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         /**
  42          * @return string
  43          */
  44         function getType() {
  45                 return 'mysql';
  46         }
  47
  48         /**
  49          * @param string $server
  50          * @param string $user
  51          * @param string $password
  52          * @param string $dbName
  53          * @throws Exception|DBConnectionError
  54          * @return bool
  55          */
  56         function open( $server, $user, $password, $dbName ) {
  57                 global $wgAllDBsAreLocalhost, $wgSQLMode;
  58                 wfProfileIn( __METHOD__ );
  59
  60                 # Debugging hack -- fake cluster
  61                 if ( $wgAllDBsAreLocalhost ) {
  62                         $realServer = 'localhost';
  63                 } else {
  64                         $realServer = $server;
  65                 }
  66                 $this->close();
  67                 $this->mServer = $server;
  68                 $this->mUser = $user;
  69                 $this->mPassword = $password;
  70                 $this->mDBname = $dbName;
  71
  72                 wfProfileIn( "dbconnect-$server" );
  73
  74                 # The kernel's default SYN retransmission period is far too slow for us,
  75                 # so we use a short timeout plus a manual retry. Retrying means that a small
  76                 # but finite rate of SYN packet loss won't cause user-visible errors.
  77                 $this->mConn = false;
  78                 $this->installErrorHandler();
  79                 try {
  80                         $this->mConn = $this->mysqlConnect( $realServer );
  81                 } catch ( Exception $ex ) {
  82                         wfProfileOut( "dbconnect-$server" );
  83                         wfProfileOut( __METHOD__ );
  84                         $this->restoreErrorHandler();
  85                         throw $ex;
  86                 }
  87                 $error = $this->restoreErrorHandler();
  88
  89                 wfProfileOut( "dbconnect-$server" );
  90
  91                 # Always log connection errors
  92                 if ( !$this->mConn ) {
  93                         if ( !$error ) {
  94                                 $error = $this->lastError();
  95                         }
  96                         wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
  97                         wfDebug( "DB connection error\n" .
  98                                 "Server: $server, User: $user, Password: " .
  99                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 100
 101                         wfProfileOut( __METHOD__ );
 102
 103                         $this->reportConnectionError( $error );
 104                 }
 105
 106                 if ( $dbName != '' ) {
 107                         wfSuppressWarnings();
 108                         $success = $this->selectDB( $dbName );
 109                         wfRestoreWarnings();
 110                         if ( !$success ) {
 111                                 wfLogDBError( "Error selecting database $dbName on server {$this->mServer}\n" );
 112                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 113                                         "from client host " . wfHostname() . "\n" );
 114
 115                                 wfProfileOut( __METHOD__ );
 116
 117                                 $this->reportConnectionError( "Error selecting database $dbName" );
 118                         }
 119                 }
 120
 121                 // Tell the server what we're communicating with
 122                 if ( !$this->connectInitCharset() ) {
 123                         $this->reportConnectionError( "Error setting character set" );
 124                 }
 125
 126                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 127                 if ( is_string( $wgSQLMode ) ) {
 128                         $mode = $this->addQuotes( $wgSQLMode );
 129                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 130                         $success = $this->doQuery( "SET sql_mode = $mode", __METHOD__ );
 131                         if ( !$success ) {
 132                                 wfLogDBError( "Error setting sql_mode to $mode on server {$this->mServer}" );
 133                                 wfProfileOut( __METHOD__ );
 134                                 $this->reportConnectionError( "Error setting sql_mode to $mode" );
 135                         }
 136                 }
 137
 138                 $this->mOpened = true;
 139                 wfProfileOut( __METHOD__ );
 140
 141                 return true;
 142         }
 143
 144         /**
 145          * Set the character set information right after connection
 146          * @return bool
 147          */
 148         protected function connectInitCharset() {
 149                 global $wgDBmysql5;
 150
 151                 if ( $wgDBmysql5 ) {
 152                         // Tell the server we're communicating with it in UTF-8.
 153                         // This may engage various charset conversions.
 154                         return $this->mysqlSetCharset( 'utf8' );
 155                 } else {
 156                         return $this->mysqlSetCharset( 'binary' );
 157                 }
 158         }
 159
 160         /**
 161          * Open a connection to a MySQL server
 162          *
 163          * @param string $realServer
 164          * @return mixed Raw connection
 165          * @throws DBConnectionError
 166          */
 167         abstract protected function mysqlConnect( $realServer );
 168
 169         /**
 170          * Set the character set of the MySQL link
 171          *
 172          * @param string $charset
 173          * @return bool
 174          */
 175         abstract protected function mysqlSetCharset( $charset );
 176
 177         /**
 178          * @param ResultWrapper|resource $res
 179          * @throws DBUnexpectedError
 180          */
 181         function freeResult( $res ) {
 182                 if ( $res instanceof ResultWrapper ) {
 183                         $res = $res->result;
 184                 }
 185                 wfSuppressWarnings();
 186                 $ok = $this->mysqlFreeResult( $res );
 187                 wfRestoreWarnings();
 188                 if ( !$ok ) {
 189                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 190                 }
 191         }
 192
 193         /**
 194          * Free result memory
 195          *
 196          * @param resource $res Raw result
 197          * @return bool
 198          */
 199         abstract protected function mysqlFreeResult( $res );
 200
 201         /**
 202          * @param ResultWrapper|resource $res
 203          * @return stdClass|bool
 204          * @throws DBUnexpectedError
 205          */
 206         function fetchObject( $res ) {
 207                 if ( $res instanceof ResultWrapper ) {
 208                         $res = $res->result;
 209                 }
 210                 wfSuppressWarnings();
 211                 $row = $this->mysqlFetchObject( $res );
 212                 wfRestoreWarnings();
 213
 214                 $errno = $this->lastErrno();
 215                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 216                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 217                 // these are the only errors mysql_fetch_object can cause.
 218                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 219                 if ( $errno == 2000 || $errno == 2013 ) {
 220                         throw new DBUnexpectedError(
 221                                 $this,
 222                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 223                         );
 224                 }
 225
 226                 return $row;
 227         }
 228
 229         /**
 230          * Fetch a result row as an object
 231          *
 232          * @param resource $res Raw result
 233          * @return stdClass
 234          */
 235         abstract protected function mysqlFetchObject( $res );
 236
 237         /**
 238          * @param ResultWrapper|resource $res
 239          * @return array|bool
 240          * @throws DBUnexpectedError
 241          */
 242         function fetchRow( $res ) {
 243                 if ( $res instanceof ResultWrapper ) {
 244                         $res = $res->result;
 245                 }
 246                 wfSuppressWarnings();
 247                 $row = $this->mysqlFetchArray( $res );
 248                 wfRestoreWarnings();
 249
 250                 $errno = $this->lastErrno();
 251                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 252                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 253                 // these are the only errors mysql_fetch_array can cause.
 254                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 255                 if ( $errno == 2000 || $errno == 2013 ) {
 256                         throw new DBUnexpectedError(
 257                                 $this,
 258                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 259                         );
 260                 }
 261
 262                 return $row;
 263         }
 264
 265         /**
 266          * Fetch a result row as an associative and numeric array
 267          *
 268          * @param resource $res Raw result
 269          * @return array
 270          */
 271         abstract protected function mysqlFetchArray( $res );
 272
 273         /**
 274          * @throws DBUnexpectedError
 275          * @param ResultWrapper|resource $res
 276          * @return int
 277          */
 278         function numRows( $res ) {
 279                 if ( $res instanceof ResultWrapper ) {
 280                         $res = $res->result;
 281                 }
 282                 wfSuppressWarnings();
 283                 $n = $this->mysqlNumRows( $res );
 284                 wfRestoreWarnings();
 285
 286                 // Unfortunately, mysql_num_rows does not reset the last errno.
 287                 // We are not checking for any errors here, since
 288                 // these are no errors mysql_num_rows can cause.
 289                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 290                 // See https://bugzilla.wikimedia.org/42430
 291                 return $n;
 292         }
 293
 294         /**
 295          * Get number of rows in result
 296          *
 297          * @param resource $res Raw result
 298          * @return int
 299          */
 300         abstract protected function mysqlNumRows( $res );
 301
 302         /**
 303          * @param ResultWrapper|resource $res
 304          * @return int
 305          */
 306         function numFields( $res ) {
 307                 if ( $res instanceof ResultWrapper ) {
 308                         $res = $res->result;
 309                 }
 310
 311                 return $this->mysqlNumFields( $res );
 312         }
 313
 314         /**
 315          * Get number of fields in result
 316          *
 317          * @param resource $res Raw result
 318          * @return int
 319          */
 320         abstract protected function mysqlNumFields( $res );
 321
 322         /**
 323          * @param ResultWrapper|resource $res
 324          * @param $n int
 325          * @return string
 326          */
 327         function fieldName( $res, $n ) {
 328                 if ( $res instanceof ResultWrapper ) {
 329                         $res = $res->result;
 330                 }
 331
 332                 return $this->mysqlFieldName( $res, $n );
 333         }
 334
 335         /**
 336          * Get the name of the specified field in a result
 337          *
 338          * @param ResultWrapper|resource $res
 339          * @param $n int
 340          * @return string
 341          */
 342         abstract protected function mysqlFieldName( $res, $n );
 343
 344         /**
 345          * mysql_field_type() wrapper
 346          * @param ResultWrapper|resource $res
 347          * @param $n int
 348          * @return string
 349          */
 350         public function fieldType( $res, $n ) {
 351                 if ( $res instanceof ResultWrapper ) {
 352                         $res = $res->result;
 353                 }
 354
 355                 return $this->mysqlFieldType( $res, $n );
 356         }
 357
 358         /**
 359          * Get the type of the specified field in a result
 360          *
 361          * @param ResultWrapper|resource $res
 362          * @param int $n
 363          * @return string
 364          */
 365         abstract protected function mysqlFieldType( $res, $n );
 366
 367         /**
 368          * @param ResultWrapper|resource $res
 369          * @param int $row
 370          * @return bool
 371          */
 372         function dataSeek( $res, $row ) {
 373                 if ( $res instanceof ResultWrapper ) {
 374                         $res = $res->result;
 375                 }
 376
 377                 return $this->mysqlDataSeek( $res, $row );
 378         }
 379
 380         /**
 381          * Move internal result pointer
 382          *
 383          * @param ResultWrapper|resource $res
 384          * @param int $row
 385          * @return bool
 386          */
 387         abstract protected function mysqlDataSeek( $res, $row );
 388
 389         /**
 390          * @return string
 391          */
 392         function lastError() {
 393                 if ( $this->mConn ) {
 394                         # Even if it's non-zero, it can still be invalid
 395                         wfSuppressWarnings();
 396                         $error = $this->mysqlError( $this->mConn );
 397                         if ( !$error ) {
 398                                 $error = $this->mysqlError();
 399                         }
 400                         wfRestoreWarnings();
 401                 } else {
 402                         $error = $this->mysqlError();
 403                 }
 404                 if ( $error ) {
 405                         $error .= ' (' . $this->mServer . ')';
 406                 }
 407
 408                 return $error;
 409         }
 410
 411         /**
 412          * Returns the text of the error message from previous MySQL operation
 413          *
 414          * @param resource $conn Raw connection
 415          * @return string
 416          */
 417         abstract protected function mysqlError( $conn = null );
 418
 419         /**
 420          * @param string $table
 421          * @param array $uniqueIndexes
 422          * @param array $rows
 423          * @param string $fname
 424          * @return ResultWrapper
 425          */
 426         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 427                 return $this->nativeReplace( $table, $rows, $fname );
 428         }
 429
 430         /**
 431          * Estimate rows in dataset
 432          * Returns estimated count, based on EXPLAIN output
 433          * Takes same arguments as Database::select()
 434          *
 435          * @param string|array $table
 436          * @param string|array $vars
 437          * @param string|array $conds
 438          * @param string $fname
 439          * @param string|array $options
 440          * @return bool|int
 441          */
 442         public function estimateRowCount( $table, $vars = '*', $conds = '',
 443                 $fname = __METHOD__, $options = array()
 444         ) {
 445                 $options['EXPLAIN'] = true;
 446                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 447                 if ( $res === false ) {
 448                         return false;
 449                 }
 450                 if ( !$this->numRows( $res ) ) {
 451                         return 0;
 452                 }
 453
 454                 $rows = 1;
 455                 foreach ( $res as $plan ) {
 456                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 457                 }
 458
 459                 return $rows;
 460         }
 461
 462         /**
 463          * @param string $table
 464          * @param string $field
 465          * @return bool|MySQLField
 466          */
 467         function fieldInfo( $table, $field ) {
 468                 $table = $this->tableName( $table );
 469                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 470                 if ( !$res ) {
 471                         return false;
 472                 }
 473                 $n = $this->mysqlNumFields( $res->result );
 474                 for ( $i = 0; $i < $n; $i++ ) {
 475                         $meta = $this->mysqlFetchField( $res->result, $i );
 476                         if ( $field == $meta->name ) {
 477                                 return new MySQLField( $meta );
 478                         }
 479                 }
 480
 481                 return false;
 482         }
 483
 484         /**
 485          * Get column information from a result
 486          *
 487          * @param resource $res Raw result
 488          * @param int $n
 489          * @return stdClass
 490          */
 491         abstract protected function mysqlFetchField( $res, $n );
 492
 493         /**
 494          * Get information about an index into an object
 495          * Returns false if the index does not exist
 496          *
 497          * @param string $table
 498          * @param string $index
 499          * @param string $fname
 500          * @return bool|array|null False or null on failure
 501          */
 502         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 503                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 504                 # SHOW INDEX should work for 3.x and up:
 505                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 506                 $table = $this->tableName( $table );
 507                 $index = $this->indexName( $index );
 508
 509                 $sql = 'SHOW INDEX FROM ' . $table;
 510                 $res = $this->query( $sql, $fname );
 511
 512                 if ( !$res ) {
 513                         return null;
 514                 }
 515
 516                 $result = array();
 517
 518                 foreach ( $res as $row ) {
 519                         if ( $row->Key_name == $index ) {
 520                                 $result[] = $row;
 521                         }
 522                 }
 523
 524                 return empty( $result ) ? false : $result;
 525         }
 526
 527         /**
 528          * @param string $s
 529          * @return string
 530          */
 531         function strencode( $s ) {
 532                 $sQuoted = $this->mysqlRealEscapeString( $s );
 533
 534                 if ( $sQuoted === false ) {
 535                         $this->ping();
 536                         $sQuoted = $this->mysqlRealEscapeString( $s );
 537                 }
 538
 539                 return $sQuoted;
 540         }
 541
 542         /**
 543          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 544          *
 545          * @param string $s
 546          * @return string
 547          */
 548         public function addIdentifierQuotes( $s ) {
 549                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 550                 // Remove NUL bytes and escape backticks by doubling
 551                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s ) . '`';
 552         }
 553
 554         /**
 555          * @param string $name
 556          * @return bool
 557          */
 558         public function isQuotedIdentifier( $name ) {
 559                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 560         }
 561
 562         /**
 563          * @return bool
 564          */
 565         function ping() {
 566                 $ping = $this->mysqlPing();
 567                 if ( $ping ) {
 568                         return true;
 569                 }
 570
 571                 $this->closeConnection();
 572                 $this->mOpened = false;
 573                 $this->mConn = false;
 574                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 575
 576                 return true;
 577         }
 578
 579         /**
 580          * Ping a server connection or reconnect if there is no connection
 581          *
 582          * @return bool
 583          */
 584         abstract protected function mysqlPing();
 585
 586         /**
 587          * Set lag time in seconds for a fake slave
 588          *
 589          * @param int $lag
 590          */
 591         public function setFakeSlaveLag( $lag ) {
 592                 $this->mFakeSlaveLag = $lag;
 593         }
 594
 595         /**
 596          * Make this connection a fake master
 597          *
 598          * @param bool $enabled
 599          */
 600         public function setFakeMaster( $enabled = true ) {
 601                 $this->mFakeMaster = $enabled;
 602         }
 603
 604         /**
 605          * Returns slave lag.
 606          *
 607          * This will do a SHOW SLAVE STATUS
 608          *
 609          * @return int
 610          */
 611         function getLag() {
 612                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 613                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 614
 615                         return $this->mFakeSlaveLag;
 616                 }
 617
 618                 return $this->getLagFromSlaveStatus();
 619         }
 620
 621         /**
 622          * @return bool|int
 623          */
 624         function getLagFromSlaveStatus() {
 625                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 626                 if ( !$res ) {
 627                         return false;
 628                 }
 629                 $row = $res->fetchObject();
 630                 if ( !$row ) {
 631                         return false;
 632                 }
 633                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 634                         return false;
 635                 } else {
 636                         return intval( $row->Seconds_Behind_Master );
 637                 }
 638         }
 639
 640         /**
 641          * @deprecated in 1.19, use getLagFromSlaveStatus
 642          *
 643          * @return bool|int
 644          */
 645         function getLagFromProcesslist() {
 646                 wfDeprecated( __METHOD__, '1.19' );
 647                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 648                 if ( !$res ) {
 649                         return false;
 650                 }
 651                 # Find slave SQL thread
 652                 foreach ( $res as $row ) {
 653                         /* This should work for most situations - when default db
 654                          * for thread is not specified, it had no events executed,
 655                          * and therefore it doesn't know yet how lagged it is.
 656                          *
 657                          * Relay log I/O thread does not select databases.
 658                          */
 659                         if ( $row->User == 'system user' &&
 660                                 $row->State != 'Waiting for master to send event' &&
 661                                 $row->State != 'Connecting to master' &&
 662                                 $row->State != 'Queueing master event to the relay log' &&
 663                                 $row->State != 'Waiting for master update' &&
 664                                 $row->State != 'Requesting binlog dump' &&
 665                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 666                                 $row->State != 'Reconnecting after a failed master event read' &&
 667                                 $row->State != 'Registering slave on master'
 668                         ) {
 669                                 # This is it, return the time (except -ve)
 670                                 if ( $row->Time > 0x7fffffff ) {
 671                                         return false;
 672                                 } else {
 673                                         return $row->Time;
 674                                 }
 675                         }
 676                 }
 677
 678                 return false;
 679         }
 680
 681         /**
 682          * Wait for the slave to catch up to a given master position.
 683          * @todo Return values for this and base class are rubbish
 684          *
 685          * @param DBMasterPos|MySQLMasterPos $pos
 686          * @param int $timeout The maximum number of seconds to wait for synchronisation
 687          * @return int Zero if the slave was past that position already,
 688          *   greater than zero if we waited for some period of time, less than
 689          *   zero if we timed out.
 690          */
 691         function masterPosWait( DBMasterPos $pos, $timeout ) {
 692                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 693                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 694                 }
 695
 696                 wfProfileIn( __METHOD__ );
 697                 # Commit any open transactions
 698                 $this->commit( __METHOD__, 'flush' );
 699
 700                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 701                         $wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
 702
 703                         if ( $wait > $timeout * 1e6 ) {
 704                                 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
 705                                 wfProfileOut( __METHOD__ );
 706
 707                                 return -1;
 708                         } elseif ( $wait > 0 ) {
 709                                 wfDebug( "Fake slave waiting $wait us\n" );
 710                                 usleep( $wait );
 711                                 wfProfileOut( __METHOD__ );
 712
 713                                 return 1;
 714                         } else {
 715                                 wfDebug( "Fake slave up to date ($wait us)\n" );
 716                                 wfProfileOut( __METHOD__ );
 717
 718                                 return 0;
 719                         }
 720                 }
 721
 722                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 723                 $encFile = $this->addQuotes( $pos->file );
 724                 $encPos = intval( $pos->pos );
 725                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 726                 $res = $this->doQuery( $sql );
 727
 728                 $status = false;
 729                 if ( $res && $row = $this->fetchRow( $res ) ) {
 730                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 731                         if ( ctype_digit( $status ) ) { // success
 732                                 $this->lastKnownSlavePos = $pos;
 733                         }
 734                 }
 735
 736                 wfProfileOut( __METHOD__ );
 737
 738                 return $status;
 739         }
 740
 741         /**
 742          * Get the position of the master from SHOW SLAVE STATUS
 743          *
 744          * @return MySQLMasterPos|bool
 745          */
 746         function getSlavePos() {
 747                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 748                         $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
 749                         wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
 750
 751                         return $pos;
 752                 }
 753
 754                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 755                 $row = $this->fetchObject( $res );
 756
 757                 if ( $row ) {
 758                         $pos = isset( $row->Exec_master_log_pos )
 759                                 ? $row->Exec_master_log_pos
 760                                 : $row->Exec_Master_Log_Pos;
 761
 762                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 763                 } else {
 764                         return false;
 765                 }
 766         }
 767
 768         /**
 769          * Get the position of the master from SHOW MASTER STATUS
 770          *
 771          * @return MySQLMasterPos|bool
 772          */
 773         function getMasterPos() {
 774                 if ( $this->mFakeMaster ) {
 775                         return new MySQLMasterPos( 'fake', microtime( true ) );
 776                 }
 777
 778                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 779                 $row = $this->fetchObject( $res );
 780
 781                 if ( $row ) {
 782                         return new MySQLMasterPos( $row->File, $row->Position );
 783                 } else {
 784                         return false;
 785                 }
 786         }
 787
 788         /**
 789          * @param string $index
 790          * @return string
 791          */
 792         function useIndexClause( $index ) {
 793                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 794         }
 795
 796         /**
 797          * @return string
 798          */
 799         function lowPriorityOption() {
 800                 return 'LOW_PRIORITY';
 801         }
 802
 803         /**
 804          * @return string
 805          */
 806         public function getSoftwareLink() {
 807                 $version = $this->getServerVersion();
 808                 if ( strpos( $version, 'MariaDB' ) !== false ) {
 809                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 810                 } elseif ( strpos( $version, 'percona' ) !== false ) {
 811                         return '[{{int:version-db-percona-url}} Percona Server]';
 812                 } else {
 813                         return '[{{int:version-db-mysql-url}} MySQL]';
 814                 }
 815         }
 816
 817         /**
 818          * @param array $options
 819          */
 820         public function setSessionOptions( array $options ) {
 821                 if ( isset( $options['connTimeout'] ) ) {
 822                         $timeout = (int)$options['connTimeout'];
 823                         $this->query( "SET net_read_timeout=$timeout" );
 824                         $this->query( "SET net_write_timeout=$timeout" );
 825                 }
 826         }
 827
 828         /**
 829          * @param string $sql
 830          * @param string $newLine
 831          * @return bool
 832          */
 833         public function streamStatementEnd( &$sql, &$newLine ) {
 834                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 835                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 836                         $this->delimiter = $m[1];
 837                         $newLine = '';
 838                 }
 839
 840                 return parent::streamStatementEnd( $sql, $newLine );
 841         }
 842
 843         /**
 844          * Check to see if a named lock is available. This is non-blocking.
 845          *
 846          * @param string $lockName name of lock to poll
 847          * @param string $method name of method calling us
 848          * @return bool
 849          * @since 1.20
 850          */
 851         public function lockIsFree( $lockName, $method ) {
 852                 $lockName = $this->addQuotes( $lockName );
 853                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 854                 $row = $this->fetchObject( $result );
 855
 856                 return ( $row->lockstatus == 1 );
 857         }
 858
 859         /**
 860          * @param string $lockName
 861          * @param string $method
 862          * @param int $timeout
 863          * @return bool
 864          */
 865         public function lock( $lockName, $method, $timeout = 5 ) {
 866                 $lockName = $this->addQuotes( $lockName );
 867                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 868                 $row = $this->fetchObject( $result );
 869
 870                 if ( $row->lockstatus == 1 ) {
 871                         return true;
 872                 } else {
 873                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 874
 875                         return false;
 876                 }
 877         }
 878
 879         /**
 880          * FROM MYSQL DOCS:
 881          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 882          * @param string $lockName
 883          * @param string $method
 884          * @return bool
 885          */
 886         public function unlock( $lockName, $method ) {
 887                 $lockName = $this->addQuotes( $lockName );
 888                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 889                 $row = $this->fetchObject( $result );
 890
 891                 return ( $row->lockstatus == 1 );
 892         }
 893
 894         /**
 895          * @param array $read
 896          * @param array $write
 897          * @param string $method
 898          * @param bool $lowPriority
 899          * @return bool
 900          */
 901         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 902                 $items = array();
 903
 904                 foreach ( $write as $table ) {
 905                         $tbl = $this->tableName( $table ) .
 906                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 907                                 ' WRITE';
 908                         $items[] = $tbl;
 909                 }
 910                 foreach ( $read as $table ) {
 911                         $items[] = $this->tableName( $table ) . ' READ';
 912                 }
 913                 $sql = "LOCK TABLES " . implode( ',', $items );
 914                 $this->query( $sql, $method );
 915
 916                 return true;
 917         }
 918
 919         /**
 920          * @param string $method
 921          * @return bool
 922          */
 923         public function unlockTables( $method ) {
 924                 $this->query( "UNLOCK TABLES", $method );
 925
 926                 return true;
 927         }
 928
 929         /**
 930          * Get search engine class. All subclasses of this
 931          * need to implement this if they wish to use searching.
 932          *
 933          * @return string
 934          */
 935         public function getSearchEngine() {
 936                 return 'SearchMySQL';
 937         }
 938
 939         /**
 940          * @param bool $value
 941          * @return mixed null|bool|ResultWrapper
 942          */
 943         public function setBigSelects( $value = true ) {
 944                 if ( $value === 'default' ) {
 945                         if ( $this->mDefaultBigSelects === null ) {
 946                                 # Function hasn't been called before so it must already be set to the default
 947                                 return;
 948                         } else {
 949                                 $value = $this->mDefaultBigSelects;
 950                         }
 951                 } elseif ( $this->mDefaultBigSelects === null ) {
 952                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 953                 }
 954                 $encValue = $value ? '1' : '0';
 955                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 956         }
 957
 958         /**
 959          * DELETE where the condition is a join. MySql uses multi-table deletes.
 960          * @param $delTable string
 961          * @param $joinTable string
 962          * @param $delVar string
 963          * @param $joinVar string
 964          * @param $conds array|string
 965          * @param bool|string $fname bool
 966          * @throws DBUnexpectedError
 967          * @return bool|ResultWrapper
 968          */
 969         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 970                 if ( !$conds ) {
 971                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 972                 }
 973
 974                 $delTable = $this->tableName( $delTable );
 975                 $joinTable = $this->tableName( $joinTable );
 976                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 977
 978                 if ( $conds != '*' ) {
 979                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 980                 }
 981
 982                 return $this->query( $sql, $fname );
 983         }
 984
 985         /**
 986          * @param string $table
 987          * @param array $rows
 988          * @param array $uniqueIndexes
 989          * @param array $set
 990          * @param string $fname
 991          * @return bool
 992          */
 993         public function upsert( $table, array $rows, array $uniqueIndexes,
 994                 array $set, $fname = __METHOD__
 995         ) {
 996                 if ( !count( $rows ) ) {
 997                         return true; // nothing to do
 998                 }
 999                 $rows = is_array( reset( $rows ) ) ? $rows : array( $rows );
1000
1001                 $table = $this->tableName( $table );
1002                 $columns = array_keys( $rows[0] );
1003
1004                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1005                 $rowTuples = array();
1006                 foreach ( $rows as $row ) {
1007                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1008                 }
1009                 $sql .= implode( ',', $rowTuples );
1010                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
1011
1012                 return (bool)$this->query( $sql, $fname );
1013         }
1014
1015         /**
1016          * Determines how long the server has been up
1017          *
1018          * @return int
1019          */
1020         function getServerUptime() {
1021                 $vars = $this->getMysqlStatus( 'Uptime' );
1022
1023                 return (int)$vars['Uptime'];
1024         }
1025
1026         /**
1027          * Determines if the last failure was due to a deadlock
1028          *
1029          * @return bool
1030          */
1031         function wasDeadlock() {
1032                 return $this->lastErrno() == 1213;
1033         }
1034
1035         /**
1036          * Determines if the last failure was due to a lock timeout
1037          *
1038          * @return bool
1039          */
1040         function wasLockTimeout() {
1041                 return $this->lastErrno() == 1205;
1042         }
1043
1044         /**
1045          * Determines if the last query error was something that should be dealt
1046          * with by pinging the connection and reissuing the query
1047          *
1048          * @return bool
1049          */
1050         function wasErrorReissuable() {
1051                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1052         }
1053
1054         /**
1055          * Determines if the last failure was due to the database being read-only.
1056          *
1057          * @return bool
1058          */
1059         function wasReadOnlyError() {
1060                 return $this->lastErrno() == 1223 ||
1061                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1062         }
1063
1064         /**
1065          * @param string $oldName
1066          * @param string $newName
1067          * @param bool $temporary
1068          * @param string $fname
1069          * @return bool
1070          */
1071         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1072                 $tmp = $temporary ? 'TEMPORARY ' : '';
1073                 $newName = $this->addIdentifierQuotes( $newName );
1074                 $oldName = $this->addIdentifierQuotes( $oldName );
1075                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1076
1077                 return $this->query( $query, $fname );
1078         }
1079
1080         /**
1081          * List all tables on the database
1082          *
1083          * @param string $prefix Only show tables with this prefix, e.g. mw_
1084          * @param string $fname Calling function name
1085          * @return array
1086          */
1087         function listTables( $prefix = null, $fname = __METHOD__ ) {
1088                 $result = $this->query( "SHOW TABLES", $fname );
1089
1090                 $endArray = array();
1091
1092                 foreach ( $result as $table ) {
1093                         $vars = get_object_vars( $table );
1094                         $table = array_pop( $vars );
1095
1096                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1097                                 $endArray[] = $table;
1098                         }
1099                 }
1100
1101                 return $endArray;
1102         }
1103
1104         /**
1105          * @param $tableName
1106          * @param $fName string
1107          * @return bool|ResultWrapper
1108          */
1109         public function dropTable( $tableName, $fName = __METHOD__ ) {
1110                 if ( !$this->tableExists( $tableName, $fName ) ) {
1111                         return false;
1112                 }
1113
1114                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1115         }
1116
1117         /**
1118          * @return array
1119          */
1120         protected function getDefaultSchemaVars() {
1121                 $vars = parent::getDefaultSchemaVars();
1122                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1123                 $vars['wgDBTableOptions'] = str_replace(
1124                         'CHARSET=mysql4',
1125                         'CHARSET=binary',
1126                         $vars['wgDBTableOptions']
1127                 );
1128
1129                 return $vars;
1130         }
1131
1132         /**
1133          * Get status information from SHOW STATUS in an associative array
1134          *
1135          * @param string $which
1136          * @return array
1137          */
1138         function getMysqlStatus( $which = "%" ) {
1139                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1140                 $status = array();
1141
1142                 foreach ( $res as $row ) {
1143                         $status[$row->Variable_name] = $row->Value;
1144                 }
1145
1146                 return $status;
1147         }
1148
1149         /**
1150          * Lists VIEWs in the database
1151          *
1152          * @param string $prefix Only show VIEWs with this prefix, eg.
1153          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1154          * @param string $fname Name of calling function
1155          * @return array
1156          * @since 1.22
1157          */
1158         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1159
1160                 if ( !isset( $this->allViews ) ) {
1161
1162                         // The name of the column containing the name of the VIEW
1163                         $propertyName = 'Tables_in_' . $this->mDBname;
1164
1165                         // Query for the VIEWS
1166                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1167                         $this->allViews = array();
1168                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1169                                 array_push( $this->allViews, $row[$propertyName] );
1170                         }
1171                 }
1172
1173                 if ( is_null( $prefix ) || $prefix === '' ) {
1174                         return $this->allViews;
1175                 }
1176
1177                 $filteredViews = array();
1178                 foreach ( $this->allViews as $viewName ) {
1179                         // Does the name of this VIEW start with the table-prefix?
1180                         if ( strpos( $viewName, $prefix ) === 0 ) {
1181                                 array_push( $filteredViews, $viewName );
1182                         }
1183                 }
1184
1185                 return $filteredViews;
1186         }
1187
1188         /**
1189          * Differentiates between a TABLE and a VIEW.
1190          *
1191          * @param string $name Name of the TABLE/VIEW to test
1192          * @param string $prefix
1193          * @return bool
1194          * @since 1.22
1195          */
1196         public function isView( $name, $prefix = null ) {
1197                 return in_array( $name, $this->listViews( $prefix ) );
1198         }
1199 }
1200
1201 /**
1202  * Utility class.
1203  * @ingroup Database
1204  */
1205 class MySQLField implements Field {
1206         private $name, $tablename, $default, $max_length, $nullable,
1207                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary;
1208
1209         function __construct( $info ) {
1210                 $this->name = $info->name;
1211                 $this->tablename = $info->table;
1212                 $this->default = $info->def;
1213                 $this->max_length = $info->max_length;
1214                 $this->nullable = !$info->not_null;
1215                 $this->is_pk = $info->primary_key;
1216                 $this->is_unique = $info->unique_key;
1217                 $this->is_multiple = $info->multiple_key;
1218                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1219                 $this->type = $info->type;
1220                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1221         }
1222
1223         /**
1224          * @return string
1225          */
1226         function name() {
1227                 return $this->name;
1228         }
1229
1230         /**
1231          * @return string
1232          */
1233         function tableName() {
1234                 return $this->tableName;
1235         }
1236
1237         /**
1238          * @return string
1239          */
1240         function type() {
1241                 return $this->type;
1242         }
1243
1244         /**
1245          * @return bool
1246          */
1247         function isNullable() {
1248                 return $this->nullable;
1249         }
1250
1251         function defaultValue() {
1252                 return $this->default;
1253         }
1254
1255         /**
1256          * @return bool
1257          */
1258         function isKey() {
1259                 return $this->is_key;
1260         }
1261
1262         /**
1263          * @return bool
1264          */
1265         function isMultipleKey() {
1266                 return $this->is_multiple;
1267         }
1268
1269         function isBinary() {
1270                 return $this->binary;
1271         }
1272 }
1273
1274 class MySQLMasterPos implements DBMasterPos {
1275         /** @var string */
1276         public $file;
1277
1278         /** @var int timestamp */
1279         public $pos;
1280
1281         function __construct( $file, $pos ) {
1282                 $this->file = $file;
1283                 $this->pos = $pos;
1284         }
1285
1286         function __toString() {
1287                 // e.g db1034-bin.000976/843431247
1288                 return "{$this->file}/{$this->pos}";
1289         }
1290
1291         /**
1292          * @return array|false (int, int)
1293          */
1294         protected function getCoordinates() {
1295                 $m = array();
1296                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1297                         return array( (int)$m[1], (int)$m[2] );
1298                 }
1299
1300                 return false;
1301         }
1302
1303         function hasReached( MySQLMasterPos $pos ) {
1304                 $thisPos = $this->getCoordinates();
1305                 $thatPos = $pos->getCoordinates();
1306
1307                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1308         }
1309 }