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