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 /** Number of times to re-try an operation in case of deadlock */
   9 define( 'DEADLOCK_TRIES', 4 );
  10 /** Minimum time to wait before retry, in microseconds */
  11 define( 'DEADLOCK_DELAY_MIN', 500000 );
  12 /** Maximum time to wait before retry */
  13 define( 'DEADLOCK_DELAY_MAX', 1500000 );
  14
  15 /******************************************************************************
  16  * Utility classes
  17  *****************************************************************************/
  18
  19 class DBObject {
  20         public $mData;
  21
  22         function DBObject($data) {
  23                 $this->mData = $data;
  24         }
  25
  26         function isLOB() {
  27                 return false;
  28         }
  29
  30         function data() {
  31                 return $this->mData;
  32         }
  33 };
  34
  35 /******************************************************************************
  36  * Error classes
  37  *****************************************************************************/
  38
  39 /**
  40  * Database error base class
  41  */
  42 class DBError extends MWException {
  43         public $db;
  44
  45         /**
  46          * Construct a database error
  47          * @param Database $db The database object which threw the error
  48          * @param string $error A simple error message to be used for debugging
  49          */
  50         function __construct( Database &$db, $error ) {
  51                 $this->db =& $db;
  52                 parent::__construct( $error );
  53         }
  54 }
  55
  56 class DBConnectionError extends DBError {
  57         public $error;
  58
  59         function __construct( Database &$db, $error = 'unknown error' ) {
  60                 $msg = 'DB connection error';
  61                 if ( trim( $error ) != '' ) {
  62                         $msg .= ": $error";
  63                 }
  64                 $this->error = $error;
  65                 parent::__construct( $db, $msg );
  66         }
  67
  68         function useOutputPage() {
  69                 // Not likely to work
  70                 return false;
  71         }
  72
  73         function useMessageCache() {
  74                 // Not likely to work
  75                 return false;
  76         }
  77
  78         function getText() {
  79                 return $this->getMessage() . "\n";
  80         }
  81
  82         function getLogMessage() {
  83                 # Don't send to the exception log
  84                 return false;
  85         }
  86
  87         function getPageTitle() {
  88                 global $wgSitename;
  89                 return "$wgSitename has a problem";
  90         }
  91
  92         function getHTML() {
  93                 global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding, $wgOutputEncoding;
  94                 global $wgSitename, $wgServer, $wgMessageCache, $wgLogo;
  95
  96                 # I give up, Brion is right. Getting the message cache to work when there is no DB is tricky.
  97                 # Hard coding strings instead.
  98
  99                 $noconnect = "<p><strong>Sorry! This site is experiencing technical difficulties.</strong></p><p>Try waiting a few minutes and reloading.</p><p><small>(Can't contact the database server: $1)</small></p>";
 100                 $mainpage = 'Main Page';
 101                 $searchdisabled = <<<EOT
 102 <p style="margin: 1.5em 2em 1em">$wgSitename search is disabled for performance reasons. You can search via Google in the meantime.
 103 <span style="font-size: 89%; display: block; margin-left: .2em">Note that their indexes of $wgSitename content may be out of date.</span></p>',
 104 EOT;
 105
 106                 $googlesearch = "
 107 <!-- SiteSearch Google -->
 108 <FORM method=GET action=\"http://www.google.com/search\">
 109 <TABLE bgcolor=\"#FFFFFF\"><tr><td>
 110 <A HREF=\"http://www.google.com/\">
 111 <IMG SRC=\"http://www.google.com/logos/Logo_40wht.gif\"
 112 border=\"0\" ALT=\"Google\"></A>
 113 </td>
 114 <td>
 115 <INPUT TYPE=text name=q size=31 maxlength=255 value=\"$1\">
 116 <INPUT type=submit name=btnG VALUE=\"Google Search\">
 117 <font size=-1>
 118 <input type=hidden name=domains value=\"$wgServer\"><br /><input type=radio name=sitesearch value=\"\"> WWW <input type=radio name=sitesearch value=\"$wgServer\" checked> $wgServer <br />
 119 <input type='hidden' name='ie' value='$2'>
 120 <input type='hidden' name='oe' value='$2'>
 121 </font>
 122 </td></tr></TABLE>
 123 </FORM>
 124 <!-- SiteSearch Google -->";
 125                 $cachederror = "The following is a cached copy of the requested page, and may not be up to date. ";
 126
 127                 # No database access
 128                 if ( is_object( $wgMessageCache ) ) {
 129                         $wgMessageCache->disable();
 130                 }
 131
 132                 if ( trim( $this->error ) == '' ) {
 133                         $this->error = $this->db->getProperty('mServer');
 134                 }
 135
 136                 $text = str_replace( '$1', $this->error, $noconnect );
 137                 $text .= wfGetSiteNotice();
 138
 139                 if($wgUseFileCache) {
 140                         if($wgTitle) {
 141                                 $t =& $wgTitle;
 142                         } else {
 143                                 if($title) {
 144                                         $t = Title::newFromURL( $title );
 145                                 } elseif (@/**/$_REQUEST['search']) {
 146                                         $search = $_REQUEST['search'];
 147                                         return $searchdisabled .
 148                                           str_replace( array( '$1', '$2' ), array( htmlspecialchars( $search ),
 149                                           $wgInputEncoding ), $googlesearch );
 150                                 } else {
 151                                         $t = Title::newFromText( $mainpage );
 152                                 }
 153                         }
 154
 155                         $cache = new HTMLFileCache( $t );
 156                         if( $cache->isFileCached() ) {
 157                                 $msg = '<p style="color: red"><b>'.$msg."<br />\n" .
 158                                         $cachederror . "</b></p>\n";
 159
 160                                 $tag = '<div id="article">';
 161                                 $text = str_replace(
 162                                         $tag,
 163                                         $tag . $msg,
 164                                         $cache->fetchPageText() );
 165                         }
 166                 }
 167
 168                 return $text;
 169         }
 170 }
 171
 172 class DBQueryError extends DBError {
 173         public $error, $errno, $sql, $fname;
 174
 175         function __construct( Database &$db, $error, $errno, $sql, $fname ) {
 176                 $message = "A database error has occurred\n" .
 177                   "Query: $sql\n" .
 178                   "Function: $fname\n" .
 179                   "Error: $errno $error\n";
 180
 181                 parent::__construct( $db, $message );
 182                 $this->error = $error;
 183                 $this->errno = $errno;
 184                 $this->sql = $sql;
 185                 $this->fname = $fname;
 186         }
 187
 188         function getText() {
 189                 if ( $this->useMessageCache() ) {
 190                         return wfMsg( 'dberrortextcl', htmlspecialchars( $this->getSQL() ),
 191                           htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) ) . "\n";
 192                 } else {
 193                         return $this->getMessage();
 194                 }
 195         }
 196
 197         function getSQL() {
 198                 global $wgShowSQLErrors;
 199                 if( !$wgShowSQLErrors ) {
 200                         return $this->msg( 'sqlhidden', 'SQL hidden' );
 201                 } else {
 202                         return $this->sql;
 203                 }
 204         }
 205
 206         function getLogMessage() {
 207                 # Don't send to the exception log
 208                 return false;
 209         }
 210
 211         function getPageTitle() {
 212                 return $this->msg( 'databaseerror', 'Database error' );
 213         }
 214
 215         function getHTML() {
 216                 if ( $this->useMessageCache() ) {
 217                         return wfMsgNoDB( 'dberrortext', htmlspecialchars( $this->getSQL() ),
 218                           htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) );
 219                 } else {
 220                         return nl2br( htmlspecialchars( $this->getMessage() ) );
 221                 }
 222         }
 223 }
 224
 225 class DBUnexpectedError extends DBError {}
 226
 227 /******************************************************************************/
 228
 229 /**
 230  * Database abstraction object
 231  * @package MediaWiki
 232  */
 233 class Database {
 234
 235 #------------------------------------------------------------------------------
 236 # Variables
 237 #------------------------------------------------------------------------------
 238
 239         protected $mLastQuery = '';
 240
 241         protected $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
 242         protected $mOut, $mOpened = false;
 243
 244         protected $mFailFunction;
 245         protected $mTablePrefix;
 246         protected $mFlags;
 247         protected $mTrxLevel = 0;
 248         protected $mErrorCount = 0;
 249         protected $mLBInfo = array();
 250         protected $mCascadingDeletes = false;
 251         protected $mCleanupTriggers = false;
 252         protected $mStrictIPs = false;
 253
 254 #------------------------------------------------------------------------------
 255 # Accessors
 256 #------------------------------------------------------------------------------
 257         # These optionally set a variable and return the previous state
 258
 259         /**
 260          * Fail function, takes a Database as a parameter
 261          * Set to false for default, 1 for ignore errors
 262          */
 263         function failFunction( $function = NULL ) {
 264                 return wfSetVar( $this->mFailFunction, $function );
 265         }
 266
 267         /**
 268          * Output page, used for reporting errors
 269          * FALSE means discard output
 270          */
 271         function setOutputPage( $out ) {
 272                 $this->mOut = $out;
 273         }
 274
 275         /**
 276          * Boolean, controls output of large amounts of debug information
 277          */
 278         function debug( $debug = NULL ) {
 279                 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
 280         }
 281
 282         /**
 283          * Turns buffering of SQL result sets on (true) or off (false).
 284          * Default is "on" and it should not be changed without good reasons.
 285          */
 286         function bufferResults( $buffer = NULL ) {
 287                 if ( is_null( $buffer ) ) {
 288                         return !(bool)( $this->mFlags & DBO_NOBUFFER );
 289                 } else {
 290                         return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
 291                 }
 292         }
 293
 294         /**
 295          * Turns on (false) or off (true) the automatic generation and sending
 296          * of a "we're sorry, but there has been a database error" page on
 297          * database errors. Default is on (false). When turned off, the
 298          * code should use wfLastErrno() and wfLastError() to handle the
 299          * situation as appropriate.
 300          */
 301         function ignoreErrors( $ignoreErrors = NULL ) {
 302                 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
 303         }
 304
 305         /**
 306          * The current depth of nested transactions
 307          * @param $level Integer: , default NULL.
 308          */
 309         function trxLevel( $level = NULL ) {
 310                 return wfSetVar( $this->mTrxLevel, $level );
 311         }
 312
 313         /**
 314          * Number of errors logged, only useful when errors are ignored
 315          */
 316         function errorCount( $count = NULL ) {
 317                 return wfSetVar( $this->mErrorCount, $count );
 318         }
 319
 320         /**
 321          * Properties passed down from the server info array of the load balancer
 322          */
 323         function getLBInfo( $name = NULL ) {
 324                 if ( is_null( $name ) ) {
 325                         return $this->mLBInfo;
 326                 } else {
 327                         if ( array_key_exists( $name, $this->mLBInfo ) ) {
 328                                 return $this->mLBInfo[$name];
 329                         } else {
 330                                 return NULL;
 331                         }
 332                 }
 333         }
 334
 335         function setLBInfo( $name, $value = NULL ) {
 336                 if ( is_null( $value ) ) {
 337                         $this->mLBInfo = $name;
 338                 } else {
 339                         $this->mLBInfo[$name] = $value;
 340                 }
 341         }
 342
 343         /**
 344          * Returns true if this database supports (and uses) cascading deletes
 345          */
 346         function cascadingDeletes() {
 347                 return $this->mCascadingDeletes;
 348         }
 349
 350         /**
 351          * Returns true if this database supports (and uses) triggers (e.g. on the page table)
 352          */
 353         function cleanupTriggers() {
 354                 return $this->mCleanupTriggers;
 355         }
 356
 357         /**
 358          * Returns true if this database is strict about what can be put into an IP field.
 359          * Specifically, it uses a NULL value instead of an empty string.
 360          */
 361         function strictIPs() {
 362                 return $this->mStrictIPs;
 363         }
 364
 365         /**#@+
 366          * Get function
 367          */
 368         function lastQuery() { return $this->mLastQuery; }
 369         function isOpen() { return $this->mOpened; }
 370         /**#@-*/
 371
 372         function setFlag( $flag ) {
 373                 $this->mFlags |= $flag;
 374         }
 375
 376         function clearFlag( $flag ) {
 377                 $this->mFlags &= ~$flag;
 378         }
 379
 380         function getFlag( $flag ) {
 381                 return !!($this->mFlags & $flag);
 382         }
 383
 384         /**
 385          * General read-only accessor
 386          */
 387         function getProperty( $name ) {
 388                 return $this->$name;
 389         }
 390
 391 #------------------------------------------------------------------------------
 392 # Other functions
 393 #------------------------------------------------------------------------------
 394
 395         /**@{{
 396          * @param string $server database server host
 397          * @param string $user database user name
 398          * @param string $password database user password
 399          * @param string $dbname database name
 400          */
 401
 402         /**
 403          * @param failFunction
 404          * @param $flags
 405          * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
 406          */
 407         function __construct( $server = false, $user = false, $password = false, $dbName = false,
 408                 $failFunction = false, $flags = 0, $tablePrefix = 'get from global' ) {
 409
 410                 global $wgOut, $wgDBprefix, $wgCommandLineMode;
 411                 # Can't get a reference if it hasn't been set yet
 412                 if ( !isset( $wgOut ) ) {
 413                         $wgOut = NULL;
 414                 }
 415                 $this->mOut =& $wgOut;
 416
 417                 $this->mFailFunction = $failFunction;
 418                 $this->mFlags = $flags;
 419
 420                 if ( $this->mFlags & DBO_DEFAULT ) {
 421                         if ( $wgCommandLineMode ) {
 422                                 $this->mFlags &= ~DBO_TRX;
 423                         } else {
 424                                 $this->mFlags |= DBO_TRX;
 425                         }
 426                 }
 427
 428                 /*
 429                 // Faster read-only access
 430                 if ( wfReadOnly() ) {
 431                         $this->mFlags |= DBO_PERSISTENT;
 432                         $this->mFlags &= ~DBO_TRX;
 433                 }*/
 434
 435                 /** Get the default table prefix*/
 436                 if ( $tablePrefix == 'get from global' ) {
 437                         $this->mTablePrefix = $wgDBprefix;
 438                 } else {
 439                         $this->mTablePrefix = $tablePrefix;
 440                 }
 441
 442                 if ( $server ) {
 443                         $this->open( $server, $user, $password, $dbName );
 444                 }
 445         }
 446
 447         /**
 448          * @static
 449          * @param failFunction
 450          * @param $flags
 451          */
 452         static function newFromParams( $server, $user, $password, $dbName,
 453                 $failFunction = false, $flags = 0 )
 454         {
 455                 return new Database( $server, $user, $password, $dbName, $failFunction, $flags );
 456         }
 457
 458         /**
 459          * Usually aborts on failure
 460          * If the failFunction is set to a non-zero integer, returns success
 461          */
 462         function open( $server, $user, $password, $dbName ) {
 463                 global $wguname;
 464                 wfProfileIn( __METHOD__ );
 465
 466                 # Test for missing mysql.so
 467                 # First try to load it
 468                 if (!@extension_loaded('mysql')) {
 469                         @dl('mysql.so');
 470                 }
 471
 472                 # Fail now
 473                 # Otherwise we get a suppressed fatal error, which is very hard to track down
 474                 if ( !function_exists( 'mysql_connect' ) ) {
 475                         throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
 476                 }
 477
 478                 $this->close();
 479                 $this->mServer = $server;
 480                 $this->mUser = $user;
 481                 $this->mPassword = $password;
 482                 $this->mDBname = $dbName;
 483
 484                 $success = false;
 485
 486                 wfProfileIn("dbconnect-$server");
 487
 488                 # LIVE PATCH by Tim, ask Domas for why: retry loop
 489                 $this->mConn = false;
 490                 $max = 3;
 491                 for ( $i = 0; $i < $max && !$this->mConn; $i++ ) {
 492                         if ( $i > 1 ) {
 493                                 usleep( 1000 );
 494                         }
 495                         if ( $this->mFlags & DBO_PERSISTENT ) {
 496                                 @/**/$this->mConn = mysql_pconnect( $server, $user, $password );
 497                         } else {
 498                                 # Create a new connection...
 499                                 @/**/$this->mConn = mysql_connect( $server, $user, $password, true );
 500                         }
 501                         if ($this->mConn === false) {
 502                                 $iplus = $i + 1;
 503                                 wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
 504                         }
 505                 }
 506
 507                 wfProfileOut("dbconnect-$server");
 508
 509                 if ( $dbName != '' ) {
 510                         if ( $this->mConn !== false ) {
 511                                 $success = @/**/mysql_select_db( $dbName, $this->mConn );
 512                                 if ( !$success ) {
 513                                         $error = "Error selecting database $dbName on server {$this->mServer} " .
 514                                                 "from client host {$wguname['nodename']}\n";
 515                                         wfLogDBError(" Error selecting database $dbName on server {$this->mServer} \n");
 516                                         wfDebug( $error );
 517                                 }
 518                         } else {
 519                                 wfDebug( "DB connection error\n" );
 520                                 wfDebug( "Server: $server, User: $user, Password: " .
 521                                         substr( $password, 0, 3 ) . "..., error: " . mysql_error() . "\n" );
 522                                 $success = false;
 523                         }
 524                 } else {
 525                         # Delay USE query
 526                         $success = (bool)$this->mConn;
 527                 }
 528
 529                 if ( $success ) {
 530                         global $wgDBmysql5;
 531                         if( $wgDBmysql5 ) {
 532                                 // Tell the server we're communicating with it in UTF-8.
 533                                 // This may engage various charset conversions.
 534                                 $this->query( 'SET NAMES utf8' );
 535                         }
 536                 } else {
 537                         $this->reportConnectionError();
 538                 }
 539
 540                 $this->mOpened = $success;
 541                 wfProfileOut( __METHOD__ );
 542                 return $success;
 543         }
 544         /**@}}*/
 545
 546         /**
 547          * Closes a database connection.
 548          * if it is open : commits any open transactions
 549          *
 550          * @return bool operation success. true if already closed.
 551          */
 552         function close()
 553         {
 554                 $this->mOpened = false;
 555                 if ( $this->mConn ) {
 556                         if ( $this->trxLevel() ) {
 557                                 $this->immediateCommit();
 558                         }
 559                         return mysql_close( $this->mConn );
 560                 } else {
 561                         return true;
 562                 }
 563         }
 564
 565         /**
 566          * @param string $error fallback error message, used if none is given by MySQL
 567          */
 568         function reportConnectionError( $error = 'Unknown error' ) {
 569                 $myError = $this->lastError();
 570                 if ( $myError ) {
 571                         $error = $myError;
 572                 }
 573
 574                 if ( $this->mFailFunction ) {
 575                         # Legacy error handling method
 576                         if ( !is_int( $this->mFailFunction ) ) {
 577                                 $ff = $this->mFailFunction;
 578                                 $ff( $this, $error );
 579                         }
 580                 } else {
 581                         # New method
 582                         wfLogDBError( "Connection error: $error\n" );
 583                         throw new DBConnectionError( $this, $error );
 584                 }
 585         }
 586
 587         /**
 588          * Usually aborts on failure
 589          * If errors are explicitly ignored, returns success
 590          */
 591         function query( $sql, $fname = '', $tempIgnore = false ) {
 592                 global $wgProfiling;
 593
 594                 if ( $wgProfiling ) {
 595                         # generalizeSQL will probably cut down the query to reasonable
 596                         # logging size most of the time. The substr is really just a sanity check.
 597
 598                         # Who's been wasting my precious column space? -- TS
 599                         #$profName = 'query: ' . $fname . ' ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 600
 601                         if ( is_null( $this->getLBInfo( 'master' ) ) ) {
 602                                 $queryProf = 'query: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 603                                 $totalProf = 'Database::query';
 604                         } else {
 605                                 $queryProf = 'query-m: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 606                                 $totalProf = 'Database::query-master';
 607                         }
 608                         wfProfileIn( $totalProf );
 609                         wfProfileIn( $queryProf );
 610                 }
 611
 612                 $this->mLastQuery = $sql;
 613
 614                 # Add a comment for easy SHOW PROCESSLIST interpretation
 615                 if ( $fname ) {
 616                         $commentedSql = preg_replace("/\s/", " /* $fname */ ", $sql, 1);
 617                 } else {
 618                         $commentedSql = $sql;
 619                 }
 620
 621                 # If DBO_TRX is set, start a transaction
 622                 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
 623                         $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK'
 624                 ) {
 625                         $this->begin();
 626                 }
 627
 628                 if ( $this->debug() ) {
 629                         $sqlx = substr( $commentedSql, 0, 500 );
 630                         $sqlx = strtr( $sqlx, "\t\n", '  ' );
 631                         wfDebug( "SQL: $sqlx\n" );
 632                 }
 633
 634                 # Do the query and handle errors
 635                 $ret = $this->doQuery( $commentedSql );
 636
 637                 # Try reconnecting if the connection was lost
 638                 if ( false === $ret && ( $this->lastErrno() == 2013 || $this->lastErrno() == 2006 ) ) {
 639                         # Transaction is gone, like it or not
 640                         $this->mTrxLevel = 0;
 641                         wfDebug( "Connection lost, reconnecting...\n" );
 642                         if ( $this->ping() ) {
 643                                 wfDebug( "Reconnected\n" );
 644                                 $ret = $this->doQuery( $commentedSql );
 645                         } else {
 646                                 wfDebug( "Failed\n" );
 647                         }
 648                 }
 649
 650                 if ( false === $ret ) {
 651                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
 652                 }
 653
 654                 if ( $wgProfiling ) {
 655                         wfProfileOut( $queryProf );
 656                         wfProfileOut( $totalProf );
 657                 }
 658                 return $ret;
 659         }
 660
 661         /**
 662          * The DBMS-dependent part of query()
 663          * @param string $sql SQL query.
 664          */
 665         function doQuery( $sql ) {
 666                 if( $this->bufferResults() ) {
 667                         $ret = mysql_query( $sql, $this->mConn );
 668                 } else {
 669                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 670                 }
 671                 return $ret;
 672         }
 673
 674         /**
 675          * @param $error
 676          * @param $errno
 677          * @param $sql
 678          * @param string $fname
 679          * @param bool $tempIgnore
 680          */
 681         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 682                 global $wgCommandLineMode, $wgFullyInitialised, $wgColorErrors;
 683                 # Ignore errors during error handling to avoid infinite recursion
 684                 $ignore = $this->ignoreErrors( true );
 685                 ++$this->mErrorCount;
 686
 687                 if( $ignore || $tempIgnore ) {
 688                         wfDebug("SQL ERROR (ignored): $error\n");
 689                         $this->ignoreErrors( $ignore );
 690                 } else {
 691                         $sql1line = str_replace( "\n", "\\n", $sql );
 692                         wfLogDBError("$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n");
 693                         wfDebug("SQL ERROR: " . $error . "\n");
 694                         throw new DBQueryError( $this, $error, $errno, $sql, $fname );
 695                 }
 696         }
 697
 698
 699         /**
 700          * Intended to be compatible with the PEAR::DB wrapper functions.
 701          * http://pear.php.net/manual/en/package.database.db.intro-execute.php
 702          *
 703          * ? = scalar value, quoted as necessary
 704          * ! = raw SQL bit (a function for instance)
 705          * & = filename; reads the file and inserts as a blob
 706          *     (we don't use this though...)
 707          */
 708         function prepare( $sql, $func = 'Database::prepare' ) {
 709                 /* MySQL doesn't support prepared statements (yet), so just
 710                    pack up the query for reference. We'll manually replace
 711                    the bits later. */
 712                 return array( 'query' => $sql, 'func' => $func );
 713         }
 714
 715         function freePrepared( $prepared ) {
 716                 /* No-op for MySQL */
 717         }
 718
 719         /**
 720          * Execute a prepared query with the various arguments
 721          * @param string $prepared the prepared sql
 722          * @param mixed $args Either an array here, or put scalars as varargs
 723          */
 724         function execute( $prepared, $args = null ) {
 725                 if( !is_array( $args ) ) {
 726                         # Pull the var args
 727                         $args = func_get_args();
 728                         array_shift( $args );
 729                 }
 730                 $sql = $this->fillPrepared( $prepared['query'], $args );
 731                 return $this->query( $sql, $prepared['func'] );
 732         }
 733
 734         /**
 735          * Prepare & execute an SQL statement, quoting and inserting arguments
 736          * in the appropriate places.
 737          * @param string $query
 738          * @param string $args ...
 739          */
 740         function safeQuery( $query, $args = null ) {
 741                 $prepared = $this->prepare( $query, 'Database::safeQuery' );
 742                 if( !is_array( $args ) ) {
 743                         # Pull the var args
 744                         $args = func_get_args();
 745                         array_shift( $args );
 746                 }
 747                 $retval = $this->execute( $prepared, $args );
 748                 $this->freePrepared( $prepared );
 749                 return $retval;
 750         }
 751
 752         /**
 753          * For faking prepared SQL statements on DBs that don't support
 754          * it directly.
 755          * @param string $preparedSql - a 'preparable' SQL statement
 756          * @param array $args - array of arguments to fill it with
 757          * @return string executable SQL
 758          */
 759         function fillPrepared( $preparedQuery, $args ) {
 760                 reset( $args );
 761                 $this->preparedArgs =& $args;
 762                 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
 763                         array( &$this, 'fillPreparedArg' ), $preparedQuery );
 764         }
 765
 766         /**
 767          * preg_callback func for fillPrepared()
 768          * The arguments should be in $this->preparedArgs and must not be touched
 769          * while we're doing this.
 770          *
 771          * @param array $matches
 772          * @return string
 773          * @private
 774          */
 775         function fillPreparedArg( $matches ) {
 776                 switch( $matches[1] ) {
 777                         case '\\?': return '?';
 778                         case '\\!': return '!';
 779                         case '\\&': return '&';
 780                 }
 781                 list( $n, $arg ) = each( $this->preparedArgs );
 782                 switch( $matches[1] ) {
 783                         case '?': return $this->addQuotes( $arg );
 784                         case '!': return $arg;
 785                         case '&':
 786                                 # return $this->addQuotes( file_get_contents( $arg ) );
 787                                 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
 788                         default:
 789                                 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
 790                 }
 791         }
 792
 793         /**#@+
 794          * @param mixed $res A SQL result
 795          */
 796         /**
 797          * Free a result object
 798          */
 799         function freeResult( $res ) {
 800                 if ( !@/**/mysql_free_result( $res ) ) {
 801                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 802                 }
 803         }
 804
 805         /**
 806          * Fetch the next row from the given result object, in object form
 807          */
 808         function fetchObject( $res ) {
 809                 @/**/$row = mysql_fetch_object( $res );
 810                 if( $this->lastErrno() ) {
 811                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 812                 }
 813                 return $row;
 814         }
 815
 816         /**
 817          * Fetch the next row from the given result object
 818          * Returns an array
 819          */
 820         function fetchRow( $res ) {
 821                 @/**/$row = mysql_fetch_array( $res );
 822                 if ( $this->lastErrno() ) {
 823                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 824                 }
 825                 return $row;
 826         }
 827
 828         /**
 829          * Get the number of rows in a result object
 830          */
 831         function numRows( $res ) {
 832                 @/**/$n = mysql_num_rows( $res );
 833                 if( $this->lastErrno() ) {
 834                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 835                 }
 836                 return $n;
 837         }
 838
 839         /**
 840          * Get the number of fields in a result object
 841          * See documentation for mysql_num_fields()
 842          */
 843         function numFields( $res ) { return mysql_num_fields( $res ); }
 844
 845         /**
 846          * Get a field name in a result object
 847          * See documentation for mysql_field_name():
 848          * http://www.php.net/mysql_field_name
 849          */
 850         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 851
 852         /**
 853          * Get the inserted value of an auto-increment row
 854          *
 855          * The value inserted should be fetched from nextSequenceValue()
 856          *
 857          * Example:
 858          * $id = $dbw->nextSequenceValue('page_page_id_seq');
 859          * $dbw->insert('page',array('page_id' => $id));
 860          * $id = $dbw->insertId();
 861          */
 862         function insertId() { return mysql_insert_id( $this->mConn ); }
 863
 864         /**
 865          * Change the position of the cursor in a result object
 866          * See mysql_data_seek()
 867          */
 868         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 869
 870         /**
 871          * Get the last error number
 872          * See mysql_errno()
 873          */
 874         function lastErrno() {
 875                 if ( $this->mConn ) {
 876                         return mysql_errno( $this->mConn );
 877                 } else {
 878                         return mysql_errno();
 879                 }
 880         }
 881
 882         /**
 883          * Get a description of the last error
 884          * See mysql_error() for more details
 885          */
 886         function lastError() {
 887                 if ( $this->mConn ) {
 888                         # Even if it's non-zero, it can still be invalid
 889                         wfSuppressWarnings();
 890                         $error = mysql_error( $this->mConn );
 891                         if ( !$error ) {
 892                                 $error = mysql_error();
 893                         }
 894                         wfRestoreWarnings();
 895                 } else {
 896                         $error = mysql_error();
 897                 }
 898                 if( $error ) {
 899                         $error .= ' (' . $this->mServer . ')';
 900                 }
 901                 return $error;
 902         }
 903         /**
 904          * Get the number of rows affected by the last write query
 905          * See mysql_affected_rows() for more details
 906          */
 907         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 908         /**#@-*/ // end of template : @param $result
 909
 910         /**
 911          * Simple UPDATE wrapper
 912          * Usually aborts on failure
 913          * If errors are explicitly ignored, returns success
 914          *
 915          * This function exists for historical reasons, Database::update() has a more standard
 916          * calling convention and feature set
 917          */
 918         function set( $table, $var, $value, $cond, $fname = 'Database::set' )
 919         {
 920                 $table = $this->tableName( $table );
 921                 $sql = "UPDATE $table SET $var = '" .
 922                   $this->strencode( $value ) . "' WHERE ($cond)";
 923                 return (bool)$this->query( $sql, $fname );
 924         }
 925
 926         /**
 927          * Simple SELECT wrapper, returns a single field, input must be encoded
 928          * Usually aborts on failure
 929          * If errors are explicitly ignored, returns FALSE on failure
 930          */
 931         function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
 932                 if ( !is_array( $options ) ) {
 933                         $options = array( $options );
 934                 }
 935                 $options['LIMIT'] = 1;
 936
 937                 $res = $this->select( $table, $var, $cond, $fname, $options );
 938                 if ( $res === false || !$this->numRows( $res ) ) {
 939                         return false;
 940                 }
 941                 $row = $this->fetchRow( $res );
 942                 if ( $row !== false ) {
 943                         $this->freeResult( $res );
 944                         return $row[0];
 945                 } else {
 946                         return false;
 947                 }
 948         }
 949
 950         /**
 951          * Returns an optional USE INDEX clause to go after the table, and a
 952          * string to go at the end of the query
 953          *
 954          * @private
 955          *
 956          * @param array $options an associative array of options to be turned into
 957          *              an SQL query, valid keys are listed in the function.
 958          * @return array
 959          */
 960         function makeSelectOptions( $options ) {
 961                 $tailOpts = '';
 962                 $startOpts = '';
 963
 964                 $noKeyOptions = array();
 965                 foreach ( $options as $key => $option ) {
 966                         if ( is_numeric( $key ) ) {
 967                                 $noKeyOptions[$option] = true;
 968                         }
 969                 }
 970
 971                 if ( isset( $options['GROUP BY'] ) ) $tailOpts .= " GROUP BY {$options['GROUP BY']}";
 972                 if ( isset( $options['ORDER BY'] ) ) $tailOpts .= " ORDER BY {$options['ORDER BY']}";
 973
 974                 if (isset($options['LIMIT'])) {
 975                         $tailOpts .= $this->limitResult('', $options['LIMIT'],
 976                                 isset($options['OFFSET']) ? $options['OFFSET'] : false);
 977                 }
 978
 979                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $tailOpts .= ' FOR UPDATE';
 980                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $tailOpts .= ' LOCK IN SHARE MODE';
 981                 if ( isset( $noKeyOptions['DISTINCT'] ) && isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
 982
 983                 # Various MySQL extensions
 984                 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) $startOpts .= ' HIGH_PRIORITY';
 985                 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) $startOpts .= ' SQL_BIG_RESULT';
 986                 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) $startOpts .= ' SQL_BUFFER_RESULT';
 987                 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) $startOpts .= ' SQL_SMALL_RESULT';
 988                 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) $startOpts .= ' SQL_CALC_FOUND_ROWS';
 989                 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) $startOpts .= ' SQL_CACHE';
 990                 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) $startOpts .= ' SQL_NO_CACHE';
 991
 992                 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
 993                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
 994                 } else {
 995                         $useIndex = '';
 996                 }
 997
 998                 return array( $startOpts, $useIndex, $tailOpts );
 999         }
1000
1001         /**
1002          * SELECT wrapper
1003          */
1004         function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array() )
1005         {
1006                 if( is_array( $vars ) ) {
1007                         $vars = implode( ',', $vars );
1008                 }
1009                 if( !is_array( $options ) ) {
1010                         $options = array( $options );
1011                 }
1012                 if( is_array( $table ) ) {
1013                         if ( @is_array( $options['USE INDEX'] ) )
1014                                 $from = ' FROM ' . $this->tableNamesWithUseIndex( $table, $options['USE INDEX'] );
1015                         else
1016                                 $from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
1017                 } elseif ($table!='') {
1018                         $from = ' FROM ' . $this->tableName( $table );
1019                 } else {
1020                         $from = '';
1021                 }
1022
1023                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $options );
1024
1025                 if( !empty( $conds ) ) {
1026                         if ( is_array( $conds ) ) {
1027                                 $conds = $this->makeList( $conds, LIST_AND );
1028                         }
1029                         $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $tailOpts";
1030                 } else {
1031                         $sql = "SELECT $startOpts $vars $from $useIndex $tailOpts";
1032                 }
1033
1034                 return $this->query( $sql, $fname );
1035         }
1036
1037         /**
1038          * Single row SELECT wrapper
1039          * Aborts or returns FALSE on error
1040          *
1041          * $vars: the selected variables
1042          * $conds: a condition map, terms are ANDed together.
1043          *   Items with numeric keys are taken to be literal conditions
1044          * Takes an array of selected variables, and a condition map, which is ANDed
1045          * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
1046          * NS_MAIN, "page_title" => "Astronomy" ) )   would return an object where
1047          * $obj- >page_id is the ID of the Astronomy article
1048          *
1049          * @todo migrate documentation to phpdocumentor format
1050          */
1051         function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
1052                 $options['LIMIT'] = 1;
1053                 $res = $this->select( $table, $vars, $conds, $fname, $options );
1054                 if ( $res === false )
1055                         return false;
1056                 if ( !$this->numRows($res) ) {
1057                         $this->freeResult($res);
1058                         return false;
1059                 }
1060                 $obj = $this->fetchObject( $res );
1061                 $this->freeResult( $res );
1062                 return $obj;
1063
1064         }
1065
1066         /**
1067          * Removes most variables from an SQL query and replaces them with X or N for numbers.
1068          * It's only slightly flawed. Don't use for anything important.
1069          *
1070          * @param string $sql A SQL Query
1071          * @static
1072          */
1073         static function generalizeSQL( $sql ) {
1074                 # This does the same as the regexp below would do, but in such a way
1075                 # as to avoid crashing php on some large strings.
1076                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1077
1078                 $sql = str_replace ( "\\\\", '', $sql);
1079                 $sql = str_replace ( "\\'", '', $sql);
1080                 $sql = str_replace ( "\\\"", '', $sql);
1081                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
1082                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
1083
1084                 # All newlines, tabs, etc replaced by single space
1085                 $sql = preg_replace ( "/\s+/", ' ', $sql);
1086
1087                 # All numbers => N
1088                 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
1089
1090                 return $sql;
1091         }
1092
1093         /**
1094          * Determines whether a field exists in a table
1095          * Usually aborts on failure
1096          * If errors are explicitly ignored, returns NULL on failure
1097          */
1098         function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
1099                 $table = $this->tableName( $table );
1100                 $res = $this->query( 'DESCRIBE '.$table, $fname );
1101                 if ( !$res ) {
1102                         return NULL;
1103                 }
1104
1105                 $found = false;
1106
1107                 while ( $row = $this->fetchObject( $res ) ) {
1108                         if ( $row->Field == $field ) {
1109                                 $found = true;
1110                                 break;
1111                         }
1112                 }
1113                 return $found;
1114         }
1115
1116         /**
1117          * Determines whether an index exists
1118          * Usually aborts on failure
1119          * If errors are explicitly ignored, returns NULL on failure
1120          */
1121         function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
1122                 $info = $this->indexInfo( $table, $index, $fname );
1123                 if ( is_null( $info ) ) {
1124                         return NULL;
1125                 } else {
1126                         return $info !== false;
1127                 }
1128         }
1129
1130
1131         /**
1132          * Get information about an index into an object
1133          * Returns false if the index does not exist
1134          */
1135         function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
1136                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
1137                 # SHOW INDEX should work for 3.x and up:
1138                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
1139                 $table = $this->tableName( $table );
1140                 $sql = 'SHOW INDEX FROM '.$table;
1141                 $res = $this->query( $sql, $fname );
1142                 if ( !$res ) {
1143                         return NULL;
1144                 }
1145
1146                 while ( $row = $this->fetchObject( $res ) ) {
1147                         if ( $row->Key_name == $index ) {
1148                                 return $row;
1149                         }
1150                 }
1151                 return false;
1152         }
1153
1154         /**
1155          * Query whether a given table exists
1156          */
1157         function tableExists( $table ) {
1158                 $table = $this->tableName( $table );
1159                 $old = $this->ignoreErrors( true );
1160                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
1161                 $this->ignoreErrors( $old );
1162                 if( $res ) {
1163                         $this->freeResult( $res );
1164                         return true;
1165                 } else {
1166                         return false;
1167                 }
1168         }
1169
1170         /**
1171          * mysql_fetch_field() wrapper
1172          * Returns false if the field doesn't exist
1173          *
1174          * @param $table
1175          * @param $field
1176          */
1177         function fieldInfo( $table, $field ) {
1178                 $table = $this->tableName( $table );
1179                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
1180                 $n = mysql_num_fields( $res );
1181                 for( $i = 0; $i < $n; $i++ ) {
1182                         $meta = mysql_fetch_field( $res, $i );
1183                         if( $field == $meta->name ) {
1184                                 return $meta;
1185                         }
1186                 }
1187                 return false;
1188         }
1189
1190         /**
1191          * mysql_field_type() wrapper
1192          */
1193         function fieldType( $res, $index ) {
1194                 return mysql_field_type( $res, $index );
1195         }
1196
1197         /**
1198          * Determines if a given index is unique
1199          */
1200         function indexUnique( $table, $index ) {
1201                 $indexInfo = $this->indexInfo( $table, $index );
1202                 if ( !$indexInfo ) {
1203                         return NULL;
1204                 }
1205                 return !$indexInfo->Non_unique;
1206         }
1207
1208         /**
1209          * INSERT wrapper, inserts an array into a table
1210          *
1211          * $a may be a single associative array, or an array of these with numeric keys, for
1212          * multi-row insert.
1213          *
1214          * Usually aborts on failure
1215          * If errors are explicitly ignored, returns success
1216          */
1217         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
1218                 # No rows to insert, easy just return now
1219                 if ( !count( $a ) ) {
1220                         return true;
1221                 }
1222
1223                 $table = $this->tableName( $table );
1224                 if ( !is_array( $options ) ) {
1225                         $options = array( $options );
1226                 }
1227                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1228                         $multi = true;
1229                         $keys = array_keys( $a[0] );
1230                 } else {
1231                         $multi = false;
1232                         $keys = array_keys( $a );
1233                 }
1234
1235                 $sql = 'INSERT ' . implode( ' ', $options ) .
1236                         " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1237
1238                 if ( $multi ) {
1239                         $first = true;
1240                         foreach ( $a as $row ) {
1241                                 if ( $first ) {
1242                                         $first = false;
1243                                 } else {
1244                                         $sql .= ',';
1245                                 }
1246                                 $sql .= '(' . $this->makeList( $row ) . ')';
1247                         }
1248                 } else {
1249                         $sql .= '(' . $this->makeList( $a ) . ')';
1250                 }
1251                 return (bool)$this->query( $sql, $fname );
1252         }
1253
1254         /**
1255          * Make UPDATE options for the Database::update function
1256          *
1257          * @private
1258          * @param array $options The options passed to Database::update
1259          * @return string
1260          */
1261         function makeUpdateOptions( $options ) {
1262                 if( !is_array( $options ) ) {
1263                         $options = array( $options );
1264                 }
1265                 $opts = array();
1266                 if ( in_array( 'LOW_PRIORITY', $options ) )
1267                         $opts[] = $this->lowPriorityOption();
1268                 if ( in_array( 'IGNORE', $options ) )
1269                         $opts[] = 'IGNORE';
1270                 return implode(' ', $opts);
1271         }
1272
1273         /**
1274          * UPDATE wrapper, takes a condition array and a SET array
1275          *
1276          * @param string $table  The table to UPDATE
1277          * @param array  $values An array of values to SET
1278          * @param array  $conds  An array of conditions (WHERE). Use '*' to update all rows.
1279          * @param string $fname  The Class::Function calling this function
1280          *                       (for the log)
1281          * @param array  $options An array of UPDATE options, can be one or
1282          *                        more of IGNORE, LOW_PRIORITY
1283          */
1284         function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
1285                 $table = $this->tableName( $table );
1286                 $opts = $this->makeUpdateOptions( $options );
1287                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1288                 if ( $conds != '*' ) {
1289                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1290                 }
1291                 $this->query( $sql, $fname );
1292         }
1293
1294         /**
1295          * Makes a wfStrencoded list from an array
1296          * $mode:
1297          *        LIST_COMMA         - comma separated, no field names
1298          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
1299          *        LIST_OR            - ORed WHERE clause (without the WHERE)
1300          *        LIST_SET           - comma separated with field names, like a SET clause
1301          *        LIST_NAMES         - comma separated field names
1302          */
1303         function makeList( $a, $mode = LIST_COMMA ) {
1304                 if ( !is_array( $a ) ) {
1305                         throw new DBUnexpectedError( $this, 'Database::makeList called with incorrect parameters' );
1306                 }
1307
1308                 $first = true;
1309                 $list = '';
1310                 foreach ( $a as $field => $value ) {
1311                         if ( !$first ) {
1312                                 if ( $mode == LIST_AND ) {
1313                                         $list .= ' AND ';
1314                                 } elseif($mode == LIST_OR) {
1315                                         $list .= ' OR ';
1316                                 } else {
1317                                         $list .= ',';
1318                                 }
1319                         } else {
1320                                 $first = false;
1321                         }
1322                         if ( ($mode == LIST_AND || $mode == LIST_OR) && is_numeric( $field ) ) {
1323                                 $list .= "($value)";
1324                         } elseif ( ($mode == LIST_AND || $mode == LIST_OR) && is_array ($value) ) {
1325                                 $list .= $field." IN (".$this->makeList($value).") ";
1326                         } else {
1327                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1328                                         $list .= "$field = ";
1329                                 }
1330                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1331                         }
1332                 }
1333                 return $list;
1334         }
1335
1336         /**
1337          * Change the current database
1338          */
1339         function selectDB( $db ) {
1340                 $this->mDBname = $db;
1341                 return mysql_select_db( $db, $this->mConn );
1342         }
1343
1344         /**
1345          * Format a table name ready for use in constructing an SQL query
1346          *
1347          * This does two important things: it quotes table names which as necessary,
1348          * and it adds a table prefix if there is one.
1349          *
1350          * All functions of this object which require a table name call this function
1351          * themselves. Pass the canonical name to such functions. This is only needed
1352          * when calling query() directly.
1353          *
1354          * @param string $name database table name
1355          */
1356         function tableName( $name ) {
1357                 global $wgSharedDB;
1358                 # Skip quoted literals
1359                 if ( $name{0} != '`' ) {
1360                         if ( $this->mTablePrefix !== '' &&  strpos( '.', $name ) === false ) {
1361                                 $name = "{$this->mTablePrefix}$name";
1362                         }
1363                         if ( isset( $wgSharedDB ) && "{$this->mTablePrefix}user" == $name ) {
1364                                 $name = "`$wgSharedDB`.`$name`";
1365                         } else {
1366                                 # Standard quoting
1367                                 $name = "`$name`";
1368                         }
1369                 }
1370                 return $name;
1371         }
1372
1373         /**
1374          * Fetch a number of table names into an array
1375          * This is handy when you need to construct SQL for joins
1376          *
1377          * Example:
1378          * extract($dbr->tableNames('user','watchlist'));
1379          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1380          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1381          */
1382         function tableNames() {
1383                 $inArray = func_get_args();
1384                 $retVal = array();
1385                 foreach ( $inArray as $name ) {
1386                         $retVal[$name] = $this->tableName( $name );
1387                 }
1388                 return $retVal;
1389         }
1390
1391         /**
1392          * @private
1393          */
1394         function tableNamesWithUseIndex( $tables, $use_index ) {
1395                 $ret = array();
1396
1397                 foreach ( $tables as $table )
1398                         if ( @$use_index[$table] !== null )
1399                                 $ret[] = $this->tableName( $table ) . ' ' . $this->useIndexClause( implode( ',', (array)$use_index[$table] ) );
1400                         else
1401                                 $ret[] = $this->tableName( $table );
1402
1403                 return implode( ',', $ret );
1404         }
1405
1406         /**
1407          * Wrapper for addslashes()
1408          * @param string $s String to be slashed.
1409          * @return string slashed string.
1410          */
1411         function strencode( $s ) {
1412                 return mysql_real_escape_string( $s, $this->mConn );
1413         }
1414
1415         /**
1416          * If it's a string, adds quotes and backslashes
1417          * Otherwise returns as-is
1418          */
1419         function addQuotes( $s ) {
1420                 if ( is_null( $s ) ) {
1421                         return 'NULL';
1422                 } else {
1423                         # This will also quote numeric values. This should be harmless,
1424                         # and protects against weird problems that occur when they really
1425                         # _are_ strings such as article titles and string->number->string
1426                         # conversion is not 1:1.
1427                         return "'" . $this->strencode( $s ) . "'";
1428                 }
1429         }
1430
1431         /**
1432          * Escape string for safe LIKE usage
1433          */
1434         function escapeLike( $s ) {
1435                 $s=$this->strencode( $s );
1436                 $s=str_replace(array('%','_'),array('\%','\_'),$s);
1437                 return $s;
1438         }
1439
1440         /**
1441          * Returns an appropriately quoted sequence value for inserting a new row.
1442          * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1443          * subclass will return an integer, and save the value for insertId()
1444          */
1445         function nextSequenceValue( $seqName ) {
1446                 return NULL;
1447         }
1448
1449         /**
1450          * USE INDEX clause
1451          * PostgreSQL doesn't have them and returns ""
1452          */
1453         function useIndexClause( $index ) {
1454                 return "FORCE INDEX ($index)";
1455         }
1456
1457         /**
1458          * REPLACE query wrapper
1459          * PostgreSQL simulates this with a DELETE followed by INSERT
1460          * $row is the row to insert, an associative array
1461          * $uniqueIndexes is an array of indexes. Each element may be either a
1462          * field name or an array of field names
1463          *
1464          * It may be more efficient to leave off unique indexes which are unlikely to collide.
1465          * However if you do this, you run the risk of encountering errors which wouldn't have
1466          * occurred in MySQL
1467          *
1468          * @todo migrate comment to phodocumentor format
1469          */
1470         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
1471                 $table = $this->tableName( $table );
1472
1473                 # Single row case
1474                 if ( !is_array( reset( $rows ) ) ) {
1475                         $rows = array( $rows );
1476                 }
1477
1478                 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) .') VALUES ';
1479                 $first = true;
1480                 foreach ( $rows as $row ) {
1481                         if ( $first ) {
1482                                 $first = false;
1483                         } else {
1484                                 $sql .= ',';
1485                         }
1486                         $sql .= '(' . $this->makeList( $row ) . ')';
1487                 }
1488                 return $this->query( $sql, $fname );
1489         }
1490
1491         /**
1492          * DELETE where the condition is a join
1493          * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1494          *
1495          * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1496          * join condition matches, set $conds='*'
1497          *
1498          * DO NOT put the join condition in $conds
1499          *
1500          * @param string $delTable The table to delete from.
1501          * @param string $joinTable The other table.
1502          * @param string $delVar The variable to join on, in the first table.
1503          * @param string $joinVar The variable to join on, in the second table.
1504          * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
1505          */
1506         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
1507                 if ( !$conds ) {
1508                         throw new DBUnexpectedError( $this, 'Database::deleteJoin() called with empty $conds' );
1509                 }
1510
1511                 $delTable = $this->tableName( $delTable );
1512                 $joinTable = $this->tableName( $joinTable );
1513                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1514                 if ( $conds != '*' ) {
1515                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1516                 }
1517
1518                 return $this->query( $sql, $fname );
1519         }
1520
1521         /**
1522          * Returns the size of a text field, or -1 for "unlimited"
1523          */
1524         function textFieldSize( $table, $field ) {
1525                 $table = $this->tableName( $table );
1526                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1527                 $res = $this->query( $sql, 'Database::textFieldSize' );
1528                 $row = $this->fetchObject( $res );
1529                 $this->freeResult( $res );
1530
1531                 if ( preg_match( "/\((.*)\)/", $row->Type, $m ) ) {
1532                         $size = $m[1];
1533                 } else {
1534                         $size = -1;
1535                 }
1536                 return $size;
1537         }
1538
1539         /**
1540          * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1541          */
1542         function lowPriorityOption() {
1543                 return 'LOW_PRIORITY';
1544         }
1545
1546         /**
1547          * DELETE query wrapper
1548          *
1549          * Use $conds == "*" to delete all rows
1550          */
1551         function delete( $table, $conds, $fname = 'Database::delete' ) {
1552                 if ( !$conds ) {
1553                         throw new DBUnexpectedError( $this, 'Database::delete() called with no conditions' );
1554                 }
1555                 $table = $this->tableName( $table );
1556                 $sql = "DELETE FROM $table";
1557                 if ( $conds != '*' ) {
1558                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1559                 }
1560                 return $this->query( $sql, $fname );
1561         }
1562
1563         /**
1564          * INSERT SELECT wrapper
1565          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1566          * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1567          * $conds may be "*" to copy the whole table
1568          * srcTable may be an array of tables.
1569          */
1570         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect',
1571                 $insertOptions = array(), $selectOptions = array() )
1572         {
1573                 $destTable = $this->tableName( $destTable );
1574                 if ( is_array( $insertOptions ) ) {
1575                         $insertOptions = implode( ' ', $insertOptions );
1576                 }
1577                 if( !is_array( $selectOptions ) ) {
1578                         $selectOptions = array( $selectOptions );
1579                 }
1580                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
1581                 if( is_array( $srcTable ) ) {
1582                         $srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
1583                 } else {
1584                         $srcTable = $this->tableName( $srcTable );
1585                 }
1586                 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1587                         " SELECT $startOpts " . implode( ',', $varMap ) .
1588                         " FROM $srcTable $useIndex ";
1589                 if ( $conds != '*' ) {
1590                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1591                 }
1592                 $sql .= " $tailOpts";
1593                 return $this->query( $sql, $fname );
1594         }
1595
1596         /**
1597          * Construct a LIMIT query with optional offset
1598          * This is used for query pages
1599          * $sql string SQL query we will append the limit too
1600          * $limit integer the SQL limit
1601          * $offset integer the SQL offset (default false)
1602          */
1603         function limitResult($sql, $limit, $offset=false) {
1604                 if( !is_numeric($limit) ) {
1605                         throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
1606                 }
1607                 return " $sql LIMIT "
1608                                 . ( (is_numeric($offset) && $offset != 0) ? "{$offset}," : "" )
1609                                 . "{$limit} ";
1610         }
1611         function limitResultForUpdate($sql, $num) {
1612                 return $this->limitResult($sql, $num, 0);
1613         }
1614
1615         /**
1616          * Returns an SQL expression for a simple conditional.
1617          * Uses IF on MySQL.
1618          *
1619          * @param string $cond SQL expression which will result in a boolean value
1620          * @param string $trueVal SQL expression to return if true
1621          * @param string $falseVal SQL expression to return if false
1622          * @return string SQL fragment
1623          */
1624         function conditional( $cond, $trueVal, $falseVal ) {
1625                 return " IF($cond, $trueVal, $falseVal) ";
1626         }
1627
1628         /**
1629          * Determines if the last failure was due to a deadlock
1630          */
1631         function wasDeadlock() {
1632                 return $this->lastErrno() == 1213;
1633         }
1634
1635         /**
1636          * Perform a deadlock-prone transaction.
1637          *
1638          * This function invokes a callback function to perform a set of write
1639          * queries. If a deadlock occurs during the processing, the transaction
1640          * will be rolled back and the callback function will be called again.
1641          *
1642          * Usage:
1643          *   $dbw->deadlockLoop( callback, ... );
1644          *
1645          * Extra arguments are passed through to the specified callback function.
1646          *
1647          * Returns whatever the callback function returned on its successful,
1648          * iteration, or false on error, for example if the retry limit was
1649          * reached.
1650          */
1651         function deadlockLoop() {
1652                 $myFname = 'Database::deadlockLoop';
1653
1654                 $this->begin();
1655                 $args = func_get_args();
1656                 $function = array_shift( $args );
1657                 $oldIgnore = $this->ignoreErrors( true );
1658                 $tries = DEADLOCK_TRIES;
1659                 if ( is_array( $function ) ) {
1660                         $fname = $function[0];
1661                 } else {
1662                         $fname = $function;
1663                 }
1664                 do {
1665                         $retVal = call_user_func_array( $function, $args );
1666                         $error = $this->lastError();
1667                         $errno = $this->lastErrno();
1668                         $sql = $this->lastQuery();
1669
1670                         if ( $errno ) {
1671                                 if ( $this->wasDeadlock() ) {
1672                                         # Retry
1673                                         usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1674                                 } else {
1675                                         $this->reportQueryError( $error, $errno, $sql, $fname );
1676                                 }
1677                         }
1678                 } while( $this->wasDeadlock() && --$tries > 0 );
1679                 $this->ignoreErrors( $oldIgnore );
1680                 if ( $tries <= 0 ) {
1681                         $this->query( 'ROLLBACK', $myFname );
1682                         $this->reportQueryError( $error, $errno, $sql, $fname );
1683                         return false;
1684                 } else {
1685                         $this->query( 'COMMIT', $myFname );
1686                         return $retVal;
1687                 }
1688         }
1689
1690         /**
1691          * Do a SELECT MASTER_POS_WAIT()
1692          *
1693          * @param string $file the binlog file
1694          * @param string $pos the binlog position
1695          * @param integer $timeout the maximum number of seconds to wait for synchronisation
1696          */
1697         function masterPosWait( $file, $pos, $timeout ) {
1698                 $fname = 'Database::masterPosWait';
1699                 wfProfileIn( $fname );
1700
1701
1702                 # Commit any open transactions
1703                 $this->immediateCommit();
1704
1705                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
1706                 $encFile = $this->strencode( $file );
1707                 $sql = "SELECT MASTER_POS_WAIT('$encFile', $pos, $timeout)";
1708                 $res = $this->doQuery( $sql );
1709                 if ( $res && $row = $this->fetchRow( $res ) ) {
1710                         $this->freeResult( $res );
1711                         wfProfileOut( $fname );
1712                         return $row[0];
1713                 } else {
1714                         wfProfileOut( $fname );
1715                         return false;
1716                 }
1717         }
1718
1719         /**
1720          * Get the position of the master from SHOW SLAVE STATUS
1721          */
1722         function getSlavePos() {
1723                 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1724                 $row = $this->fetchObject( $res );
1725                 if ( $row ) {
1726                         return array( $row->Master_Log_File, $row->Read_Master_Log_Pos );
1727                 } else {
1728                         return array( false, false );
1729                 }
1730         }
1731
1732         /**
1733          * Get the position of the master from SHOW MASTER STATUS
1734          */
1735         function getMasterPos() {
1736                 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1737                 $row = $this->fetchObject( $res );
1738                 if ( $row ) {
1739                         return array( $row->File, $row->Position );
1740                 } else {
1741                         return array( false, false );
1742                 }
1743         }
1744
1745         /**
1746          * Begin a transaction, committing any previously open transaction
1747          */
1748         function begin( $fname = 'Database::begin' ) {
1749                 $this->query( 'BEGIN', $fname );
1750                 $this->mTrxLevel = 1;
1751         }
1752
1753         /**
1754          * End a transaction
1755          */
1756         function commit( $fname = 'Database::commit' ) {
1757                 $this->query( 'COMMIT', $fname );
1758                 $this->mTrxLevel = 0;
1759         }
1760
1761         /**
1762          * Rollback a transaction
1763          */
1764         function rollback( $fname = 'Database::rollback' ) {
1765                 $this->query( 'ROLLBACK', $fname );
1766                 $this->mTrxLevel = 0;
1767         }
1768
1769         /**
1770          * Begin a transaction, committing any previously open transaction
1771          * @deprecated use begin()
1772          */
1773         function immediateBegin( $fname = 'Database::immediateBegin' ) {
1774                 $this->begin();
1775         }
1776
1777         /**
1778          * Commit transaction, if one is open
1779          * @deprecated use commit()
1780          */
1781         function immediateCommit( $fname = 'Database::immediateCommit' ) {
1782                 $this->commit();
1783         }
1784
1785         /**
1786          * Return MW-style timestamp used for MySQL schema
1787          */
1788         function timestamp( $ts=0 ) {
1789                 return wfTimestamp(TS_MW,$ts);
1790         }
1791
1792         /**
1793          * Local database timestamp format or null
1794          */
1795         function timestampOrNull( $ts = null ) {
1796                 if( is_null( $ts ) ) {
1797                         return null;
1798                 } else {
1799                         return $this->timestamp( $ts );
1800                 }
1801         }
1802
1803         /**
1804          * @todo document
1805          */
1806         function resultObject( $result ) {
1807                 if( empty( $result ) ) {
1808                         return NULL;
1809                 } else {
1810                         return new ResultWrapper( $this, $result );
1811                 }
1812         }
1813
1814         /**
1815          * Return aggregated value alias
1816          */
1817         function aggregateValue ($valuedata,$valuename='value') {
1818                 return $valuename;
1819         }
1820
1821         /**
1822          * @return string wikitext of a link to the server software's web site
1823          */
1824         function getSoftwareLink() {
1825                 return "[http://www.mysql.com/ MySQL]";
1826         }
1827
1828         /**
1829          * @return string Version information from the database
1830          */
1831         function getServerVersion() {
1832                 return mysql_get_server_info();
1833         }
1834
1835         /**
1836          * Ping the server and try to reconnect if it there is no connection
1837          */
1838         function ping() {
1839                 if( function_exists( 'mysql_ping' ) ) {
1840                         return mysql_ping( $this->mConn );
1841                 } else {
1842                         wfDebug( "Tried to call mysql_ping but this is ancient PHP version. Faking it!\n" );
1843                         return true;
1844                 }
1845         }
1846
1847         /**
1848          * Get slave lag.
1849          * At the moment, this will only work if the DB user has the PROCESS privilege
1850          */
1851         function getLag() {
1852                 $res = $this->query( 'SHOW PROCESSLIST' );
1853                 # Find slave SQL thread. Assumed to be the second one running, which is a bit
1854                 # dubious, but unfortunately there's no easy rigorous way
1855                 $slaveThreads = 0;
1856                 while ( $row = $this->fetchObject( $res ) ) {
1857                         /* This should work for most situations - when default db
1858                          * for thread is not specified, it had no events executed,
1859                          * and therefore it doesn't know yet how lagged it is.
1860                          *
1861                          * Relay log I/O thread does not select databases.
1862                          */
1863                         if ( $row->User == 'system user' &&
1864                                 $row->State != 'Waiting for master to send event' &&
1865                                 $row->State != 'Connecting to master' &&
1866                                 $row->State != 'Queueing master event to the relay log' &&
1867                                 $row->State != 'Waiting for master update' &&
1868                                 $row->State != 'Requesting binlog dump'
1869                                 ) {
1870                                 # This is it, return the time (except -ve)
1871                                 if ( $row->Time > 0x7fffffff ) {
1872                                         return false;
1873                                 } else {
1874                                         return $row->Time;
1875                                 }
1876                         }
1877                 }
1878                 return false;
1879         }
1880
1881         /**
1882          * Get status information from SHOW STATUS in an associative array
1883          */
1884         function getStatus($which="%") {
1885                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1886                 $status = array();
1887                 while ( $row = $this->fetchObject( $res ) ) {
1888                         $status[$row->Variable_name] = $row->Value;
1889                 }
1890                 return $status;
1891         }
1892
1893         /**
1894          * Return the maximum number of items allowed in a list, or 0 for unlimited.
1895          */
1896         function maxListLen() {
1897                 return 0;
1898         }
1899
1900         function encodeBlob($b) {
1901                 return $b;
1902         }
1903
1904         function decodeBlob($b) {
1905                 return $b;
1906         }
1907
1908         /**
1909          * Read and execute SQL commands from a file.
1910          * Returns true on success, error string on failure
1911          */
1912         function sourceFile( $filename ) {
1913                 $fp = fopen( $filename, 'r' );
1914                 if ( false === $fp ) {
1915                         return "Could not open \"{$filename}\".\n";
1916                 }
1917
1918                 $cmd = "";
1919                 $done = false;
1920                 $dollarquote = false;
1921
1922                 while ( ! feof( $fp ) ) {
1923                         $line = trim( fgets( $fp, 1024 ) );
1924                         $sl = strlen( $line ) - 1;
1925
1926                         if ( $sl < 0 ) { continue; }
1927                         if ( '-' == $line{0} && '-' == $line{1} ) { continue; }
1928
1929                         ## Allow dollar quoting for function declarations
1930                         if (substr($line,0,4) == '$mw$') {
1931                                 if ($dollarquote) {
1932                                         $dollarquote = false;
1933                                         $done = true;
1934                                 }
1935                                 else {
1936                                         $dollarquote = true;
1937                                 }
1938                         }
1939                         else if (!$dollarquote) {
1940                                 if ( ';' == $line{$sl} && ($sl < 2 || ';' != $line{$sl - 1})) {
1941                                         $done = true;
1942                                         $line = substr( $line, 0, $sl );
1943                                 }
1944                         }
1945
1946                         if ( '' != $cmd ) { $cmd .= ' '; }
1947                         $cmd .= "$line\n";
1948
1949                         if ( $done ) {
1950                                 $cmd = str_replace(';;', ";", $cmd);
1951                                 $cmd = $this->replaceVars( $cmd );
1952                                 $res = $this->query( $cmd, 'dbsource', true );
1953
1954                                 if ( false === $res ) {
1955                                         $err = $this->lastError();
1956                                         return "Query \"{$cmd}\" failed with error code \"$err\".\n";
1957                                 }
1958
1959                                 $cmd = '';
1960                                 $done = false;
1961                         }
1962                 }
1963                 fclose( $fp );
1964                 return true;
1965         }
1966
1967         /**
1968          * Replace variables in sourced SQL
1969          */
1970         protected function replaceVars( $ins ) {
1971                 $varnames = array(
1972                         'wgDBserver', 'wgDBname', 'wgDBintlname', 'wgDBuser',
1973                         'wgDBpassword', 'wgDBsqluser', 'wgDBsqlpassword',
1974                         'wgDBadminuser', 'wgDBadminpassword',
1975                 );
1976
1977                 // Ordinary variables
1978                 foreach ( $varnames as $var ) {
1979                         if( isset( $GLOBALS[$var] ) ) {
1980                                 $val = addslashes( $GLOBALS[$var] ); // FIXME: safety check?
1981                                 $ins = str_replace( '{$' . $var . '}', $val, $ins );
1982                                 $ins = str_replace( '/*$' . $var . '*/`', '`' . $val, $ins );
1983                                 $ins = str_replace( '/*$' . $var . '*/', $val, $ins );
1984                         }
1985                 }
1986
1987                 // Table prefixes
1988                 $ins = preg_replace_callback( '/\/\*(?:\$wgDBprefix|_)\*\/([a-z_]*)/',
1989                         array( &$this, 'tableNameCallback' ), $ins );
1990                 return $ins;
1991         }
1992
1993         /**
1994          * Table name callback
1995          * @private
1996          */
1997         protected function tableNameCallback( $matches ) {
1998                 return $this->tableName( $matches[1] );
1999         }
2000
2001 }
2002
2003 /**
2004  * Database abstraction object for mySQL
2005  * Inherit all methods and properties of Database::Database()
2006  *
2007  * @package MediaWiki
2008  * @see Database
2009  */
2010 class DatabaseMysql extends Database {
2011         # Inherit all
2012 }
2013
2014
2015 /**
2016  * Result wrapper for grabbing data queried by someone else
2017  *
2018  * @package MediaWiki
2019  */
2020 class ResultWrapper {
2021         var $db, $result;
2022
2023         /**
2024          * @todo document
2025          */
2026         function ResultWrapper( &$database, $result ) {
2027                 $this->db =& $database;
2028                 $this->result =& $result;
2029         }
2030
2031         /**
2032          * @todo document
2033          */
2034         function numRows() {
2035                 return $this->db->numRows( $this->result );
2036         }
2037
2038         /**
2039          * @todo document
2040          */
2041         function fetchObject() {
2042                 return $this->db->fetchObject( $this->result );
2043         }
2044
2045         /**
2046          * @todo document
2047          */
2048         function fetchRow() {
2049                 return $this->db->fetchRow( $this->result );
2050         }
2051
2052         /**
2053          * @todo document
2054          */
2055         function free() {
2056                 $this->db->freeResult( $this->result );
2057                 unset( $this->result );
2058                 unset( $this->db );
2059         }
2060
2061         function seek( $row ) {
2062                 $this->db->dataSeek( $this->result, $row );
2063         }
2064
2065 }
2066
2067 ?>