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                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 473                 // Remove NUL bytes and escape backticks by doubling
 474                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s )  . '`';
 475         }
 476
 477         /**
 478          * @param $name string
 479          * @return bool
 480          */
 481         public function isQuotedIdentifier( $name ) {
 482                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 483         }
 484
 485         /**
 486          * @return bool
 487          */
 488         function ping() {
 489                 $ping = $this->mysqlPing();
 490                 if ( $ping ) {
 491                         return true;
 492                 }
 493
 494                 $this->closeConnection();
 495                 $this->mOpened = false;
 496                 $this->mConn = false;
 497                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 498                 return true;
 499         }
 500
 501         /**
 502          * Ping a server connection or reconnect if there is no connection
 503          *
 504          * @return bool
 505          */
 506         abstract protected function mysqlPing();
 507
 508         /**
 509          * Returns slave lag.
 510          *
 511          * This will do a SHOW SLAVE STATUS
 512          *
 513          * @return int
 514          */
 515         function getLag() {
 516                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 517                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 518                         return $this->mFakeSlaveLag;
 519                 }
 520
 521                 return $this->getLagFromSlaveStatus();
 522         }
 523
 524         /**
 525          * @return bool|int
 526          */
 527         function getLagFromSlaveStatus() {
 528                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 529                 if ( !$res ) {
 530                         return false;
 531                 }
 532                 $row = $res->fetchObject();
 533                 if ( !$row ) {
 534                         return false;
 535                 }
 536                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 537                         return false;
 538                 } else {
 539                         return intval( $row->Seconds_Behind_Master );
 540                 }
 541         }
 542
 543         /**
 544          * @deprecated in 1.19, use getLagFromSlaveStatus
 545          *
 546          * @return bool|int
 547          */
 548         function getLagFromProcesslist() {
 549                 wfDeprecated( __METHOD__, '1.19' );
 550                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 551                 if ( !$res ) {
 552                         return false;
 553                 }
 554                 # Find slave SQL thread
 555                 foreach ( $res as $row ) {
 556                         /* This should work for most situations - when default db
 557                          * for thread is not specified, it had no events executed,
 558                          * and therefore it doesn't know yet how lagged it is.
 559                          *
 560                          * Relay log I/O thread does not select databases.
 561                          */
 562                         if ( $row->User == 'system user' &&
 563                                 $row->State != 'Waiting for master to send event' &&
 564                                 $row->State != 'Connecting to master' &&
 565                                 $row->State != 'Queueing master event to the relay log' &&
 566                                 $row->State != 'Waiting for master update' &&
 567                                 $row->State != 'Requesting binlog dump' &&
 568                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 569                                 $row->State != 'Reconnecting after a failed master event read' &&
 570                                 $row->State != 'Registering slave on master'
 571                                 ) {
 572                                 # This is it, return the time (except -ve)
 573                                 if ( $row->Time > 0x7fffffff ) {
 574                                         return false;
 575                                 } else {
 576                                         return $row->Time;
 577                                 }
 578                         }
 579                 }
 580                 return false;
 581         }
 582
 583         /**
 584          * Wait for the slave to catch up to a given master position.
 585          * @TODO: return values for this and base class are rubbish
 586          *
 587          * @param $pos DBMasterPos object
 588          * @param $timeout Integer: the maximum number of seconds to wait for synchronisation
 589          * @return bool|string
 590          */
 591         function masterPosWait( DBMasterPos $pos, $timeout ) {
 592                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 593                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 594                 }
 595
 596                 wfProfileIn( __METHOD__ );
 597                 # Commit any open transactions
 598                 $this->commit( __METHOD__, 'flush' );
 599
 600                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 601                         $status = parent::masterPosWait( $pos, $timeout );
 602                         wfProfileOut( __METHOD__ );
 603                         return $status;
 604                 }
 605
 606                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 607                 $encFile = $this->addQuotes( $pos->file );
 608                 $encPos = intval( $pos->pos );
 609                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 610                 $res = $this->doQuery( $sql );
 611
 612                 $status = false;
 613                 if ( $res && $row = $this->fetchRow( $res ) ) {
 614                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 615                         if ( ctype_digit( $status ) ) { // success
 616                                 $this->lastKnownSlavePos = $pos;
 617                         }
 618                 }
 619
 620                 wfProfileOut( __METHOD__ );
 621                 return $status;
 622         }
 623
 624         /**
 625          * Get the position of the master from SHOW SLAVE STATUS
 626          *
 627          * @return MySQLMasterPos|bool
 628          */
 629         function getSlavePos() {
 630                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 631                         return parent::getSlavePos();
 632                 }
 633
 634                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 635                 $row = $this->fetchObject( $res );
 636
 637                 if ( $row ) {
 638                         $pos = isset( $row->Exec_master_log_pos ) ? $row->Exec_master_log_pos : $row->Exec_Master_Log_Pos;
 639                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 640                 } else {
 641                         return false;
 642                 }
 643         }
 644
 645         /**
 646          * Get the position of the master from SHOW MASTER STATUS
 647          *
 648          * @return MySQLMasterPos|bool
 649          */
 650         function getMasterPos() {
 651                 if ( $this->mFakeMaster ) {
 652                         return parent::getMasterPos();
 653                 }
 654
 655                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 656                 $row = $this->fetchObject( $res );
 657
 658                 if ( $row ) {
 659                         return new MySQLMasterPos( $row->File, $row->Position );
 660                 } else {
 661                         return false;
 662                 }
 663         }
 664
 665         /**
 666          * @param $index
 667          * @return string
 668          */
 669         function useIndexClause( $index ) {
 670                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 671         }
 672
 673         /**
 674          * @return string
 675          */
 676         function lowPriorityOption() {
 677                 return 'LOW_PRIORITY';
 678         }
 679
 680         /**
 681          * @return string
 682          */
 683         public function getSoftwareLink() {
 684                 return '[http://www.mysql.com/ MySQL]';
 685         }
 686
 687         /**
 688          * @param $options array
 689          */
 690         public function setSessionOptions( array $options ) {
 691                 if ( isset( $options['connTimeout'] ) ) {
 692                         $timeout = (int)$options['connTimeout'];
 693                         $this->query( "SET net_read_timeout=$timeout" );
 694                         $this->query( "SET net_write_timeout=$timeout" );
 695                 }
 696         }
 697
 698         public function streamStatementEnd( &$sql, &$newLine ) {
 699                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 700                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 701                         $this->delimiter = $m[1];
 702                         $newLine = '';
 703                 }
 704                 return parent::streamStatementEnd( $sql, $newLine );
 705         }
 706
 707         /**
 708          * Check to see if a named lock is available. This is non-blocking.
 709          *
 710          * @param string $lockName name of lock to poll
 711          * @param string $method name of method calling us
 712          * @return Boolean
 713          * @since 1.20
 714          */
 715         public function lockIsFree( $lockName, $method ) {
 716                 $lockName = $this->addQuotes( $lockName );
 717                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 718                 $row = $this->fetchObject( $result );
 719                 return ( $row->lockstatus == 1 );
 720         }
 721
 722         /**
 723          * @param $lockName string
 724          * @param $method string
 725          * @param $timeout int
 726          * @return bool
 727          */
 728         public function lock( $lockName, $method, $timeout = 5 ) {
 729                 $lockName = $this->addQuotes( $lockName );
 730                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 731                 $row = $this->fetchObject( $result );
 732
 733                 if ( $row->lockstatus == 1 ) {
 734                         return true;
 735                 } else {
 736                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 737                         return false;
 738                 }
 739         }
 740
 741         /**
 742          * FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 743          * @param $lockName string
 744          * @param $method string
 745          * @return bool
 746          */
 747         public function unlock( $lockName, $method ) {
 748                 $lockName = $this->addQuotes( $lockName );
 749                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 750                 $row = $this->fetchObject( $result );
 751                 return ( $row->lockstatus == 1 );
 752         }
 753
 754         /**
 755          * @param $read array
 756          * @param $write array
 757          * @param $method string
 758          * @param $lowPriority bool
 759          * @return bool
 760          */
 761         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 762                 $items = array();
 763
 764                 foreach ( $write as $table ) {
 765                         $tbl = $this->tableName( $table ) .
 766                                         ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 767                                         ' WRITE';
 768                         $items[] = $tbl;
 769                 }
 770                 foreach ( $read as $table ) {
 771                         $items[] = $this->tableName( $table ) . ' READ';
 772                 }
 773                 $sql = "LOCK TABLES " . implode( ',', $items );
 774                 $this->query( $sql, $method );
 775                 return true;
 776         }
 777
 778         /**
 779          * @param $method string
 780          * @return bool
 781          */
 782         public function unlockTables( $method ) {
 783                 $this->query( "UNLOCK TABLES", $method );
 784                 return true;
 785         }
 786
 787         /**
 788          * Get search engine class. All subclasses of this
 789          * need to implement this if they wish to use searching.
 790          *
 791          * @return String
 792          */
 793         public function getSearchEngine() {
 794                 return 'SearchMySQL';
 795         }
 796
 797         /**
 798          * @param bool $value
 799          * @return mixed
 800          */
 801         public function setBigSelects( $value = true ) {
 802                 if ( $value === 'default' ) {
 803                         if ( $this->mDefaultBigSelects === null ) {
 804                                 # Function hasn't been called before so it must already be set to the default
 805                                 return;
 806                         } else {
 807                                 $value = $this->mDefaultBigSelects;
 808                         }
 809                 } elseif ( $this->mDefaultBigSelects === null ) {
 810                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 811                 }
 812                 $encValue = $value ? '1' : '0';
 813                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 814         }
 815
 816         /**
 817          * DELETE where the condition is a join. MySql uses multi-table deletes.
 818          * @param $delTable string
 819          * @param $joinTable string
 820          * @param $delVar string
 821          * @param $joinVar string
 822          * @param $conds array|string
 823          * @param bool|string $fname bool
 824          * @throws DBUnexpectedError
 825          * @return bool|ResultWrapper
 826          */
 827         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 828                 if ( !$conds ) {
 829                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 830                 }
 831
 832                 $delTable = $this->tableName( $delTable );
 833                 $joinTable = $this->tableName( $joinTable );
 834                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 835
 836                 if ( $conds != '*' ) {
 837                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 838                 }
 839
 840                 return $this->query( $sql, $fname );
 841         }
 842
 843         /**
 844          * @param string $table
 845          * @param array $rows
 846          * @param array $uniqueIndexes
 847          * @param array $set
 848          * @param string $fname
 849          * @param array $options
 850          * @return bool
 851          */
 852         public function upsert(
 853                 $table, array $rows, array $uniqueIndexes, array $set, $fname = __METHOD__
 854         ) {
 855                 if ( !count( $rows ) ) {
 856                         return true; // nothing to do
 857                 }
 858                 $rows = is_array( reset( $rows ) ) ? $rows : array( $rows );
 859
 860                 $table = $this->tableName( $table );
 861                 $columns = array_keys( $rows[0] );
 862
 863                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
 864                 $rowTuples = array();
 865                 foreach ( $rows as $row ) {
 866                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
 867                 }
 868                 $sql .= implode( ',', $rowTuples );
 869                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
 870
 871                 return (bool)$this->query( $sql, $fname );
 872         }
 873
 874         /**
 875          * Determines how long the server has been up
 876          *
 877          * @return int
 878          */
 879         function getServerUptime() {
 880                 $vars = $this->getMysqlStatus( 'Uptime' );
 881                 return (int)$vars['Uptime'];
 882         }
 883
 884         /**
 885          * Determines if the last failure was due to a deadlock
 886          *
 887          * @return bool
 888          */
 889         function wasDeadlock() {
 890                 return $this->lastErrno() == 1213;
 891         }
 892
 893         /**
 894          * Determines if the last failure was due to a lock timeout
 895          *
 896          * @return bool
 897          */
 898         function wasLockTimeout() {
 899                 return $this->lastErrno() == 1205;
 900         }
 901
 902         /**
 903          * Determines if the last query error was something that should be dealt
 904          * with by pinging the connection and reissuing the query
 905          *
 906          * @return bool
 907          */
 908         function wasErrorReissuable() {
 909                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
 910         }
 911
 912         /**
 913          * Determines if the last failure was due to the database being read-only.
 914          *
 915          * @return bool
 916          */
 917         function wasReadOnlyError() {
 918                 return $this->lastErrno() == 1223 ||
 919                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
 920         }
 921
 922         /**
 923          * @param $oldName
 924          * @param $newName
 925          * @param $temporary bool
 926          * @param $fname string
 927          */
 928         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
 929                 $tmp = $temporary ? 'TEMPORARY ' : '';
 930                 $newName = $this->addIdentifierQuotes( $newName );
 931                 $oldName = $this->addIdentifierQuotes( $oldName );
 932                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
 933                 $this->query( $query, $fname );
 934         }
 935
 936         /**
 937          * List all tables on the database
 938          *
 939          * @param string $prefix Only show tables with this prefix, e.g. mw_
 940          * @param string $fname calling function name
 941          * @return array
 942          */
 943         function listTables( $prefix = null, $fname = __METHOD__ ) {
 944                 $result = $this->query( "SHOW TABLES", $fname );
 945
 946                 $endArray = array();
 947
 948                 foreach ( $result as $table ) {
 949                         $vars = get_object_vars( $table );
 950                         $table = array_pop( $vars );
 951
 952                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
 953                                 $endArray[] = $table;
 954                         }
 955                 }
 956
 957                 return $endArray;
 958         }
 959
 960         /**
 961          * @param $tableName
 962          * @param $fName string
 963          * @return bool|ResultWrapper
 964          */
 965         public function dropTable( $tableName, $fName = __METHOD__ ) {
 966                 if ( !$this->tableExists( $tableName, $fName ) ) {
 967                         return false;
 968                 }
 969                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
 970         }
 971
 972         /**
 973          * @return array
 974          */
 975         protected function getDefaultSchemaVars() {
 976                 $vars = parent::getDefaultSchemaVars();
 977                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
 978                 $vars['wgDBTableOptions'] = str_replace( 'CHARSET=mysql4', 'CHARSET=binary', $vars['wgDBTableOptions'] );
 979                 return $vars;
 980         }
 981
 982         /**
 983          * Get status information from SHOW STATUS in an associative array
 984          *
 985          * @param $which string
 986          * @return array
 987          */
 988         function getMysqlStatus( $which = "%" ) {
 989                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
 990                 $status = array();
 991
 992                 foreach ( $res as $row ) {
 993                         $status[$row->Variable_name] = $row->Value;
 994                 }
 995
 996                 return $status;
 997         }
 998
 999 }
1000
1001
1002
1003 /**
1004  * Utility class.
1005  * @ingroup Database
1006  */
1007 class MySQLField implements Field {
1008         private $name, $tablename, $default, $max_length, $nullable,
1009                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary;
1010
1011         function __construct( $info ) {
1012                 $this->name = $info->name;
1013                 $this->tablename = $info->table;
1014                 $this->default = $info->def;
1015                 $this->max_length = $info->max_length;
1016                 $this->nullable = !$info->not_null;
1017                 $this->is_pk = $info->primary_key;
1018                 $this->is_unique = $info->unique_key;
1019                 $this->is_multiple = $info->multiple_key;
1020                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1021                 $this->type = $info->type;
1022                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1023         }
1024
1025         /**
1026          * @return string
1027          */
1028         function name() {
1029                 return $this->name;
1030         }
1031
1032         /**
1033          * @return string
1034          */
1035         function tableName() {
1036                 return $this->tableName;
1037         }
1038
1039         /**
1040          * @return string
1041          */
1042         function type() {
1043                 return $this->type;
1044         }
1045
1046         /**
1047          * @return bool
1048          */
1049         function isNullable() {
1050                 return $this->nullable;
1051         }
1052
1053         function defaultValue() {
1054                 return $this->default;
1055         }
1056
1057         /**
1058          * @return bool
1059          */
1060         function isKey() {
1061                 return $this->is_key;
1062         }
1063
1064         /**
1065          * @return bool
1066          */
1067         function isMultipleKey() {
1068                 return $this->is_multiple;
1069         }
1070
1071         function isBinary() {
1072                 return $this->binary;
1073         }
1074 }
1075
1076 class MySQLMasterPos implements DBMasterPos {
1077         var $file, $pos;
1078
1079         function __construct( $file, $pos ) {
1080                 $this->file = $file;
1081                 $this->pos = $pos;
1082         }
1083
1084         function __toString() {
1085                 // e.g db1034-bin.000976/843431247
1086                 return "{$this->file}/{$this->pos}";
1087         }
1088
1089         /**
1090          * @return array|false (int, int)
1091          */
1092         protected function getCoordinates() {
1093                 $m = array();
1094                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1095                         return array( (int)$m[1], (int)$m[2] );
1096                 }
1097                 return false;
1098         }
1099
1100         function hasReached( MySQLMasterPos $pos ) {
1101                 $thisPos = $this->getCoordinates();
1102                 $thatPos = $pos->getCoordinates();
1103                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1104         }
1105 }