includes/db/DatabaseMysqlBase.php

   1 <?php
   2 /**
   3  * This is the MySQL database abstraction layer.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Database
  22  */
  23
  24 /**
  25  * Database abstraction object for MySQL.
  26  * Defines methods independent on used MySQL extension.
  27  *
  28  * @ingroup Database
  29  * @since 1.22
  30  * @see Database
  31  */
  32 abstract class DatabaseMysqlBase extends DatabaseBase {
  33         /** @var MysqlMasterPos */
  34         protected $lastKnownSlavePos;
  35
  36         /** @var null|int */
  37         protected $mFakeSlaveLag = null;
  38
  39         protected $mFakeMaster = false;
  40
  41         /** @var string|null */
  42         private $serverVersion = null;
  43
  44         /**
  45          * @return string
  46          */
  47         function getType() {
  48                 return 'mysql';
  49         }
  50
  51         /**
  52          * @param string $server
  53          * @param string $user
  54          * @param string $password
  55          * @param string $dbName
  56          * @throws Exception|DBConnectionError
  57          * @return bool
  58          */
  59         function open( $server, $user, $password, $dbName ) {
  60                 global $wgAllDBsAreLocalhost, $wgSQLMode;
  61
  62                 # Close/unset connection handle
  63                 $this->close();
  64
  65                 # Debugging hack -- fake cluster
  66                 $realServer = $wgAllDBsAreLocalhost ? 'localhost' : $server;
  67                 $this->mServer = $server;
  68                 $this->mUser = $user;
  69                 $this->mPassword = $password;
  70                 $this->mDBname = $dbName;
  71
  72                 $this->installErrorHandler();
  73                 try {
  74                         $this->mConn = $this->mysqlConnect( $realServer );
  75                 } catch ( Exception $ex ) {
  76                         $this->restoreErrorHandler();
  77                         throw $ex;
  78                 }
  79                 $error = $this->restoreErrorHandler();
  80
  81                 # Always log connection errors
  82                 if ( !$this->mConn ) {
  83                         if ( !$error ) {
  84                                 $error = $this->lastError();
  85                         }
  86                         wfLogDBError(
  87                                 "Error connecting to {db_server}: {error}",
  88                                 $this->getLogContext( array(
  89                                         'method' => __METHOD__,
  90                                         'error' => $error,
  91                                 ) )
  92                         );
  93                         wfDebug( "DB connection error\n" .
  94                                 "Server: $server, User: $user, Password: " .
  95                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
  96
  97                         $this->reportConnectionError( $error );
  98                 }
  99
 100                 if ( $dbName != '' ) {
 101                         MediaWiki\suppressWarnings();
 102                         $success = $this->selectDB( $dbName );
 103                         MediaWiki\restoreWarnings();
 104                         if ( !$success ) {
 105                                 wfLogDBError(
 106                                         "Error selecting database {db_name} on server {db_server}",
 107                                         $this->getLogContext( array(
 108                                                 'method' => __METHOD__,
 109                                         ) )
 110                                 );
 111                                 wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
 112                                         "from client host " . wfHostname() . "\n" );
 113
 114                                 $this->reportConnectionError( "Error selecting database $dbName" );
 115                         }
 116                 }
 117
 118                 // Tell the server what we're communicating with
 119                 if ( !$this->connectInitCharset() ) {
 120                         $this->reportConnectionError( "Error setting character set" );
 121                 }
 122
 123                 // Abstract over any insane MySQL defaults
 124                 $set = array( 'group_concat_max_len = 262144' );
 125                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 126                 if ( is_string( $wgSQLMode ) ) {
 127                         $set[] = 'sql_mode = ' . $this->addQuotes( $wgSQLMode );
 128                 }
 129                 // Set any custom settings defined by site config
 130                 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 131                 foreach ( $this->mSessionVars as $var => $val ) {
 132                         // Escape strings but not numbers to avoid MySQL complaining
 133                         if ( !is_int( $val ) && !is_float( $val ) ) {
 134                                 $val = $this->addQuotes( $val );
 135                         }
 136                         $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 137                 }
 138
 139                 if ( $set ) {
 140                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 141                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ), __METHOD__ );
 142                         if ( !$success ) {
 143                                 wfLogDBError(
 144                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 145                                         $this->getLogContext( array(
 146                                                 'method' => __METHOD__,
 147                                         ) )
 148                                 );
 149                                 $this->reportConnectionError(
 150                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 151                         }
 152                 }
 153
 154                 $this->mOpened = true;
 155
 156                 return true;
 157         }
 158
 159         /**
 160          * Set the character set information right after connection
 161          * @return bool
 162          */
 163         protected function connectInitCharset() {
 164                 global $wgDBmysql5;
 165
 166                 if ( $wgDBmysql5 ) {
 167                         // Tell the server we're communicating with it in UTF-8.
 168                         // This may engage various charset conversions.
 169                         return $this->mysqlSetCharset( 'utf8' );
 170                 } else {
 171                         return $this->mysqlSetCharset( 'binary' );
 172                 }
 173         }
 174
 175         /**
 176          * Open a connection to a MySQL server
 177          *
 178          * @param string $realServer
 179          * @return mixed Raw connection
 180          * @throws DBConnectionError
 181          */
 182         abstract protected function mysqlConnect( $realServer );
 183
 184         /**
 185          * Set the character set of the MySQL link
 186          *
 187          * @param string $charset
 188          * @return bool
 189          */
 190         abstract protected function mysqlSetCharset( $charset );
 191
 192         /**
 193          * @param ResultWrapper|resource $res
 194          * @throws DBUnexpectedError
 195          */
 196         function freeResult( $res ) {
 197                 if ( $res instanceof ResultWrapper ) {
 198                         $res = $res->result;
 199                 }
 200                 MediaWiki\suppressWarnings();
 201                 $ok = $this->mysqlFreeResult( $res );
 202                 MediaWiki\restoreWarnings();
 203                 if ( !$ok ) {
 204                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 205                 }
 206         }
 207
 208         /**
 209          * Free result memory
 210          *
 211          * @param resource $res Raw result
 212          * @return bool
 213          */
 214         abstract protected function mysqlFreeResult( $res );
 215
 216         /**
 217          * @param ResultWrapper|resource $res
 218          * @return stdClass|bool
 219          * @throws DBUnexpectedError
 220          */
 221         function fetchObject( $res ) {
 222                 if ( $res instanceof ResultWrapper ) {
 223                         $res = $res->result;
 224                 }
 225                 MediaWiki\suppressWarnings();
 226                 $row = $this->mysqlFetchObject( $res );
 227                 MediaWiki\restoreWarnings();
 228
 229                 $errno = $this->lastErrno();
 230                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 231                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 232                 // these are the only errors mysql_fetch_object can cause.
 233                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 234                 if ( $errno == 2000 || $errno == 2013 ) {
 235                         throw new DBUnexpectedError(
 236                                 $this,
 237                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 238                         );
 239                 }
 240
 241                 return $row;
 242         }
 243
 244         /**
 245          * Fetch a result row as an object
 246          *
 247          * @param resource $res Raw result
 248          * @return stdClass
 249          */
 250         abstract protected function mysqlFetchObject( $res );
 251
 252         /**
 253          * @param ResultWrapper|resource $res
 254          * @return array|bool
 255          * @throws DBUnexpectedError
 256          */
 257         function fetchRow( $res ) {
 258                 if ( $res instanceof ResultWrapper ) {
 259                         $res = $res->result;
 260                 }
 261                 MediaWiki\suppressWarnings();
 262                 $row = $this->mysqlFetchArray( $res );
 263                 MediaWiki\restoreWarnings();
 264
 265                 $errno = $this->lastErrno();
 266                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 267                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 268                 // these are the only errors mysql_fetch_array can cause.
 269                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 270                 if ( $errno == 2000 || $errno == 2013 ) {
 271                         throw new DBUnexpectedError(
 272                                 $this,
 273                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 274                         );
 275                 }
 276
 277                 return $row;
 278         }
 279
 280         /**
 281          * Fetch a result row as an associative and numeric array
 282          *
 283          * @param resource $res Raw result
 284          * @return array
 285          */
 286         abstract protected function mysqlFetchArray( $res );
 287
 288         /**
 289          * @throws DBUnexpectedError
 290          * @param ResultWrapper|resource $res
 291          * @return int
 292          */
 293         function numRows( $res ) {
 294                 if ( $res instanceof ResultWrapper ) {
 295                         $res = $res->result;
 296                 }
 297                 MediaWiki\suppressWarnings();
 298                 $n = $this->mysqlNumRows( $res );
 299                 MediaWiki\restoreWarnings();
 300
 301                 // Unfortunately, mysql_num_rows does not reset the last errno.
 302                 // We are not checking for any errors here, since
 303                 // these are no errors mysql_num_rows can cause.
 304                 // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 305                 // See https://bugzilla.wikimedia.org/42430
 306                 return $n;
 307         }
 308
 309         /**
 310          * Get number of rows in result
 311          *
 312          * @param resource $res Raw result
 313          * @return int
 314          */
 315         abstract protected function mysqlNumRows( $res );
 316
 317         /**
 318          * @param ResultWrapper|resource $res
 319          * @return int
 320          */
 321         function numFields( $res ) {
 322                 if ( $res instanceof ResultWrapper ) {
 323                         $res = $res->result;
 324                 }
 325
 326                 return $this->mysqlNumFields( $res );
 327         }
 328
 329         /**
 330          * Get number of fields in result
 331          *
 332          * @param resource $res Raw result
 333          * @return int
 334          */
 335         abstract protected function mysqlNumFields( $res );
 336
 337         /**
 338          * @param ResultWrapper|resource $res
 339          * @param int $n
 340          * @return string
 341          */
 342         function fieldName( $res, $n ) {
 343                 if ( $res instanceof ResultWrapper ) {
 344                         $res = $res->result;
 345                 }
 346
 347                 return $this->mysqlFieldName( $res, $n );
 348         }
 349
 350         /**
 351          * Get the name of the specified field in a result
 352          *
 353          * @param ResultWrapper|resource $res
 354          * @param int $n
 355          * @return string
 356          */
 357         abstract protected function mysqlFieldName( $res, $n );
 358
 359         /**
 360          * mysql_field_type() wrapper
 361          * @param ResultWrapper|resource $res
 362          * @param int $n
 363          * @return string
 364          */
 365         public function fieldType( $res, $n ) {
 366                 if ( $res instanceof ResultWrapper ) {
 367                         $res = $res->result;
 368                 }
 369
 370                 return $this->mysqlFieldType( $res, $n );
 371         }
 372
 373         /**
 374          * Get the type of the specified field in a result
 375          *
 376          * @param ResultWrapper|resource $res
 377          * @param int $n
 378          * @return string
 379          */
 380         abstract protected function mysqlFieldType( $res, $n );
 381
 382         /**
 383          * @param ResultWrapper|resource $res
 384          * @param int $row
 385          * @return bool
 386          */
 387         function dataSeek( $res, $row ) {
 388                 if ( $res instanceof ResultWrapper ) {
 389                         $res = $res->result;
 390                 }
 391
 392                 return $this->mysqlDataSeek( $res, $row );
 393         }
 394
 395         /**
 396          * Move internal result pointer
 397          *
 398          * @param ResultWrapper|resource $res
 399          * @param int $row
 400          * @return bool
 401          */
 402         abstract protected function mysqlDataSeek( $res, $row );
 403
 404         /**
 405          * @return string
 406          */
 407         function lastError() {
 408                 if ( $this->mConn ) {
 409                         # Even if it's non-zero, it can still be invalid
 410                         MediaWiki\suppressWarnings();
 411                         $error = $this->mysqlError( $this->mConn );
 412                         if ( !$error ) {
 413                                 $error = $this->mysqlError();
 414                         }
 415                         MediaWiki\restoreWarnings();
 416                 } else {
 417                         $error = $this->mysqlError();
 418                 }
 419                 if ( $error ) {
 420                         $error .= ' (' . $this->mServer . ')';
 421                 }
 422
 423                 return $error;
 424         }
 425
 426         /**
 427          * Returns the text of the error message from previous MySQL operation
 428          *
 429          * @param resource $conn Raw connection
 430          * @return string
 431          */
 432         abstract protected function mysqlError( $conn = null );
 433
 434         /**
 435          * @param string $table
 436          * @param array $uniqueIndexes
 437          * @param array $rows
 438          * @param string $fname
 439          * @return ResultWrapper
 440          */
 441         function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 442                 return $this->nativeReplace( $table, $rows, $fname );
 443         }
 444
 445         /**
 446          * Estimate rows in dataset
 447          * Returns estimated count, based on EXPLAIN output
 448          * Takes same arguments as Database::select()
 449          *
 450          * @param string|array $table
 451          * @param string|array $vars
 452          * @param string|array $conds
 453          * @param string $fname
 454          * @param string|array $options
 455          * @return bool|int
 456          */
 457         public function estimateRowCount( $table, $vars = '*', $conds = '',
 458                 $fname = __METHOD__, $options = array()
 459         ) {
 460                 $options['EXPLAIN'] = true;
 461                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 462                 if ( $res === false ) {
 463                         return false;
 464                 }
 465                 if ( !$this->numRows( $res ) ) {
 466                         return 0;
 467                 }
 468
 469                 $rows = 1;
 470                 foreach ( $res as $plan ) {
 471                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 472                 }
 473
 474                 return (int)$rows;
 475         }
 476
 477         /**
 478          * @param string $table
 479          * @param string $field
 480          * @return bool|MySQLField
 481          */
 482         function fieldInfo( $table, $field ) {
 483                 $table = $this->tableName( $table );
 484                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 485                 if ( !$res ) {
 486                         return false;
 487                 }
 488                 $n = $this->mysqlNumFields( $res->result );
 489                 for ( $i = 0; $i < $n; $i++ ) {
 490                         $meta = $this->mysqlFetchField( $res->result, $i );
 491                         if ( $field == $meta->name ) {
 492                                 return new MySQLField( $meta );
 493                         }
 494                 }
 495
 496                 return false;
 497         }
 498
 499         /**
 500          * Get column information from a result
 501          *
 502          * @param resource $res Raw result
 503          * @param int $n
 504          * @return stdClass
 505          */
 506         abstract protected function mysqlFetchField( $res, $n );
 507
 508         /**
 509          * Get information about an index into an object
 510          * Returns false if the index does not exist
 511          *
 512          * @param string $table
 513          * @param string $index
 514          * @param string $fname
 515          * @return bool|array|null False or null on failure
 516          */
 517         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 518                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 519                 # SHOW INDEX should work for 3.x and up:
 520                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 521                 $table = $this->tableName( $table );
 522                 $index = $this->indexName( $index );
 523
 524                 $sql = 'SHOW INDEX FROM ' . $table;
 525                 $res = $this->query( $sql, $fname );
 526
 527                 if ( !$res ) {
 528                         return null;
 529                 }
 530
 531                 $result = array();
 532
 533                 foreach ( $res as $row ) {
 534                         if ( $row->Key_name == $index ) {
 535                                 $result[] = $row;
 536                         }
 537                 }
 538
 539                 return empty( $result ) ? false : $result;
 540         }
 541
 542         /**
 543          * @param string $s
 544          * @return string
 545          */
 546         function strencode( $s ) {
 547                 $sQuoted = $this->mysqlRealEscapeString( $s );
 548
 549                 if ( $sQuoted === false ) {
 550                         $this->ping();
 551                         $sQuoted = $this->mysqlRealEscapeString( $s );
 552                 }
 553
 554                 return $sQuoted;
 555         }
 556
 557         /**
 558          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 559          *
 560          * @param string $s
 561          * @return string
 562          */
 563         public function addIdentifierQuotes( $s ) {
 564                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 565                 // Remove NUL bytes and escape backticks by doubling
 566                 return '`' . str_replace( array( "\0", '`' ), array( '', '``' ), $s ) . '`';
 567         }
 568
 569         /**
 570          * @param string $name
 571          * @return bool
 572          */
 573         public function isQuotedIdentifier( $name ) {
 574                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 575         }
 576
 577         /**
 578          * @return bool
 579          */
 580         function ping() {
 581                 $ping = $this->mysqlPing();
 582                 if ( $ping ) {
 583                         return true;
 584                 }
 585
 586                 $this->closeConnection();
 587                 $this->mOpened = false;
 588                 $this->mConn = false;
 589                 $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
 590
 591                 return true;
 592         }
 593
 594         /**
 595          * Ping a server connection or reconnect if there is no connection
 596          *
 597          * @return bool
 598          */
 599         abstract protected function mysqlPing();
 600
 601         /**
 602          * Set lag time in seconds for a fake slave
 603          *
 604          * @param int $lag
 605          */
 606         public function setFakeSlaveLag( $lag ) {
 607                 $this->mFakeSlaveLag = $lag;
 608         }
 609
 610         /**
 611          * Make this connection a fake master
 612          *
 613          * @param bool $enabled
 614          */
 615         public function setFakeMaster( $enabled = true ) {
 616                 $this->mFakeMaster = $enabled;
 617         }
 618
 619         /**
 620          * Returns slave lag.
 621          *
 622          * This will do a SHOW SLAVE STATUS
 623          *
 624          * @return int
 625          */
 626         function getLag() {
 627                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 628                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
 629
 630                         return $this->mFakeSlaveLag;
 631                 }
 632
 633                 return $this->getLagFromSlaveStatus();
 634         }
 635
 636         /**
 637          * @return bool|int
 638          */
 639         function getLagFromSlaveStatus() {
 640                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 641                 if ( !$res ) {
 642                         return false;
 643                 }
 644                 $row = $res->fetchObject();
 645                 if ( !$row ) {
 646                         return false;
 647                 }
 648                 if ( strval( $row->Seconds_Behind_Master ) === '' ) {
 649                         return false;
 650                 } else {
 651                         return intval( $row->Seconds_Behind_Master );
 652                 }
 653         }
 654
 655         /**
 656          * Wait for the slave to catch up to a given master position.
 657          * @todo Return values for this and base class are rubbish
 658          *
 659          * @param DBMasterPos|MySQLMasterPos $pos
 660          * @param int $timeout The maximum number of seconds to wait for synchronisation
 661          * @return int Zero if the slave was past that position already,
 662          *   greater than zero if we waited for some period of time, less than
 663          *   zero if we timed out.
 664          */
 665         function masterPosWait( DBMasterPos $pos, $timeout ) {
 666                 if ( $this->lastKnownSlavePos && $this->lastKnownSlavePos->hasReached( $pos ) ) {
 667                         return '0'; // http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html
 668                 }
 669
 670                 # Commit any open transactions
 671                 $this->commit( __METHOD__, 'flush' );
 672
 673                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 674                         $wait = intval( ( $pos->pos - microtime( true ) + $this->mFakeSlaveLag ) * 1e6 );
 675
 676                         if ( $wait > $timeout * 1e6 ) {
 677                                 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
 678
 679                                 return -1;
 680                         } elseif ( $wait > 0 ) {
 681                                 wfDebug( "Fake slave waiting $wait us\n" );
 682                                 usleep( $wait );
 683
 684                                 return 1;
 685                         } else {
 686                                 wfDebug( "Fake slave up to date ($wait us)\n" );
 687
 688                                 return 0;
 689                         }
 690                 }
 691
 692                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 693                 $encFile = $this->addQuotes( $pos->file );
 694                 $encPos = intval( $pos->pos );
 695                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 696                 $res = $this->doQuery( $sql );
 697
 698                 $status = false;
 699                 if ( $res && $row = $this->fetchRow( $res ) ) {
 700                         $status = $row[0]; // can be NULL, -1, or 0+ per the MySQL manual
 701                         if ( ctype_digit( $status ) ) { // success
 702                                 $this->lastKnownSlavePos = $pos;
 703                         }
 704                 }
 705
 706                 return $status;
 707         }
 708
 709         /**
 710          * Get the position of the master from SHOW SLAVE STATUS
 711          *
 712          * @return MySQLMasterPos|bool
 713          */
 714         function getSlavePos() {
 715                 if ( !is_null( $this->mFakeSlaveLag ) ) {
 716                         $pos = new MySQLMasterPos( 'fake', microtime( true ) - $this->mFakeSlaveLag );
 717                         wfDebug( __METHOD__ . ": fake slave pos = $pos\n" );
 718
 719                         return $pos;
 720                 }
 721
 722                 $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
 723                 $row = $this->fetchObject( $res );
 724
 725                 if ( $row ) {
 726                         $pos = isset( $row->Exec_master_log_pos )
 727                                 ? $row->Exec_master_log_pos
 728                                 : $row->Exec_Master_Log_Pos;
 729
 730                         return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
 731                 } else {
 732                         return false;
 733                 }
 734         }
 735
 736         /**
 737          * Get the position of the master from SHOW MASTER STATUS
 738          *
 739          * @return MySQLMasterPos|bool
 740          */
 741         function getMasterPos() {
 742                 if ( $this->mFakeMaster ) {
 743                         return new MySQLMasterPos( 'fake', microtime( true ) );
 744                 }
 745
 746                 $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
 747                 $row = $this->fetchObject( $res );
 748
 749                 if ( $row ) {
 750                         return new MySQLMasterPos( $row->File, $row->Position );
 751                 } else {
 752                         return false;
 753                 }
 754         }
 755
 756         /**
 757          * @param string $index
 758          * @return string
 759          */
 760         function useIndexClause( $index ) {
 761                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
 762         }
 763
 764         /**
 765          * @return string
 766          */
 767         function lowPriorityOption() {
 768                 return 'LOW_PRIORITY';
 769         }
 770
 771         /**
 772          * @return string
 773          */
 774         public function getSoftwareLink() {
 775                 // MariaDB includes its name in its version string; this is how MariaDB's version of
 776                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
 777                 // in libmysql/libmysql.c).
 778                 $version = $this->getServerVersion();
 779                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
 780                         return '[{{int:version-db-mariadb-url}} MariaDB]';
 781                 }
 782
 783                 // Percona Server's version suffix is not very distinctive, and @@version_comment
 784                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
 785                 // (Even Percona's version of mysql doesn't try to make the distinction.)
 786                 return '[{{int:version-db-mysql-url}} MySQL]';
 787         }
 788
 789         /**
 790          * @return string
 791          */
 792         public function getServerVersion() {
 793                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
 794                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
 795                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
 796                 if ( $this->serverVersion === null ) {
 797                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
 798                 }
 799                 return $this->serverVersion;
 800         }
 801
 802         /**
 803          * @param array $options
 804          */
 805         public function setSessionOptions( array $options ) {
 806                 if ( isset( $options['connTimeout'] ) ) {
 807                         $timeout = (int)$options['connTimeout'];
 808                         $this->query( "SET net_read_timeout=$timeout" );
 809                         $this->query( "SET net_write_timeout=$timeout" );
 810                 }
 811         }
 812
 813         /**
 814          * @param string $sql
 815          * @param string $newLine
 816          * @return bool
 817          */
 818         public function streamStatementEnd( &$sql, &$newLine ) {
 819                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
 820                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
 821                         $this->delimiter = $m[1];
 822                         $newLine = '';
 823                 }
 824
 825                 return parent::streamStatementEnd( $sql, $newLine );
 826         }
 827
 828         /**
 829          * Check to see if a named lock is available. This is non-blocking.
 830          *
 831          * @param string $lockName Name of lock to poll
 832          * @param string $method Name of method calling us
 833          * @return bool
 834          * @since 1.20
 835          */
 836         public function lockIsFree( $lockName, $method ) {
 837                 $lockName = $this->addQuotes( $lockName );
 838                 $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
 839                 $row = $this->fetchObject( $result );
 840
 841                 return ( $row->lockstatus == 1 );
 842         }
 843
 844         /**
 845          * @param string $lockName
 846          * @param string $method
 847          * @param int $timeout
 848          * @return bool
 849          */
 850         public function lock( $lockName, $method, $timeout = 5 ) {
 851                 $lockName = $this->addQuotes( $lockName );
 852                 $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
 853                 $row = $this->fetchObject( $result );
 854
 855                 if ( $row->lockstatus == 1 ) {
 856                         return true;
 857                 } else {
 858                         wfDebug( __METHOD__ . " failed to acquire lock\n" );
 859
 860                         return false;
 861                 }
 862         }
 863
 864         /**
 865          * FROM MYSQL DOCS:
 866          * http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
 867          * @param string $lockName
 868          * @param string $method
 869          * @return bool
 870          */
 871         public function unlock( $lockName, $method ) {
 872                 $lockName = $this->addQuotes( $lockName );
 873                 $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
 874                 $row = $this->fetchObject( $result );
 875
 876                 return ( $row->lockstatus == 1 );
 877         }
 878
 879         public function namedLocksEnqueue() {
 880                 return true;
 881         }
 882
 883         /**
 884          * @param array $read
 885          * @param array $write
 886          * @param string $method
 887          * @param bool $lowPriority
 888          * @return bool
 889          */
 890         public function lockTables( $read, $write, $method, $lowPriority = true ) {
 891                 $items = array();
 892
 893                 foreach ( $write as $table ) {
 894                         $tbl = $this->tableName( $table ) .
 895                                 ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
 896                                 ' WRITE';
 897                         $items[] = $tbl;
 898                 }
 899                 foreach ( $read as $table ) {
 900                         $items[] = $this->tableName( $table ) . ' READ';
 901                 }
 902                 $sql = "LOCK TABLES " . implode( ',', $items );
 903                 $this->query( $sql, $method );
 904
 905                 return true;
 906         }
 907
 908         /**
 909          * @param string $method
 910          * @return bool
 911          */
 912         public function unlockTables( $method ) {
 913                 $this->query( "UNLOCK TABLES", $method );
 914
 915                 return true;
 916         }
 917
 918         /**
 919          * Get search engine class. All subclasses of this
 920          * need to implement this if they wish to use searching.
 921          *
 922          * @return string
 923          */
 924         public function getSearchEngine() {
 925                 return 'SearchMySQL';
 926         }
 927
 928         /**
 929          * @param bool $value
 930          */
 931         public function setBigSelects( $value = true ) {
 932                 if ( $value === 'default' ) {
 933                         if ( $this->mDefaultBigSelects === null ) {
 934                                 # Function hasn't been called before so it must already be set to the default
 935                                 return;
 936                         } else {
 937                                 $value = $this->mDefaultBigSelects;
 938                         }
 939                 } elseif ( $this->mDefaultBigSelects === null ) {
 940                         $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
 941                 }
 942                 $encValue = $value ? '1' : '0';
 943                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
 944         }
 945
 946         /**
 947          * DELETE where the condition is a join. MySql uses multi-table deletes.
 948          * @param string $delTable
 949          * @param string $joinTable
 950          * @param string $delVar
 951          * @param string $joinVar
 952          * @param array|string $conds
 953          * @param bool|string $fname
 954          * @throws DBUnexpectedError
 955          * @return bool|ResultWrapper
 956          */
 957         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__ ) {
 958                 if ( !$conds ) {
 959                         throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
 960                 }
 961
 962                 $delTable = $this->tableName( $delTable );
 963                 $joinTable = $this->tableName( $joinTable );
 964                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 965
 966                 if ( $conds != '*' ) {
 967                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 968                 }
 969
 970                 return $this->query( $sql, $fname );
 971         }
 972
 973         /**
 974          * @param string $table
 975          * @param array $rows
 976          * @param array $uniqueIndexes
 977          * @param array $set
 978          * @param string $fname
 979          * @return bool
 980          */
 981         public function upsert( $table, array $rows, array $uniqueIndexes,
 982                 array $set, $fname = __METHOD__
 983         ) {
 984                 if ( !count( $rows ) ) {
 985                         return true; // nothing to do
 986                 }
 987
 988                 if ( !is_array( reset( $rows ) ) ) {
 989                         $rows = array( $rows );
 990                 }
 991
 992                 $table = $this->tableName( $table );
 993                 $columns = array_keys( $rows[0] );
 994
 995                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
 996                 $rowTuples = array();
 997                 foreach ( $rows as $row ) {
 998                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
 999                 }
1000                 $sql .= implode( ',', $rowTuples );
1001                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, LIST_SET );
1002
1003                 return (bool)$this->query( $sql, $fname );
1004         }
1005
1006         /**
1007          * Determines how long the server has been up
1008          *
1009          * @return int
1010          */
1011         function getServerUptime() {
1012                 $vars = $this->getMysqlStatus( 'Uptime' );
1013
1014                 return (int)$vars['Uptime'];
1015         }
1016
1017         /**
1018          * Determines if the last failure was due to a deadlock
1019          *
1020          * @return bool
1021          */
1022         function wasDeadlock() {
1023                 return $this->lastErrno() == 1213;
1024         }
1025
1026         /**
1027          * Determines if the last failure was due to a lock timeout
1028          *
1029          * @return bool
1030          */
1031         function wasLockTimeout() {
1032                 return $this->lastErrno() == 1205;
1033         }
1034
1035         /**
1036          * Determines if the last query error was something that should be dealt
1037          * with by pinging the connection and reissuing the query
1038          *
1039          * @return bool
1040          */
1041         function wasErrorReissuable() {
1042                 return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
1043         }
1044
1045         /**
1046          * Determines if the last failure was due to the database being read-only.
1047          *
1048          * @return bool
1049          */
1050         function wasReadOnlyError() {
1051                 return $this->lastErrno() == 1223 ||
1052                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1053         }
1054
1055         /**
1056          * @param string $oldName
1057          * @param string $newName
1058          * @param bool $temporary
1059          * @param string $fname
1060          * @return bool
1061          */
1062         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1063                 $tmp = $temporary ? 'TEMPORARY ' : '';
1064                 $newName = $this->addIdentifierQuotes( $newName );
1065                 $oldName = $this->addIdentifierQuotes( $oldName );
1066                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1067
1068                 return $this->query( $query, $fname );
1069         }
1070
1071         /**
1072          * List all tables on the database
1073          *
1074          * @param string $prefix Only show tables with this prefix, e.g. mw_
1075          * @param string $fname Calling function name
1076          * @return array
1077          */
1078         function listTables( $prefix = null, $fname = __METHOD__ ) {
1079                 $result = $this->query( "SHOW TABLES", $fname );
1080
1081                 $endArray = array();
1082
1083                 foreach ( $result as $table ) {
1084                         $vars = get_object_vars( $table );
1085                         $table = array_pop( $vars );
1086
1087                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1088                                 $endArray[] = $table;
1089                         }
1090                 }
1091
1092                 return $endArray;
1093         }
1094
1095         /**
1096          * @param string $tableName
1097          * @param string $fName
1098          * @return bool|ResultWrapper
1099          */
1100         public function dropTable( $tableName, $fName = __METHOD__ ) {
1101                 if ( !$this->tableExists( $tableName, $fName ) ) {
1102                         return false;
1103                 }
1104
1105                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1106         }
1107
1108         /**
1109          * @return array
1110          */
1111         protected function getDefaultSchemaVars() {
1112                 $vars = parent::getDefaultSchemaVars();
1113                 $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
1114                 $vars['wgDBTableOptions'] = str_replace(
1115                         'CHARSET=mysql4',
1116                         'CHARSET=binary',
1117                         $vars['wgDBTableOptions']
1118                 );
1119
1120                 return $vars;
1121         }
1122
1123         /**
1124          * Get status information from SHOW STATUS in an associative array
1125          *
1126          * @param string $which
1127          * @return array
1128          */
1129         function getMysqlStatus( $which = "%" ) {
1130                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1131                 $status = array();
1132
1133                 foreach ( $res as $row ) {
1134                         $status[$row->Variable_name] = $row->Value;
1135                 }
1136
1137                 return $status;
1138         }
1139
1140         /**
1141          * Lists VIEWs in the database
1142          *
1143          * @param string $prefix Only show VIEWs with this prefix, eg.
1144          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1145          * @param string $fname Name of calling function
1146          * @return array
1147          * @since 1.22
1148          */
1149         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1150
1151                 if ( !isset( $this->allViews ) ) {
1152
1153                         // The name of the column containing the name of the VIEW
1154                         $propertyName = 'Tables_in_' . $this->mDBname;
1155
1156                         // Query for the VIEWS
1157                         $result = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1158                         $this->allViews = array();
1159                         while ( ( $row = $this->fetchRow( $result ) ) !== false ) {
1160                                 array_push( $this->allViews, $row[$propertyName] );
1161                         }
1162                 }
1163
1164                 if ( is_null( $prefix ) || $prefix === '' ) {
1165                         return $this->allViews;
1166                 }
1167
1168                 $filteredViews = array();
1169                 foreach ( $this->allViews as $viewName ) {
1170                         // Does the name of this VIEW start with the table-prefix?
1171                         if ( strpos( $viewName, $prefix ) === 0 ) {
1172                                 array_push( $filteredViews, $viewName );
1173                         }
1174                 }
1175
1176                 return $filteredViews;
1177         }
1178
1179         /**
1180          * Differentiates between a TABLE and a VIEW.
1181          *
1182          * @param string $name Name of the TABLE/VIEW to test
1183          * @param string $prefix
1184          * @return bool
1185          * @since 1.22
1186          */
1187         public function isView( $name, $prefix = null ) {
1188                 return in_array( $name, $this->listViews( $prefix ) );
1189         }
1190 }
1191
1192 /**
1193  * Utility class.
1194  * @ingroup Database
1195  */
1196 class MySQLField implements Field {
1197         private $name, $tablename, $default, $max_length, $nullable,
1198                 $is_pk, $is_unique, $is_multiple, $is_key, $type, $binary,
1199                 $is_numeric, $is_blob, $is_unsigned, $is_zerofill;
1200
1201         function __construct( $info ) {
1202                 $this->name = $info->name;
1203                 $this->tablename = $info->table;
1204                 $this->default = $info->def;
1205                 $this->max_length = $info->max_length;
1206                 $this->nullable = !$info->not_null;
1207                 $this->is_pk = $info->primary_key;
1208                 $this->is_unique = $info->unique_key;
1209                 $this->is_multiple = $info->multiple_key;
1210                 $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
1211                 $this->type = $info->type;
1212                 $this->binary = isset( $info->binary ) ? $info->binary : false;
1213                 $this->is_numeric = isset( $info->numeric ) ? $info->numeric : false;
1214                 $this->is_blob = isset( $info->blob ) ? $info->blob : false;
1215                 $this->is_unsigned = isset( $info->unsigned ) ? $info->unsigned : false;
1216                 $this->is_zerofill = isset( $info->zerofill ) ? $info->zerofill : false;
1217         }
1218
1219         /**
1220          * @return string
1221          */
1222         function name() {
1223                 return $this->name;
1224         }
1225
1226         /**
1227          * @return string
1228          */
1229         function tableName() {
1230                 return $this->tableName;
1231         }
1232
1233         /**
1234          * @return string
1235          */
1236         function type() {
1237                 return $this->type;
1238         }
1239
1240         /**
1241          * @return bool
1242          */
1243         function isNullable() {
1244                 return $this->nullable;
1245         }
1246
1247         function defaultValue() {
1248                 return $this->default;
1249         }
1250
1251         /**
1252          * @return bool
1253          */
1254         function isKey() {
1255                 return $this->is_key;
1256         }
1257
1258         /**
1259          * @return bool
1260          */
1261         function isMultipleKey() {
1262                 return $this->is_multiple;
1263         }
1264
1265         /**
1266          * @return bool
1267          */
1268         function isBinary() {
1269                 return $this->binary;
1270         }
1271
1272         /**
1273          * @return bool
1274          */
1275         function isNumeric() {
1276                 return $this->is_numeric;
1277         }
1278
1279         /**
1280          * @return bool
1281          */
1282         function isBlob() {
1283                 return $this->is_blob;
1284         }
1285
1286         /**
1287          * @return bool
1288          */
1289         function isUnsigned() {
1290                 return $this->is_unsigned;
1291         }
1292
1293         /**
1294          * @return bool
1295          */
1296         function isZerofill() {
1297                 return $this->is_zerofill;
1298         }
1299 }
1300
1301 class MySQLMasterPos implements DBMasterPos {
1302         /** @var string */
1303         public $file;
1304         /** @var int Position */
1305         public $pos;
1306         /** @var float UNIX timestamp */
1307         public $asOfTime = 0.0;
1308
1309         function __construct( $file, $pos ) {
1310                 $this->file = $file;
1311                 $this->pos = $pos;
1312                 $this->asOfTime = microtime( true );
1313         }
1314
1315         function __toString() {
1316                 // e.g db1034-bin.000976/843431247
1317                 return "{$this->file}/{$this->pos}";
1318         }
1319
1320         /**
1321          * @return array|bool (int, int)
1322          */
1323         protected function getCoordinates() {
1324                 $m = array();
1325                 if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
1326                         return array( (int)$m[1], (int)$m[2] );
1327                 }
1328
1329                 return false;
1330         }
1331
1332         function hasReached( MySQLMasterPos $pos ) {
1333                 $thisPos = $this->getCoordinates();
1334                 $thatPos = $pos->getCoordinates();
1335
1336                 return ( $thisPos && $thatPos && $thisPos >= $thatPos );
1337         }
1338
1339         function asOfTime() {
1340                 return $this->asOfTime;
1341         }
1342 }