includes/Database.php

   1 <?php
   2 /**
   3  * This file deals with MySQL interface functions
   4  * and query specifics/optimisations
   5  * @package MediaWiki
   6  */
   7
   8 /**
   9  * Depends on the CacheManager
  10  */
  11 require_once( 'CacheManager.php' );
  12
  13 /** See Database::makeList() */
  14 define( 'LIST_COMMA', 0 );
  15 define( 'LIST_AND', 1 );
  16 define( 'LIST_SET', 2 );
  17 define( 'LIST_NAMES', 3);
  18
  19 /** Number of times to re-try an operation in case of deadlock */
  20 define( 'DEADLOCK_TRIES', 4 );
  21 /** Minimum time to wait before retry, in microseconds */
  22 define( 'DEADLOCK_DELAY_MIN', 500000 );
  23 /** Maximum time to wait before retry */
  24 define( 'DEADLOCK_DELAY_MAX', 1500000 );
  25
  26 /**
  27  * Database abstraction object
  28  * @package MediaWiki
  29  */
  30 class Database {
  31
  32 #------------------------------------------------------------------------------
  33 # Variables
  34 #------------------------------------------------------------------------------
  35         /**#@+
  36          * @access private
  37          */
  38         var $mLastQuery = '';
  39
  40         var $mServer, $mUser, $mPassword, $mConn, $mDBname;
  41         var $mOut, $mOpened = false;
  42
  43         var $mFailFunction;
  44         var $mTablePrefix;
  45         var $mFlags;
  46         var $mTrxLevel = 0;
  47         /**#@-*/
  48
  49 #------------------------------------------------------------------------------
  50 # Accessors
  51 #------------------------------------------------------------------------------
  52         # These optionally set a variable and return the previous state
  53
  54         /**
  55          * Fail function, takes a Database as a parameter
  56          * Set to false for default, 1 for ignore errors
  57          */
  58         function failFunction( $function = NULL ) {
  59                 return wfSetVar( $this->mFailFunction, $function );
  60         }
  61
  62         /**
  63          * Output page, used for reporting errors
  64          * FALSE means discard output
  65          */
  66         function &setOutputPage( &$out ) {
  67                 $this->mOut =& $out;
  68         }
  69
  70         /**
  71          * Boolean, controls output of large amounts of debug information
  72          */
  73         function debug( $debug = NULL ) {
  74                 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
  75         }
  76
  77         /**
  78          * Turns buffering of SQL result sets on (true) or off (false).
  79          * Default is "on" and it should not be changed without good reasons.
  80          */
  81         function bufferResults( $buffer = NULL ) {
  82                 if ( is_null( $buffer ) ) {
  83                         return !(bool)( $this->mFlags & DBO_NOBUFFER );
  84                 } else {
  85                         return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
  86                 }
  87         }
  88
  89         /**
  90          * Turns on (false) or off (true) the automatic generation and sending
  91          * of a "we're sorry, but there has been a database error" page on
  92          * database errors. Default is on (false). When turned off, the
  93          * code should use wfLastErrno() and wfLastError() to handle the
  94          * situation as appropriate.
  95          */
  96         function ignoreErrors( $ignoreErrors = NULL ) {
  97                 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
  98         }
  99
 100         /**
 101          * The current depth of nested transactions
 102          * @param integer $level
 103          */
 104         function trxLevel( $level = NULL ) {
 105                 return wfSetVar( $this->mTrxLevel, $level );
 106         }
 107
 108         /**#@+
 109          * Get function
 110          */
 111         function lastQuery() { return $this->mLastQuery; }
 112         function isOpen() { return $this->mOpened; }
 113         /**#@-*/
 114
 115 #------------------------------------------------------------------------------
 116 # Other functions
 117 #------------------------------------------------------------------------------
 118
 119         /**#@+
 120          * @param string $server database server host
 121          * @param string $user database user name
 122          * @param string $password database user password
 123          * @param string $dbname database name
 124          */
 125
 126         /**
 127          * @param failFunction
 128          * @param $flags
 129          * @param string $tablePrefix Database table prefixes. By default use the prefix gave in LocalSettings.php
 130          */
 131         function Database( $server = false, $user = false, $password = false, $dbName = false,
 132                 $failFunction = false, $flags = 0, $tablePrefix = 'get from global' ) {
 133
 134                 global $wgOut, $wgDBprefix, $wgCommandLineMode;
 135                 # Can't get a reference if it hasn't been set yet
 136                 if ( !isset( $wgOut ) ) {
 137                         $wgOut = NULL;
 138                 }
 139                 $this->mOut =& $wgOut;
 140
 141                 $this->mFailFunction = $failFunction;
 142                 $this->mFlags = $flags;
 143
 144                 if ( $this->mFlags & DBO_DEFAULT ) {
 145                         if ( $wgCommandLineMode ) {
 146                                 $this->mFlags &= ~DBO_TRX;
 147                         } else {
 148                                 $this->mFlags |= DBO_TRX;
 149                         }
 150                 }
 151
 152                 /** Get the default table prefix*/
 153                 if ( $tablePrefix == 'get from global' ) {
 154                         $this->mTablePrefix = $wgDBprefix;
 155                 } else {
 156                         $this->mTablePrefix = $tablePrefix;
 157                 }
 158
 159                 if ( $server ) {
 160                         $this->open( $server, $user, $password, $dbName );
 161                 }
 162         }
 163
 164         /**
 165          * @static
 166          * @param failFunction
 167          * @param $flags
 168          */
 169         function newFromParams( $server, $user, $password, $dbName,
 170                 $failFunction = false, $flags = 0 )
 171         {
 172                 return new Database( $server, $user, $password, $dbName, $failFunction, $flags );
 173         }
 174
 175         /**
 176          * Usually aborts on failure
 177          * If the failFunction is set to a non-zero integer, returns success
 178          */
 179         function open( $server, $user, $password, $dbName ) {
 180                 # Test for missing mysql.so
 181                 # First try to load it
 182                 if (!@extension_loaded('mysql')) {
 183                         @dl('mysql.so');
 184                 }
 185
 186                 # Otherwise we get a suppressed fatal error, which is very hard to track down
 187                 if ( !function_exists( 'mysql_connect' ) ) {
 188                         die( "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
 189                 }
 190
 191                 $this->close();
 192                 $this->mServer = $server;
 193                 $this->mUser = $user;
 194                 $this->mPassword = $password;
 195                 $this->mDBname = $dbName;
 196
 197                 $success = false;
 198
 199                 @/**/$this->mConn = mysql_connect( $server, $user, $password );
 200                 if ( $dbName != '' ) {
 201                         if ( $this->mConn !== false ) {
 202                                 $success = @/**/mysql_select_db( $dbName, $this->mConn );
 203                                 if ( !$success ) {
 204                                         wfDebug( "Error selecting database \"$dbName\": " . $this->lastError() . "\n" );
 205                                 }
 206                         } else {
 207                                 wfDebug( "DB connection error\n" );
 208                                 wfDebug( "Server: $server, User: $user, Password: " .
 209                                         substr( $password, 0, 3 ) . "...\n" );
 210                                 $success = false;
 211                         }
 212                 } else {
 213                         # Delay USE query
 214                         $success = !!$this->mConn;
 215                 }
 216
 217                 if ( !$success ) {
 218                         $this->reportConnectionError();
 219                         $this->close();
 220                 }
 221                 $this->mOpened = $success;
 222                 return $success;
 223         }
 224         /**#@-*/
 225
 226         /**
 227          * Closes a database connection.
 228          * if it is open : commits any open transactions
 229          *
 230          * @return bool operation success. true if already closed.
 231          */
 232         function close()
 233         {
 234                 $this->mOpened = false;
 235                 if ( $this->mConn ) {
 236                         if ( $this->trxLevel() ) {
 237                                 $this->immediateCommit();
 238                         }
 239                         return mysql_close( $this->mConn );
 240                 } else {
 241                         return true;
 242                 }
 243         }
 244
 245         /**
 246          * @access private
 247          * @param string $msg error message ?
 248          * @todo parameter $msg is not used
 249          */
 250         function reportConnectionError( $msg = '') {
 251                 if ( $this->mFailFunction ) {
 252                         if ( !is_int( $this->mFailFunction ) ) {
 253                                 $ff = $this->mFailFunction;
 254                                 $ff( $this, mysql_error() );
 255                         }
 256                 } else {
 257                         wfEmergencyAbort( $this, mysql_error() );
 258                 }
 259         }
 260
 261         /**
 262          * Usually aborts on failure
 263          * If errors are explicitly ignored, returns success
 264          */
 265         function query( $sql, $fname = '', $tempIgnore = false ) {
 266                 global $wgProfiling, $wgCommandLineMode;
 267
 268                 if ( $wgProfiling ) {
 269                         # generalizeSQL will probably cut down the query to reasonable
 270                         # logging size most of the time. The substr is really just a sanity check.
 271                         $profName = 'query: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 272                         wfProfileIn( $profName );
 273                 }
 274
 275                 $this->mLastQuery = $sql;
 276
 277                 # Add a comment for easy SHOW PROCESSLIST interpretation
 278                 if ( $fname ) {
 279                         $commentedSql = "/* $fname */ $sql";
 280                 } else {
 281                         $commentedSql = $sql;
 282                 }
 283
 284                 # If DBO_TRX is set, start a transaction
 285                 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() && $sql != 'BEGIN' ) {
 286                         $this->begin();
 287                 }
 288
 289                 if ( $this->debug() ) {
 290                         $sqlx = substr( $sql, 0, 500 );
 291                         $sqlx = strtr($sqlx,"\t\n",'  ');
 292                         wfDebug( "SQL: $sqlx\n" );
 293                 }
 294
 295                 # Do the query and handle errors
 296                 $ret = $this->doQuery( $commentedSql );
 297                 if ( false === $ret ) {
 298                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
 299                 }
 300
 301                 if ( $wgProfiling ) {
 302                         wfProfileOut( $profName );
 303                 }
 304                 return $ret;
 305         }
 306
 307         /**
 308          * The DBMS-dependent part of query()
 309          * @param string $sql SQL query.
 310          */
 311         function doQuery( $sql ) {
 312                 if( $this->bufferResults() ) {
 313                         $ret = mysql_query( $sql, $this->mConn );
 314                 } else {
 315                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 316                 }
 317                 return $ret;
 318         }
 319
 320         /**
 321          * @param $error
 322          * @param $errno
 323          * @param $sql
 324          * @param string $fname
 325          * @param bool $tempIgnore
 326          */
 327         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 328                 global $wgCommandLineMode, $wgFullyInitialised;
 329                 # Ignore errors during error handling to avoid infinite recursion
 330                 $ignore = $this->ignoreErrors( true );
 331
 332                 if( $ignore || $tempIgnore ) {
 333                         wfDebug("SQL ERROR (ignored): " . $error . "\n");
 334                 } else {
 335                         $sql1line = str_replace( "\n", "\\n", $sql );
 336                         wfLogDBError("$fname\t$errno\t$error\t$sql1line\n");
 337                         wfDebug("SQL ERROR: " . $error . "\n");
 338                         if ( $wgCommandLineMode || !$this->mOut || empty( $wgFullyInitialised ) ) {
 339                                 $message = "A database error has occurred\n" .
 340                                   "Query: $sql\n" .
 341                                   "Function: $fname\n" .
 342                                   "Error: $errno $error\n";
 343                                 if ( !$wgCommandLineMode ) {
 344                                         $message = nl2br( $message );
 345                                 }
 346                                 wfDebugDieBacktrace( $message );
 347                         } else {
 348                                 // this calls wfAbruptExit()
 349                                 $this->mOut->databaseError( $fname, $sql, $error, $errno );
 350                         }
 351                 }
 352                 $this->ignoreErrors( $ignore );
 353         }
 354
 355
 356         /**
 357          * Intended to be compatible with the PEAR::DB wrapper functions.
 358          * http://pear.php.net/manual/en/package.database.db.intro-execute.php
 359          *
 360          * ? = scalar value, quoted as necessary
 361          * ! = raw SQL bit (a function for instance)
 362          * & = filename; reads the file and inserts as a blob
 363          *     (we don't use this though...)
 364          */
 365         function prepare( $sql, $func = 'Database::prepare' ) {
 366                 /* MySQL doesn't support prepared statements (yet), so just
 367                    pack up the query for reference. We'll manually replace
 368                    the bits later. */
 369                 return array( 'query' => $sql, 'func' => $func );
 370         }
 371
 372         function freePrepared( $prepared ) {
 373                 /* No-op for MySQL */
 374         }
 375
 376         /**
 377          * Execute a prepared query with the various arguments
 378          * @param string $prepared the prepared sql
 379          * @param mixed $args Either an array here, or put scalars as varargs
 380          */
 381         function execute( $prepared, $args = null ) {
 382                 if( !is_array( $args ) ) {
 383                         # Pull the var args
 384                         $args = func_get_args();
 385                         array_shift( $args );
 386                 }
 387                 $sql = $this->fillPrepared( $prepared['query'], $args );
 388                 return $this->query( $sql, $prepared['func'] );
 389         }
 390
 391         /**
 392          * Prepare & execute an SQL statement, quoting and inserting arguments
 393          * in the appropriate places.
 394          * @param string $query
 395          * @param string $args (default null)
 396          */
 397         function safeQuery( $query, $args = null ) {
 398                 $prepared = $this->prepare( $query, 'Database::safeQuery' );
 399                 if( !is_array( $args ) ) {
 400                         # Pull the var args
 401                         $args = func_get_args();
 402                         array_shift( $args );
 403                 }
 404                 $retval = $this->execute( $prepared, $args );
 405                 $this->freePrepared( $prepared );
 406                 return $retval;
 407         }
 408
 409         /**
 410          * For faking prepared SQL statements on DBs that don't support
 411          * it directly.
 412          * @param string $preparedSql - a 'preparable' SQL statement
 413          * @param array $args - array of arguments to fill it with
 414          * @return string executable SQL
 415          */
 416         function fillPrepared( $preparedQuery, $args ) {
 417                 $n = 0;
 418                 reset( $args );
 419                 $this->preparedArgs =& $args;
 420                 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
 421                         array( &$this, 'fillPreparedArg' ), $preparedQuery );
 422         }
 423
 424         /**
 425          * preg_callback func for fillPrepared()
 426          * The arguments should be in $this->preparedArgs and must not be touched
 427          * while we're doing this.
 428          *
 429          * @param array $matches
 430          * @return string
 431          * @access private
 432          */
 433         function fillPreparedArg( $matches ) {
 434                 switch( $matches[1] ) {
 435                         case '\\?': return '?';
 436                         case '\\!': return '!';
 437                         case '\\&': return '&';
 438                 }
 439                 list( $n, $arg ) = each( $this->preparedArgs );
 440                 switch( $matches[1] ) {
 441                         case '?': return $this->addQuotes( $arg );
 442                         case '!': return $arg;
 443                         case '&':
 444                                 # return $this->addQuotes( file_get_contents( $arg ) );
 445                                 wfDebugDieBacktrace( '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
 446                         default:
 447                                 wfDebugDieBacktrace( 'Received invalid match. This should never happen!' );
 448                 }
 449         }
 450
 451         /**#@+
 452          * @param mixed $res A SQL result
 453          */
 454         /**
 455          * Free a result object
 456          */
 457         function freeResult( $res ) {
 458                 if ( !@/**/mysql_free_result( $res ) ) {
 459                         wfDebugDieBacktrace( "Unable to free MySQL result\n" );
 460                 }
 461         }
 462
 463         /**
 464          * Fetch the next row from the given result object, in object form
 465          */
 466         function fetchObject( $res ) {
 467                 @/**/$row = mysql_fetch_object( $res );
 468                 if( mysql_errno() ) {
 469                         wfDebugDieBacktrace( 'Error in fetchObject(): ' . htmlspecialchars( mysql_error() ) );
 470                 }
 471                 return $row;
 472         }
 473
 474         /**
 475          * Fetch the next row from the given result object
 476          * Returns an array
 477          */
 478         function fetchRow( $res ) {
 479                 @/**/$row = mysql_fetch_array( $res );
 480                 if (mysql_errno() ) {
 481                         wfDebugDieBacktrace( 'Error in fetchRow(): ' . htmlspecialchars( mysql_error() ) );
 482                 }
 483                 return $row;
 484         }
 485
 486         /**
 487          * Get the number of rows in a result object
 488          */
 489         function numRows( $res ) {
 490                 @/**/$n = mysql_num_rows( $res );
 491                 if( mysql_errno() ) {
 492                         wfDebugDieBacktrace( 'Error in numRows(): ' . htmlspecialchars( mysql_error() ) );
 493                 }
 494                 return $n;
 495         }
 496
 497         /**
 498          * Get the number of fields in a result object
 499          * See documentation for mysql_num_fields()
 500          */
 501         function numFields( $res ) { return mysql_num_fields( $res ); }
 502
 503         /**
 504          * Get a field name in a result object
 505          * See documentation for mysql_field_name()
 506          */
 507         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 508
 509         /**
 510          * Get the inserted value of an auto-increment row
 511          *
 512          * The value inserted should be fetched from nextSequenceValue()
 513          *
 514          * Example:
 515          * $id = $dbw->nextSequenceValue('page_page_id_seq');
 516          * $dbw->insert('page',array('page_id' => $id));
 517          * $id = $dbw->insertId();
 518          */
 519         function insertId() { return mysql_insert_id( $this->mConn ); }
 520
 521         /**
 522          * Change the position of the cursor in a result object
 523          * See mysql_data_seek()
 524          */
 525         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 526
 527         /**
 528          * Get the last error number
 529          * See mysql_errno()
 530          */
 531         function lastErrno() {
 532                 if ( $this->mConn ) {
 533                         return mysql_errno( $this->mConn );
 534                 } else {
 535                         return mysql_errno();
 536                 }
 537         }
 538
 539         /**
 540          * Get a description of the last error
 541          * See mysql_error() for more details
 542          */
 543         function lastError() {
 544                 if ( $this->mConn ) {
 545                         $error = mysql_error( $this->mConn );
 546                 } else {
 547                         $error = mysql_error();
 548                 }
 549                 if( $error ) {
 550                         $error .= ' (' . $this->mServer . ')';
 551                 }
 552                 return $error;
 553         }
 554         /**
 555          * Get the number of rows affected by the last write query
 556          * See mysql_affected_rows() for more details
 557          */
 558         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 559         /**#@-*/ // end of template : @param $result
 560
 561         /**
 562          * Simple UPDATE wrapper
 563          * Usually aborts on failure
 564          * If errors are explicitly ignored, returns success
 565          *
 566          * This function exists for historical reasons, Database::update() has a more standard
 567          * calling convention and feature set
 568          */
 569         function set( $table, $var, $value, $cond, $fname = 'Database::set' )
 570         {
 571                 $table = $this->tableName( $table );
 572                 $sql = "UPDATE $table SET $var = '" .
 573                   $this->strencode( $value ) . "' WHERE ($cond)";
 574                 return !!$this->query( $sql, DB_MASTER, $fname );
 575         }
 576
 577         /**
 578          * Simple SELECT wrapper, returns a single field, input must be encoded
 579          * Usually aborts on failure
 580          * If errors are explicitly ignored, returns FALSE on failure
 581          */
 582         function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
 583                 if ( !is_array( $options ) ) {
 584                         $options = array( $options );
 585                 }
 586                 $options['LIMIT'] = 1;
 587
 588                 $res = $this->select( $table, $var, $cond, $fname, $options );
 589                 if ( $res === false || !$this->numRows( $res ) ) {
 590                         return false;
 591                 }
 592                 $row = $this->fetchRow( $res );
 593                 if ( $row !== false ) {
 594                         $this->freeResult( $res );
 595                         return $row[0];
 596                 } else {
 597                         return false;
 598                 }
 599         }
 600
 601         /**
 602          * Returns an optional USE INDEX clause to go after the table, and a
 603          * string to go at the end of the query
 604          */
 605         function makeSelectOptions( $options ) {
 606                 if ( !is_array( $options ) ) {
 607                         $options = array( $options );
 608                 }
 609
 610                 $tailOpts = '';
 611
 612                 if ( isset( $options['ORDER BY'] ) ) {
 613                         $tailOpts .= " ORDER BY {$options['ORDER BY']}";
 614                 }
 615                 if ( isset( $options['LIMIT'] ) ) {
 616                         $tailOpts .= " LIMIT {$options['LIMIT']}";
 617                 }
 618
 619                 if ( is_numeric( array_search( 'FOR UPDATE', $options ) ) ) {
 620                         $tailOpts .= ' FOR UPDATE';
 621                 }
 622
 623                 if ( is_numeric( array_search( 'LOCK IN SHARE MODE', $options ) ) ) {
 624                         $tailOpts .= ' LOCK IN SHARE MODE';
 625                 }
 626
 627                 if ( isset( $options['USE INDEX'] ) ) {
 628                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
 629                 } else {
 630                         $useIndex = '';
 631                 }
 632                 return array( $useIndex, $tailOpts );
 633         }
 634
 635         /**
 636          * SELECT wrapper
 637          */
 638         function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array() )
 639         {
 640                 if( is_array( $vars ) ) {
 641                         $vars = implode( ',', $vars );
 642                 }
 643                 if( is_array( $table ) ) {
 644                         $from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
 645                 } elseif ($table!='') {
 646                         $from = ' FROM ' .$this->tableName( $table );
 647                 } else {
 648                         $from = '';
 649                 }
 650
 651                 list( $useIndex, $tailOpts ) = $this->makeSelectOptions( $options );
 652
 653                 if( !empty( $conds ) ) {
 654                         if ( is_array( $conds ) ) {
 655                                 $conds = $this->makeList( $conds, LIST_AND );
 656                         }
 657                         $sql = "SELECT $vars $from $useIndex WHERE $conds $tailOpts";
 658                 } else {
 659                         $sql = "SELECT $vars $from $useIndex $tailOpts";
 660                 }
 661                 return $this->query( $sql, $fname );
 662         }
 663
 664         /**
 665          * Single row SELECT wrapper
 666          * Aborts or returns FALSE on error
 667          *
 668          * $vars: the selected variables
 669          * $conds: a condition map, terms are ANDed together.
 670          *   Items with numeric keys are taken to be literal conditions
 671          * Takes an array of selected variables, and a condition map, which is ANDed
 672          * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
 673          * NS_MAIN, "page_title" => "Astronomy" ) )   would return an object where
 674          * $obj- >page_id is the ID of the Astronomy article
 675          *
 676          * @todo migrate documentation to phpdocumentor format
 677          */
 678         function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
 679                 $options['LIMIT'] = 1;
 680                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 681                 if ( $res === false || !$this->numRows( $res ) ) {
 682                         return false;
 683                 }
 684                 $obj = $this->fetchObject( $res );
 685                 $this->freeResult( $res );
 686                 return $obj;
 687
 688         }
 689
 690         /**
 691          * Removes most variables from an SQL query and replaces them with X or N for numbers.
 692          * It's only slightly flawed. Don't use for anything important.
 693          *
 694          * @param string $sql A SQL Query
 695          * @static
 696          */
 697         function generalizeSQL( $sql ) {
 698                 # This does the same as the regexp below would do, but in such a way
 699                 # as to avoid crashing php on some large strings.
 700                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
 701
 702                 $sql = str_replace ( "\\\\", '', $sql);
 703                 $sql = str_replace ( "\\'", '', $sql);
 704                 $sql = str_replace ( "\\\"", '', $sql);
 705                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
 706                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
 707
 708                 # All newlines, tabs, etc replaced by single space
 709                 $sql = preg_replace ( "/\s+/", ' ', $sql);
 710
 711                 # All numbers => N
 712                 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
 713
 714                 return $sql;
 715         }
 716
 717         /**
 718          * Determines whether a field exists in a table
 719          * Usually aborts on failure
 720          * If errors are explicitly ignored, returns NULL on failure
 721          */
 722         function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
 723                 $table = $this->tableName( $table );
 724                 $res = $this->query( 'DESCRIBE '.$table, DB_SLAVE, $fname );
 725                 if ( !$res ) {
 726                         return NULL;
 727                 }
 728
 729                 $found = false;
 730
 731                 while ( $row = $this->fetchObject( $res ) ) {
 732                         if ( $row->Field == $field ) {
 733                                 $found = true;
 734                                 break;
 735                         }
 736                 }
 737                 return $found;
 738         }
 739
 740         /**
 741          * Determines whether an index exists
 742          * Usually aborts on failure
 743          * If errors are explicitly ignored, returns NULL on failure
 744          */
 745         function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
 746                 $info = $this->indexInfo( $table, $index, $fname );
 747                 if ( is_null( $info ) ) {
 748                         return NULL;
 749                 } else {
 750                         return $info !== false;
 751                 }
 752         }
 753
 754
 755         /**
 756          * Get information about an index into an object
 757          * Returns false if the index does not exist
 758          */
 759         function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
 760                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 761                 # SHOW INDEX should work for 3.x and up:
 762                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 763                 $table = $this->tableName( $table );
 764                 $sql = 'SHOW INDEX FROM '.$table;
 765                 $res = $this->query( $sql, $fname );
 766                 if ( !$res ) {
 767                         return NULL;
 768                 }
 769
 770                 while ( $row = $this->fetchObject( $res ) ) {
 771                         if ( $row->Key_name == $index ) {
 772                                 return $row;
 773                         }
 774                 }
 775                 return false;
 776         }
 777
 778         /**
 779          * Query whether a given table exists
 780          */
 781         function tableExists( $table ) {
 782                 $table = $this->tableName( $table );
 783                 $old = $this->ignoreErrors( true );
 784                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
 785                 $this->ignoreErrors( $old );
 786                 if( $res ) {
 787                         $this->freeResult( $res );
 788                         return true;
 789                 } else {
 790                         return false;
 791                 }
 792         }
 793
 794         /**
 795          * mysql_fetch_field() wrapper
 796          * Returns false if the field doesn't exist
 797          *
 798          * @param $table
 799          * @param $field
 800          */
 801         function fieldInfo( $table, $field ) {
 802                 $table = $this->tableName( $table );
 803                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
 804                 $n = mysql_num_fields( $res );
 805                 for( $i = 0; $i < $n; $i++ ) {
 806                         $meta = mysql_fetch_field( $res, $i );
 807                         if( $field == $meta->name ) {
 808                                 return $meta;
 809                         }
 810                 }
 811                 return false;
 812         }
 813
 814         /**
 815          * mysql_field_type() wrapper
 816          */
 817         function fieldType( $res, $index ) {
 818                 return mysql_field_type( $res, $index );
 819         }
 820
 821         /**
 822          * Determines if a given index is unique
 823          */
 824         function indexUnique( $table, $index ) {
 825                 $indexInfo = $this->indexInfo( $table, $index );
 826                 if ( !$indexInfo ) {
 827                         return NULL;
 828                 }
 829                 return !$indexInfo->Non_unique;
 830         }
 831
 832         /**
 833          * INSERT wrapper, inserts an array into a table
 834          *
 835          * $a may be a single associative array, or an array of these with numeric keys, for
 836          * multi-row insert.
 837          *
 838          * Usually aborts on failure
 839          * If errors are explicitly ignored, returns success
 840          */
 841         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
 842                 # No rows to insert, easy just return now
 843                 if ( !count( $a ) ) {
 844                         return true;
 845                 }
 846
 847                 $table = $this->tableName( $table );
 848                 if ( !is_array( $options ) ) {
 849                         $options = array( $options );
 850                 }
 851                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 852                         $multi = true;
 853                         $keys = array_keys( $a[0] );
 854                 } else {
 855                         $multi = false;
 856                         $keys = array_keys( $a );
 857                 }
 858
 859                 $sql = 'INSERT ' . implode( ' ', $options ) .
 860                         " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
 861
 862                 if ( $multi ) {
 863                         $first = true;
 864                         foreach ( $a as $row ) {
 865                                 if ( $first ) {
 866                                         $first = false;
 867                                 } else {
 868                                         $sql .= ',';
 869                                 }
 870                                 $sql .= '(' . $this->makeList( $row ) . ')';
 871                         }
 872                 } else {
 873                         $sql .= '(' . $this->makeList( $a ) . ')';
 874                 }
 875                 return !!$this->query( $sql, $fname );
 876         }
 877
 878         /**
 879          * UPDATE wrapper, takes a condition array and a SET array
 880          */
 881         function update( $table, $values, $conds, $fname = 'Database::update' ) {
 882                 $table = $this->tableName( $table );
 883                 $sql = "UPDATE $table SET " . $this->makeList( $values, LIST_SET );
 884                 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
 885                 $this->query( $sql, $fname );
 886         }
 887
 888         /**
 889          * Makes a wfStrencoded list from an array
 890          * $mode: LIST_COMMA         - comma separated, no field names
 891          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
 892          *        LIST_SET           - comma separated with field names, like a SET clause
 893          *        LIST_NAMES         - comma separated field names
 894          */
 895         function makeList( $a, $mode = LIST_COMMA ) {
 896                 if ( !is_array( $a ) ) {
 897                         wfDebugDieBacktrace( 'Database::makeList called with incorrect parameters' );
 898                 }
 899
 900                 $first = true;
 901                 $list = '';
 902                 foreach ( $a as $field => $value ) {
 903                         if ( !$first ) {
 904                                 if ( $mode == LIST_AND ) {
 905                                         $list .= ' AND ';
 906                                 } else {
 907                                         $list .= ',';
 908                                 }
 909                         } else {
 910                                 $first = false;
 911                         }
 912                         if ( $mode == LIST_AND && is_numeric( $field ) ) {
 913                                 $list .= "($value)";
 914                         } elseif ( $mode == LIST_AND && is_array ($value) ) {
 915                                 $list .= $field." IN (".$this->makeList($value).") ";
 916                         } else {
 917                                 if ( $mode == LIST_AND || $mode == LIST_SET ) {
 918                                         $list .= $field.'=';
 919                                 }
 920                                 $list .= ($mode==LIST_NAMES?$value:$this->addQuotes( $value ));
 921                         }
 922                 }
 923                 return $list;
 924         }
 925
 926         /**
 927          * Change the current database
 928          */
 929         function selectDB( $db ) {
 930                 $this->mDBname = $db;
 931                 return mysql_select_db( $db, $this->mConn );
 932         }
 933
 934         /**
 935          * Starts a timer which will kill the DB thread after $timeout seconds
 936          */
 937         function startTimer( $timeout ) {
 938                 global $IP;
 939                 if( function_exists( 'mysql_thread_id' ) ) {
 940                         # This will kill the query if it's still running after $timeout seconds.
 941                         $tid = mysql_thread_id( $this->mConn );
 942                         exec( "php $IP/includes/killthread.php $timeout $tid &>/dev/null &" );
 943                 }
 944         }
 945
 946         /**
 947          * Stop a timer started by startTimer()
 948          * Currently unimplemented.
 949          *
 950          */
 951         function stopTimer() { }
 952
 953         /**
 954          * Format a table name ready for use in constructing an SQL query
 955          *
 956          * This does two important things: it quotes table names which as necessary,
 957          * and it adds a table prefix if there is one.
 958          *
 959          * All functions of this object which require a table name call this function
 960          * themselves. Pass the canonical name to such functions. This is only needed
 961          * when calling query() directly.
 962          *
 963          * @param string $name database table name
 964          */
 965         function tableName( $name ) {
 966                 global $wgSharedDB;
 967                 if ( $this->mTablePrefix !== '' ) {
 968                         if ( strpos( '.', $name ) === false ) {
 969                                 $name = $this->mTablePrefix . $name;
 970                         }
 971                 }
 972                 if ( isset( $wgSharedDB ) && 'user' == $name ) {
 973                         $name = $wgSharedDB . '.' . $name;
 974                 }
 975                 if( $name == 'group' ) {
 976                         $name = '`' . $name . '`';
 977                 }
 978                 return $name;
 979         }
 980
 981         /**
 982          * Fetch a number of table names into an array
 983          * This is handy when you need to construct SQL for joins
 984          *
 985          * Example:
 986          * extract($dbr->tableNames('user','watchlist'));
 987          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
 988          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
 989          */
 990         function tableNames() {
 991                 $inArray = func_get_args();
 992                 $retVal = array();
 993                 foreach ( $inArray as $name ) {
 994                         $retVal[$name] = $this->tableName( $name );
 995                 }
 996                 return $retVal;
 997         }
 998
 999         /**
1000          * Wrapper for addslashes()
1001          * @param string $s String to be slashed.
1002          * @return string slashed string.
1003          */
1004         function strencode( $s ) {
1005                 return addslashes( $s );
1006         }
1007
1008         /**
1009          * If it's a string, adds quotes and backslashes
1010          * Otherwise returns as-is
1011          */
1012         function addQuotes( $s ) {
1013                 if ( is_null( $s ) ) {
1014                         $s = 'NULL';
1015                 } else {
1016                         # This will also quote numeric values. This should be harmless,
1017                         # and protects against weird problems that occur when they really
1018                         # _are_ strings such as article titles and string->number->string
1019                         # conversion is not 1:1.
1020                         $s = "'" . $this->strencode( $s ) . "'";
1021                 }
1022                 return $s;
1023         }
1024
1025         /**
1026          * Returns an appropriately quoted sequence value for inserting a new row.
1027          * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1028          * subclass will return an integer, and save the value for insertId()
1029          */
1030         function nextSequenceValue( $seqName ) {
1031                 return NULL;
1032         }
1033
1034         /**
1035          * USE INDEX clause
1036          * PostgreSQL doesn't have them and returns ""
1037          */
1038         function useIndexClause( $index ) {
1039                 return 'USE INDEX ('.$index.')';
1040         }
1041
1042         /**
1043          * REPLACE query wrapper
1044          * PostgreSQL simulates this with a DELETE followed by INSERT
1045          * $row is the row to insert, an associative array
1046          * $uniqueIndexes is an array of indexes. Each element may be either a
1047          * field name or an array of field names
1048          *
1049          * It may be more efficient to leave off unique indexes which are unlikely to collide.
1050          * However if you do this, you run the risk of encountering errors which wouldn't have
1051          * occurred in MySQL
1052          *
1053          * @todo migrate comment to phodocumentor format
1054          */
1055         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
1056                 $table = $this->tableName( $table );
1057
1058                 # Single row case
1059                 if ( !is_array( reset( $rows ) ) ) {
1060                         $rows = array( $rows );
1061                 }
1062
1063                 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) .') VALUES ';
1064                 $first = true;
1065                 foreach ( $rows as $row ) {
1066                         if ( $first ) {
1067                                 $first = false;
1068                         } else {
1069                                 $sql .= ',';
1070                         }
1071                         $sql .= '(' . $this->makeList( $row ) . ')';
1072                 }
1073                 return $this->query( $sql, $fname );
1074         }
1075
1076         /**
1077          * DELETE where the condition is a join
1078          * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1079          *
1080          * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1081          * join condition matches, set $conds='*'
1082          *
1083          * DO NOT put the join condition in $conds
1084          *
1085          * @param string $delTable The table to delete from.
1086          * @param string $joinTable The other table.
1087          * @param string $delVar The variable to join on, in the first table.
1088          * @param string $joinVar The variable to join on, in the second table.
1089          * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
1090          */
1091         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
1092                 if ( !$conds ) {
1093                         wfDebugDieBacktrace( 'Database::deleteJoin() called with empty $conds' );
1094                 }
1095
1096                 $delTable = $this->tableName( $delTable );
1097                 $joinTable = $this->tableName( $joinTable );
1098                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1099                 if ( $conds != '*' ) {
1100                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1101                 }
1102
1103                 return $this->query( $sql, $fname );
1104         }
1105
1106         /**
1107          * Returns the size of a text field, or -1 for "unlimited"
1108          */
1109         function textFieldSize( $table, $field ) {
1110                 $table = $this->tableName( $table );
1111                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1112                 $res = $this->query( $sql, 'Database::textFieldSize' );
1113                 $row = $this->fetchObject( $res );
1114                 $this->freeResult( $res );
1115
1116                 if ( preg_match( "/\((.*)\)/", $row->Type, $m ) ) {
1117                         $size = $m[1];
1118                 } else {
1119                         $size = -1;
1120                 }
1121                 return $size;
1122         }
1123
1124         /**
1125          * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1126          */
1127         function lowPriorityOption() {
1128                 return 'LOW_PRIORITY';
1129         }
1130
1131         /**
1132          * DELETE query wrapper
1133          *
1134          * Use $conds == "*" to delete all rows
1135          */
1136         function delete( $table, $conds, $fname = 'Database::delete' ) {
1137                 if ( !$conds ) {
1138                         wfDebugDieBacktrace( 'Database::delete() called with no conditions' );
1139                 }
1140                 $table = $this->tableName( $table );
1141                 $sql = "DELETE FROM $table ";
1142                 if ( $conds != '*' ) {
1143                         $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
1144                 }
1145                 return $this->query( $sql, $fname );
1146         }
1147
1148         /**
1149          * INSERT SELECT wrapper
1150          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1151          * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1152          * $conds may be "*" to copy the whole table
1153          * srcTable may be an array of tables.
1154          */
1155         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect' ) {
1156                 $destTable = $this->tableName( $destTable );
1157                 if( is_array( $srcTable ) ) {
1158                         $srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
1159                 } else {
1160                         $srcTable = $this->tableName( $srcTable );
1161                 }
1162                 $sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1163                         ' SELECT ' . implode( ',', $varMap ) .
1164                         " FROM $srcTable";
1165                 if ( $conds != '*' ) {
1166                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1167                 }
1168                 return $this->query( $sql, $fname );
1169         }
1170
1171         /**
1172          * Construct a LIMIT query with optional offset
1173          * This is used for query pages
1174          */
1175         function limitResult($limit,$offset) {
1176                 return ' LIMIT '.(is_numeric($offset)?"{$offset},":"")."{$limit} ";
1177         }
1178
1179         /**
1180          * Returns an SQL expression for a simple conditional.
1181          * Uses IF on MySQL.
1182          *
1183          * @param string $cond SQL expression which will result in a boolean value
1184          * @param string $trueVal SQL expression to return if true
1185          * @param string $falseVal SQL expression to return if false
1186          * @return string SQL fragment
1187          */
1188         function conditional( $cond, $trueVal, $falseVal ) {
1189                 return " IF($cond, $trueVal, $falseVal) ";
1190         }
1191
1192         /**
1193          * Determines if the last failure was due to a deadlock
1194          */
1195         function wasDeadlock() {
1196                 return $this->lastErrno() == 1213;
1197         }
1198
1199         /**
1200          * Perform a deadlock-prone transaction.
1201          *
1202          * This function invokes a callback function to perform a set of write
1203          * queries. If a deadlock occurs during the processing, the transaction
1204          * will be rolled back and the callback function will be called again.
1205          *
1206          * Usage:
1207          *   $dbw->deadlockLoop( callback, ... );
1208          *
1209          * Extra arguments are passed through to the specified callback function.
1210          *
1211          * Returns whatever the callback function returned on its successful,
1212          * iteration, or false on error, for example if the retry limit was
1213          * reached.
1214          */
1215         function deadlockLoop() {
1216                 $myFname = 'Database::deadlockLoop';
1217
1218                 $this->query( 'BEGIN', $myFname );
1219                 $args = func_get_args();
1220                 $function = array_shift( $args );
1221                 $oldIgnore = $this->ignoreErrors( true );
1222                 $tries = DEADLOCK_TRIES;
1223                 if ( is_array( $function ) ) {
1224                         $fname = $function[0];
1225                 } else {
1226                         $fname = $function;
1227                 }
1228                 do {
1229                         $retVal = call_user_func_array( $function, $args );
1230                         $error = $this->lastError();
1231                         $errno = $this->lastErrno();
1232                         $sql = $this->lastQuery();
1233
1234                         if ( $errno ) {
1235                                 if ( $this->wasDeadlock() ) {
1236                                         # Retry
1237                                         usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1238                                 } else {
1239                                         $this->reportQueryError( $error, $errno, $sql, $fname );
1240                                 }
1241                         }
1242                 } while( $this->wasDeadlock() && --$tries > 0 );
1243                 $this->ignoreErrors( $oldIgnore );
1244                 if ( $tries <= 0 ) {
1245                         $this->query( 'ROLLBACK', $myFname );
1246                         $this->reportQueryError( $error, $errno, $sql, $fname );
1247                         return false;
1248                 } else {
1249                         $this->query( 'COMMIT', $myFname );
1250                         return $retVal;
1251                 }
1252         }
1253
1254         /**
1255          * Do a SELECT MASTER_POS_WAIT()
1256          *
1257          * @param string $file the binlog file
1258          * @param string $pos the binlog position
1259          * @param integer $timeout the maximum number of seconds to wait for synchronisation
1260          */
1261         function masterPosWait( $file, $pos, $timeout ) {
1262                 $fname = 'Database::masterPosWait';
1263                 wfProfileIn( $fname );
1264
1265
1266                 # Commit any open transactions
1267                 $this->immediateCommit();
1268
1269                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
1270                 $encFile = $this->strencode( $file );
1271                 $sql = "SELECT MASTER_POS_WAIT('$encFile', $pos, $timeout)";
1272                 $res = $this->doQuery( $sql );
1273                 if ( $res && $row = $this->fetchRow( $res ) ) {
1274                         $this->freeResult( $res );
1275                         return $row[0];
1276                 } else {
1277                         return false;
1278                 }
1279         }
1280
1281         /**
1282          * Get the position of the master from SHOW SLAVE STATUS
1283          */
1284         function getSlavePos() {
1285                 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1286                 $row = $this->fetchObject( $res );
1287                 if ( $row ) {
1288                         return array( $row->Master_Log_File, $row->Read_Master_Log_Pos );
1289                 } else {
1290                         return array( false, false );
1291                 }
1292         }
1293
1294         /**
1295          * Get the position of the master from SHOW MASTER STATUS
1296          */
1297         function getMasterPos() {
1298                 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1299                 $row = $this->fetchObject( $res );
1300                 if ( $row ) {
1301                         return array( $row->File, $row->Position );
1302                 } else {
1303                         return array( false, false );
1304                 }
1305         }
1306
1307         /**
1308          * Begin a transaction, or if a transaction has already started, continue it
1309          */
1310         function begin( $fname = 'Database::begin' ) {
1311                 if ( !$this->mTrxLevel ) {
1312                         $this->immediateBegin( $fname );
1313                 } else {
1314                         $this->mTrxLevel++;
1315                 }
1316         }
1317
1318         /**
1319          * End a transaction, or decrement the nest level if transactions are nested
1320          */
1321         function commit( $fname = 'Database::commit' ) {
1322                 if ( $this->mTrxLevel ) {
1323                         $this->mTrxLevel--;
1324                 }
1325                 if ( !$this->mTrxLevel ) {
1326                         $this->immediateCommit( $fname );
1327                 }
1328         }
1329
1330         /**
1331          * Rollback a transaction
1332          */
1333         function rollback( $fname = 'Database::rollback' ) {
1334                 $this->query( 'ROLLBACK', $fname );
1335                 $this->mTrxLevel = 0;
1336         }
1337
1338         /**
1339          * Begin a transaction, committing any previously open transaction
1340          */
1341         function immediateBegin( $fname = 'Database::immediateBegin' ) {
1342                 $this->query( 'BEGIN', $fname );
1343                 $this->mTrxLevel = 1;
1344         }
1345
1346         /**
1347          * Commit transaction, if one is open
1348          */
1349         function immediateCommit( $fname = 'Database::immediateCommit' ) {
1350                 $this->query( 'COMMIT', $fname );
1351                 $this->mTrxLevel = 0;
1352         }
1353
1354         /**
1355          * Return MW-style timestamp used for MySQL schema
1356          */
1357         function timestamp( $ts=0 ) {
1358                 return wfTimestamp(TS_MW,$ts);
1359         }
1360
1361         /**
1362          * @todo document
1363          */
1364         function &resultObject( &$result ) {
1365                 if( empty( $result ) ) {
1366                         return NULL;
1367                 } else {
1368                         return new ResultWrapper( $this, $result );
1369                 }
1370         }
1371
1372         /**
1373          * Return aggregated value alias
1374          */
1375         function aggregateValue ($valuedata,$valuename='value') {
1376                 return $valuename;
1377         }
1378
1379         /**
1380          * @return string wikitext of a link to the server software's web site
1381          */
1382         function getSoftwareLink() {
1383                 return "[http://www.mysql.com/ MySQL]";
1384         }
1385
1386         /**
1387          * @return string Version information from the database
1388          */
1389         function getServerVersion() {
1390                 return mysql_get_server_info();
1391         }
1392 }
1393
1394 /**
1395  * Database abstraction object for mySQL
1396  * Inherit all methods and properties of Database::Database()
1397  *
1398  * @package MediaWiki
1399  * @see Database
1400  */
1401 class DatabaseMysql extends Database {
1402         # Inherit all
1403 }
1404
1405
1406 /**
1407  * Result wrapper for grabbing data queried by someone else
1408  *
1409  * @package MediaWiki
1410  */
1411 class ResultWrapper {
1412         var $db, $result;
1413
1414         /**
1415          * @todo document
1416          */
1417         function ResultWrapper( $database, $result ) {
1418                 $this->db =& $database;
1419                 $this->result =& $result;
1420         }
1421
1422         /**
1423          * @todo document
1424          */
1425         function numRows() {
1426                 return $this->db->numRows( $this->result );
1427         }
1428
1429         /**
1430          * @todo document
1431          */
1432         function &fetchObject() {
1433                 return $this->db->fetchObject( $this->result );
1434         }
1435
1436         /**
1437          * @todo document
1438          */
1439         function &fetchRow() {
1440                 return $this->db->fetchRow( $this->result );
1441         }
1442
1443         /**
1444          * @todo document
1445          */
1446         function free() {
1447                 $this->db->freeResult( $this->result );
1448                 unset( $this->result );
1449                 unset( $this->db );
1450         }
1451
1452         function seek( $row ) {
1453                 $this->db->dataSeek( $this->result, $row );
1454         }
1455 }
1456
1457 #------------------------------------------------------------------------------
1458 # Global functions
1459 #------------------------------------------------------------------------------
1460
1461 /**
1462  * Standard fail function, called by default when a connection cannot be
1463  * established.
1464  * Displays the file cache if possible
1465  */
1466 function wfEmergencyAbort( &$conn, $error ) {
1467         global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding, $wgOutputEncoding;
1468         global $wgSitename, $wgServer;
1469
1470         # I give up, Brion is right. Getting the message cache to work when there is no DB is tricky.
1471         # Hard coding strings instead.
1472
1473         $noconnect = 'Sorry! The wiki is experiencing some technical difficulties, and cannot contact the database server. <br />
1474 $1';
1475         $mainpage = 'Main Page';
1476         $searchdisabled = <<<EOT
1477 <p style="margin: 1.5em 2em 1em">$wgSitename search is disabled for performance reasons. You can search via Google in the meantime.
1478 <span style="font-size: 89%; display: block; margin-left: .2em">Note that their indexes of $wgSitename content may be out of date.</span></p>',
1479 EOT;
1480
1481         $googlesearch = "
1482 <!-- SiteSearch Google -->
1483 <FORM method=GET action=\"http://www.google.com/search\">
1484 <TABLE bgcolor=\"#FFFFFF\"><tr><td>
1485 <A HREF=\"http://www.google.com/\">
1486 <IMG SRC=\"http://www.google.com/logos/Logo_40wht.gif\"
1487 border=\"0\" ALT=\"Google\"></A>
1488 </td>
1489 <td>
1490 <INPUT TYPE=text name=q size=31 maxlength=255 value=\"$1\">
1491 <INPUT type=submit name=btnG VALUE=\"Google Search\">
1492 <font size=-1>
1493 <input type=hidden name=domains value=\"$wgServer\"><br /><input type=radio name=sitesearch value=\"\"> WWW <input type=radio name=sitesearch value=\"$wgServer\" checked> $wgServer <br />
1494 <input type='hidden' name='ie' value='$2'>
1495 <input type='hidden' name='oe' value='$2'>
1496 </font>
1497 </td></tr></TABLE>
1498 </FORM>
1499 <!-- SiteSearch Google -->";
1500         $cachederror = "The following is a cached copy of the requested page, and may not be up to date. ";
1501
1502
1503         if( !headers_sent() ) {
1504                 header( 'HTTP/1.0 500 Internal Server Error' );
1505                 header( 'Content-type: text/html; charset='.$wgOutputEncoding );
1506                 /* Don't cache error pages!  They cause no end of trouble... */
1507                 header( 'Cache-control: none' );
1508                 header( 'Pragma: nocache' );
1509         }
1510         $msg = wfGetSiteNotice();
1511         if($msg == '') {
1512                 $msg = str_replace( '$1', $error, $noconnect );
1513         }
1514         $text = $msg;
1515
1516         if($wgUseFileCache) {
1517                 if($wgTitle) {
1518                         $t =& $wgTitle;
1519                 } else {
1520                         if($title) {
1521                                 $t = Title::newFromURL( $title );
1522                         } elseif (@/**/$_REQUEST['search']) {
1523                                 $search = $_REQUEST['search'];
1524                                 echo $searchdisabled;
1525                                 echo str_replace( array( '$1', '$2' ), array( htmlspecialchars( $search ),
1526                                   $wgInputEncoding ), $googlesearch );
1527                                 wfErrorExit();
1528                         } else {
1529                                 $t = Title::newFromText( $mainpage );
1530                         }
1531                 }
1532
1533                 $cache = new CacheManager( $t );
1534                 if( $cache->isFileCached() ) {
1535                         $msg = '<p style="color: red"><b>'.$msg."<br />\n" .
1536                                 $cachederror . "</b></p>\n";
1537
1538                         $tag = '<div id="article">';
1539                         $text = str_replace(
1540                                 $tag,
1541                                 $tag . $msg,
1542                                 $cache->fetchPageText() );
1543                 }
1544         }
1545
1546         echo $text;
1547         wfErrorExit();
1548 }
1549
1550 ?>