includes/db/DatabaseMysqlBase.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  * Defines methods independent on used MySQL extension.
  27  *
  28  * @ingroup Database
  29  * @since 1.22
  30  * @see Database
  31  */
  32 abstract class DatabaseMysqlBase extends DatabaseBase {
  33         /** @var MysqlMasterPos */
  34         protected $lastKnownSlavePos;
  35
  36         /**
  37          * @return string
  38          */
  39         function getType() {
  40                 return 'mysql';
  41         }
  42
  43         /**
  44          * @param $server string
  45          * @param $user string
  46          * @param $password string
  47          * @param $dbName string
  48          * @return bool
  49          * @throws DBConnectionError
  50          */
  51         function open( $server, $user, $password, $dbName ) {
  52                 global $wgAllDBsAreLocalhost, $wgDBmysql5, $wgSQLMode;
  53                 wfProfileIn( __METHOD__ );
  54
  55                 # Debugging hack -- fake cluster
  56                 if ( $wgAllDBsAreLocalhost ) {
  57                         $realServer = 'localhost';
  58                 } else {
  59                         $realServer = $server;
  60                 }
  61                 $this->close();
  62                 $this->mServer = $server;
  63                 $this->mUser = $user;
  64                 $this->mPassword = $password;
  65                 $this->mDBname = $dbName;
  66
  67                 wfProfileIn( "dbconnect-$server" );
  68
  69                 # The kernel's default SYN retransmission period is far too slow for us,
  70                 # so we use a short timeout plus a manual retry. Retrying means that a small
  71                 # but finite rate of SYN packet loss won't cause user-visible errors.
  72                 $this->mConn = false;
  73                 $this->installErrorHandler();
  74                 try {
  75                         $this->mConn = $this->mysqlConnect( $realServer );
  76                 } catch ( Exception $ex ) {
  77                         wfProfileOut( "dbconnect-$server" );
  78                         wfProfileOut( __METHOD__ );
  79                         $this->restoreErrorHandler();
  80                         throw $ex;
  81                 }
  82                 $error = $this->restoreErrorHandler();
  83
  84                 wfProfileOut( "dbconnect-$server" );
  85
  86                 # Always log connection errors
  87                 if ( !$this->mConn ) {
  88                         if ( !$error ) {
  89                                 $error = $this->lastError();
  90                         }
  91                         wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
  92                         wfDebug( "DB connection error\n" .
  93                                 "Server: $server, User: $user, Password: " .
  94                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
  95
  96                         wfProfileOut( __METHOD__ );
  97                         return $this->reportConnectionError( $error );
  98                 }
  99
 100                 if ( $dbName != '' ) {
 101                         wfSuppressWarnings();
 102                         $success = $this->selectDB( $dbName );
 103                         wfRestoreWarnings();
 104                         if ( !$success ) {
 105                                 wfLogDBError( "Error selecting database $dbName on server {$this->mServer}\n" );
 106                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 107                                         "from client host " . wfHostname() . "\n" );
 108
 109                                 wfProfileOut( __METHOD__ );
 110                                 return $this->reportConnectionError( "Error selecting database $dbName" );
 111                         }
 112                 }
 113
 114                 // Tell the server we're communicating with it in UTF-8.
 115                 // This may engage various charset conversions.
 116                 if ( $wgDBmysql5 ) {
 117                         $this->mysqlSetCharset( 'utf8' );
 118                 } else {
 119                         $this->mysqlSetCharset( 'binary' );
 120                 }
 121                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 122                 if ( is_string( $wgSQLMode ) ) {
 123                         $mode = $this->addQuotes( $wgSQLMode );
 124                         $this->query( "SET sql_mode = $mode", __METHOD__ );
 125                 }
 126
 127                 $this->mOpened = true;
 128                 wfProfileOut( __METHOD__ );
 129                 return true;
 130         }
 131
 132         /**
 133          * Open a connection to a MySQL server
 134          *
 135          * @param $realServer string
 136          * @return mixed Raw connection
 137          * @throws DBConnectionError
 138          */
 139         abstract protected function mysqlConnect( $realServer );
 140
 141         /**
 142          * Set the character set of the MySQL link
 143          *
 144          * @param string $charset
 145          * @return bool
 146          */
 147         abstract protected function mysqlSetCharset( $charset );
 148
 149         /**
 150          * @param $res ResultWrapper
 151          * @throws DBUnexpectedError
 152          */
 153         function freeResult( $res ) {
 154                 if ( $res instanceof ResultWrapper ) {
 155                         $res = $res->result;
 156                 }
 157                 wfSuppressWarnings();
 158                 $ok = $this->mysqlFreeResult( $res );
 159                 wfRestoreWarnings();
 160                 if ( !$ok ) {
 161                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 162                 }
 163         }
 164
 165         /**
 166          * Free result memory
 167          *
 168          * @param $res Raw result
 169          * @return bool
 170          */
 171         abstract protected function mysqlFreeResult( $res );
 172
 173         /**
 174          * @param $res ResultWrapper
 175          * @return object|bool
 176          * @throws DBUnexpectedError
 177          */
 178         function fetchObject( $res ) {
 179                 if ( $res instanceof ResultWrapper ) {
 180                         $res = $res->result;
 181                 }
 182                 wfSuppressWarnings();
 183                 $row = $this->mysqlFetchObject( $res );
 184                 wfRestoreWarnings();
 185
 186                 $errno = $this->lastErrno();
 187                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 188                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 189                 // these are the only errors mysql_fetch_object can cause.
 190                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 191                 if ( $errno == 2000 || $errno == 2013 ) {
 192                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 193                 }
 194                 return $row;
 195         }
 196
 197         /**
 198          * Fetch a result row as an object
 199          *
 200          * @param $res Raw result
 201          * @return stdClass
 202          */
 203         abstract protected function mysqlFetchObject( $res );
 204
 205         /**
 206          * @param $res ResultWrapper
 207          * @return array|bool
 208          * @throws DBUnexpectedError
 209          */
 210         function fetchRow( $res ) {
 211                 if ( $res instanceof ResultWrapper ) {
 212                         $res = $res->result;
 213                 }
 214                 wfSuppressWarnings();
 215                 $row = $this->mysqlFetchArray( $res );
 216                 wfRestoreWarnings();
 217
 218                 $errno = $this->lastErrno();
 219                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 220                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 221                 // these are the only errors mysql_fetch_array can cause.
 222                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 223                 if ( $errno == 2000 || $errno == 2013 ) {
 224                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 225                 }
 226                 return $row;
 227         }
 228
 229         /**
 230          * Fetch a result row as an associative and numeric array
 231          *
 232          * @param $res Raw result
 233          * @return array
 234          */
 235         abstract protected function mysqlFetchArray( $res );
 236
 237         /**
 238          * @throws DBUnexpectedError
 239          * @param $res ResultWrapper
 240          * @return int
 241          */
 242         function numRows( $res ) {
 243                 if ( $res instanceof ResultWrapper ) {
 244                         $res = $res->result;
 245                 }
 246                 wfSuppressWarnings();
 247                 $n = $this->mysqlNumRows( $res );
 248                 wfRestoreWarnings();
 249                 // Unfortunately, mysql_num_rows does not reset the last errno.
 250                 // We are not checking for any errors here, since
 251                 // these are no errors mysql_num_rows can cause.
 252                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 253                 // See https://bugzilla.wikimedia.org/42430
 254                 return $n;
 255         }
 256
 257         /**
 258          * Get number of rows in result
 259          *
 260          * @param $res Raw result
 261          * @return int
 262          */
 263         abstract protected function mysqlNumRows( $res );
 264
 265         /**
 266          * @param $res ResultWrapper
 267          * @return int
 268          */
 269         function numFields( $res ) {
 270                 if ( $res instanceof ResultWrapper ) {
 271                         $res = $res->result;
 272                 }
 273                 return $this->mysqlNumFields( $res );
 274         }
 275
 276         /**
 277          * Get number of fields in result
 278          *
 279          * @param $res Raw result
 280          * @return int
 281          */
 282         abstract protected function mysqlNumFields( $res );
 283
 284         /**
 285          * @param $res ResultWrapper
 286          * @param $n string
 287          * @return string
 288          */
 289         function fieldName( $res, $n ) {
 290                 if ( $res instanceof ResultWrapper ) {
 291                         $res = $res->result;
 292                 }
 293                 return $this->mysqlFieldName( $res, $n );
 294         }
 295
 296         /**
 297          * Get the name of the specified field in a result
 298          *
 299          * @param $res Raw result
 300          * @param $n int
 301          * @return string
 302          */
 303         abstract protected function mysqlFieldName( $res, $n );
 304
 305         /**
 306          * @param $res ResultWrapper
 307          * @param $row
 308          * @return bool
 309          */
 310         function dataSeek( $res, $row ) {
 311                 if ( $res instanceof ResultWrapper ) {
 312                         $res = $res->result;
 313                 }
 314                 return $this->mysqlDataSeek( $res, $row );
 315         }
 316
 317         /**
 318          * Move internal result pointer
 319          *
 320          * @param $res Raw result
 321          * @param $row int
 322          * @return bool
 323          */
 324         abstract protected function mysqlDataSeek( $res, $row );
 325
 326         /**
 327          * @return string
 328          */
 329         function lastError() {
 330                 if ( $this->mConn ) {
 331                         # Even if it's non-zero, it can still be invalid
 332                         wfSuppressWarnings();
 333                         $error = $this->mysqlError( $this->mConn );
 334                         if ( !$error ) {
 335                                 $error = $this->mysqlError();
 336                         }
 337                         wfRestoreWarnings();
 338                 } else {
 339                         $error = $this->mysqlError();
 340                 }
 341                 if ( $error ) {
 342                         $error .= ' (' . $this->mServer . ')';
 343                 }
 344                 return $error;
 345         }
 346
 347         /**
 348          * Returns the text of the error message from previous MySQL operation
 349          *
 350          * @param $conn Raw connection
 351          * @return string
 352          */
 353         abstract protected function mysqlError( $conn = null );
 354
 355         /**
 356          * @param $table string
 357          * @param $uniqueIndexes
 358          * @param $rows array
 359          * @param $fname string
 360          * @return ResultWrapper
 361          */
 362         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 363                 return $this->nativeReplace( $table, $rows, $fname );
 364         }
 365
 366         /**
 367          * Estimate rows in dataset
 368          * Returns estimated count, based on EXPLAIN output
 369          * Takes same arguments as Database::select()
 370          *
 371          * @param $table string|array
 372          * @param $vars string|array
 373          * @param $conds string|array
 374          * @param $fname string
 375          * @param $options string|array
 376          * @return int
 377          */
 378         public function estimateRowCount( $table, $vars = '*', $conds = '', $fname = __METHOD__, $options = array() ) {
 379                 $options['EXPLAIN'] = true;
 380                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 381                 if ( $res === false ) {
 382                         return false;
 383                 }
 384                 if ( !$this->numRows( $res ) ) {
 385                         return 0;
 386                 }
 387
 388                 $rows = 1;
 389                 foreach ( $res as $plan ) {
 390                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 391                 }
 392                 return $rows;
 393         }
 394
 395         /**
 396          * @param $table string
 397          * @param $field string
 398          * @return bool|MySQLField
 399          */
 400         function fieldInfo( $table, $field ) {
 401                 $table = $this->tableName( $table );
 402                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 403                 if ( !$res ) {
 404                         return false;
 405                 }
 406                 $n = $this->mysqlNumFields( $res->result );
 407                 for ( $i = 0; $i < $n; $i++ ) {
 408                         $meta = $this->mysqlFetchField( $res->result, $i );
 409                         if ( $field == $meta->name ) {
 410                                 return new MySQLField( $meta );
 411                         }
 412                 }
 413                 return false;
 414         }
 415
 416         /**
 417          * Get column information from a result
 418          *
 419          * @param $res Raw result
 420          * @param $n int
 421          * @return stdClass
 422          */
 423         abstract protected function mysqlFetchField( $res, $n );
 424
 425         /**
 426          * Get information about an index into an object
 427          * Returns false if the index does not exist
 428          *
 429          * @param $table string
 430          * @param $index string
 431          * @param $fname string
 432          * @return bool|array|null False or null on failure
 433          */
 434         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 435                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 436                 # SHOW INDEX should work for 3.x and up:
 437                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 438                 $table = $this->tableName( $table );
 439                 $index = $this->indexName( $index );
 440
 441                 $sql = 'SHOW INDEX FROM ' . $table;
 442                 $res = $this->query( $sql, $fname );
 443
 444                 if ( !$res ) {
 445                         return null;
 446                 }
 447
 448                 $result = array();
 449
 450                 foreach ( $res as $row ) {
 451                         if ( $row->Key_name == $index ) {
 452                                 $result[] = $row;
 453                         }
 454                 }
 455                 return empty( $result ) ? false : $result;
 456         }
 457
 458         /**
 459          * @param $s string
 460          *
 461          * @return string
 462          */
 463         function strencode( $s ) {
 464                 $sQuoted = $this->mysqlRealEscapeString( $s );
 465
 466                 if ( $sQuoted === false ) {
 467                         $this->ping();
 468                         $sQuoted = $this->mysqlRealEscapeString( $s );
 469                 }
 470                 return $sQuoted;
 471         }
 472
 473         /**
 474          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 475          *
 476          * @param $s string
 477          *
 478          * @return string
 479          */
 480         public function addIdentifierQuotes( $s ) {
 481                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 482                 // Remove NUL bytes and escape backticks by doubling
 483                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s )  . '`';
 484         }
 485
 486         /**
 487          * @param $name string
 488          * @return bool
 489          */
 490         public function isQuotedIdentifier( $name ) {
 491                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 492         }
 493
 494         /**
 495          * @return bool
 496          */
 497         function ping() {
 498                 $ping = $this->mysqlPing();
 499                 if ( $ping ) {
 500                         return true;
 501                 }
 502
 503                 $this->closeConnection();
 504                 $this->mOpened = false;
 505                 $this->mConn = false;
 506                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 507                 return true;
 508         }
 509
 510         /**
 511          * Ping a server connection or reconnect if there is no connection
 512          *
 513          * @return bool
 514          */
 515         abstract protected function mysqlPing();
 516
 517         /**
 518          * Returns slave lag.
 519          *
 520          * This will do a SHOW SLAVE STATUS
 521          *
 522          * @return int
 523          */
 524         function getLag() {
 525                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 526                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 527                         return $this->mFakeSlaveLag;
 528                 }
 529
 530                 return $this->getLagFromSlaveStatus();
 531         }
 532
 533         /**
 534          * @return bool|int
 535          */
 536         function getLagFromSlaveStatus() {
 537                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 538                 if ( !$res ) {
 539                         return false;
 540                 }
 541                 $row = $res->fetchObject();
 542                 if ( !$row ) {
 543                         return false;
 544                 }
 545                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 546                         return false;
 547                 } else {
 548                         return intval( $row->Seconds_Behind_Master );
 549                 }
 550         }
 551
 552         /**
 553          * @deprecated in 1.19, use getLagFromSlaveStatus
 554          *
 555          * @return bool|int
 556          */
 557         function getLagFromProcesslist() {
 558                 wfDeprecated( __METHOD__, '1.19' );
 559                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 560                 if ( !$res ) {
 561                         return false;
 562                 }
 563                 # Find slave SQL thread
 564                 foreach ( $res as $row ) {
 565                         /* This should work for most situations - when default db
 566                          * for thread is not specified, it had no events executed,
 567                          * and therefore it doesn't know yet how lagged it is.
 568                          *
 569                          * Relay log I/O thread does not select databases.
 570                          */
 571                         if ( $row->User == 'system user' &&
 572                                 $row->State != 'Waiting for master to send event' &&
 573                                 $row->State != 'Connecting to master' &&
 574                                 $row->State != 'Queueing master event to the relay log' &&
 575                                 $row->State != 'Waiting for master update' &&
 576                                 $row->State != 'Requesting binlog dump' &&
 577                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 578                                 $row->State != 'Reconnecting after a failed master event read' &&
 579                                 $row->State != 'Registering slave on master'
 580                                 ) {
 581                                 # This is it, return the time (except -ve)
 582                                 if ( $row->Time > 0x7fffffff ) {
 583                                         return false;
 584                                 } else {
 585                                         return $row->Time;
 586                                 }
 587                         }
 588                 }
 589                 return false;
 590         }
 591
 592         /**
 593          * Wait for the slave to catch up to a given master position.
 594          * @TODO: return values for this and base class are rubbish
 595          *
 596          * @param $pos DBMasterPos object
 597          * @param $timeout Integer: the maximum number of seconds to wait for synchronisation
 598          * @return bool|string
 599          */
 600         function masterPosWait( DBMasterPos $pos, $timeout ) {
 601                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 602                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 603                 }
 604
 605                 wfProfileIn( __METHOD__ );
 606                 # Commit any open transactions
 607                 $this->commit( __METHOD__, 'flush' );
 608
 609                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 610                         $status = parent::masterPosWait( $pos, $timeout );
 611                         wfProfileOut( __METHOD__ );
 612                         return $status;
 613                 }
 614
 615                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 616                 $encFile = $this->addQuotes( $pos->file );
 617                 $encPos = intval( $pos->pos );
 618                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 619                 $res = $this->doQuery( $sql );
 620
 621                 $status = false;
 622                 if ( $res && $row = $this->fetchRow( $res ) ) {
 623                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 624                         if ( ctype_digit( $status ) ) { // success
 625                                 $this->lastKnownSlavePos = $pos;
 626                         }
 627                 }
 628
 629                 wfProfileOut( __METHOD__ );
 630                 return $status;
 631         }
 632
 633         /**
 634          * Get the position of the master from SHOW SLAVE STATUS
 635          *
 636          * @return MySQLMasterPos|bool
 637          */
 638         function getSlavePos() {
 639                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 640                         return parent::getSlavePos();
 641                 }
 642
 643                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 644                 $row = $this->fetchObject( $res );
 645
 646                 if ( $row ) {
 647                         $pos = isset( $row->Exec_master_log_pos ) ? $row->Exec_master_log_pos : $row->Exec_Master_Log_Pos;
 648                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 649                 } else {
 650                         return false;
 651                 }
 652         }
 653
 654         /**
 655          * Get the position of the master from SHOW MASTER STATUS
 656          *
 657          * @return MySQLMasterPos|bool
 658          */
 659         function getMasterPos() {
 660                 if ( $this->mFakeMaster ) {
 661                         return parent::getMasterPos();
 662                 }
 663
 664                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 665                 $row = $this->fetchObject( $res );
 666
 667                 if ( $row ) {
 668                         return new MySQLMasterPos( $row->File, $row->Position );
 669                 } else {
 670                         return false;
 671                 }
 672         }
 673
 674         /**
 675          * @param $index
 676          * @return string
 677          */
 678         function useIndexClause( $index ) {
 679                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 680         }
 681
 682         /**
 683          * @return string
 684          */
 685         function lowPriorityOption() {
 686                 return 'LOW_PRIORITY';
 687         }
 688
 689         /**
 690          * @return string
 691          */
 692         public function getSoftwareLink() {
 693                 return '[http://www.mysql.com/ MySQL]';
 694         }
 695
 696         /**
 697          * @param $options array
 698          */
 699         public function setSessionOptions( array $options ) {
 700                 if ( isset( $options['connTimeout'] ) ) {
 701                         $timeout = (int)$options['connTimeout'];
 702                         $this->query( "SET net_read_timeout=$timeout" );
 703                         $this->query( "SET net_write_timeout=$timeout" );
 704                 }
 705         }
 706
 707         public function streamStatementEnd( &$sql, &$newLine ) {
 708                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 709                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 710                         $this->delimiter = $m[1];
 711                         $newLine = '';
 712                 }
 713                 return parent::streamStatementEnd( $sql, $newLine );
 714         }
 715
 716         /**
 717          * Check to see if a named lock is available. This is non-blocking.
 718          *
 719          * @param string $lockName name of lock to poll
 720          * @param string $method name of method calling us
 721          * @return Boolean
 722          * @since 1.20
 723          */
 724         public function lockIsFree( $lockName, $method ) {
 725                 $lockName = $this->addQuotes( $lockName );
 726                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 727                 $row = $this->fetchObject( $result );
 728                 return ( $row->lockstatus == 1 );
 729         }
 730
 731         /**
 732          * @param $lockName string
 733          * @param $method string
 734          * @param $timeout int
 735          * @return bool
 736          */
 737         public function lock( $lockName, $method, $timeout = 5 ) {
 738                 $lockName = $this->addQuotes( $lockName );
 739                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 740                 $row = $this->fetchObject( $result );
 741
 742                 if ( $row->lockstatus == 1 ) {
 743                         return true;
 744                 } else {
 745                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 746                         return false;
 747                 }
 748         }
 749
 750         /**
 751          * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 752          * @param $lockName string
 753          * @param $method string
 754          * @return bool
 755          */
 756         public function unlock( $lockName, $method ) {
 757                 $lockName = $this->addQuotes( $lockName );
 758                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 759                 $row = $this->fetchObject( $result );
 760                 return ( $row->lockstatus == 1 );
 761         }
 762
 763         /**
 764          * @param $read array
 765          * @param $write array
 766          * @param $method string
 767          * @param $lowPriority bool
 768          * @return bool
 769          */
 770         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 771                 $items = array();
 772
 773                 foreach ( $write as $table ) {
 774                         $tbl = $this->tableName( $table ) .
 775                                         ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 776                                         ' WRITE';
 777                         $items[] = $tbl;
 778                 }
 779                 foreach ( $read as $table ) {
 780                         $items[] = $this->tableName( $table ) . ' READ';
 781                 }
 782                 $sql = "LOCK TABLES " . implode( ',', $items );
 783                 $this->query( $sql, $method );
 784                 return true;
 785         }
 786
 787         /**
 788          * @param $method string
 789          * @return bool
 790          */
 791         public function unlockTables( $method ) {
 792                 $this->query( "UNLOCK TABLES", $method );
 793                 return true;
 794         }
 795
 796         /**
 797          * Get search engine class. All subclasses of this
 798          * need to implement this if they wish to use searching.
 799          *
 800          * @return String
 801          */
 802         public function getSearchEngine() {
 803                 return 'SearchMySQL';
 804         }
 805
 806         /**
 807          * @param bool $value
 808          * @return mixed
 809          */
 810         public function setBigSelects( $value = true ) {
 811                 if ( $value === 'default' ) {
 812                         if ( $this->mDefaultBigSelects === null ) {
 813                                 # Function hasn't been called before so it must already be set to the default
 814                                 return;
 815                         } else {
 816                                 $value = $this->mDefaultBigSelects;
 817                         }
 818                 } elseif ( $this->mDefaultBigSelects === null ) {
 819                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 820                 }
 821                 $encValue = $value ? '1' : '0';
 822                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 823         }
 824
 825         /**
 826          * DELETE where the condition is a join. MySql uses multi-table deletes.
 827          * @param $delTable string
 828          * @param $joinTable string
 829          * @param $delVar string
 830          * @param $joinVar string
 831          * @param $conds array|string
 832          * @param bool|string $fname bool
 833          * @throws DBUnexpectedError
 834          * @return bool|ResultWrapper
 835          */
 836         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 837                 if ( !$conds ) {
 838                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 839                 }
 840
 841                 $delTable = $this->tableName( $delTable );
 842                 $joinTable = $this->tableName( $joinTable );
 843                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 844
 845                 if ( $conds != '*' ) {
 846                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 847                 }
 848
 849                 return $this->query( $sql, $fname );
 850         }
 851
 852         /**
 853          * @param string $table
 854          * @param array $rows
 855          * @param array $uniqueIndexes
 856          * @param array $set
 857          * @param string $fname
 858          * @param array $options
 859          * @return bool
 860          */
 861         public function upsert(
 862                 $table, array $rows, array $uniqueIndexes, array $set, $fname = __METHOD__
 863         ) {
 864                 if ( !count( $rows ) ) {
 865                         return true; // nothing to do
 866                 }
 867                 $rows = is_array( reset( $rows ) ) ? $rows : array( $rows );
 868
 869                 $table = $this->tableName( $table );
 870                 $columns = array_keys( $rows[0] );
 871
 872                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
 873                 $rowTuples = array();
 874                 foreach ( $rows as $row ) {
 875                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
 876                 }
 877                 $sql .= implode( ',', $rowTuples );
 878                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
 879
 880                 return (bool)$this->query( $sql, $fname );
 881         }
 882
 883         /**
 884          * Determines how long the server has been up
 885          *
 886          * @return int
 887          */
 888         function getServerUptime() {
 889                 $vars = $this->getMysqlStatus( 'Uptime' );
 890                 return (int)$vars['Uptime'];
 891         }
 892
 893         /**
 894          * Determines if the last failure was due to a deadlock
 895          *
 896          * @return bool
 897          */
 898         function wasDeadlock() {
 899                 return $this->lastErrno() == 1213;
 900         }
 901
 902         /**
 903          * Determines if the last failure was due to a lock timeout
 904          *
 905          * @return bool
 906          */
 907         function wasLockTimeout() {
 908                 return $this->lastErrno() == 1205;
 909         }
 910
 911         /**
 912          * Determines if the last query error was something that should be dealt
 913          * with by pinging the connection and reissuing the query
 914          *
 915          * @return bool
 916          */
 917         function wasErrorReissuable() {
 918                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
 919         }
 920
 921         /**
 922          * Determines if the last failure was due to the database being read-only.
 923          *
 924          * @return bool
 925          */
 926         function wasReadOnlyError() {
 927                 return $this->lastErrno() == 1223 ||
 928                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
 929         }
 930
 931         /**
 932          * @param $oldName
 933          * @param $newName
 934          * @param $temporary bool
 935          * @param $fname string
 936          */
 937         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 938                 $tmp = $temporary ? 'TEMPORARY ' : '';
 939                 $newName = $this->addIdentifierQuotes( $newName );
 940                 $oldName = $this->addIdentifierQuotes( $oldName );
 941                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
 942                 $this->query( $query, $fname );
 943         }
 944
 945         /**
 946          * List all tables on the database
 947          *
 948          * @param string $prefix Only show tables with this prefix, e.g. mw_
 949          * @param string $fname calling function name
 950          * @return array
 951          */
 952         function listTables( $prefix = null, $fname = __METHOD__ ) {
 953                 $result = $this->query( "SHOW TABLES", $fname );
 954
 955                 $endArray = array();
 956
 957                 foreach ( $result as $table ) {
 958                         $vars = get_object_vars( $table );
 959                         $table = array_pop( $vars );
 960
 961                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
 962                                 $endArray[] = $table;
 963                         }
 964                 }
 965
 966                 return $endArray;
 967         }
 968
 969         /**
 970          * @param $tableName
 971          * @param $fName string
 972          * @return bool|ResultWrapper
 973          */
 974         public function dropTable( $tableName, $fName = __METHOD__ ) {
 975                 if ( !$this->tableExists( $tableName, $fName ) ) {
 976                         return false;
 977                 }
 978                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
 979         }
 980
 981         /**
 982          * @return array
 983          */
 984         protected function getDefaultSchemaVars() {
 985                 $vars = parent::getDefaultSchemaVars();
 986                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
 987                 $vars['wgDBTableOptions'] = str_replace( 'CHARSET=mysql4', 'CHARSET=binary', $vars['wgDBTableOptions'] );
 988                 return $vars;
 989         }
 990
 991         /**
 992          * Get status information from SHOW STATUS in an associative array
 993          *
 994          * @param $which string
 995          * @return array
 996          */
 997         function getMysqlStatus( $which = "%" ) {
 998                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
 999                 $status = array();
1000
1001                 foreach ( $res as $row ) {
1002                         $status[$row->Variable_name] = $row->Value;
1003                 }
1004
1005                 return $status;
1006         }
1007
1008         /**
1009          * Lists VIEWs in the database
1010          *
1011          * @param string $prefix   Only show VIEWs with this prefix, eg.
1012          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1013          * @param string $fname    Name of calling function
1014          * @return array
1015          * @since 1.22
1016          */
1017         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1018
1019                 if ( !isset( $this->allViews ) ) {
1020
1021                         // The name of the column containing the name of the VIEW
1022                         $propertyName = 'Tables_in_' . $this->mDBname;
1023
1024                         // Query for the VIEWS
1025                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1026                         $this->allViews = array();
1027                         while ( ($row = $this->fetchRow($result)) !== false ) {
1028                                 array_push( $this->allViews, $row[$propertyName] );
1029                         }
1030                 }
1031
1032                 if ( is_null($prefix) || $prefix === '' ) {
1033                         return $this->allViews;
1034                 }
1035
1036                 $filteredViews = array();
1037                 foreach ( $this->allViews as $viewName ) {
1038                         // Does the name of this VIEW start with the table-prefix?
1039                         if ( strpos( $viewName, $prefix ) === 0 ) {
1040                                 array_push( $filteredViews, $viewName );
1041                         }
1042                 }
1043                 return $filteredViews;
1044         }
1045
1046         /**
1047          * Differentiates between a TABLE and a VIEW.
1048          *
1049          * @param $name string: Name of the TABLE/VIEW to test
1050          * @return bool
1051          * @since 1.22
1052          */
1053         public function isView( $name, $prefix = null ) {
1054                 return in_array( $name, $this->listViews( $prefix ) );
1055         }
1056
1057 }
1058
1059
1060
1061 /**
1062  * Utility class.
1063  * @ingroup Database
1064  */
1065 class MySQLField implements Field {
1066         private $name, $tablename, $default, $max_length, $nullable,
1067                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary;
1068
1069         function __construct( $info ) {
1070                 $this->name = $info->name;
1071                 $this->tablename = $info->table;
1072                 $this->default = $info->def;
1073                 $this->max_length = $info->max_length;
1074                 $this->nullable = !$info->not_null;
1075                 $this->is_pk = $info->primary_key;
1076                 $this->is_unique = $info->unique_key;
1077                 $this->is_multiple = $info->multiple_key;
1078                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1079                 $this->type = $info->type;
1080                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1081         }
1082
1083         /**
1084          * @return string
1085          */
1086         function name() {
1087                 return $this->name;
1088         }
1089
1090         /**
1091          * @return string
1092          */
1093         function tableName() {
1094                 return $this->tableName;
1095         }
1096
1097         /**
1098          * @return string
1099          */
1100         function type() {
1101                 return $this->type;
1102         }
1103
1104         /**
1105          * @return bool
1106          */
1107         function isNullable() {
1108                 return $this->nullable;
1109         }
1110
1111         function defaultValue() {
1112                 return $this->default;
1113         }
1114
1115         /**
1116          * @return bool
1117          */
1118         function isKey() {
1119                 return $this->is_key;
1120         }
1121
1122         /**
1123          * @return bool
1124          */
1125         function isMultipleKey() {
1126                 return $this->is_multiple;
1127         }
1128
1129         function isBinary() {
1130                 return $this->binary;
1131         }
1132 }
1133
1134 class MySQLMasterPos implements DBMasterPos {
1135         var $file, $pos;
1136
1137         function __construct( $file, $pos ) {
1138                 $this->file = $file;
1139                 $this->pos = $pos;
1140         }
1141
1142         function __toString() {
1143                 // e.g db1034-bin.000976/843431247
1144                 return "{$this->file}/{$this->pos}";
1145         }
1146
1147         /**
1148          * @return array|false (int, int)
1149          */
1150         protected function getCoordinates() {
1151                 $m = array();
1152                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1153                         return array( (int)$m[1], (int)$m[2] );
1154                 }
1155                 return false;
1156         }
1157
1158         function hasReached( MySQLMasterPos $pos ) {
1159                 $thisPos = $this->getCoordinates();
1160                 $thatPos = $pos->getCoordinates();
1161                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1162         }
1163 }