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