includes/db/DatabaseMysqlBase.php

   1 <?php
   2 /**
   3  * This is the MySQL database abstraction layer.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Database
  22  */
  23
  24 /**
  25  * Database abstraction object for MySQL.
  26  * Defines methods independent on used MySQL extension.
  27  *
  28  * @ingroup Database
  29  * @since 1.22
  30  * @see Database
  31  */
  32 abstract class DatabaseMysqlBase extends DatabaseBase {
  33         /** @var MysqlMasterPos */
  34         protected $lastKnownSlavePos;
  35
  36         /**
  37          * @return string
  38          */
  39         function getType() {
  40                 return 'mysql';
  41         }
  42
  43         /**
  44          * @param $server string
  45          * @param $user string
  46          * @param $password string
  47          * @param $dbName string
  48          * @return bool
  49          * @throws DBConnectionError
  50          */
  51         function open( $server, $user, $password, $dbName ) {
  52                 global $wgAllDBsAreLocalhost, $wgSQLMode;
  53                 wfProfileIn( __METHOD__ );
  54
  55                 # Debugging hack -- fake cluster
  56                 if ( $wgAllDBsAreLocalhost ) {
  57                         $realServer = 'localhost';
  58                 } else {
  59                         $realServer = $server;
  60                 }
  61                 $this->close();
  62                 $this->mServer = $server;
  63                 $this->mUser = $user;
  64                 $this->mPassword = $password;
  65                 $this->mDBname = $dbName;
  66
  67                 wfProfileIn( "dbconnect-$server" );
  68
  69                 # The kernel's default SYN retransmission period is far too slow for us,
  70                 # so we use a short timeout plus a manual retry. Retrying means that a small
  71                 # but finite rate of SYN packet loss won't cause user-visible errors.
  72                 $this->mConn = false;
  73                 $this->installErrorHandler();
  74                 try {
  75                         $this->mConn = $this->mysqlConnect( $realServer );
  76                 } catch ( Exception $ex ) {
  77                         wfProfileOut( "dbconnect-$server" );
  78                         wfProfileOut( __METHOD__ );
  79                         $this->restoreErrorHandler();
  80                         throw $ex;
  81                 }
  82                 $error = $this->restoreErrorHandler();
  83
  84                 wfProfileOut( "dbconnect-$server" );
  85
  86                 # Always log connection errors
  87                 if ( !$this->mConn ) {
  88                         if ( !$error ) {
  89                                 $error = $this->lastError();
  90                         }
  91                         wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
  92                         wfDebug( "DB connection error\n" .
  93                                 "Server: $server, User: $user, Password: " .
  94                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
  95
  96                         wfProfileOut( __METHOD__ );
  97
  98                         $this->reportConnectionError( $error );
  99                 }
 100
 101                 if ( $dbName != '' ) {
 102                         wfSuppressWarnings();
 103                         $success = $this->selectDB( $dbName );
 104                         wfRestoreWarnings();
 105                         if ( !$success ) {
 106                                 wfLogDBError( "Error selecting database $dbName on server {$this->mServer}\n" );
 107                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 108                                         "from client host " . wfHostname() . "\n" );
 109
 110                                 wfProfileOut( __METHOD__ );
 111
 112                                 $this->reportConnectionError( "Error selecting database $dbName" );
 113                         }
 114                 }
 115
 116                 // Tell the server what we're communicating with
 117                 if ( !$this->connectInitCharset() ) {
 118                         $this->reportConnectionError( "Error setting character set" );
 119                 }
 120
 121                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 122                 if ( is_string( $wgSQLMode ) ) {
 123                         $mode = $this->addQuotes( $wgSQLMode );
 124                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 125                         $success = $this->doQuery( "SET sql_mode = $mode", __METHOD__ );
 126                         if ( !$success ) {
 127                                 wfLogDBError( "Error setting sql_mode to $mode on server {$this->mServer}" );
 128                                 wfProfileOut( __METHOD__ );
 129                                 $this->reportConnectionError( "Error setting sql_mode to $mode" );
 130                         }
 131                 }
 132
 133                 $this->mOpened = true;
 134                 wfProfileOut( __METHOD__ );
 135
 136                 return true;
 137         }
 138
 139         /**
 140          * Set the character set information right after connection
 141          * @return bool
 142          */
 143         protected function connectInitCharset() {
 144                 global $wgDBmysql5;
 145
 146                 if ( $wgDBmysql5 ) {
 147                         // Tell the server we're communicating with it in UTF-8.
 148                         // This may engage various charset conversions.
 149                         return $this->mysqlSetCharset( 'utf8' );
 150                 } else {
 151                         return $this->mysqlSetCharset( 'binary' );
 152                 }
 153         }
 154
 155         /**
 156          * Open a connection to a MySQL server
 157          *
 158          * @param $realServer string
 159          * @return mixed Raw connection
 160          * @throws DBConnectionError
 161          */
 162         abstract protected function mysqlConnect( $realServer );
 163
 164         /**
 165          * Set the character set of the MySQL link
 166          *
 167          * @param string $charset
 168          * @return bool
 169          */
 170         abstract protected function mysqlSetCharset( $charset );
 171
 172         /**
 173          * @param $res ResultWrapper
 174          * @throws DBUnexpectedError
 175          */
 176         function freeResult( $res ) {
 177                 if ( $res instanceof ResultWrapper ) {
 178                         $res = $res->result;
 179                 }
 180                 wfSuppressWarnings();
 181                 $ok = $this->mysqlFreeResult( $res );
 182                 wfRestoreWarnings();
 183                 if ( !$ok ) {
 184                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 185                 }
 186         }
 187
 188         /**
 189          * Free result memory
 190          *
 191          * @param $res Raw result
 192          * @return bool
 193          */
 194         abstract protected function mysqlFreeResult( $res );
 195
 196         /**
 197          * @param $res ResultWrapper
 198          * @return object|bool
 199          * @throws DBUnexpectedError
 200          */
 201         function fetchObject( $res ) {
 202                 if ( $res instanceof ResultWrapper ) {
 203                         $res = $res->result;
 204                 }
 205                 wfSuppressWarnings();
 206                 $row = $this->mysqlFetchObject( $res );
 207                 wfRestoreWarnings();
 208
 209                 $errno = $this->lastErrno();
 210                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 211                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 212                 // these are the only errors mysql_fetch_object can cause.
 213                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 214                 if ( $errno == 2000 || $errno == 2013 ) {
 215                         throw new DBUnexpectedError(
 216                                 $this,
 217                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 218                         );
 219                 }
 220
 221                 return $row;
 222         }
 223
 224         /**
 225          * Fetch a result row as an object
 226          *
 227          * @param $res Raw result
 228          * @return stdClass
 229          */
 230         abstract protected function mysqlFetchObject( $res );
 231
 232         /**
 233          * @param $res ResultWrapper
 234          * @return array|bool
 235          * @throws DBUnexpectedError
 236          */
 237         function fetchRow( $res ) {
 238                 if ( $res instanceof ResultWrapper ) {
 239                         $res = $res->result;
 240                 }
 241                 wfSuppressWarnings();
 242                 $row = $this->mysqlFetchArray( $res );
 243                 wfRestoreWarnings();
 244
 245                 $errno = $this->lastErrno();
 246                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 247                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 248                 // these are the only errors mysql_fetch_array can cause.
 249                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 250                 if ( $errno == 2000 || $errno == 2013 ) {
 251                         throw new DBUnexpectedError(
 252                                 $this,
 253                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 254                         );
 255                 }
 256
 257                 return $row;
 258         }
 259
 260         /**
 261          * Fetch a result row as an associative and numeric array
 262          *
 263          * @param $res Raw result
 264          * @return array
 265          */
 266         abstract protected function mysqlFetchArray( $res );
 267
 268         /**
 269          * @throws DBUnexpectedError
 270          * @param $res ResultWrapper
 271          * @return int
 272          */
 273         function numRows( $res ) {
 274                 if ( $res instanceof ResultWrapper ) {
 275                         $res = $res->result;
 276                 }
 277                 wfSuppressWarnings();
 278                 $n = $this->mysqlNumRows( $res );
 279                 wfRestoreWarnings();
 280
 281                 // Unfortunately, mysql_num_rows does not reset the last errno.
 282                 // We are not checking for any errors here, since
 283                 // these are no errors mysql_num_rows can cause.
 284                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 285                 // See https://bugzilla.wikimedia.org/42430
 286                 return $n;
 287         }
 288
 289         /**
 290          * Get number of rows in result
 291          *
 292          * @param $res Raw result
 293          * @return int
 294          */
 295         abstract protected function mysqlNumRows( $res );
 296
 297         /**
 298          * @param $res ResultWrapper
 299          * @return int
 300          */
 301         function numFields( $res ) {
 302                 if ( $res instanceof ResultWrapper ) {
 303                         $res = $res->result;
 304                 }
 305
 306                 return $this->mysqlNumFields( $res );
 307         }
 308
 309         /**
 310          * Get number of fields in result
 311          *
 312          * @param $res Raw result
 313          * @return int
 314          */
 315         abstract protected function mysqlNumFields( $res );
 316
 317         /**
 318          * @param $res ResultWrapper
 319          * @param $n int
 320          * @return string
 321          */
 322         function fieldName( $res, $n ) {
 323                 if ( $res instanceof ResultWrapper ) {
 324                         $res = $res->result;
 325                 }
 326
 327                 return $this->mysqlFieldName( $res, $n );
 328         }
 329
 330         /**
 331          * Get the name of the specified field in a result
 332          *
 333          * @param $res Raw result
 334          * @param $n int
 335          * @return string
 336          */
 337         abstract protected function mysqlFieldName( $res, $n );
 338
 339         /**
 340          * mysql_field_type() wrapper
 341          * @param $res
 342          * @param $n int
 343          * @return string
 344          */
 345         public function fieldType( $res, $n ) {
 346                 if ( $res instanceof ResultWrapper ) {
 347                         $res = $res->result;
 348                 }
 349
 350                 return $this->mysqlFieldType( $res, $n );
 351         }
 352
 353         /**
 354          * Get the type of the specified field in a result
 355          *
 356          * @param $res Raw result
 357          * @param $n int
 358          * @return string
 359          */
 360         abstract protected function mysqlFieldType( $res, $n );
 361
 362         /**
 363          * @param $res ResultWrapper
 364          * @param $row
 365          * @return bool
 366          */
 367         function dataSeek( $res, $row ) {
 368                 if ( $res instanceof ResultWrapper ) {
 369                         $res = $res->result;
 370                 }
 371
 372                 return $this->mysqlDataSeek( $res, $row );
 373         }
 374
 375         /**
 376          * Move internal result pointer
 377          *
 378          * @param $res Raw result
 379          * @param $row int
 380          * @return bool
 381          */
 382         abstract protected function mysqlDataSeek( $res, $row );
 383
 384         /**
 385          * @return string
 386          */
 387         function lastError() {
 388                 if ( $this->mConn ) {
 389                         # Even if it's non-zero, it can still be invalid
 390                         wfSuppressWarnings();
 391                         $error = $this->mysqlError( $this->mConn );
 392                         if ( !$error ) {
 393                                 $error = $this->mysqlError();
 394                         }
 395                         wfRestoreWarnings();
 396                 } else {
 397                         $error = $this->mysqlError();
 398                 }
 399                 if ( $error ) {
 400                         $error .= ' (' . $this->mServer . ')';
 401                 }
 402
 403                 return $error;
 404         }
 405
 406         /**
 407          * Returns the text of the error message from previous MySQL operation
 408          *
 409          * @param $conn Raw connection
 410          * @return string
 411          */
 412         abstract protected function mysqlError( $conn = null );
 413
 414         /**
 415          * @param $table string
 416          * @param $uniqueIndexes
 417          * @param $rows array
 418          * @param $fname string
 419          * @return ResultWrapper
 420          */
 421         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 422                 return $this->nativeReplace( $table, $rows, $fname );
 423         }
 424
 425         /**
 426          * Estimate rows in dataset
 427          * Returns estimated count, based on EXPLAIN output
 428          * Takes same arguments as Database::select()
 429          *
 430          * @param $table string|array
 431          * @param $vars string|array
 432          * @param $conds string|array
 433          * @param $fname string
 434          * @param $options string|array
 435          * @return int
 436          */
 437         public function estimateRowCount( $table, $vars = '*', $conds = '',
 438                 $fname = __METHOD__, $options = array()
 439         ) {
 440                 $options['EXPLAIN'] = true;
 441                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 442                 if ( $res === false ) {
 443                         return false;
 444                 }
 445                 if ( !$this->numRows( $res ) ) {
 446                         return 0;
 447                 }
 448
 449                 $rows = 1;
 450                 foreach ( $res as $plan ) {
 451                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 452                 }
 453
 454                 return $rows;
 455         }
 456
 457         /**
 458          * @param $table string
 459          * @param $field string
 460          * @return bool|MySQLField
 461          */
 462         function fieldInfo( $table, $field ) {
 463                 $table = $this->tableName( $table );
 464                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 465                 if ( !$res ) {
 466                         return false;
 467                 }
 468                 $n = $this->mysqlNumFields( $res->result );
 469                 for ( $i = 0; $i < $n; $i++ ) {
 470                         $meta = $this->mysqlFetchField( $res->result, $i );
 471                         if ( $field == $meta->name ) {
 472                                 return new MySQLField( $meta );
 473                         }
 474                 }
 475
 476                 return false;
 477         }
 478
 479         /**
 480          * Get column information from a result
 481          *
 482          * @param $res Raw result
 483          * @param $n int
 484          * @return stdClass
 485          */
 486         abstract protected function mysqlFetchField( $res, $n );
 487
 488         /**
 489          * Get information about an index into an object
 490          * Returns false if the index does not exist
 491          *
 492          * @param $table string
 493          * @param $index string
 494          * @param $fname string
 495          * @return bool|array|null False or null on failure
 496          */
 497         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 498                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 499                 # SHOW INDEX should work for 3.x and up:
 500                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 501                 $table = $this->tableName( $table );
 502                 $index = $this->indexName( $index );
 503
 504                 $sql = 'SHOW INDEX FROM ' . $table;
 505                 $res = $this->query( $sql, $fname );
 506
 507                 if ( !$res ) {
 508                         return null;
 509                 }
 510
 511                 $result = array();
 512
 513                 foreach ( $res as $row ) {
 514                         if ( $row->Key_name == $index ) {
 515                                 $result[] = $row;
 516                         }
 517                 }
 518
 519                 return empty( $result ) ? false : $result;
 520         }
 521
 522         /**
 523          * @param $s string
 524          *
 525          * @return string
 526          */
 527         function strencode( $s ) {
 528                 $sQuoted = $this->mysqlRealEscapeString( $s );
 529
 530                 if ( $sQuoted === false ) {
 531                         $this->ping();
 532                         $sQuoted = $this->mysqlRealEscapeString( $s );
 533                 }
 534
 535                 return $sQuoted;
 536         }
 537
 538         /**
 539          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 540          *
 541          * @param $s string
 542          *
 543          * @return string
 544          */
 545         public function addIdentifierQuotes( $s ) {
 546                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 547                 // Remove NUL bytes and escape backticks by doubling
 548                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s ) . '`';
 549         }
 550
 551         /**
 552          * @param $name string
 553          * @return bool
 554          */
 555         public function isQuotedIdentifier( $name ) {
 556                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 557         }
 558
 559         /**
 560          * @return bool
 561          */
 562         function ping() {
 563                 $ping = $this->mysqlPing();
 564                 if ( $ping ) {
 565                         return true;
 566                 }
 567
 568                 $this->closeConnection();
 569                 $this->mOpened = false;
 570                 $this->mConn = false;
 571                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 572
 573                 return true;
 574         }
 575
 576         /**
 577          * Ping a server connection or reconnect if there is no connection
 578          *
 579          * @return bool
 580          */
 581         abstract protected function mysqlPing();
 582
 583         /**
 584          * Returns slave lag.
 585          *
 586          * This will do a SHOW SLAVE STATUS
 587          *
 588          * @return int
 589          */
 590         function getLag() {
 591                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 592                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 593
 594                         return $this->mFakeSlaveLag;
 595                 }
 596
 597                 return $this->getLagFromSlaveStatus();
 598         }
 599
 600         /**
 601          * @return bool|int
 602          */
 603         function getLagFromSlaveStatus() {
 604                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 605                 if ( !$res ) {
 606                         return false;
 607                 }
 608                 $row = $res->fetchObject();
 609                 if ( !$row ) {
 610                         return false;
 611                 }
 612                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 613                         return false;
 614                 } else {
 615                         return intval( $row->Seconds_Behind_Master );
 616                 }
 617         }
 618
 619         /**
 620          * @deprecated in 1.19, use getLagFromSlaveStatus
 621          *
 622          * @return bool|int
 623          */
 624         function getLagFromProcesslist() {
 625                 wfDeprecated( __METHOD__, '1.19' );
 626                 $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
 627                 if ( !$res ) {
 628                         return false;
 629                 }
 630                 # Find slave SQL thread
 631                 foreach ( $res as $row ) {
 632                         /* This should work for most situations - when default db
 633                          * for thread is not specified, it had no events executed,
 634                          * and therefore it doesn't know yet how lagged it is.
 635                          *
 636                          * Relay log I/O thread does not select databases.
 637                          */
 638                         if ( $row->User == 'system user' &&
 639                                 $row->State != 'Waiting for master to send event' &&
 640                                 $row->State != 'Connecting to master' &&
 641                                 $row->State != 'Queueing master event to the relay log' &&
 642                                 $row->State != 'Waiting for master update' &&
 643                                 $row->State != 'Requesting binlog dump' &&
 644                                 $row->State != 'Waiting to reconnect after a failed master event read' &&
 645                                 $row->State != 'Reconnecting after a failed master event read' &&
 646                                 $row->State != 'Registering slave on master'
 647                         ) {
 648                                 # This is it, return the time (except -ve)
 649                                 if ( $row->Time > 0x7fffffff ) {
 650                                         return false;
 651                                 } else {
 652                                         return $row->Time;
 653                                 }
 654                         }
 655                 }
 656
 657                 return false;
 658         }
 659
 660         /**
 661          * Wait for the slave to catch up to a given master position.
 662          * @TODO: return values for this and base class are rubbish
 663          *
 664          * @param $pos DBMasterPos object
 665          * @param $timeout Integer: the maximum number of seconds to wait for synchronisation
 666          * @return bool|string
 667          */
 668         function masterPosWait( DBMasterPos $pos, $timeout ) {
 669                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 670                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 671                 }
 672
 673                 wfProfileIn( __METHOD__ );
 674                 # Commit any open transactions
 675                 $this->commit( __METHOD__, 'flush' );
 676
 677                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 678                         $status = parent::masterPosWait( $pos, $timeout );
 679                         wfProfileOut( __METHOD__ );
 680
 681                         return $status;
 682                 }
 683
 684                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 685                 $encFile = $this->addQuotes( $pos->file );
 686                 $encPos = intval( $pos->pos );
 687                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 688                 $res = $this->doQuery( $sql );
 689
 690                 $status = false;
 691                 if ( $res && $row = $this->fetchRow( $res ) ) {
 692                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 693                         if ( ctype_digit( $status ) ) { // success
 694                                 $this->lastKnownSlavePos = $pos;
 695                         }
 696                 }
 697
 698                 wfProfileOut( __METHOD__ );
 699
 700                 return $status;
 701         }
 702
 703         /**
 704          * Get the position of the master from SHOW SLAVE STATUS
 705          *
 706          * @return MySQLMasterPos|bool
 707          */
 708         function getSlavePos() {
 709                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 710                         return parent::getSlavePos();
 711                 }
 712
 713                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 714                 $row = $this->fetchObject( $res );
 715
 716                 if ( $row ) {
 717                         $pos = isset( $row->Exec_master_log_pos )
 718                                 ? $row->Exec_master_log_pos
 719                                 : $row->Exec_Master_Log_Pos;
 720
 721                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 722                 } else {
 723                         return false;
 724                 }
 725         }
 726
 727         /**
 728          * Get the position of the master from SHOW MASTER STATUS
 729          *
 730          * @return MySQLMasterPos|bool
 731          */
 732         function getMasterPos() {
 733                 if ( $this->mFakeMaster ) {
 734                         return parent::getMasterPos();
 735                 }
 736
 737                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 738                 $row = $this->fetchObject( $res );
 739
 740                 if ( $row ) {
 741                         return new MySQLMasterPos( $row->File, $row->Position );
 742                 } else {
 743                         return false;
 744                 }
 745         }
 746
 747         /**
 748          * @param $index
 749          * @return string
 750          */
 751         function useIndexClause( $index ) {
 752                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 753         }
 754
 755         /**
 756          * @return string
 757          */
 758         function lowPriorityOption() {
 759                 return 'LOW_PRIORITY';
 760         }
 761
 762         /**
 763          * @return string
 764          */
 765         public function getSoftwareLink() {
 766                 return '[http://www.mysql.com/ MySQL]';
 767         }
 768
 769         /**
 770          * @param $options array
 771          */
 772         public function setSessionOptions( array $options ) {
 773                 if ( isset( $options['connTimeout'] ) ) {
 774                         $timeout = (int)$options['connTimeout'];
 775                         $this->query( "SET net_read_timeout=$timeout" );
 776                         $this->query( "SET net_write_timeout=$timeout" );
 777                 }
 778         }
 779
 780         public function streamStatementEnd( &$sql, &$newLine ) {
 781                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 782                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 783                         $this->delimiter = $m[1];
 784                         $newLine = '';
 785                 }
 786
 787                 return parent::streamStatementEnd( $sql, $newLine );
 788         }
 789
 790         /**
 791          * Check to see if a named lock is available. This is non-blocking.
 792          *
 793          * @param string $lockName name of lock to poll
 794          * @param string $method name of method calling us
 795          * @return Boolean
 796          * @since 1.20
 797          */
 798         public function lockIsFree( $lockName, $method ) {
 799                 $lockName = $this->addQuotes( $lockName );
 800                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 801                 $row = $this->fetchObject( $result );
 802
 803                 return ( $row->lockstatus == 1 );
 804         }
 805
 806         /**
 807          * @param $lockName string
 808          * @param $method string
 809          * @param $timeout int
 810          * @return bool
 811          */
 812         public function lock( $lockName, $method, $timeout = 5 ) {
 813                 $lockName = $this->addQuotes( $lockName );
 814                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 815                 $row = $this->fetchObject( $result );
 816
 817                 if ( $row->lockstatus == 1 ) {
 818                         return true;
 819                 } else {
 820                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 821
 822                         return false;
 823                 }
 824         }
 825
 826         /**
 827          * FROM MYSQL DOCS:
 828          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 829          * @param $lockName string
 830          * @param $method string
 831          * @return bool
 832          */
 833         public function unlock( $lockName, $method ) {
 834                 $lockName = $this->addQuotes( $lockName );
 835                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 836                 $row = $this->fetchObject( $result );
 837
 838                 return ( $row->lockstatus == 1 );
 839         }
 840
 841         /**
 842          * @param $read array
 843          * @param $write array
 844          * @param $method string
 845          * @param $lowPriority bool
 846          * @return bool
 847          */
 848         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 849                 $items = array();
 850
 851                 foreach ( $write as $table ) {
 852                         $tbl = $this->tableName( $table ) .
 853                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 854                                 ' WRITE';
 855                         $items[] = $tbl;
 856                 }
 857                 foreach ( $read as $table ) {
 858                         $items[] = $this->tableName( $table ) . ' READ';
 859                 }
 860                 $sql = "LOCK TABLES " . implode( ',', $items );
 861                 $this->query( $sql, $method );
 862
 863                 return true;
 864         }
 865
 866         /**
 867          * @param $method string
 868          * @return bool
 869          */
 870         public function unlockTables( $method ) {
 871                 $this->query( "UNLOCK TABLES", $method );
 872
 873                 return true;
 874         }
 875
 876         /**
 877          * Get search engine class. All subclasses of this
 878          * need to implement this if they wish to use searching.
 879          *
 880          * @return String
 881          */
 882         public function getSearchEngine() {
 883                 return 'SearchMySQL';
 884         }
 885
 886         /**
 887          * @param bool $value
 888          * @return mixed
 889          */
 890         public function setBigSelects( $value = true ) {
 891                 if ( $value === 'default' ) {
 892                         if ( $this->mDefaultBigSelects === null ) {
 893                                 # Function hasn't been called before so it must already be set to the default
 894                                 return;
 895                         } else {
 896                                 $value = $this->mDefaultBigSelects;
 897                         }
 898                 } elseif ( $this->mDefaultBigSelects === null ) {
 899                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 900                 }
 901                 $encValue = $value ? '1' : '0';
 902                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 903         }
 904
 905         /**
 906          * DELETE where the condition is a join. MySql uses multi-table deletes.
 907          * @param $delTable string
 908          * @param $joinTable string
 909          * @param $delVar string
 910          * @param $joinVar string
 911          * @param $conds array|string
 912          * @param bool|string $fname bool
 913          * @throws DBUnexpectedError
 914          * @return bool|ResultWrapper
 915          */
 916         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 917                 if ( !$conds ) {
 918                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 919                 }
 920
 921                 $delTable = $this->tableName( $delTable );
 922                 $joinTable = $this->tableName( $joinTable );
 923                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 924
 925                 if ( $conds != '*' ) {
 926                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 927                 }
 928
 929                 return $this->query( $sql, $fname );
 930         }
 931
 932         /**
 933          * @param string $table
 934          * @param array $rows
 935          * @param array $uniqueIndexes
 936          * @param array $set
 937          * @param string $fname
 938          * @param array $options
 939          * @return bool
 940          */
 941         public function upsert(
 942                 $table, array $rows, array $uniqueIndexes, array $set, $fname = __METHOD__
 943         ) {
 944                 if ( !count( $rows ) ) {
 945                         return true; // nothing to do
 946                 }
 947                 $rows = is_array( reset( $rows ) ) ? $rows : array( $rows );
 948
 949                 $table = $this->tableName( $table );
 950                 $columns = array_keys( $rows[0] );
 951
 952                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
 953                 $rowTuples = array();
 954                 foreach ( $rows as $row ) {
 955                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
 956                 }
 957                 $sql .= implode( ',', $rowTuples );
 958                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
 959
 960                 return (bool)$this->query( $sql, $fname );
 961         }
 962
 963         /**
 964          * Determines how long the server has been up
 965          *
 966          * @return int
 967          */
 968         function getServerUptime() {
 969                 $vars = $this->getMysqlStatus( 'Uptime' );
 970
 971                 return (int)$vars['Uptime'];
 972         }
 973
 974         /**
 975          * Determines if the last failure was due to a deadlock
 976          *
 977          * @return bool
 978          */
 979         function wasDeadlock() {
 980                 return $this->lastErrno() == 1213;
 981         }
 982
 983         /**
 984          * Determines if the last failure was due to a lock timeout
 985          *
 986          * @return bool
 987          */
 988         function wasLockTimeout() {
 989                 return $this->lastErrno() == 1205;
 990         }
 991
 992         /**
 993          * Determines if the last query error was something that should be dealt
 994          * with by pinging the connection and reissuing the query
 995          *
 996          * @return bool
 997          */
 998         function wasErrorReissuable() {
 999                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1000         }
1001
1002         /**
1003          * Determines if the last failure was due to the database being read-only.
1004          *
1005          * @return bool
1006          */
1007         function wasReadOnlyError() {
1008                 return $this->lastErrno() == 1223 ||
1009                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1010         }
1011
1012         /**
1013          * @param $oldName
1014          * @param $newName
1015          * @param $temporary bool
1016          * @param $fname string
1017          */
1018         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1019                 $tmp = $temporary ? 'TEMPORARY ' : '';
1020                 $newName = $this->addIdentifierQuotes( $newName );
1021                 $oldName = $this->addIdentifierQuotes( $oldName );
1022                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1023                 $this->query( $query, $fname );
1024         }
1025
1026         /**
1027          * List all tables on the database
1028          *
1029          * @param string $prefix Only show tables with this prefix, e.g. mw_
1030          * @param string $fname calling function name
1031          * @return array
1032          */
1033         function listTables( $prefix = null, $fname = __METHOD__ ) {
1034                 $result = $this->query( "SHOW TABLES", $fname );
1035
1036                 $endArray = array();
1037
1038                 foreach ( $result as $table ) {
1039                         $vars = get_object_vars( $table );
1040                         $table = array_pop( $vars );
1041
1042                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1043                                 $endArray[] = $table;
1044                         }
1045                 }
1046
1047                 return $endArray;
1048         }
1049
1050         /**
1051          * @param $tableName
1052          * @param $fName string
1053          * @return bool|ResultWrapper
1054          */
1055         public function dropTable( $tableName, $fName = __METHOD__ ) {
1056                 if ( !$this->tableExists( $tableName, $fName ) ) {
1057                         return false;
1058                 }
1059
1060                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1061         }
1062
1063         /**
1064          * @return array
1065          */
1066         protected function getDefaultSchemaVars() {
1067                 $vars = parent::getDefaultSchemaVars();
1068                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1069                 $vars['wgDBTableOptions'] = str_replace(
1070                         'CHARSET=mysql4',
1071                         'CHARSET=binary',
1072                         $vars['wgDBTableOptions']
1073                 );
1074
1075                 return $vars;
1076         }
1077
1078         /**
1079          * Get status information from SHOW STATUS in an associative array
1080          *
1081          * @param $which string
1082          * @return array
1083          */
1084         function getMysqlStatus( $which = "%" ) {
1085                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1086                 $status = array();
1087
1088                 foreach ( $res as $row ) {
1089                         $status[$row->Variable_name] = $row->Value;
1090                 }
1091
1092                 return $status;
1093         }
1094
1095         /**
1096          * Lists VIEWs in the database
1097          *
1098          * @param string $prefix Only show VIEWs with this prefix, eg.
1099          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1100          * @param string $fname Name of calling function
1101          * @return array
1102          * @since 1.22
1103          */
1104         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1105
1106                 if ( !isset( $this->allViews ) ) {
1107
1108                         // The name of the column containing the name of the VIEW
1109                         $propertyName = 'Tables_in_' . $this->mDBname;
1110
1111                         // Query for the VIEWS
1112                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1113                         $this->allViews = array();
1114                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1115                                 array_push( $this->allViews, $row[$propertyName] );
1116                         }
1117                 }
1118
1119                 if ( is_null( $prefix ) || $prefix === '' ) {
1120                         return $this->allViews;
1121                 }
1122
1123                 $filteredViews = array();
1124                 foreach ( $this->allViews as $viewName ) {
1125                         // Does the name of this VIEW start with the table-prefix?
1126                         if ( strpos( $viewName, $prefix ) === 0 ) {
1127                                 array_push( $filteredViews, $viewName );
1128                         }
1129                 }
1130
1131                 return $filteredViews;
1132         }
1133
1134         /**
1135          * Differentiates between a TABLE and a VIEW.
1136          *
1137          * @param $name string: Name of the TABLE/VIEW to test
1138          * @return bool
1139          * @since 1.22
1140          */
1141         public function isView( $name, $prefix = null ) {
1142                 return in_array( $name, $this->listViews( $prefix ) );
1143         }
1144 }
1145
1146 /**
1147  * Utility class.
1148  * @ingroup Database
1149  */
1150 class MySQLField implements Field {
1151         private $name, $tablename, $default, $max_length, $nullable,
1152                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary;
1153
1154         function __construct( $info ) {
1155                 $this->name = $info->name;
1156                 $this->tablename = $info->table;
1157                 $this->default = $info->def;
1158                 $this->max_length = $info->max_length;
1159                 $this->nullable = !$info->not_null;
1160                 $this->is_pk = $info->primary_key;
1161                 $this->is_unique = $info->unique_key;
1162                 $this->is_multiple = $info->multiple_key;
1163                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1164                 $this->type = $info->type;
1165                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1166         }
1167
1168         /**
1169          * @return string
1170          */
1171         function name() {
1172                 return $this->name;
1173         }
1174
1175         /**
1176          * @return string
1177          */
1178         function tableName() {
1179                 return $this->tableName;
1180         }
1181
1182         /**
1183          * @return string
1184          */
1185         function type() {
1186                 return $this->type;
1187         }
1188
1189         /**
1190          * @return bool
1191          */
1192         function isNullable() {
1193                 return $this->nullable;
1194         }
1195
1196         function defaultValue() {
1197                 return $this->default;
1198         }
1199
1200         /**
1201          * @return bool
1202          */
1203         function isKey() {
1204                 return $this->is_key;
1205         }
1206
1207         /**
1208          * @return bool
1209          */
1210         function isMultipleKey() {
1211                 return $this->is_multiple;
1212         }
1213
1214         function isBinary() {
1215                 return $this->binary;
1216         }
1217 }
1218
1219 class MySQLMasterPos implements DBMasterPos {
1220         var $file, $pos;
1221
1222         function __construct( $file, $pos ) {
1223                 $this->file = $file;
1224                 $this->pos = $pos;
1225         }
1226
1227         function __toString() {
1228                 // e.g db1034-bin.000976/843431247
1229                 return "{$this->file}/{$this->pos}";
1230         }
1231
1232         /**
1233          * @return array|false (int, int)
1234          */
1235         protected function getCoordinates() {
1236                 $m = array();
1237                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1238                         return array( (int)$m[1], (int)$m[2] );
1239                 }
1240
1241                 return false;
1242         }
1243
1244         function hasReached( MySQLMasterPos $pos ) {
1245                 $thisPos = $this->getCoordinates();
1246                 $thatPos = $pos->getCoordinates();
1247
1248                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1249         }
1250 }