includes/Database.php

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