
 572         /**
 573          * Wait for the slave to catch up to a given master position.
 574          *
 575          * @param $pos DBMasterPos object
 576          * @param $timeout Integer: the maximum number of seconds to wait for synchronisation
 577          * @return bool|string
 578          */
 579         function masterPosWait( DBMasterPos $pos, $timeout ) {
 580                 $fname = 'DatabaseBase::masterPosWait';
 581                 wfProfileIn( $fname );
 582
 583                 # Commit any open transactions
 584                 if ( $this->mTrxLevel ) {
 585                         $this->commit( __METHOD__ );
 586                 }
 587
 588                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 589                         $status = parent::masterPosWait( $pos, $timeout );
 590                         wfProfileOut( $fname );
 591                         return $status;
 592                 }
 593
 594                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 595                 $encFile = $this->addQuotes( $pos->file );
 596                 $encPos = intval( $pos->pos );
 597                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 598                 $res = $this->doQuery( $sql );
 599
 600                 if ( $res && $row = $this->fetchRow( $res ) ) {
 601                         wfProfileOut( $fname );
 602                         return $row[0];
 603                 }
 604                 wfProfileOut( $fname );
 605                 return false;
 606         }
 607
 608         /**
 609          * Get the position of the master from SHOW SLAVE STATUS
 610          *
 611          * @return MySQLMasterPos|bool
 612          */
 613         function getSlavePos() {
 614                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 615                         return parent::getSlavePos();
 616                 }
 617
 618                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 619                 $row = $this->fetchObject( $res );
 620
 621                 if ( $row ) {
 622                         $pos = isset( $row->Exec_master_log_pos ) ? $row->Exec_master_log_pos : $row->Exec_Master_Log_Pos;
 623                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 624                 } else {
 625                         return false;
 626                 }
 627         }
 628
 629         /**
 630          * Get the position of the master from SHOW MASTER STATUS
 631          *
 632          * @return MySQLMasterPos|bool
 633          */
 634         function getMasterPos() {
 635                 if ( $this->mFakeMaster ) {
 636                         return parent::getMasterPos();
 637                 }
 638
 639                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 640                 $row = $this->fetchObject( $res );
 641
 642                 if ( $row ) {
 643                         return new MySQLMasterPos( $row->File, $row->Position );
 644                 } else {
 645                         return false;
 646                 }
 647         }
 648
 649         /**
 650          * @return string
 651          */
 652         function getServerVersion() {
 653                 return mysql_get_server_info( $this->mConn );
 654         }
 655
 656         /**
 657          * @param $index
 658          * @return string
 659          */
 660         function useIndexClause( $index ) {
 661                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 662         }
 663
 664         /**
 665          * @return string
 666          */
 667         function lowPriorityOption() {
 668                 return 'LOW_PRIORITY';
 669         }
 670
 671         /**
 672          * @return string
 673          */
 674         public static function getSoftwareLink() {
 675                 return '[http://www.mysql.com/ MySQL]';
 676         }
 677
 678         /**
 679          * @param $options array
 680          */
 681         public function setSessionOptions( array $options ) {
 682                 if ( isset( $options['connTimeout'] ) ) {
 683                         $timeout = (int)$options['connTimeout'];
 684                         $this->query( "SET net_read_timeout=$timeout" );
 685                         $this->query( "SET net_write_timeout=$timeout" );
 686                 }
 687         }
 688
 689         public function streamStatementEnd( &$sql, &$newLine ) {
 690                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 691                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 692                         $this->delimiter = $m[1];
 693                         $newLine = '';
 694                 }
 695                 return parent::streamStatementEnd( $sql, $newLine );
 696         }
 697
 698         /**
 699          * Check to see if a named lock is available. This is non-blocking.
 700          *
 701          * @param string $lockName name of lock to poll
 702          * @param string $method name of method calling us
 703          * @return Boolean
 704          * @since 1.20
 705          */
 706         public function lockIsFree( $lockName, $method ) {
 707                 $lockName = $this->addQuotes( $lockName );
 708                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 709                 $row = $this->fetchObject( $result );
 710                 return ( $row->lockstatus == 1 );
 711         }
 712
 713         /**
 714          * @param $lockName string
 715          * @param $method string
 716          * @param $timeout int
 717          * @return bool
 718          */
 719         public function lock( $lockName, $method, $timeout = 5 ) {
 720                 $lockName = $this->addQuotes( $lockName );
 721                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 722                 $row = $this->fetchObject( $result );
 723
 724                 if( $row->lockstatus == 1 ) {
 725                         return true;
 726                 } else {
 727                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 728                         return false;
 729                 }
 730         }
 731
 732         /**
 733          * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 734          * @param $lockName string
 735          * @param $method string
 736          * @return bool
 737          */
 738         public function unlock( $lockName, $method ) {
 739                 $lockName = $this->addQuotes( $lockName );
 740                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 741                 $row = $this->fetchObject( $result );
 742                 return ( $row->lockstatus == 1 );
 743         }
 744
 745         /**
 746          * @param $read array
 747          * @param $write array
 748          * @param $method string
 749          * @param $lowPriority bool
 750          * @return bool
 751          */
 752         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 753                 $items = array();
 754
 755                 foreach( $write as $table ) {
 756                         $tbl = $this->tableName( $table ) .
 757                                         ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 758                                         ' WRITE';
 759                         $items[] = $tbl;
 760                 }
 761                 foreach( $read as $table ) {
 762                         $items[] = $this->tableName( $table ) . ' READ';
 763                 }
 764                 $sql = "LOCK TABLES " . implode( ',', $items );
 765                 $this->query( $sql, $method );
 766                 return true;
 767         }
 768
 769         /**
 770          * @param $method string
 771          * @return bool
 772          */
 773         public function unlockTables( $method ) {
 774                 $this->query( "UNLOCK TABLES", $method );
 775                 return true;
 776         }
 777
 778         /**
 779          * Get search engine class. All subclasses of this
 780          * need to implement this if they wish to use searching.
 781          *
 782          * @return String
 783          */
 784         public function getSearchEngine() {
 785                 return 'SearchMySQL';
 786         }
 787
 788         /**
 789          * @param bool $value
 790          * @return mixed
 791          */
 792         public function setBigSelects( $value = true ) {
 793                 if ( $value === 'default' ) {
 794                         if ( $this->mDefaultBigSelects === null ) {
 795                                 # Function hasn't been called before so it must already be set to the default
 796                                 return;
 797                         } else {
 798                                 $value = $this->mDefaultBigSelects;
 799                         }
 800                 } elseif ( $this->mDefaultBigSelects === null ) {
 801                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 802                 }
 803                 $encValue = $value ? '1' : '0';
 804                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 805         }
 806
 807         /**
 808          * DELETE where the condition is a join. MySql uses multi-table deletes.
 809          * @param $delTable string
 810          * @param $joinTable string
 811          * @param $delVar string
 812          * @param $joinVar string
 813          * @param $conds array|string
 814          * @param bool|string $fname bool
 815          * @throws DBUnexpectedError
 816          * @return bool|ResultWrapper
 817          */
 818         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'DatabaseBase::deleteJoin' ) {
 819                 if ( !$conds ) {
 820                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 821                 }
 822
 823                 $delTable = $this->tableName( $delTable );
 824                 $joinTable = $this->tableName( $joinTable );
 825                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 826
 827                 if ( $conds != '*' ) {
 828                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 829                 }
 830
 831                 return $this->query( $sql, $fname );
 832         }
 833
 834         /**
 835          * Determines how long the server has been up
 836          *
 837          * @return int
 838          */
 839         function getServerUptime() {
 840                 $vars = $this->getMysqlStatus( 'Uptime' );
 841                 return (int)$vars['Uptime'];
 842         }
 843
 844         /**
 845          * Determines if the last failure was due to a deadlock
 846          *
 847          * @return bool
 848          */
 849         function wasDeadlock() {
 850                 return $this->lastErrno() == 1213;
 851         }
 852
 853         /**
 854          * Determines if the last failure was due to a lock timeout
 855          *
 856          * @return bool
 857          */
 858         function wasLockTimeout() {
 859                 return $this->lastErrno() == 1205;
 860         }
 861
 862         /**
 863          * Determines if the last query error was something that should be dealt
 864          * with by pinging the connection and reissuing the query
 865          *
 866          * @return bool
 867          */
 868         function wasErrorReissuable() {
 869                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
 870         }
 871
 872         /**
 873          * Determines if the last failure was due to the database being read-only.
 874          *
 875          * @return bool
 876          */
 877         function wasReadOnlyError() {
 878                 return $this->lastErrno() == 1223 ||
 879                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
 880         }
 881
 882         /**
 883          * @param $oldName
 884          * @param $newName
 885          * @param $temporary bool
 886          * @param $fname string
 887          */
 888         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseMysql::duplicateTableStructure' ) {
 889                 $tmp = $temporary ? 'TEMPORARY ' : '';
 890                 $newName = $this->addIdentifierQuotes( $newName );
 891                 $oldName = $this->addIdentifierQuotes( $oldName );
 892                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
 893                 $this->query( $query, $fname );
 894         }
 895
 896         /**
 897          * List all tables on the database
 898          *
 899          * @param string $prefix Only show tables with this prefix, e.g. mw_
 900          * @param string $fname calling function name
 901          * @return array
 902          */
 903         function listTables( $prefix = null, $fname = 'DatabaseMysql::listTables' ) {
 904                 $result = $this->query( "SHOW TABLES", $fname);
 905
 906                 $endArray = array();
 907
 908                 foreach( $result as $table ) {
 909                         $vars = get_object_vars( $table );
 910                         $table = array_pop( $vars );
 911
 912                         if( !$prefix || strpos( $table, $prefix ) === 0 ) {
 913                                 $endArray[] = $table;
 914                         }
 915                 }
 916
 917                 return $endArray;
 918         }
 919
 920         /**
 921          * @param $tableName
 922          * @param $fName string
 923          * @return bool|ResultWrapper
 924          */
 925         public function dropTable( $tableName, $fName = 'DatabaseMysql::dropTable' ) {
 926                 if( !$this->tableExists( $tableName, $fName ) ) {
 927                         return false;
 928                 }
 929                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
 930         }
 931
 932         /**
 933          * @return array
 934          */
 935         protected function getDefaultSchemaVars() {
 936                 $vars = parent::getDefaultSchemaVars();
 937                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
 938                 $vars['wgDBTableOptions'] = str_replace( 'CHARSET=mysql4', 'CHARSET=binary', $vars['wgDBTableOptions'] );
 939                 return $vars;
 940         }
 941
 942         /**
 943          * Get status information from SHOW STATUS in an associative array
 944          *
 945          * @param $which string
 946          * @return array
 947          */
 948         function getMysqlStatus( $which = "%" ) {
 949                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
 950                 $status = array();
 951
 952                 foreach ( $res as $row ) {
 953                         $status[$row->Variable_name] = $row->Value;
 954                 }
 955
 956                 return $status;
 957         }
 958
 959 }
 960
 961 /**
 962  * Utility class.
 963  * @ingroup Database
 964  */
 965 class MySQLField implements Field {
 966         private $name, $tablename, $default, $max_length, $nullable,
 967                 $is_pk, $is_unique, $is_multiple, $is_key, $type;
 968
 969         function __construct( $info ) {
 970                 $this->name = $info->name;
 971                 $this->tablename = $info->table;
 972                 $this->default = $info->def;
 973                 $this->max_length = $info->max_length;
 974                 $this->nullable = !$info->not_null;
 975                 $this->is_pk = $info->primary_key;
 976                 $this->is_unique = $info->unique_key;
 977                 $this->is_multiple = $info->multiple_key;
 978                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
 979                 $this->type = $info->type;
 980         }
 981
 982         /**
 983          * @return string
 984          */
 985         function name() {
 986                 return $this->name;
 987         }
 988
 989         /**
 990          * @return string
 991          */
 992         function tableName() {
 993                 return $this->tableName;
 994         }
 995
 996         /**
 997          * @return string
 998          */
 999         function type() {
1000                 return $this->type;
1001         }
1002
1003         /**
1004          * @return bool
1005          */
1006         function isNullable() {
1007                 return $this->nullable;
1008         }
1009
1010         function defaultValue() {
1011                 return $this->default;
1012         }
1013
1014         /**
1015          * @return bool
1016          */
1017         function isKey() {
1018                 return $this->is_key;
1019         }
1020
1021         /**
1022          * @return bool
1023          */
1024         function isMultipleKey() {
1025                 return $this->is_multiple;
1026         }
1027 }
1028
1029 class MySQLMasterPos implements DBMasterPos {
1030         var $file, $pos;
1031
1032         function __construct( $file, $pos ) {
1033                 $this->file = $file;
1034                 $this->pos = $pos;
1035         }
1036
1037         function __toString() {
1038                 return "{$this->file}/{$this->pos}";
1039         }
1040 }