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