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         /** @var null|int */
  37         protected $mFakeSlaveLag = null;
  38
  39         protected $mFakeMaster = false;
  40
  41         /** @var string|null */
  42         private $serverVersion = null;
  43
  44         /**
  45          * @return string
  46          */
  47         function getType() {
  48                 return 'mysql';
  49         }
  50
  51         /**
  52          * @param string $server
  53          * @param string $user
  54          * @param string $password
  55          * @param string $dbName
  56          * @throws Exception|DBConnectionError
  57          * @return bool
  58          */
  59         function open( $server, $user, $password, $dbName ) {
  60                 global $wgAllDBsAreLocalhost, $wgSQLMode;
  61                 wfProfileIn( __METHOD__ );
  62
  63                 # Debugging hack -- fake cluster
  64                 if ( $wgAllDBsAreLocalhost ) {
  65                         $realServer = 'localhost';
  66                 } else {
  67                         $realServer = $server;
  68                 }
  69                 $this->close();
  70                 $this->mServer = $server;
  71                 $this->mUser = $user;
  72                 $this->mPassword = $password;
  73                 $this->mDBname = $dbName;
  74
  75                 wfProfileIn( "dbconnect-$server" );
  76
  77                 # The kernel's default SYN retransmission period is far too slow for us,
  78                 # so we use a short timeout plus a manual retry. Retrying means that a small
  79                 # but finite rate of SYN packet loss won't cause user-visible errors.
  80                 $this->mConn = false;
  81                 $this->installErrorHandler();
  82                 try {
  83                         $this->mConn = $this->mysqlConnect( $realServer );
  84                 } catch ( Exception $ex ) {
  85                         wfProfileOut( "dbconnect-$server" );
  86                         wfProfileOut( __METHOD__ );
  87                         $this->restoreErrorHandler();
  88                         throw $ex;
  89                 }
  90                 $error = $this->restoreErrorHandler();
  91
  92                 wfProfileOut( "dbconnect-$server" );
  93
  94                 # Always log connection errors
  95                 if ( !$this->mConn ) {
  96                         if ( !$error ) {
  97                                 $error = $this->lastError();
  98                         }
  99                         wfLogDBError(
 100                                 "Error connecting to {db_server}: {error}",
 101                                 $this->getLogContext( array(
 102                                         'method' => __METHOD__,
 103                                         'error' => $error,
 104                                 ) )
 105                         );
 106                         wfDebug( "DB connection error\n" .
 107                                 "Server: $server, User: $user, Password: " .
 108                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 109
 110                         wfProfileOut( __METHOD__ );
 111
 112                         $this->reportConnectionError( $error );
 113                 }
 114
 115                 if ( $dbName != '' ) {
 116                         wfSuppressWarnings();
 117                         $success = $this->selectDB( $dbName );
 118                         wfRestoreWarnings();
 119                         if ( !$success ) {
 120                                 wfLogDBError(
 121                                         "Error selecting database {db_name} on server {db_server}",
 122                                         $this->getLogContext( array(
 123                                                 'method' => __METHOD__,
 124                                         ) )
 125                                 );
 126                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 127                                         "from client host " . wfHostname() . "\n" );
 128
 129                                 wfProfileOut( __METHOD__ );
 130
 131                                 $this->reportConnectionError( "Error selecting database $dbName" );
 132                         }
 133                 }
 134
 135                 // Tell the server what we're communicating with
 136                 if ( !$this->connectInitCharset() ) {
 137                         $this->reportConnectionError( "Error setting character set" );
 138                 }
 139
 140                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 141                 if ( is_string( $wgSQLMode ) ) {
 142                         $mode = $this->addQuotes( $wgSQLMode );
 143                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 144                         $success = $this->doQuery( "SET sql_mode = $mode", __METHOD__ );
 145                         if ( !$success ) {
 146                                 wfLogDBError(
 147                                         "Error setting sql_mode to $mode on server {db_server}",
 148                                         $this->getLogContext( array(
 149                                                 'method' => __METHOD__,
 150                                         ) )
 151                                 );
 152                                 wfProfileOut( __METHOD__ );
 153                                 $this->reportConnectionError( "Error setting sql_mode to $mode" );
 154                         }
 155                 }
 156
 157                 $this->mOpened = true;
 158                 wfProfileOut( __METHOD__ );
 159
 160                 return true;
 161         }
 162
 163         /**
 164          * Set the character set information right after connection
 165          * @return bool
 166          */
 167         protected function connectInitCharset() {
 168                 global $wgDBmysql5;
 169
 170                 if ( $wgDBmysql5 ) {
 171                         // Tell the server we're communicating with it in UTF-8.
 172                         // This may engage various charset conversions.
 173                         return $this->mysqlSetCharset( 'utf8' );
 174                 } else {
 175                         return $this->mysqlSetCharset( 'binary' );
 176                 }
 177         }
 178
 179         /**
 180          * Open a connection to a MySQL server
 181          *
 182          * @param string $realServer
 183          * @return mixed Raw connection
 184          * @throws DBConnectionError
 185          */
 186         abstract protected function mysqlConnect( $realServer );
 187
 188         /**
 189          * Set the character set of the MySQL link
 190          *
 191          * @param string $charset
 192          * @return bool
 193          */
 194         abstract protected function mysqlSetCharset( $charset );
 195
 196         /**
 197          * @param ResultWrapper|resource $res
 198          * @throws DBUnexpectedError
 199          */
 200         function freeResult( $res ) {
 201                 if ( $res instanceof ResultWrapper ) {
 202                         $res = $res->result;
 203                 }
 204                 wfSuppressWarnings();
 205                 $ok = $this->mysqlFreeResult( $res );
 206                 wfRestoreWarnings();
 207                 if ( !$ok ) {
 208                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 209                 }
 210         }
 211
 212         /**
 213          * Free result memory
 214          *
 215          * @param resource $res Raw result
 216          * @return bool
 217          */
 218         abstract protected function mysqlFreeResult( $res );
 219
 220         /**
 221          * @param ResultWrapper|resource $res
 222          * @return stdClass|bool
 223          * @throws DBUnexpectedError
 224          */
 225         function fetchObject( $res ) {
 226                 if ( $res instanceof ResultWrapper ) {
 227                         $res = $res->result;
 228                 }
 229                 wfSuppressWarnings();
 230                 $row = $this->mysqlFetchObject( $res );
 231                 wfRestoreWarnings();
 232
 233                 $errno = $this->lastErrno();
 234                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 235                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 236                 // these are the only errors mysql_fetch_object can cause.
 237                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 238                 if ( $errno == 2000 || $errno == 2013 ) {
 239                         throw new DBUnexpectedError(
 240                                 $this,
 241                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 242                         );
 243                 }
 244
 245                 return $row;
 246         }
 247
 248         /**
 249          * Fetch a result row as an object
 250          *
 251          * @param resource $res Raw result
 252          * @return stdClass
 253          */
 254         abstract protected function mysqlFetchObject( $res );
 255
 256         /**
 257          * @param ResultWrapper|resource $res
 258          * @return array|bool
 259          * @throws DBUnexpectedError
 260          */
 261         function fetchRow( $res ) {
 262                 if ( $res instanceof ResultWrapper ) {
 263                         $res = $res->result;
 264                 }
 265                 wfSuppressWarnings();
 266                 $row = $this->mysqlFetchArray( $res );
 267                 wfRestoreWarnings();
 268
 269                 $errno = $this->lastErrno();
 270                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 271                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 272                 // these are the only errors mysql_fetch_array can cause.
 273                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 274                 if ( $errno == 2000 || $errno == 2013 ) {
 275                         throw new DBUnexpectedError(
 276                                 $this,
 277                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 278                         );
 279                 }
 280
 281                 return $row;
 282         }
 283
 284         /**
 285          * Fetch a result row as an associative and numeric array
 286          *
 287          * @param resource $res Raw result
 288          * @return array
 289          */
 290         abstract protected function mysqlFetchArray( $res );
 291
 292         /**
 293          * @throws DBUnexpectedError
 294          * @param ResultWrapper|resource $res
 295          * @return int
 296          */
 297         function numRows( $res ) {
 298                 if ( $res instanceof ResultWrapper ) {
 299                         $res = $res->result;
 300                 }
 301                 wfSuppressWarnings();
 302                 $n = $this->mysqlNumRows( $res );
 303                 wfRestoreWarnings();
 304
 305                 // Unfortunately, mysql_num_rows does not reset the last errno.
 306                 // We are not checking for any errors here, since
 307                 // these are no errors mysql_num_rows can cause.
 308                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 309                 // See https://bugzilla.wikimedia.org/42430
 310                 return $n;
 311         }
 312
 313         /**
 314          * Get number of rows in result
 315          *
 316          * @param resource $res Raw result
 317          * @return int
 318          */
 319         abstract protected function mysqlNumRows( $res );
 320
 321         /**
 322          * @param ResultWrapper|resource $res
 323          * @return int
 324          */
 325         function numFields( $res ) {
 326                 if ( $res instanceof ResultWrapper ) {
 327                         $res = $res->result;
 328                 }
 329
 330                 return $this->mysqlNumFields( $res );
 331         }
 332
 333         /**
 334          * Get number of fields in result
 335          *
 336          * @param resource $res Raw result
 337          * @return int
 338          */
 339         abstract protected function mysqlNumFields( $res );
 340
 341         /**
 342          * @param ResultWrapper|resource $res
 343          * @param int $n
 344          * @return string
 345          */
 346         function fieldName( $res, $n ) {
 347                 if ( $res instanceof ResultWrapper ) {
 348                         $res = $res->result;
 349                 }
 350
 351                 return $this->mysqlFieldName( $res, $n );
 352         }
 353
 354         /**
 355          * Get the name of the specified field in a result
 356          *
 357          * @param ResultWrapper|resource $res
 358          * @param int $n
 359          * @return string
 360          */
 361         abstract protected function mysqlFieldName( $res, $n );
 362
 363         /**
 364          * mysql_field_type() wrapper
 365          * @param ResultWrapper|resource $res
 366          * @param int $n
 367          * @return string
 368          */
 369         public function fieldType( $res, $n ) {
 370                 if ( $res instanceof ResultWrapper ) {
 371                         $res = $res->result;
 372                 }
 373
 374                 return $this->mysqlFieldType( $res, $n );
 375         }
 376
 377         /**
 378          * Get the type of the specified field in a result
 379          *
 380          * @param ResultWrapper|resource $res
 381          * @param int $n
 382          * @return string
 383          */
 384         abstract protected function mysqlFieldType( $res, $n );
 385
 386         /**
 387          * @param ResultWrapper|resource $res
 388          * @param int $row
 389          * @return bool
 390          */
 391         function dataSeek( $res, $row ) {
 392                 if ( $res instanceof ResultWrapper ) {
 393                         $res = $res->result;
 394                 }
 395
 396                 return $this->mysqlDataSeek( $res, $row );
 397         }
 398
 399         /**
 400          * Move internal result pointer
 401          *
 402          * @param ResultWrapper|resource $res
 403          * @param int $row
 404          * @return bool
 405          */
 406         abstract protected function mysqlDataSeek( $res, $row );
 407
 408         /**
 409          * @return string
 410          */
 411         function lastError() {
 412                 if ( $this->mConn ) {
 413                         # Even if it's non-zero, it can still be invalid
 414                         wfSuppressWarnings();
 415                         $error = $this->mysqlError( $this->mConn );
 416                         if ( !$error ) {
 417                                 $error = $this->mysqlError();
 418                         }
 419                         wfRestoreWarnings();
 420                 } else {
 421                         $error = $this->mysqlError();
 422                 }
 423                 if ( $error ) {
 424                         $error .= ' (' . $this->mServer . ')';
 425                 }
 426
 427                 return $error;
 428         }
 429
 430         /**
 431          * Returns the text of the error message from previous MySQL operation
 432          *
 433          * @param resource $conn Raw connection
 434          * @return string
 435          */
 436         abstract protected function mysqlError( $conn = null );
 437
 438         /**
 439          * @param string $table
 440          * @param array $uniqueIndexes
 441          * @param array $rows
 442          * @param string $fname
 443          * @return ResultWrapper
 444          */
 445         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 446                 return $this->nativeReplace( $table, $rows, $fname );
 447         }
 448
 449         /**
 450          * Estimate rows in dataset
 451          * Returns estimated count, based on EXPLAIN output
 452          * Takes same arguments as Database::select()
 453          *
 454          * @param string|array $table
 455          * @param string|array $vars
 456          * @param string|array $conds
 457          * @param string $fname
 458          * @param string|array $options
 459          * @return bool|int
 460          */
 461         public function estimateRowCount( $table, $vars = '*', $conds = '',
 462                 $fname = __METHOD__, $options = array()
 463         ) {
 464                 $options['EXPLAIN'] = true;
 465                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 466                 if ( $res === false ) {
 467                         return false;
 468                 }
 469                 if ( !$this->numRows( $res ) ) {
 470                         return 0;
 471                 }
 472
 473                 $rows = 1;
 474                 foreach ( $res as $plan ) {
 475                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 476                 }
 477
 478                 return $rows;
 479         }
 480
 481         /**
 482          * @param string $table
 483          * @param string $field
 484          * @return bool|MySQLField
 485          */
 486         function fieldInfo( $table, $field ) {
 487                 $table = $this->tableName( $table );
 488                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 489                 if ( !$res ) {
 490                         return false;
 491                 }
 492                 $n = $this->mysqlNumFields( $res->result );
 493                 for ( $i = 0; $i < $n; $i++ ) {
 494                         $meta = $this->mysqlFetchField( $res->result, $i );
 495                         if ( $field == $meta->name ) {
 496                                 return new MySQLField( $meta );
 497                         }
 498                 }
 499
 500                 return false;
 501         }
 502
 503         /**
 504          * Get column information from a result
 505          *
 506          * @param resource $res Raw result
 507          * @param int $n
 508          * @return stdClass
 509          */
 510         abstract protected function mysqlFetchField( $res, $n );
 511
 512         /**
 513          * Get information about an index into an object
 514          * Returns false if the index does not exist
 515          *
 516          * @param string $table
 517          * @param string $index
 518          * @param string $fname
 519          * @return bool|array|null False or null on failure
 520          */
 521         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 522                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 523                 # SHOW INDEX should work for 3.x and up:
 524                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 525                 $table = $this->tableName( $table );
 526                 $index = $this->indexName( $index );
 527
 528                 $sql = 'SHOW INDEX FROM ' . $table;
 529                 $res = $this->query( $sql, $fname );
 530
 531                 if ( !$res ) {
 532                         return null;
 533                 }
 534
 535                 $result = array();
 536
 537                 foreach ( $res as $row ) {
 538                         if ( $row->Key_name == $index ) {
 539                                 $result[] = $row;
 540                         }
 541                 }
 542
 543                 return empty( $result ) ? false : $result;
 544         }
 545
 546         /**
 547          * @param string $s
 548          * @return string
 549          */
 550         function strencode( $s ) {
 551                 $sQuoted = $this->mysqlRealEscapeString( $s );
 552
 553                 if ( $sQuoted === false ) {
 554                         $this->ping();
 555                         $sQuoted = $this->mysqlRealEscapeString( $s );
 556                 }
 557
 558                 return $sQuoted;
 559         }
 560
 561         /**
 562          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 563          *
 564          * @param string $s
 565          * @return string
 566          */
 567         public function addIdentifierQuotes( $s ) {
 568                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 569                 // Remove NUL bytes and escape backticks by doubling
 570                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s ) . '`';
 571         }
 572
 573         /**
 574          * @param string $name
 575          * @return bool
 576          */
 577         public function isQuotedIdentifier( $name ) {
 578                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 579         }
 580
 581         /**
 582          * @return bool
 583          */
 584         function ping() {
 585                 $ping = $this->mysqlPing();
 586                 if ( $ping ) {
 587                         return true;
 588                 }
 589
 590                 $this->closeConnection();
 591                 $this->mOpened = false;
 592                 $this->mConn = false;
 593                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 594
 595                 return true;
 596         }
 597
 598         /**
 599          * Ping a server connection or reconnect if there is no connection
 600          *
 601          * @return bool
 602          */
 603         abstract protected function mysqlPing();
 604
 605         /**
 606          * Set lag time in seconds for a fake slave
 607          *
 608          * @param int $lag
 609          */
 610         public function setFakeSlaveLag( $lag ) {
 611                 $this->mFakeSlaveLag = $lag;
 612         }
 613
 614         /**
 615          * Make this connection a fake master
 616          *
 617          * @param bool $enabled
 618          */
 619         public function setFakeMaster( $enabled = true ) {
 620                 $this->mFakeMaster = $enabled;
 621         }
 622
 623         /**
 624          * Returns slave lag.
 625          *
 626          * This will do a SHOW SLAVE STATUS
 627          *
 628          * @return int
 629          */
 630         function getLag() {
 631                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 632                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 633
 634                         return $this->mFakeSlaveLag;
 635                 }
 636
 637                 return $this->getLagFromSlaveStatus();
 638         }
 639
 640         /**
 641          * @return bool|int
 642          */
 643         function getLagFromSlaveStatus() {
 644                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 645                 if ( !$res ) {
 646                         return false;
 647                 }
 648                 $row = $res->fetchObject();
 649                 if ( !$row ) {
 650                         return false;
 651                 }
 652                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 653                         return false;
 654                 } else {
 655                         return intval( $row->Seconds_Behind_Master );
 656                 }
 657         }
 658
 659         /**
 660          * Wait for the slave to catch up to a given master position.
 661          * @todo Return values for this and base class are rubbish
 662          *
 663          * @param DBMasterPos|MySQLMasterPos $pos
 664          * @param int $timeout The maximum number of seconds to wait for synchronisation
 665          * @return int Zero if the slave was past that position already,
 666          *   greater than zero if we waited for some period of time, less than
 667          *   zero if we timed out.
 668          */
 669         function masterPosWait( DBMasterPos $pos, $timeout ) {
 670                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 671                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 672                 }
 673
 674                 wfProfileIn( __METHOD__ );
 675                 # Commit any open transactions
 676                 $this->commit( __METHOD__, 'flush' );
 677
 678                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 679                         $wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
 680
 681                         if ( $wait > $timeout * 1e6 ) {
 682                                 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
 683                                 wfProfileOut( __METHOD__ );
 684
 685                                 return -1;
 686                         } elseif ( $wait > 0 ) {
 687                                 wfDebug( "Fake slave waiting $wait us\n" );
 688                                 usleep( $wait );
 689                                 wfProfileOut( __METHOD__ );
 690
 691                                 return 1;
 692                         } else {
 693                                 wfDebug( "Fake slave up to date ($wait us)\n" );
 694                                 wfProfileOut( __METHOD__ );
 695
 696                                 return 0;
 697                         }
 698                 }
 699
 700                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 701                 $encFile = $this->addQuotes( $pos->file );
 702                 $encPos = intval( $pos->pos );
 703                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 704                 $res = $this->doQuery( $sql );
 705
 706                 $status = false;
 707                 if ( $res && $row = $this->fetchRow( $res ) ) {
 708                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 709                         if ( ctype_digit( $status ) ) { // success
 710                                 $this->lastKnownSlavePos = $pos;
 711                         }
 712                 }
 713
 714                 wfProfileOut( __METHOD__ );
 715
 716                 return $status;
 717         }
 718
 719         /**
 720          * Get the position of the master from SHOW SLAVE STATUS
 721          *
 722          * @return MySQLMasterPos|bool
 723          */
 724         function getSlavePos() {
 725                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 726                         $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
 727                         wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
 728
 729                         return $pos;
 730                 }
 731
 732                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 733                 $row = $this->fetchObject( $res );
 734
 735                 if ( $row ) {
 736                         $pos = isset( $row->Exec_master_log_pos )
 737                                 ? $row->Exec_master_log_pos
 738                                 : $row->Exec_Master_Log_Pos;
 739
 740                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 741                 } else {
 742                         return false;
 743                 }
 744         }
 745
 746         /**
 747          * Get the position of the master from SHOW MASTER STATUS
 748          *
 749          * @return MySQLMasterPos|bool
 750          */
 751         function getMasterPos() {
 752                 if ( $this->mFakeMaster ) {
 753                         return new MySQLMasterPos( 'fake', microtime( true ) );
 754                 }
 755
 756                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 757                 $row = $this->fetchObject( $res );
 758
 759                 if ( $row ) {
 760                         return new MySQLMasterPos( $row->File, $row->Position );
 761                 } else {
 762                         return false;
 763                 }
 764         }
 765
 766         /**
 767          * @param string $index
 768          * @return string
 769          */
 770         function useIndexClause( $index ) {
 771                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 772         }
 773
 774         /**
 775          * @return string
 776          */
 777         function lowPriorityOption() {
 778                 return 'LOW_PRIORITY';
 779         }
 780
 781         /**
 782          * @return string
 783          */
 784         public function getSoftwareLink() {
 785                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 786                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 787                 // in libmysql/libmysql.c).
 788                 $version = $this->getServerVersion();
 789                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 790                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 791                 }
 792
 793                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 794                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 795                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 796                 return '[{{int:version-db-mysql-url}} MySQL]';
 797         }
 798
 799         /**
 800          * @return string
 801          */
 802         public function getServerVersion() {
 803                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 804                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 805                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 806                 if ( $this->serverVersion === null ) {
 807                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 808                 }
 809                 return $this->serverVersion;
 810         }
 811
 812         /**
 813          * @param array $options
 814          */
 815         public function setSessionOptions( array $options ) {
 816                 if ( isset( $options['connTimeout'] ) ) {
 817                         $timeout = (int)$options['connTimeout'];
 818                         $this->query( "SET net_read_timeout=$timeout" );
 819                         $this->query( "SET net_write_timeout=$timeout" );
 820                 }
 821         }
 822
 823         /**
 824          * @param string $sql
 825          * @param string $newLine
 826          * @return bool
 827          */
 828         public function streamStatementEnd( &$sql, &$newLine ) {
 829                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 830                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 831                         $this->delimiter = $m[1];
 832                         $newLine = '';
 833                 }
 834
 835                 return parent::streamStatementEnd( $sql, $newLine );
 836         }
 837
 838         /**
 839          * Check to see if a named lock is available. This is non-blocking.
 840          *
 841          * @param string $lockName Name of lock to poll
 842          * @param string $method Name of method calling us
 843          * @return bool
 844          * @since 1.20
 845          */
 846         public function lockIsFree( $lockName, $method ) {
 847                 $lockName = $this->addQuotes( $lockName );
 848                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 849                 $row = $this->fetchObject( $result );
 850
 851                 return ( $row->lockstatus == 1 );
 852         }
 853
 854         /**
 855          * @param string $lockName
 856          * @param string $method
 857          * @param int $timeout
 858          * @return bool
 859          */
 860         public function lock( $lockName, $method, $timeout = 5 ) {
 861                 $lockName = $this->addQuotes( $lockName );
 862                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 863                 $row = $this->fetchObject( $result );
 864
 865                 if ( $row->lockstatus == 1 ) {
 866                         return true;
 867                 } else {
 868                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 869
 870                         return false;
 871                 }
 872         }
 873
 874         /**
 875          * FROM MYSQL DOCS:
 876          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 877          * @param string $lockName
 878          * @param string $method
 879          * @return bool
 880          */
 881         public function unlock( $lockName, $method ) {
 882                 $lockName = $this->addQuotes( $lockName );
 883                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 884                 $row = $this->fetchObject( $result );
 885
 886                 return ( $row->lockstatus == 1 );
 887         }
 888
 889         /**
 890          * @param array $read
 891          * @param array $write
 892          * @param string $method
 893          * @param bool $lowPriority
 894          * @return bool
 895          */
 896         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 897                 $items = array();
 898
 899                 foreach ( $write as $table ) {
 900                         $tbl = $this->tableName( $table ) .
 901                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 902                                 ' WRITE';
 903                         $items[] = $tbl;
 904                 }
 905                 foreach ( $read as $table ) {
 906                         $items[] = $this->tableName( $table ) . ' READ';
 907                 }
 908                 $sql = "LOCK TABLES " . implode( ',', $items );
 909                 $this->query( $sql, $method );
 910
 911                 return true;
 912         }
 913
 914         /**
 915          * @param string $method
 916          * @return bool
 917          */
 918         public function unlockTables( $method ) {
 919                 $this->query( "UNLOCK TABLES", $method );
 920
 921                 return true;
 922         }
 923
 924         /**
 925          * Get search engine class. All subclasses of this
 926          * need to implement this if they wish to use searching.
 927          *
 928          * @return string
 929          */
 930         public function getSearchEngine() {
 931                 return 'SearchMySQL';
 932         }
 933
 934         /**
 935          * @param bool $value
 936          */
 937         public function setBigSelects( $value = true ) {
 938                 if ( $value === 'default' ) {
 939                         if ( $this->mDefaultBigSelects === null ) {
 940                                 # Function hasn't been called before so it must already be set to the default
 941                                 return;
 942                         } else {
 943                                 $value = $this->mDefaultBigSelects;
 944                         }
 945                 } elseif ( $this->mDefaultBigSelects === null ) {
 946                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 947                 }
 948                 $encValue = $value ? '1' : '0';
 949                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 950         }
 951
 952         /**
 953          * DELETE where the condition is a join. MySql uses multi-table deletes.
 954          * @param string $delTable
 955          * @param string $joinTable
 956          * @param string $delVar
 957          * @param string $joinVar
 958          * @param array|string $conds
 959          * @param bool|string $fname
 960          * @throws DBUnexpectedError
 961          * @return bool|ResultWrapper
 962          */
 963         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 964                 if ( !$conds ) {
 965                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 966                 }
 967
 968                 $delTable = $this->tableName( $delTable );
 969                 $joinTable = $this->tableName( $joinTable );
 970                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 971
 972                 if ( $conds != '*' ) {
 973                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 974                 }
 975
 976                 return $this->query( $sql, $fname );
 977         }
 978
 979         /**
 980          * @param string $table
 981          * @param array $rows
 982          * @param array $uniqueIndexes
 983          * @param array $set
 984          * @param string $fname
 985          * @return bool
 986          */
 987         public function upsert( $table, array $rows, array $uniqueIndexes,
 988                 array $set, $fname = __METHOD__
 989         ) {
 990                 if ( !count( $rows ) ) {
 991                         return true; // nothing to do
 992                 }
 993
 994                 if ( !is_array( reset( $rows ) ) ) {
 995                         $rows = array( $rows );
 996                 }
 997
 998                 $table = $this->tableName( $table );
 999                 $columns = array_keys( $rows[0] );
1000
1001                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1002                 $rowTuples = array();
1003                 foreach ( $rows as $row ) {
1004                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1005                 }
1006                 $sql .= implode( ',', $rowTuples );
1007                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
1008
1009                 return (bool)$this->query( $sql, $fname );
1010         }
1011
1012         /**
1013          * Determines how long the server has been up
1014          *
1015          * @return int
1016          */
1017         function getServerUptime() {
1018                 $vars = $this->getMysqlStatus( 'Uptime' );
1019
1020                 return (int)$vars['Uptime'];
1021         }
1022
1023         /**
1024          * Determines if the last failure was due to a deadlock
1025          *
1026          * @return bool
1027          */
1028         function wasDeadlock() {
1029                 return $this->lastErrno() == 1213;
1030         }
1031
1032         /**
1033          * Determines if the last failure was due to a lock timeout
1034          *
1035          * @return bool
1036          */
1037         function wasLockTimeout() {
1038                 return $this->lastErrno() == 1205;
1039         }
1040
1041         /**
1042          * Determines if the last query error was something that should be dealt
1043          * with by pinging the connection and reissuing the query
1044          *
1045          * @return bool
1046          */
1047         function wasErrorReissuable() {
1048                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1049         }
1050
1051         /**
1052          * Determines if the last failure was due to the database being read-only.
1053          *
1054          * @return bool
1055          */
1056         function wasReadOnlyError() {
1057                 return $this->lastErrno() == 1223 ||
1058                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1059         }
1060
1061         /**
1062          * @param string $oldName
1063          * @param string $newName
1064          * @param bool $temporary
1065          * @param string $fname
1066          * @return bool
1067          */
1068         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1069                 $tmp = $temporary ? 'TEMPORARY ' : '';
1070                 $newName = $this->addIdentifierQuotes( $newName );
1071                 $oldName = $this->addIdentifierQuotes( $oldName );
1072                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1073
1074                 return $this->query( $query, $fname );
1075         }
1076
1077         /**
1078          * List all tables on the database
1079          *
1080          * @param string $prefix Only show tables with this prefix, e.g. mw_
1081          * @param string $fname Calling function name
1082          * @return array
1083          */
1084         function listTables( $prefix = null, $fname = __METHOD__ ) {
1085                 $result = $this->query( "SHOW TABLES", $fname );
1086
1087                 $endArray = array();
1088
1089                 foreach ( $result as $table ) {
1090                         $vars = get_object_vars( $table );
1091                         $table = array_pop( $vars );
1092
1093                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1094                                 $endArray[] = $table;
1095                         }
1096                 }
1097
1098                 return $endArray;
1099         }
1100
1101         /**
1102          * @param string $tableName
1103          * @param string $fName
1104          * @return bool|ResultWrapper
1105          */
1106         public function dropTable( $tableName, $fName = __METHOD__ ) {
1107                 if ( !$this->tableExists( $tableName, $fName ) ) {
1108                         return false;
1109                 }
1110
1111                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1112         }
1113
1114         /**
1115          * @return array
1116          */
1117         protected function getDefaultSchemaVars() {
1118                 $vars = parent::getDefaultSchemaVars();
1119                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1120                 $vars['wgDBTableOptions'] = str_replace(
1121                         'CHARSET=mysql4',
1122                         'CHARSET=binary',
1123                         $vars['wgDBTableOptions']
1124                 );
1125
1126                 return $vars;
1127         }
1128
1129         /**
1130          * Get status information from SHOW STATUS in an associative array
1131          *
1132          * @param string $which
1133          * @return array
1134          */
1135         function getMysqlStatus( $which = "%" ) {
1136                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1137                 $status = array();
1138
1139                 foreach ( $res as $row ) {
1140                         $status[$row->Variable_name] = $row->Value;
1141                 }
1142
1143                 return $status;
1144         }
1145
1146         /**
1147          * Lists VIEWs in the database
1148          *
1149          * @param string $prefix Only show VIEWs with this prefix, eg.
1150          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1151          * @param string $fname Name of calling function
1152          * @return array
1153          * @since 1.22
1154          */
1155         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1156
1157                 if ( !isset( $this->allViews ) ) {
1158
1159                         // The name of the column containing the name of the VIEW
1160                         $propertyName = 'Tables_in_' . $this->mDBname;
1161
1162                         // Query for the VIEWS
1163                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1164                         $this->allViews = array();
1165                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1166                                 array_push( $this->allViews, $row[$propertyName] );
1167                         }
1168                 }
1169
1170                 if ( is_null( $prefix ) || $prefix === '' ) {
1171                         return $this->allViews;
1172                 }
1173
1174                 $filteredViews = array();
1175                 foreach ( $this->allViews as $viewName ) {
1176                         // Does the name of this VIEW start with the table-prefix?
1177                         if ( strpos( $viewName, $prefix ) === 0 ) {
1178                                 array_push( $filteredViews, $viewName );
1179                         }
1180                 }
1181
1182                 return $filteredViews;
1183         }
1184
1185         /**
1186          * Differentiates between a TABLE and a VIEW.
1187          *
1188          * @param string $name Name of the TABLE/VIEW to test
1189          * @param string $prefix
1190          * @return bool
1191          * @since 1.22
1192          */
1193         public function isView( $name, $prefix = null ) {
1194                 return in_array( $name, $this->listViews( $prefix ) );
1195         }
1196 }
1197
1198 /**
1199  * Utility class.
1200  * @ingroup Database
1201  */
1202 class MySQLField implements Field {
1203         private $name, $tablename, $default, $max_length, $nullable,
1204                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary;
1205
1206         function __construct( $info ) {
1207                 $this->name = $info->name;
1208                 $this->tablename = $info->table;
1209                 $this->default = $info->def;
1210                 $this->max_length = $info->max_length;
1211                 $this->nullable = !$info->not_null;
1212                 $this->is_pk = $info->primary_key;
1213                 $this->is_unique = $info->unique_key;
1214                 $this->is_multiple = $info->multiple_key;
1215                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1216                 $this->type = $info->type;
1217                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1218         }
1219
1220         /**
1221          * @return string
1222          */
1223         function name() {
1224                 return $this->name;
1225         }
1226
1227         /**
1228          * @return string
1229          */
1230         function tableName() {
1231                 return $this->tableName;
1232         }
1233
1234         /**
1235          * @return string
1236          */
1237         function type() {
1238                 return $this->type;
1239         }
1240
1241         /**
1242          * @return bool
1243          */
1244         function isNullable() {
1245                 return $this->nullable;
1246         }
1247
1248         function defaultValue() {
1249                 return $this->default;
1250         }
1251
1252         /**
1253          * @return bool
1254          */
1255         function isKey() {
1256                 return $this->is_key;
1257         }
1258
1259         /**
1260          * @return bool
1261          */
1262         function isMultipleKey() {
1263                 return $this->is_multiple;
1264         }
1265
1266         function isBinary() {
1267                 return $this->binary;
1268         }
1269 }
1270
1271 class MySQLMasterPos implements DBMasterPos {
1272         /** @var string */
1273         public $file;
1274         /** @var int Position */
1275         public $pos;
1276         /** @var float UNIX timestamp */
1277         public $asOfTime = 0.0;
1278
1279         function __construct( $file, $pos ) {
1280                 $this->file = $file;
1281                 $this->pos = $pos;
1282                 $this->asOfTime = microtime( true );
1283         }
1284
1285         function __toString() {
1286                 // e.g db1034-bin.000976/843431247
1287                 return "{$this->file}/{$this->pos}";
1288         }
1289
1290         /**
1291          * @return array|bool (int, int)
1292          */
1293         protected function getCoordinates() {
1294                 $m = array();
1295                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1296                         return array( (int)$m[1], (int)$m[2] );
1297                 }
1298
1299                 return false;
1300         }
1301
1302         function hasReached( MySQLMasterPos $pos ) {
1303                 $thisPos = $this->getCoordinates();
1304                 $thatPos = $pos->getCoordinates();
1305
1306                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1307         }
1308
1309         function asOfTime() {
1310                 return $this->asOfTime;
1311         }
1312 }