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->getMasterPos() );
 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                 $version = $this->getServerVersion();
 765                 if ( strpos( $version, 'MariaDB' ) !== false ) {
 766                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 767                 } elseif ( strpos( $version, 'percona' ) !== false ) {
 768                         return '[{{int:version-db-percona-url}} Percona Server]';
 769                 } else {
 770                         return '[{{int:version-db-mysql-url}} MySQL]';
 771                 }
 772         }
 773
 774         /**
 775          * @param array $options
 776          */
 777         public function setSessionOptions( array $options ) {
 778                 if ( isset( $options['connTimeout'] ) ) {
 779                         $timeout = (int)$options['connTimeout'];
 780                         $this->query( "SET net_read_timeout=$timeout" );
 781                         $this->query( "SET net_write_timeout=$timeout" );
 782                 }
 783         }
 784
 785         /**
 786          * @param string $sql
 787          * @param string $newLine
 788          * @return bool
 789          */
 790         public function streamStatementEnd( &$sql, &$newLine ) {
 791                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 792                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 793                         $this->delimiter = $m[1];
 794                         $newLine = '';
 795                 }
 796
 797                 return parent::streamStatementEnd( $sql, $newLine );
 798         }
 799
 800         /**
 801          * Check to see if a named lock is available. This is non-blocking.
 802          *
 803          * @param string $lockName name of lock to poll
 804          * @param string $method name of method calling us
 805          * @return bool
 806          * @since 1.20
 807          */
 808         public function lockIsFree( $lockName, $method ) {
 809                 $lockName = $this->addQuotes( $lockName );
 810                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 811                 $row = $this->fetchObject( $result );
 812
 813                 return ( $row->lockstatus == 1 );
 814         }
 815
 816         /**
 817          * @param string $lockName
 818          * @param string $method
 819          * @param int $timeout
 820          * @return bool
 821          */
 822         public function lock( $lockName, $method, $timeout = 5 ) {
 823                 $lockName = $this->addQuotes( $lockName );
 824                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 825                 $row = $this->fetchObject( $result );
 826
 827                 if ( $row->lockstatus == 1 ) {
 828                         return true;
 829                 } else {
 830                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 831
 832                         return false;
 833                 }
 834         }
 835
 836         /**
 837          * FROM MYSQL DOCS:
 838          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 839          * @param string $lockName
 840          * @param string $method
 841          * @return bool
 842          */
 843         public function unlock( $lockName, $method ) {
 844                 $lockName = $this->addQuotes( $lockName );
 845                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 846                 $row = $this->fetchObject( $result );
 847
 848                 return ( $row->lockstatus == 1 );
 849         }
 850
 851         /**
 852          * @param array $read
 853          * @param array $write
 854          * @param string $method
 855          * @param bool $lowPriority
 856          * @return bool
 857          */
 858         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 859                 $items = array();
 860
 861                 foreach ( $write as $table ) {
 862                         $tbl = $this->tableName( $table ) .
 863                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 864                                 ' WRITE';
 865                         $items[] = $tbl;
 866                 }
 867                 foreach ( $read as $table ) {
 868                         $items[] = $this->tableName( $table ) . ' READ';
 869                 }
 870                 $sql = "LOCK TABLES " . implode( ',', $items );
 871                 $this->query( $sql, $method );
 872
 873                 return true;
 874         }
 875
 876         /**
 877          * @param string $method
 878          * @return bool
 879          */
 880         public function unlockTables( $method ) {
 881                 $this->query( "UNLOCK TABLES", $method );
 882
 883                 return true;
 884         }
 885
 886         /**
 887          * Get search engine class. All subclasses of this
 888          * need to implement this if they wish to use searching.
 889          *
 890          * @return string
 891          */
 892         public function getSearchEngine() {
 893                 return 'SearchMySQL';
 894         }
 895
 896         /**
 897          * @param bool $value
 898          * @return mixed null|bool|ResultWrapper
 899          */
 900         public function setBigSelects( $value = true ) {
 901                 if ( $value === 'default' ) {
 902                         if ( $this->mDefaultBigSelects === null ) {
 903                                 # Function hasn't been called before so it must already be set to the default
 904                                 return;
 905                         } else {
 906                                 $value = $this->mDefaultBigSelects;
 907                         }
 908                 } elseif ( $this->mDefaultBigSelects === null ) {
 909                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 910                 }
 911                 $encValue = $value ? '1' : '0';
 912                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 913         }
 914
 915         /**
 916          * DELETE where the condition is a join. MySql uses multi-table deletes.
 917          * @param $delTable string
 918          * @param $joinTable string
 919          * @param $delVar string
 920          * @param $joinVar string
 921          * @param $conds array|string
 922          * @param bool|string $fname bool
 923          * @throws DBUnexpectedError
 924          * @return bool|ResultWrapper
 925          */
 926         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 927                 if ( !$conds ) {
 928                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 929                 }
 930
 931                 $delTable = $this->tableName( $delTable );
 932                 $joinTable = $this->tableName( $joinTable );
 933                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 934
 935                 if ( $conds != '*' ) {
 936                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 937                 }
 938
 939                 return $this->query( $sql, $fname );
 940         }
 941
 942         /**
 943          * @param string $table
 944          * @param array $rows
 945          * @param array $uniqueIndexes
 946          * @param array $set
 947          * @param string $fname
 948          * @return bool
 949          */
 950         public function upsert( $table, array $rows, array $uniqueIndexes,
 951                 array $set, $fname = __METHOD__
 952         ) {
 953                 if ( !count( $rows ) ) {
 954                         return true; // nothing to do
 955                 }
 956                 $rows = is_array( reset( $rows ) ) ? $rows : array( $rows );
 957
 958                 $table = $this->tableName( $table );
 959                 $columns = array_keys( $rows[0] );
 960
 961                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
 962                 $rowTuples = array();
 963                 foreach ( $rows as $row ) {
 964                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
 965                 }
 966                 $sql .= implode( ',', $rowTuples );
 967                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
 968
 969                 return (bool)$this->query( $sql, $fname );
 970         }
 971
 972         /**
 973          * Determines how long the server has been up
 974          *
 975          * @return int
 976          */
 977         function getServerUptime() {
 978                 $vars = $this->getMysqlStatus( 'Uptime' );
 979
 980                 return (int)$vars['Uptime'];
 981         }
 982
 983         /**
 984          * Determines if the last failure was due to a deadlock
 985          *
 986          * @return bool
 987          */
 988         function wasDeadlock() {
 989                 return $this->lastErrno() == 1213;
 990         }
 991
 992         /**
 993          * Determines if the last failure was due to a lock timeout
 994          *
 995          * @return bool
 996          */
 997         function wasLockTimeout() {
 998                 return $this->lastErrno() == 1205;
 999         }
1000
1001         /**
1002          * Determines if the last query error was something that should be dealt
1003          * with by pinging the connection and reissuing the query
1004          *
1005          * @return bool
1006          */
1007         function wasErrorReissuable() {
1008                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1009         }
1010
1011         /**
1012          * Determines if the last failure was due to the database being read-only.
1013          *
1014          * @return bool
1015          */
1016         function wasReadOnlyError() {
1017                 return $this->lastErrno() == 1223 ||
1018                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1019         }
1020
1021         /**
1022          * @param string $oldName
1023          * @param string $newName
1024          * @param bool $temporary
1025          * @param string $fname
1026          * @return bool
1027          */
1028         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1029                 $tmp = $temporary ? 'TEMPORARY ' : '';
1030                 $newName = $this->addIdentifierQuotes( $newName );
1031                 $oldName = $this->addIdentifierQuotes( $oldName );
1032                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1033
1034                 return $this->query( $query, $fname );
1035         }
1036
1037         /**
1038          * List all tables on the database
1039          *
1040          * @param string $prefix Only show tables with this prefix, e.g. mw_
1041          * @param string $fname Calling function name
1042          * @return array
1043          */
1044         function listTables( $prefix = null, $fname = __METHOD__ ) {
1045                 $result = $this->query( "SHOW TABLES", $fname );
1046
1047                 $endArray = array();
1048
1049                 foreach ( $result as $table ) {
1050                         $vars = get_object_vars( $table );
1051                         $table = array_pop( $vars );
1052
1053                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1054                                 $endArray[] = $table;
1055                         }
1056                 }
1057
1058                 return $endArray;
1059         }
1060
1061         /**
1062          * @param $tableName
1063          * @param $fName string
1064          * @return bool|ResultWrapper
1065          */
1066         public function dropTable( $tableName, $fName = __METHOD__ ) {
1067                 if ( !$this->tableExists( $tableName, $fName ) ) {
1068                         return false;
1069                 }
1070
1071                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1072         }
1073
1074         /**
1075          * @return array
1076          */
1077         protected function getDefaultSchemaVars() {
1078                 $vars = parent::getDefaultSchemaVars();
1079                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1080                 $vars['wgDBTableOptions'] = str_replace(
1081                         'CHARSET=mysql4',
1082                         'CHARSET=binary',
1083                         $vars['wgDBTableOptions']
1084                 );
1085
1086                 return $vars;
1087         }
1088
1089         /**
1090          * Get status information from SHOW STATUS in an associative array
1091          *
1092          * @param string $which
1093          * @return array
1094          */
1095         function getMysqlStatus( $which = "%" ) {
1096                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1097                 $status = array();
1098
1099                 foreach ( $res as $row ) {
1100                         $status[$row->Variable_name] = $row->Value;
1101                 }
1102
1103                 return $status;
1104         }
1105
1106         /**
1107          * Lists VIEWs in the database
1108          *
1109          * @param string $prefix Only show VIEWs with this prefix, eg.
1110          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1111          * @param string $fname Name of calling function
1112          * @return array
1113          * @since 1.22
1114          */
1115         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1116
1117                 if ( !isset( $this->allViews ) ) {
1118
1119                         // The name of the column containing the name of the VIEW
1120                         $propertyName = 'Tables_in_' . $this->mDBname;
1121
1122                         // Query for the VIEWS
1123                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1124                         $this->allViews = array();
1125                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1126                                 array_push( $this->allViews, $row[$propertyName] );
1127                         }
1128                 }
1129
1130                 if ( is_null( $prefix ) || $prefix === '' ) {
1131                         return $this->allViews;
1132                 }
1133
1134                 $filteredViews = array();
1135                 foreach ( $this->allViews as $viewName ) {
1136                         // Does the name of this VIEW start with the table-prefix?
1137                         if ( strpos( $viewName, $prefix ) === 0 ) {
1138                                 array_push( $filteredViews, $viewName );
1139                         }
1140                 }
1141
1142                 return $filteredViews;
1143         }
1144
1145         /**
1146          * Differentiates between a TABLE and a VIEW.
1147          *
1148          * @param string $name Name of the TABLE/VIEW to test
1149          * @param string $prefix
1150          * @return bool
1151          * @since 1.22
1152          */
1153         public function isView( $name, $prefix = null ) {
1154                 return in_array( $name, $this->listViews( $prefix ) );
1155         }
1156 }
1157
1158 /**
1159  * Utility class.
1160  * @ingroup Database
1161  */
1162 class MySQLField implements Field {
1163         private $name, $tablename, $default, $max_length, $nullable,
1164                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary;
1165
1166         function __construct( $info ) {
1167                 $this->name = $info->name;
1168                 $this->tablename = $info->table;
1169                 $this->default = $info->def;
1170                 $this->max_length = $info->max_length;
1171                 $this->nullable = !$info->not_null;
1172                 $this->is_pk = $info->primary_key;
1173                 $this->is_unique = $info->unique_key;
1174                 $this->is_multiple = $info->multiple_key;
1175                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1176                 $this->type = $info->type;
1177                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1178         }
1179
1180         /**
1181          * @return string
1182          */
1183         function name() {
1184                 return $this->name;
1185         }
1186
1187         /**
1188          * @return string
1189          */
1190         function tableName() {
1191                 return $this->tableName;
1192         }
1193
1194         /**
1195          * @return string
1196          */
1197         function type() {
1198                 return $this->type;
1199         }
1200
1201         /**
1202          * @return bool
1203          */
1204         function isNullable() {
1205                 return $this->nullable;
1206         }
1207
1208         function defaultValue() {
1209                 return $this->default;
1210         }
1211
1212         /**
1213          * @return bool
1214          */
1215         function isKey() {
1216                 return $this->is_key;
1217         }
1218
1219         /**
1220          * @return bool
1221          */
1222         function isMultipleKey() {
1223                 return $this->is_multiple;
1224         }
1225
1226         function isBinary() {
1227                 return $this->binary;
1228         }
1229 }
1230
1231 class MySQLMasterPos implements DBMasterPos {
1232         /** @var string */
1233         public $file;
1234
1235         /** @var int */
1236         private $pos;
1237
1238         function __construct( $file, $pos ) {
1239                 $this->file = $file;
1240                 $this->pos = $pos;
1241         }
1242
1243         function __toString() {
1244                 // e.g db1034-bin.000976/843431247
1245                 return "{$this->file}/{$this->pos}";
1246         }
1247
1248         /**
1249          * @return array|false (int, int)
1250          */
1251         protected function getCoordinates() {
1252                 $m = array();
1253                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1254                         return array( (int)$m[1], (int)$m[2] );
1255                 }
1256
1257                 return false;
1258         }
1259
1260         function hasReached( MySQLMasterPos $pos ) {
1261                 $thisPos = $this->getCoordinates();
1262                 $thatPos = $pos->getCoordinates();
1263
1264                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1265         }
1266
1267         /**
1268          * @return int
1269          */
1270         public function getMasterPos() {
1271                 return $this->pos;
1272         }
1273 }