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