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 string $server
  45          * @param string $user
  46          * @param string $password
  47          * @param string $dbName
  48          * @throws Exception|DBConnectionError
  49          * @return bool
  50          */
  51         function open( $server, $user, $password, $dbName ) {
  52                 global $wgAllDBsAreLocalhost, $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
  98                         $this->reportConnectionError( $error );
  99                 }
 100
 101                 if ( $dbName != '' ) {
 102                         wfSuppressWarnings();
 103                         $success = $this->selectDB( $dbName );
 104                         wfRestoreWarnings();
 105                         if ( !$success ) {
 106                                 wfLogDBError( "Error selecting database $dbName on server {$this->mServer}\n" );
 107                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 108                                         "from client host " . wfHostname() . "\n" );
 109
 110                                 wfProfileOut( __METHOD__ );
 111
 112                                 $this->reportConnectionError( "Error selecting database $dbName" );
 113                         }
 114                 }
 115
 116                 // Tell the server what we're communicating with
 117                 if ( !$this->connectInitCharset() ) {
 118                         $this->reportConnectionError( "Error setting character set" );
 119                 }
 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                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 125                         $success = $this->doQuery( "SET sql_mode = $mode", __METHOD__ );
 126                         if ( !$success ) {
 127                                 wfLogDBError( "Error setting sql_mode to $mode on server {$this->mServer}" );
 128                                 wfProfileOut( __METHOD__ );
 129                                 $this->reportConnectionError( "Error setting sql_mode to $mode" );
 130                         }
 131                 }
 132
 133                 $this->mOpened = true;
 134                 wfProfileOut( __METHOD__ );
 135
 136                 return true;
 137         }
 138
 139         /**
 140          * Set the character set information right after connection
 141          * @return bool
 142          */
 143         protected function connectInitCharset() {
 144                 global $wgDBmysql5;
 145
 146                 if ( $wgDBmysql5 ) {
 147                         // Tell the server we're communicating with it in UTF-8.
 148                         // This may engage various charset conversions.
 149                         return $this->mysqlSetCharset( 'utf8' );
 150                 } else {
 151                         return $this->mysqlSetCharset( 'binary' );
 152                 }
 153         }
 154
 155         /**
 156          * Open a connection to a MySQL server
 157          *
 158          * @param string $realServer
 159          * @return mixed Raw connection
 160          * @throws DBConnectionError
 161          */
 162         abstract protected function mysqlConnect( $realServer );
 163
 164         /**
 165          * Set the character set of the MySQL link
 166          *
 167          * @param string $charset
 168          * @return bool
 169          */
 170         abstract protected function mysqlSetCharset( $charset );
 171
 172         /**
 173          * @param ResultWrapper|resource $res
 174          * @throws DBUnexpectedError
 175          */
 176         function freeResult( $res ) {
 177                 if ( $res instanceof ResultWrapper ) {
 178                         $res = $res->result;
 179                 }
 180                 wfSuppressWarnings();
 181                 $ok = $this->mysqlFreeResult( $res );
 182                 wfRestoreWarnings();
 183                 if ( !$ok ) {
 184                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 185                 }
 186         }
 187
 188         /**
 189          * Free result memory
 190          *
 191          * @param resource $res Raw result
 192          * @return bool
 193          */
 194         abstract protected function mysqlFreeResult( $res );
 195
 196         /**
 197          * @param ResultWrapper|resource $res
 198          * @return stdClass|bool
 199          * @throws DBUnexpectedError
 200          */
 201         function fetchObject( $res ) {
 202                 if ( $res instanceof ResultWrapper ) {
 203                         $res = $res->result;
 204                 }
 205                 wfSuppressWarnings();
 206                 $row = $this->mysqlFetchObject( $res );
 207                 wfRestoreWarnings();
 208
 209                 $errno = $this->lastErrno();
 210                 // Unfortunately, mysql_fetch_object 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_object 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(
 216                                 $this,
 217                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 218                         );
 219                 }
 220
 221                 return $row;
 222         }
 223
 224         /**
 225          * Fetch a result row as an object
 226          *
 227          * @param resource $res Raw result
 228          * @return stdClass
 229          */
 230         abstract protected function mysqlFetchObject( $res );
 231
 232         /**
 233          * @param ResultWrapper|resource $res
 234          * @return array|bool
 235          * @throws DBUnexpectedError
 236          */
 237         function fetchRow( $res ) {
 238                 if ( $res instanceof ResultWrapper ) {
 239                         $res = $res->result;
 240                 }
 241                 wfSuppressWarnings();
 242                 $row = $this->mysqlFetchArray( $res );
 243                 wfRestoreWarnings();
 244
 245                 $errno = $this->lastErrno();
 246                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 247                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 248                 // these are the only errors mysql_fetch_array can cause.
 249                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 250                 if ( $errno == 2000 || $errno == 2013 ) {
 251                         throw new DBUnexpectedError(
 252                                 $this,
 253                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 254                         );
 255                 }
 256
 257                 return $row;
 258         }
 259
 260         /**
 261          * Fetch a result row as an associative and numeric array
 262          *
 263          * @param resource $res Raw result
 264          * @return array
 265          */
 266         abstract protected function mysqlFetchArray( $res );
 267
 268         /**
 269          * @throws DBUnexpectedError
 270          * @param ResultWrapper|resource $res
 271          * @return int
 272          */
 273         function numRows( $res ) {
 274                 if ( $res instanceof ResultWrapper ) {
 275                         $res = $res->result;
 276                 }
 277                 wfSuppressWarnings();
 278                 $n = $this->mysqlNumRows( $res );
 279                 wfRestoreWarnings();
 280
 281                 // Unfortunately, mysql_num_rows does not reset the last errno.
 282                 // We are not checking for any errors here, since
 283                 // these are no errors mysql_num_rows can cause.
 284                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 285                 // See https://bugzilla.wikimedia.org/42430
 286                 return $n;
 287         }
 288
 289         /**
 290          * Get number of rows in result
 291          *
 292          * @param resource $res Raw result
 293          * @return int
 294          */
 295         abstract protected function mysqlNumRows( $res );
 296
 297         /**
 298          * @param ResultWrapper|resource $res
 299          * @return int
 300          */
 301         function numFields( $res ) {
 302                 if ( $res instanceof ResultWrapper ) {
 303                         $res = $res->result;
 304                 }
 305
 306                 return $this->mysqlNumFields( $res );
 307         }
 308
 309         /**
 310          * Get number of fields in result
 311          *
 312          * @param resource $res Raw result
 313          * @return int
 314          */
 315         abstract protected function mysqlNumFields( $res );
 316
 317         /**
 318          * @param ResultWrapper|resource $res
 319          * @param $n int
 320          * @return string
 321          */
 322         function fieldName( $res, $n ) {
 323                 if ( $res instanceof ResultWrapper ) {
 324                         $res = $res->result;
 325                 }
 326
 327                 return $this->mysqlFieldName( $res, $n );
 328         }
 329
 330         /**
 331          * Get the name of the specified field in a result
 332          *
 333          * @param ResultWrapper|resource $res
 334          * @param $n int
 335          * @return string
 336          */
 337         abstract protected function mysqlFieldName( $res, $n );
 338
 339         /**
 340          * mysql_field_type() wrapper
 341          * @param ResultWrapper|resource $res
 342          * @param $n int
 343          * @return string
 344          */
 345         public function fieldType( $res, $n ) {
 346                 if ( $res instanceof ResultWrapper ) {
 347                         $res = $res->result;
 348                 }
 349
 350                 return $this->mysqlFieldType( $res, $n );
 351         }
 352
 353         /**
 354          * Get the type of the specified field in a result
 355          *
 356          * @param ResultWrapper|resource $res
 357          * @param int $n
 358          * @return string
 359          */
 360         abstract protected function mysqlFieldType( $res, $n );
 361
 362         /**
 363          * @param ResultWrapper|resource $res
 364          * @param int $row
 365          * @return bool
 366          */
 367         function dataSeek( $res, $row ) {
 368                 if ( $res instanceof ResultWrapper ) {
 369                         $res = $res->result;
 370                 }
 371
 372                 return $this->mysqlDataSeek( $res, $row );
 373         }
 374
 375         /**
 376          * Move internal result pointer
 377          *
 378          * @param ResultWrapper|resource $res
 379          * @param int $row
 380          * @return bool
 381          */
 382         abstract protected function mysqlDataSeek( $res, $row );
 383
 384         /**
 385          * @return string
 386          */
 387         function lastError() {
 388                 if ( $this->mConn ) {
 389                         # Even if it's non-zero, it can still be invalid
 390                         wfSuppressWarnings();
 391                         $error = $this->mysqlError( $this->mConn );
 392                         if ( !$error ) {
 393                                 $error = $this->mysqlError();
 394                         }
 395                         wfRestoreWarnings();
 396                 } else {
 397                         $error = $this->mysqlError();
 398                 }
 399                 if ( $error ) {
 400                         $error .= ' (' . $this->mServer . ')';
 401                 }
 402
 403                 return $error;
 404         }
 405
 406         /**
 407          * Returns the text of the error message from previous MySQL operation
 408          *
 409          * @param resource $conn Raw connection
 410          * @return string
 411          */
 412         abstract protected function mysqlError( $conn = null );
 413
 414         /**
 415          * @param string $table
 416          * @param array $uniqueIndexes
 417          * @param array $rows
 418          * @param string $fname
 419          * @return ResultWrapper
 420          */
 421         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 422                 return $this->nativeReplace( $table, $rows, $fname );
 423         }
 424
 425         /**
 426          * Estimate rows in dataset
 427          * Returns estimated count, based on EXPLAIN output
 428          * Takes same arguments as Database::select()
 429          *
 430          * @param string|array $table
 431          * @param string|array $vars
 432          * @param string|array $conds
 433          * @param string $fname
 434          * @param string|array $options
 435          * @return bool|int
 436          */
 437         public function estimateRowCount( $table, $vars = '*', $conds = '',
 438                 $fname = __METHOD__, $options = array()
 439         ) {
 440                 $options['EXPLAIN'] = true;
 441                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 442                 if ( $res === false ) {
 443                         return false;
 444                 }
 445                 if ( !$this->numRows( $res ) ) {
 446                         return 0;
 447                 }
 448
 449                 $rows = 1;
 450                 foreach ( $res as $plan ) {
 451                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 452                 }
 453
 454                 return $rows;
 455         }
 456
 457         /**
 458          * @param string $table
 459          * @param string $field
 460          * @return bool|MySQLField
 461          */
 462         function fieldInfo( $table, $field ) {
 463                 $table = $this->tableName( $table );
 464                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 465                 if ( !$res ) {
 466                         return false;
 467                 }
 468                 $n = $this->mysqlNumFields( $res->result );
 469                 for ( $i = 0; $i < $n; $i++ ) {
 470                         $meta = $this->mysqlFetchField( $res->result, $i );
 471                         if ( $field == $meta->name ) {
 472                                 return new MySQLField( $meta );
 473                         }
 474                 }
 475
 476                 return false;
 477         }
 478
 479         /**
 480          * Get column information from a result
 481          *
 482          * @param resource $res Raw result
 483          * @param int $n
 484          * @return stdClass
 485          */
 486         abstract protected function mysqlFetchField( $res, $n );
 487
 488         /**
 489          * Get information about an index into an object
 490          * Returns false if the index does not exist
 491          *
 492          * @param string $table
 493          * @param string $index
 494          * @param string $fname
 495          * @return bool|array|null False or null on failure
 496          */
 497         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 498                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 499                 # SHOW INDEX should work for 3.x and up:
 500                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 501                 $table = $this->tableName( $table );
 502                 $index = $this->indexName( $index );
 503
 504                 $sql = 'SHOW INDEX FROM ' . $table;
 505                 $res = $this->query( $sql, $fname );
 506
 507                 if ( !$res ) {
 508                         return null;
 509                 }
 510
 511                 $result = array();
 512
 513                 foreach ( $res as $row ) {
 514                         if ( $row->Key_name == $index ) {
 515                                 $result[] = $row;
 516                         }
 517                 }
 518
 519                 return empty( $result ) ? false : $result;
 520         }
 521
 522         /**
 523          * @param string $s
 524          * @return string
 525          */
 526         function strencode( $s ) {
 527                 $sQuoted = $this->mysqlRealEscapeString( $s );
 528
 529                 if ( $sQuoted === false ) {
 530                         $this->ping();
 531                         $sQuoted = $this->mysqlRealEscapeString( $s );
 532                 }
 533
 534                 return $sQuoted;
 535         }
 536
 537         /**
 538          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 539          *
 540          * @param string $s
 541          * @return string
 542          */
 543         public function addIdentifierQuotes( $s ) {
 544                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 545                 // Remove NUL bytes and escape backticks by doubling
 546                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s ) . '`';
 547         }
 548
 549         /**
 550          * @param string $name
 551          * @return bool
 552          */
 553         public function isQuotedIdentifier( $name ) {
 554                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 555         }
 556
 557         /**
 558          * @return bool
 559          */
 560         function ping() {
 561                 $ping = $this->mysqlPing();
 562                 if ( $ping ) {
 563                         return true;
 564                 }
 565
 566                 $this->closeConnection();
 567                 $this->mOpened = false;
 568                 $this->mConn = false;
 569                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 570
 571                 return true;
 572         }
 573
 574         /**
 575          * Ping a server connection or reconnect if there is no connection
 576          *
 577          * @return bool
 578          */
 579         abstract protected function mysqlPing();
 580
 581         /**
 582          * Returns slave lag.
 583          *
 584          * This will do a SHOW SLAVE STATUS
 585          *
 586          * @return int
 587          */
 588         function getLag() {
 589                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 590                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 591
 592                         return $this->mFakeSlaveLag;
 593                 }
 594
 595                 return $this->getLagFromSlaveStatus();
 596         }
 597
 598         /**
 599          * @return bool|int
 600          */
 601         function getLagFromSlaveStatus() {
 602                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 603                 if ( !$res ) {
 604                         return false;
 605                 }
 606                 $row = $res->fetchObject();
 607                 if ( !$row ) {
 608                         return false;
 609                 }
 610                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 611                         return false;
 612                 } else {
 613                         return intval( $row->Seconds_Behind_Master );
 614                 }
 615         }
 616
 617         /**
 618          * @deprecated in 1.19, use getLagFromSlaveStatus
 619          *
 620          * @return bool|int
 621          */
 622         function getLagFromProcesslist() {
 623                 wfDeprecated( __METHOD__, '1.19' );
 624                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 625                 if ( !$res ) {
 626                         return false;
 627                 }
 628                 # Find slave SQL thread
 629                 foreach ( $res as $row ) {
 630                         /* This should work for most situations - when default db
 631                          * for thread is not specified, it had no events executed,
 632                          * and therefore it doesn't know yet how lagged it is.
 633                          *
 634                          * Relay log I/O thread does not select databases.
 635                          */
 636                         if ( $row->User == 'system user' &&
 637                                 $row->State != 'Waiting for master to send event' &&
 638                                 $row->State != 'Connecting to master' &&
 639                                 $row->State != 'Queueing master event to the relay log' &&
 640                                 $row->State != 'Waiting for master update' &&
 641                                 $row->State != 'Requesting binlog dump' &&
 642                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 643                                 $row->State != 'Reconnecting after a failed master event read' &&
 644                                 $row->State != 'Registering slave on master'
 645                         ) {
 646                                 # This is it, return the time (except -ve)
 647                                 if ( $row->Time > 0x7fffffff ) {
 648                                         return false;
 649                                 } else {
 650                                         return $row->Time;
 651                                 }
 652                         }
 653                 }
 654
 655                 return false;
 656         }
 657
 658         /**
 659          * Wait for the slave to catch up to a given master position.
 660          * @todo Return values for this and base class are rubbish
 661          *
 662          * @param DBMasterPos|MySQLMasterPos $pos
 663          * @param int $timeout The maximum number of seconds to wait for synchronisation
 664          * @return bool|string
 665          */
 666         function masterPosWait( DBMasterPos $pos, $timeout ) {
 667                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 668                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 669                 }
 670
 671                 wfProfileIn( __METHOD__ );
 672                 # Commit any open transactions
 673                 $this->commit( __METHOD__, 'flush' );
 674
 675                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 676                         $status = parent::masterPosWait( $pos, $timeout );
 677                         wfProfileOut( __METHOD__ );
 678
 679                         return $status;
 680                 }
 681
 682                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 683                 $encFile = $this->addQuotes( $pos->file );
 684                 $encPos = intval( $pos->pos );
 685                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 686                 $res = $this->doQuery( $sql );
 687
 688                 $status = false;
 689                 if ( $res && $row = $this->fetchRow( $res ) ) {
 690                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 691                         if ( ctype_digit( $status ) ) { // success
 692                                 $this->lastKnownSlavePos = $pos;
 693                         }
 694                 }
 695
 696                 wfProfileOut( __METHOD__ );
 697
 698                 return $status;
 699         }
 700
 701         /**
 702          * Get the position of the master from SHOW SLAVE STATUS
 703          *
 704          * @return MySQLMasterPos|bool
 705          */
 706         function getSlavePos() {
 707                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 708                         return parent::getSlavePos();
 709                 }
 710
 711                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 712                 $row = $this->fetchObject( $res );
 713
 714                 if ( $row ) {
 715                         $pos = isset( $row->Exec_master_log_pos )
 716                                 ? $row->Exec_master_log_pos
 717                                 : $row->Exec_Master_Log_Pos;
 718
 719                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 720                 } else {
 721                         return false;
 722                 }
 723         }
 724
 725         /**
 726          * Get the position of the master from SHOW MASTER STATUS
 727          *
 728          * @return MySQLMasterPos|bool
 729          */
 730         function getMasterPos() {
 731                 if ( $this->mFakeMaster ) {
 732                         return parent::getMasterPos();
 733                 }
 734
 735                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 736                 $row = $this->fetchObject( $res );
 737
 738                 if ( $row ) {
 739                         return new MySQLMasterPos( $row->File, $row->Position );
 740                 } else {
 741                         return false;
 742                 }
 743         }
 744
 745         /**
 746          * @param string $index
 747          * @return string
 748          */
 749         function useIndexClause( $index ) {
 750                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 751         }
 752
 753         /**
 754          * @return string
 755          */
 756         function lowPriorityOption() {
 757                 return 'LOW_PRIORITY';
 758         }
 759
 760         /**
 761          * @return string
 762          */
 763         public function getSoftwareLink() {
 764                 return '[http://www.mysql.com/ MySQL]';
 765         }
 766
 767         /**
 768          * @param array $options
 769          */
 770         public function setSessionOptions( array $options ) {
 771                 if ( isset( $options['connTimeout'] ) ) {
 772                         $timeout = (int)$options['connTimeout'];
 773                         $this->query( "SET net_read_timeout=$timeout" );
 774                         $this->query( "SET net_write_timeout=$timeout" );
 775                 }
 776         }
 777
 778         /**
 779          * @param string $sql
 780          * @param string $newLine
 781          * @return bool
 782          */
 783         public function streamStatementEnd( &$sql, &$newLine ) {
 784                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 785                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 786                         $this->delimiter = $m[1];
 787                         $newLine = '';
 788                 }
 789
 790                 return parent::streamStatementEnd( $sql, $newLine );
 791         }
 792
 793         /**
 794          * Check to see if a named lock is available. This is non-blocking.
 795          *
 796          * @param string $lockName name of lock to poll
 797          * @param string $method name of method calling us
 798          * @return bool
 799          * @since 1.20
 800          */
 801         public function lockIsFree( $lockName, $method ) {
 802                 $lockName = $this->addQuotes( $lockName );
 803                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 804                 $row = $this->fetchObject( $result );
 805
 806                 return ( $row->lockstatus == 1 );
 807         }
 808
 809         /**
 810          * @param string $lockName
 811          * @param string $method
 812          * @param int $timeout
 813          * @return bool
 814          */
 815         public function lock( $lockName, $method, $timeout = 5 ) {
 816                 $lockName = $this->addQuotes( $lockName );
 817                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 818                 $row = $this->fetchObject( $result );
 819
 820                 if ( $row->lockstatus == 1 ) {
 821                         return true;
 822                 } else {
 823                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 824
 825                         return false;
 826                 }
 827         }
 828
 829         /**
 830          * FROM MYSQL DOCS:
 831          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 832          * @param string $lockName
 833          * @param string $method
 834          * @return bool
 835          */
 836         public function unlock( $lockName, $method ) {
 837                 $lockName = $this->addQuotes( $lockName );
 838                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 839                 $row = $this->fetchObject( $result );
 840
 841                 return ( $row->lockstatus == 1 );
 842         }
 843
 844         /**
 845          * @param array $read
 846          * @param array $write
 847          * @param string $method
 848          * @param bool $lowPriority
 849          * @return bool
 850          */
 851         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 852                 $items = array();
 853
 854                 foreach ( $write as $table ) {
 855                         $tbl = $this->tableName( $table ) .
 856                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 857                                 ' WRITE';
 858                         $items[] = $tbl;
 859                 }
 860                 foreach ( $read as $table ) {
 861                         $items[] = $this->tableName( $table ) . ' READ';
 862                 }
 863                 $sql = "LOCK TABLES " . implode( ',', $items );
 864                 $this->query( $sql, $method );
 865
 866                 return true;
 867         }
 868
 869         /**
 870          * @param string $method
 871          * @return bool
 872          */
 873         public function unlockTables( $method ) {
 874                 $this->query( "UNLOCK TABLES", $method );
 875
 876                 return true;
 877         }
 878
 879         /**
 880          * Get search engine class. All subclasses of this
 881          * need to implement this if they wish to use searching.
 882          *
 883          * @return string
 884          */
 885         public function getSearchEngine() {
 886                 return 'SearchMySQL';
 887         }
 888
 889         /**
 890          * @param bool $value
 891          * @return mixed null|bool|ResultWrapper
 892          */
 893         public function setBigSelects( $value = true ) {
 894                 if ( $value === 'default' ) {
 895                         if ( $this->mDefaultBigSelects === null ) {
 896                                 # Function hasn't been called before so it must already be set to the default
 897                                 return;
 898                         } else {
 899                                 $value = $this->mDefaultBigSelects;
 900                         }
 901                 } elseif ( $this->mDefaultBigSelects === null ) {
 902                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 903                 }
 904                 $encValue = $value ? '1' : '0';
 905                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 906         }
 907
 908         /**
 909          * DELETE where the condition is a join. MySql uses multi-table deletes.
 910          * @param $delTable string
 911          * @param $joinTable string
 912          * @param $delVar string
 913          * @param $joinVar string
 914          * @param $conds array|string
 915          * @param bool|string $fname bool
 916          * @throws DBUnexpectedError
 917          * @return bool|ResultWrapper
 918          */
 919         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 920                 if ( !$conds ) {
 921                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 922                 }
 923
 924                 $delTable = $this->tableName( $delTable );
 925                 $joinTable = $this->tableName( $joinTable );
 926                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 927
 928                 if ( $conds != '*' ) {
 929                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 930                 }
 931
 932                 return $this->query( $sql, $fname );
 933         }
 934
 935         /**
 936          * @param string $table
 937          * @param array $rows
 938          * @param array $uniqueIndexes
 939          * @param array $set
 940          * @param string $fname
 941          * @return bool
 942          */
 943         public function upsert(
 944                 $table, array $rows, array $uniqueIndexes, array $set, $fname = __METHOD__
 945         ) {
 946                 if ( !count( $rows ) ) {
 947                         return true; // nothing to do
 948                 }
 949                 $rows = is_array( reset( $rows ) ) ? $rows : array( $rows );
 950
 951                 $table = $this->tableName( $table );
 952                 $columns = array_keys( $rows[0] );
 953
 954                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
 955                 $rowTuples = array();
 956                 foreach ( $rows as $row ) {
 957                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
 958                 }
 959                 $sql .= implode( ',', $rowTuples );
 960                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
 961
 962                 return (bool)$this->query( $sql, $fname );
 963         }
 964
 965         /**
 966          * Determines how long the server has been up
 967          *
 968          * @return int
 969          */
 970         function getServerUptime() {
 971                 $vars = $this->getMysqlStatus( 'Uptime' );
 972
 973                 return (int)$vars['Uptime'];
 974         }
 975
 976         /**
 977          * Determines if the last failure was due to a deadlock
 978          *
 979          * @return bool
 980          */
 981         function wasDeadlock() {
 982                 return $this->lastErrno() == 1213;
 983         }
 984
 985         /**
 986          * Determines if the last failure was due to a lock timeout
 987          *
 988          * @return bool
 989          */
 990         function wasLockTimeout() {
 991                 return $this->lastErrno() == 1205;
 992         }
 993
 994         /**
 995          * Determines if the last query error was something that should be dealt
 996          * with by pinging the connection and reissuing the query
 997          *
 998          * @return bool
 999          */
1000         function wasErrorReissuable() {
1001                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1002         }
1003
1004         /**
1005          * Determines if the last failure was due to the database being read-only.
1006          *
1007          * @return bool
1008          */
1009         function wasReadOnlyError() {
1010                 return $this->lastErrno() == 1223 ||
1011                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1012         }
1013
1014         /**
1015          * @param string $oldName
1016          * @param string $newName
1017          * @param bool $temporary
1018          * @param string $fname
1019          * @return bool
1020          */
1021         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1022                 $tmp = $temporary ? 'TEMPORARY ' : '';
1023                 $newName = $this->addIdentifierQuotes( $newName );
1024                 $oldName = $this->addIdentifierQuotes( $oldName );
1025                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1026
1027                 return $this->query( $query, $fname );
1028         }
1029
1030         /**
1031          * List all tables on the database
1032          *
1033          * @param string $prefix Only show tables with this prefix, e.g. mw_
1034          * @param string $fname Calling function name
1035          * @return array
1036          */
1037         function listTables( $prefix = null, $fname = __METHOD__ ) {
1038                 $result = $this->query( "SHOW TABLES", $fname );
1039
1040                 $endArray = array();
1041
1042                 foreach ( $result as $table ) {
1043                         $vars = get_object_vars( $table );
1044                         $table = array_pop( $vars );
1045
1046                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1047                                 $endArray[] = $table;
1048                         }
1049                 }
1050
1051                 return $endArray;
1052         }
1053
1054         /**
1055          * @param $tableName
1056          * @param $fName string
1057          * @return bool|ResultWrapper
1058          */
1059         public function dropTable( $tableName, $fName = __METHOD__ ) {
1060                 if ( !$this->tableExists( $tableName, $fName ) ) {
1061                         return false;
1062                 }
1063
1064                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1065         }
1066
1067         /**
1068          * @return array
1069          */
1070         protected function getDefaultSchemaVars() {
1071                 $vars = parent::getDefaultSchemaVars();
1072                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1073                 $vars['wgDBTableOptions'] = str_replace(
1074                         'CHARSET=mysql4',
1075                         'CHARSET=binary',
1076                         $vars['wgDBTableOptions']
1077                 );
1078
1079                 return $vars;
1080         }
1081
1082         /**
1083          * Get status information from SHOW STATUS in an associative array
1084          *
1085          * @param string $which
1086          * @return array
1087          */
1088         function getMysqlStatus( $which = "%" ) {
1089                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1090                 $status = array();
1091
1092                 foreach ( $res as $row ) {
1093                         $status[$row->Variable_name] = $row->Value;
1094                 }
1095
1096                 return $status;
1097         }
1098
1099         /**
1100          * Lists VIEWs in the database
1101          *
1102          * @param string $prefix Only show VIEWs with this prefix, eg.
1103          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1104          * @param string $fname Name of calling function
1105          * @return array
1106          * @since 1.22
1107          */
1108         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1109
1110                 if ( !isset( $this->allViews ) ) {
1111
1112                         // The name of the column containing the name of the VIEW
1113                         $propertyName = 'Tables_in_' . $this->mDBname;
1114
1115                         // Query for the VIEWS
1116                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1117                         $this->allViews = array();
1118                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1119                                 array_push( $this->allViews, $row[$propertyName] );
1120                         }
1121                 }
1122
1123                 if ( is_null( $prefix ) || $prefix === '' ) {
1124                         return $this->allViews;
1125                 }
1126
1127                 $filteredViews = array();
1128                 foreach ( $this->allViews as $viewName ) {
1129                         // Does the name of this VIEW start with the table-prefix?
1130                         if ( strpos( $viewName, $prefix ) === 0 ) {
1131                                 array_push( $filteredViews, $viewName );
1132                         }
1133                 }
1134
1135                 return $filteredViews;
1136         }
1137
1138         /**
1139          * Differentiates between a TABLE and a VIEW.
1140          *
1141          * @param string $name Name of the TABLE/VIEW to test
1142          * @param string $prefix
1143          * @return bool
1144          * @since 1.22
1145          */
1146         public function isView( $name, $prefix = null ) {
1147                 return in_array( $name, $this->listViews( $prefix ) );
1148         }
1149 }
1150
1151 /**
1152  * Utility class.
1153  * @ingroup Database
1154  */
1155 class MySQLField implements Field {
1156         private $name, $tablename, $default, $max_length, $nullable,
1157                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary;
1158
1159         function __construct( $info ) {
1160                 $this->name = $info->name;
1161                 $this->tablename = $info->table;
1162                 $this->default = $info->def;
1163                 $this->max_length = $info->max_length;
1164                 $this->nullable = !$info->not_null;
1165                 $this->is_pk = $info->primary_key;
1166                 $this->is_unique = $info->unique_key;
1167                 $this->is_multiple = $info->multiple_key;
1168                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1169                 $this->type = $info->type;
1170                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1171         }
1172
1173         /**
1174          * @return string
1175          */
1176         function name() {
1177                 return $this->name;
1178         }
1179
1180         /**
1181          * @return string
1182          */
1183         function tableName() {
1184                 return $this->tableName;
1185         }
1186
1187         /**
1188          * @return string
1189          */
1190         function type() {
1191                 return $this->type;
1192         }
1193
1194         /**
1195          * @return bool
1196          */
1197         function isNullable() {
1198                 return $this->nullable;
1199         }
1200
1201         function defaultValue() {
1202                 return $this->default;
1203         }
1204
1205         /**
1206          * @return bool
1207          */
1208         function isKey() {
1209                 return $this->is_key;
1210         }
1211
1212         /**
1213          * @return bool
1214          */
1215         function isMultipleKey() {
1216                 return $this->is_multiple;
1217         }
1218
1219         function isBinary() {
1220                 return $this->binary;
1221         }
1222 }
1223
1224 class MySQLMasterPos implements DBMasterPos {
1225         /** @var string */
1226         public $file;
1227
1228         /** @var int */
1229         private $pos;
1230
1231         function __construct( $file, $pos ) {
1232                 $this->file = $file;
1233                 $this->pos = $pos;
1234         }
1235
1236         function __toString() {
1237                 // e.g db1034-bin.000976/843431247
1238                 return "{$this->file}/{$this->pos}";
1239         }
1240
1241         /**
1242          * @return array|false (int, int)
1243          */
1244         protected function getCoordinates() {
1245                 $m = array();
1246                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1247                         return array( (int)$m[1], (int)$m[2] );
1248                 }
1249
1250                 return false;
1251         }
1252
1253         function hasReached( MySQLMasterPos $pos ) {
1254                 $thisPos = $this->getCoordinates();
1255                 $thatPos = $pos->getCoordinates();
1256
1257                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1258         }
1259 }