includes/Database.php

   1 <?php
   2 /**
   3  * This file deals with MySQL interface functions
   4  * and query specifics/optimisations
   5  */
   6
   7 /** Number of times to re-try an operation in case of deadlock */
   8 define( 'DEADLOCK_TRIES', 4 );
   9 /** Minimum time to wait before retry, in microseconds */
  10 define( 'DEADLOCK_DELAY_MIN', 500000 );
  11 /** Maximum time to wait before retry */
  12 define( 'DEADLOCK_DELAY_MAX', 1500000 );
  13
  14 /******************************************************************************
  15  * Utility classes
  16  *****************************************************************************/
  17
  18 /**
  19  * Utility class.
  20  * @addtogroup Database
  21  */
  22 class DBObject {
  23         public $mData;
  24
  25         function DBObject($data) {
  26                 $this->mData = $data;
  27         }
  28
  29         function isLOB() {
  30                 return false;
  31         }
  32
  33         function data() {
  34                 return $this->mData;
  35         }
  36 };
  37
  38 /**
  39  * Utility class.
  40  * @addtogroup Database
  41  */
  42 class MySQLField {
  43         private $name, $tablename, $default, $max_length, $nullable,
  44                 $is_pk, $is_unique, $is_key, $type;
  45         function __construct ($info) {
  46                 $this->name = $info->name;
  47                 $this->tablename = $info->table;
  48                 $this->default = $info->def;
  49                 $this->max_length = $info->max_length;
  50                 $this->nullable = !$info->not_null;
  51                 $this->is_pk = $info->primary_key;
  52                 $this->is_unique = $info->unique_key;
  53                 $this->is_multiple = $info->multiple_key;
  54                 $this->is_key = ($this->is_pk || $this->is_unique || $this->is_multiple);
  55                 $this->type = $info->type;
  56         }
  57
  58         function name() {
  59                 return $this->name;
  60         }
  61
  62         function tableName() {
  63                 return $this->tableName;
  64         }
  65
  66         function defaultValue() {
  67                 return $this->default;
  68         }
  69
  70         function maxLength() {
  71                 return $this->max_length;
  72         }
  73
  74         function nullable() {
  75                 return $this->nullable;
  76         }
  77
  78         function isKey() {
  79                 return $this->is_key;
  80         }
  81
  82         function isMultipleKey() {
  83                 return $this->is_multiple;
  84         }
  85
  86         function type() {
  87                 return $this->type;
  88         }
  89 }
  90
  91 /******************************************************************************
  92  * Error classes
  93  *****************************************************************************/
  94
  95 /**
  96  * Database error base class
  97  * @addtogroup Database
  98  */
  99 class DBError extends MWException {
 100         public $db;
 101
 102         /**
 103          * Construct a database error
 104          * @param Database $db The database object which threw the error
 105          * @param string $error A simple error message to be used for debugging
 106          */
 107         function __construct( Database &$db, $error ) {
 108                 $this->db =& $db;
 109                 parent::__construct( $error );
 110         }
 111 }
 112
 113 /**
 114  * @addtogroup Database
 115  */
 116 class DBConnectionError extends DBError {
 117         public $error;
 118
 119         function __construct( Database &$db, $error = 'unknown error' ) {
 120                 $msg = 'DB connection error';
 121                 if ( trim( $error ) != '' ) {
 122                         $msg .= ": $error";
 123                 }
 124                 $this->error = $error;
 125                 parent::__construct( $db, $msg );
 126         }
 127
 128         function useOutputPage() {
 129                 // Not likely to work
 130                 return false;
 131         }
 132
 133         function useMessageCache() {
 134                 // Not likely to work
 135                 return false;
 136         }
 137
 138         function getText() {
 139                 return $this->getMessage() . "\n";
 140         }
 141
 142         function getLogMessage() {
 143                 # Don't send to the exception log
 144                 return false;
 145         }
 146
 147         function getPageTitle() {
 148                 global $wgSitename;
 149                 return "$wgSitename has a problem";
 150         }
 151
 152         function getHTML() {
 153                 global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding;
 154                 global $wgSitename, $wgServer, $wgMessageCache;
 155
 156                 # I give up, Brion is right. Getting the message cache to work when there is no DB is tricky.
 157                 # Hard coding strings instead.
 158
 159                 $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>";
 160                 $mainpage = 'Main Page';
 161                 $searchdisabled = <<<EOT
 162 <p style="margin: 1.5em 2em 1em">$wgSitename search is disabled for performance reasons. You can search via Google in the meantime.
 163 <span style="font-size: 89%; display: block; margin-left: .2em">Note that their indexes of $wgSitename content may be out of date.</span></p>',
 164 EOT;
 165
 166                 $googlesearch = "
 167 <!-- SiteSearch Google -->
 168 <FORM method=GET action=\"http://www.google.com/search\">
 169 <TABLE bgcolor=\"#FFFFFF\"><tr><td>
 170 <A HREF=\"http://www.google.com/\">
 171 <IMG SRC=\"http://www.google.com/logos/Logo_40wht.gif\"
 172 border=\"0\" ALT=\"Google\"></A>
 173 </td>
 174 <td>
 175 <INPUT TYPE=text name=q size=31 maxlength=255 value=\"$1\">
 176 <INPUT type=submit name=btnG VALUE=\"Google Search\">
 177 <font size=-1>
 178 <input type=hidden name=domains value=\"$wgServer\"><br /><input type=radio name=sitesearch value=\"\"> WWW <input type=radio name=sitesearch value=\"$wgServer\" checked> $wgServer <br />
 179 <input type='hidden' name='ie' value='$2'>
 180 <input type='hidden' name='oe' value='$2'>
 181 </font>
 182 </td></tr></TABLE>
 183 </FORM>
 184 <!-- SiteSearch Google -->";
 185                 $cachederror = "The following is a cached copy of the requested page, and may not be up to date. ";
 186
 187                 # No database access
 188                 if ( is_object( $wgMessageCache ) ) {
 189                         $wgMessageCache->disable();
 190                 }
 191
 192                 if ( trim( $this->error ) == '' ) {
 193                         $this->error = $this->db->getProperty('mServer');
 194                 }
 195
 196                 $text = str_replace( '$1', $this->error, $noconnect );
 197                 $text .= wfGetSiteNotice();
 198
 199                 if($wgUseFileCache) {
 200                         if($wgTitle) {
 201                                 $t =& $wgTitle;
 202                         } else {
 203                                 if($title) {
 204                                         $t = Title::newFromURL( $title );
 205                                 } elseif (@/**/$_REQUEST['search']) {
 206                                         $search = $_REQUEST['search'];
 207                                         return $searchdisabled .
 208                                           str_replace( array( '$1', '$2' ), array( htmlspecialchars( $search ),
 209                                           $wgInputEncoding ), $googlesearch );
 210                                 } else {
 211                                         $t = Title::newFromText( $mainpage );
 212                                 }
 213                         }
 214
 215                         $cache = new HTMLFileCache( $t );
 216                         if( $cache->isFileCached() ) {
 217                                 // FIXME: $msg is not defined on the next line.
 218                                 $msg = '<p style="color: red"><b>'.$msg."<br />\n" .
 219                                         $cachederror . "</b></p>\n";
 220
 221                                 $tag = '<div id="article">';
 222                                 $text = str_replace(
 223                                         $tag,
 224                                         $tag . $msg,
 225                                         $cache->fetchPageText() );
 226                         }
 227                 }
 228
 229                 return $text;
 230         }
 231 }
 232
 233 /**
 234  * @addtogroup Database
 235  */
 236 class DBQueryError extends DBError {
 237         public $error, $errno, $sql, $fname;
 238
 239         function __construct( Database &$db, $error, $errno, $sql, $fname ) {
 240                 $message = "A database error has occurred\n" .
 241                   "Query: $sql\n" .
 242                   "Function: $fname\n" .
 243                   "Error: $errno $error\n";
 244
 245                 parent::__construct( $db, $message );
 246                 $this->error = $error;
 247                 $this->errno = $errno;
 248                 $this->sql = $sql;
 249                 $this->fname = $fname;
 250         }
 251
 252         function getText() {
 253                 if ( $this->useMessageCache() ) {
 254                         return wfMsg( 'dberrortextcl', htmlspecialchars( $this->getSQL() ),
 255                           htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) ) . "\n";
 256                 } else {
 257                         return $this->getMessage();
 258                 }
 259         }
 260
 261         function getSQL() {
 262                 global $wgShowSQLErrors;
 263                 if( !$wgShowSQLErrors ) {
 264                         return $this->msg( 'sqlhidden', 'SQL hidden' );
 265                 } else {
 266                         return $this->sql;
 267                 }
 268         }
 269
 270         function getLogMessage() {
 271                 # Don't send to the exception log
 272                 return false;
 273         }
 274
 275         function getPageTitle() {
 276                 return $this->msg( 'databaseerror', 'Database error' );
 277         }
 278
 279         function getHTML() {
 280                 if ( $this->useMessageCache() ) {
 281                         return wfMsgNoDB( 'dberrortext', htmlspecialchars( $this->getSQL() ),
 282                           htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) );
 283                 } else {
 284                         return nl2br( htmlspecialchars( $this->getMessage() ) );
 285                 }
 286         }
 287 }
 288
 289 /**
 290  * @addtogroup Database
 291  */
 292 class DBUnexpectedError extends DBError {}
 293
 294 /******************************************************************************/
 295
 296 /**
 297  * Database abstraction object
 298  * @addtogroup Database
 299  */
 300 class Database {
 301
 302 #------------------------------------------------------------------------------
 303 # Variables
 304 #------------------------------------------------------------------------------
 305
 306         protected $mLastQuery = '';
 307
 308         protected $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
 309         protected $mOut, $mOpened = false;
 310
 311         protected $mFailFunction;
 312         protected $mTablePrefix;
 313         protected $mFlags;
 314         protected $mTrxLevel = 0;
 315         protected $mErrorCount = 0;
 316         protected $mLBInfo = array();
 317
 318 #------------------------------------------------------------------------------
 319 # Accessors
 320 #------------------------------------------------------------------------------
 321         # These optionally set a variable and return the previous state
 322
 323         /**
 324          * Fail function, takes a Database as a parameter
 325          * Set to false for default, 1 for ignore errors
 326          */
 327         function failFunction( $function = NULL ) {
 328                 return wfSetVar( $this->mFailFunction, $function );
 329         }
 330
 331         /**
 332          * Output page, used for reporting errors
 333          * FALSE means discard output
 334          */
 335         function setOutputPage( $out ) {
 336                 $this->mOut = $out;
 337         }
 338
 339         /**
 340          * Boolean, controls output of large amounts of debug information
 341          */
 342         function debug( $debug = NULL ) {
 343                 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
 344         }
 345
 346         /**
 347          * Turns buffering of SQL result sets on (true) or off (false).
 348          * Default is "on" and it should not be changed without good reasons.
 349          */
 350         function bufferResults( $buffer = NULL ) {
 351                 if ( is_null( $buffer ) ) {
 352                         return !(bool)( $this->mFlags & DBO_NOBUFFER );
 353                 } else {
 354                         return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
 355                 }
 356         }
 357
 358         /**
 359          * Turns on (false) or off (true) the automatic generation and sending
 360          * of a "we're sorry, but there has been a database error" page on
 361          * database errors. Default is on (false). When turned off, the
 362          * code should use lastErrno() and lastError() to handle the
 363          * situation as appropriate.
 364          */
 365         function ignoreErrors( $ignoreErrors = NULL ) {
 366                 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
 367         }
 368
 369         /**
 370          * The current depth of nested transactions
 371          * @param $level Integer: , default NULL.
 372          */
 373         function trxLevel( $level = NULL ) {
 374                 return wfSetVar( $this->mTrxLevel, $level );
 375         }
 376
 377         /**
 378          * Number of errors logged, only useful when errors are ignored
 379          */
 380         function errorCount( $count = NULL ) {
 381                 return wfSetVar( $this->mErrorCount, $count );
 382         }
 383
 384         /**
 385          * Properties passed down from the server info array of the load balancer
 386          */
 387         function getLBInfo( $name = NULL ) {
 388                 if ( is_null( $name ) ) {
 389                         return $this->mLBInfo;
 390                 } else {
 391                         if ( array_key_exists( $name, $this->mLBInfo ) ) {
 392                                 return $this->mLBInfo[$name];
 393                         } else {
 394                                 return NULL;
 395                         }
 396                 }
 397         }
 398
 399         function setLBInfo( $name, $value = NULL ) {
 400                 if ( is_null( $value ) ) {
 401                         $this->mLBInfo = $name;
 402                 } else {
 403                         $this->mLBInfo[$name] = $value;
 404                 }
 405         }
 406
 407         /**
 408          * Returns true if this database supports (and uses) cascading deletes
 409          */
 410         function cascadingDeletes() {
 411                 return false;
 412         }
 413
 414         /**
 415          * Returns true if this database supports (and uses) triggers (e.g. on the page table)
 416          */
 417         function cleanupTriggers() {
 418                 return false;
 419         }
 420
 421         /**
 422          * Returns true if this database is strict about what can be put into an IP field.
 423          * Specifically, it uses a NULL value instead of an empty string.
 424          */
 425         function strictIPs() {
 426                 return false;
 427         }
 428
 429         /**
 430          * Returns true if this database uses timestamps rather than integers
 431         */
 432         function realTimestamps() {
 433                 return false;
 434         }
 435
 436         /**
 437          * Returns true if this database does an implicit sort when doing GROUP BY
 438          */
 439         function implicitGroupby() {
 440                 return true;
 441         }
 442
 443         /**
 444          * Returns true if this database can do a native search on IP columns
 445          * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
 446          */
 447         function searchableIPs() {
 448                 return false;
 449         }
 450
 451         /**#@+
 452          * Get function
 453          */
 454         function lastQuery() { return $this->mLastQuery; }
 455         function isOpen() { return $this->mOpened; }
 456         /**#@-*/
 457
 458         function setFlag( $flag ) {
 459                 $this->mFlags |= $flag;
 460         }
 461
 462         function clearFlag( $flag ) {
 463                 $this->mFlags &= ~$flag;
 464         }
 465
 466         function getFlag( $flag ) {
 467                 return !!($this->mFlags & $flag);
 468         }
 469
 470         /**
 471          * General read-only accessor
 472          */
 473         function getProperty( $name ) {
 474                 return $this->$name;
 475         }
 476
 477 #------------------------------------------------------------------------------
 478 # Other functions
 479 #------------------------------------------------------------------------------
 480
 481         /**@{{
 482          * Constructor.
 483          * @param string $server database server host
 484          * @param string $user database user name
 485          * @param string $password database user password
 486          * @param string $dbname database name
 487          * @param failFunction
 488          * @param $flags
 489          * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
 490          */
 491         function __construct( $server = false, $user = false, $password = false, $dbName = false,
 492                 $failFunction = false, $flags = 0, $tablePrefix = 'get from global' ) {
 493
 494                 global $wgOut, $wgDBprefix, $wgCommandLineMode;
 495                 # Can't get a reference if it hasn't been set yet
 496                 if ( !isset( $wgOut ) ) {
 497                         $wgOut = NULL;
 498                 }
 499                 $this->mOut =& $wgOut;
 500
 501                 $this->mFailFunction = $failFunction;
 502                 $this->mFlags = $flags;
 503
 504                 if ( $this->mFlags & DBO_DEFAULT ) {
 505                         if ( $wgCommandLineMode ) {
 506                                 $this->mFlags &= ~DBO_TRX;
 507                         } else {
 508                                 $this->mFlags |= DBO_TRX;
 509                         }
 510                 }
 511
 512                 /*
 513                 // Faster read-only access
 514                 if ( wfReadOnly() ) {
 515                         $this->mFlags |= DBO_PERSISTENT;
 516                         $this->mFlags &= ~DBO_TRX;
 517                 }*/
 518
 519                 /** Get the default table prefix*/
 520                 if ( $tablePrefix == 'get from global' ) {
 521                         $this->mTablePrefix = $wgDBprefix;
 522                 } else {
 523                         $this->mTablePrefix = $tablePrefix;
 524                 }
 525
 526                 if ( $server ) {
 527                         $this->open( $server, $user, $password, $dbName );
 528                 }
 529         }
 530
 531         /**
 532          * @static
 533          * @param failFunction
 534          * @param $flags
 535          */
 536         static function newFromParams( $server, $user, $password, $dbName, $failFunction = false, $flags = 0 )
 537         {
 538                 return new Database( $server, $user, $password, $dbName, $failFunction, $flags );
 539         }
 540
 541         /**
 542          * Usually aborts on failure
 543          * If the failFunction is set to a non-zero integer, returns success
 544          */
 545         function open( $server, $user, $password, $dbName ) {
 546                 global $wguname;
 547                 wfProfileIn( __METHOD__ );
 548
 549                 # Test for missing mysql.so
 550                 # First try to load it
 551                 if (!@extension_loaded('mysql')) {
 552                         @dl('mysql.so');
 553                 }
 554
 555                 # Fail now
 556                 # Otherwise we get a suppressed fatal error, which is very hard to track down
 557                 if ( !function_exists( 'mysql_connect' ) ) {
 558                         throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
 559                 }
 560
 561                 $this->close();
 562                 $this->mServer = $server;
 563                 $this->mUser = $user;
 564                 $this->mPassword = $password;
 565                 $this->mDBname = $dbName;
 566
 567                 $success = false;
 568
 569                 wfProfileIn("dbconnect-$server");
 570
 571                 # LIVE PATCH by Tim, ask Domas for why: retry loop
 572                 $this->mConn = false;
 573                 $max = 3;
 574                 for ( $i = 0; $i < $max && !$this->mConn; $i++ ) {
 575                         if ( $i > 1 ) {
 576                                 usleep( 1000 );
 577                         }
 578                         if ( $this->mFlags & DBO_PERSISTENT ) {
 579                                 @/**/$this->mConn = mysql_pconnect( $server, $user, $password );
 580                         } else {
 581                                 # Create a new connection...
 582                                 @/**/$this->mConn = mysql_connect( $server, $user, $password, true );
 583                         }
 584                         if ($this->mConn === false) {
 585                                 #$iplus = $i + 1;
 586                                 #wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
 587                         }
 588                 }
 589
 590                 wfProfileOut("dbconnect-$server");
 591
 592                 if ( $dbName != '' ) {
 593                         if ( $this->mConn !== false ) {
 594                                 $success = @/**/mysql_select_db( $dbName, $this->mConn );
 595                                 if ( !$success ) {
 596                                         $error = "Error selecting database $dbName on server {$this->mServer} " .
 597                                                 "from client host {$wguname['nodename']}\n";
 598                                         wfLogDBError(" Error selecting database $dbName on server {$this->mServer} \n");
 599                                         wfDebug( $error );
 600                                 }
 601                         } else {
 602                                 wfDebug( "DB connection error\n" );
 603                                 wfDebug( "Server: $server, User: $user, Password: " .
 604                                         substr( $password, 0, 3 ) . "..., error: " . mysql_error() . "\n" );
 605                                 $success = false;
 606                         }
 607                 } else {
 608                         # Delay USE query
 609                         $success = (bool)$this->mConn;
 610                 }
 611
 612                 if ( $success ) {
 613                         $version = $this->getServerVersion();
 614                         if ( version_compare( $version, '4.1' ) >= 0 ) {
 615                                 // Tell the server we're communicating with it in UTF-8.
 616                                 // This may engage various charset conversions.
 617                                 global $wgDBmysql5;
 618                                 if( $wgDBmysql5 ) {
 619                                         $this->query( 'SET NAMES utf8', __METHOD__ );
 620                                 }
 621                                 // Turn off strict mode
 622                                 $this->query( "SET sql_mode = ''", __METHOD__ );
 623                         }
 624
 625                         // Turn off strict mode if it is on
 626                 } else {
 627                         $this->reportConnectionError();
 628                 }
 629
 630                 $this->mOpened = $success;
 631                 wfProfileOut( __METHOD__ );
 632                 return $success;
 633         }
 634         /**@}}*/
 635
 636         /**
 637          * Closes a database connection.
 638          * if it is open : commits any open transactions
 639          *
 640          * @return bool operation success. true if already closed.
 641          */
 642         function close()
 643         {
 644                 $this->mOpened = false;
 645                 if ( $this->mConn ) {
 646                         if ( $this->trxLevel() ) {
 647                                 $this->immediateCommit();
 648                         }
 649                         return mysql_close( $this->mConn );
 650                 } else {
 651                         return true;
 652                 }
 653         }
 654
 655         /**
 656          * @param string $error fallback error message, used if none is given by MySQL
 657          */
 658         function reportConnectionError( $error = 'Unknown error' ) {
 659                 $myError = $this->lastError();
 660                 if ( $myError ) {
 661                         $error = $myError;
 662                 }
 663
 664                 if ( $this->mFailFunction ) {
 665                         # Legacy error handling method
 666                         if ( !is_int( $this->mFailFunction ) ) {
 667                                 $ff = $this->mFailFunction;
 668                                 $ff( $this, $error );
 669                         }
 670                 } else {
 671                         # New method
 672                         wfLogDBError( "Connection error: $error\n" );
 673                         throw new DBConnectionError( $this, $error );
 674                 }
 675         }
 676
 677         /**
 678          * Usually aborts on failure.  If errors are explicitly ignored, returns success.
 679          *
 680          * @param  $sql        String: SQL query
 681          * @param  $fname      String: Name of the calling function, for profiling/SHOW PROCESSLIST comment (you can use __METHOD__ or add some extra info)
 682          * @param  $tempIgnore Bool:   Whether to avoid throwing an exception on errors... maybe best to catch the exception instead?
 683          * @return Result object to feed to fetchObject, fetchRow, ...; or false on failure if $tempIgnore set
 684          * @throws DBQueryError Thrown when the database returns an error of any kind
 685          */
 686         public function query( $sql, $fname = '', $tempIgnore = false ) {
 687                 global $wgProfiling;
 688
 689                 if ( $wgProfiling ) {
 690                         # generalizeSQL will probably cut down the query to reasonable
 691                         # logging size most of the time. The substr is really just a sanity check.
 692
 693                         # Who's been wasting my precious column space? -- TS
 694                         #$profName = 'query: ' . $fname . ' ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 695
 696                         if ( is_null( $this->getLBInfo( 'master' ) ) ) {
 697                                 $queryProf = 'query: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 698                                 $totalProf = 'Database::query';
 699                         } else {
 700                                 $queryProf = 'query-m: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 701                                 $totalProf = 'Database::query-master';
 702                         }
 703                         wfProfileIn( $totalProf );
 704                         wfProfileIn( $queryProf );
 705                 }
 706
 707                 $this->mLastQuery = $sql;
 708
 709                 # Add a comment for easy SHOW PROCESSLIST interpretation
 710                 #if ( $fname ) {
 711                         global $wgUser;
 712                         if ( is_object( $wgUser ) && !($wgUser instanceof StubObject) ) {
 713                                 $userName = $wgUser->getName();
 714                                 if ( strlen( $userName ) > 15 ) {
 715                                         $userName = substr( $userName, 0, 15 ) . '...';
 716                                 }
 717                                 $userName = str_replace( '/', '', $userName );
 718                         } else {
 719                                 $userName = '';
 720                         }
 721                         $commentedSql = preg_replace('/\s/', " /* $fname $userName */ ", $sql, 1);
 722                 #} else {
 723                 #       $commentedSql = $sql;
 724                 #}
 725
 726                 # If DBO_TRX is set, start a transaction
 727                 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
 728                         $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK'
 729                 ) {
 730                         $this->begin();
 731                 }
 732
 733                 if ( $this->debug() ) {
 734                         $sqlx = substr( $commentedSql, 0, 500 );
 735                         $sqlx = strtr( $sqlx, "\t\n", '  ' );
 736                         wfDebug( "SQL: $sqlx\n" );
 737                 }
 738
 739                 # Do the query and handle errors
 740                 $ret = $this->doQuery( $commentedSql );
 741
 742                 # Try reconnecting if the connection was lost
 743                 if ( false === $ret && ( $this->lastErrno() == 2013 || $this->lastErrno() == 2006 ) ) {
 744                         # Transaction is gone, like it or not
 745                         $this->mTrxLevel = 0;
 746                         wfDebug( "Connection lost, reconnecting...\n" );
 747                         if ( $this->ping() ) {
 748                                 wfDebug( "Reconnected\n" );
 749                                 $sqlx = substr( $commentedSql, 0, 500 );
 750                                 $sqlx = strtr( $sqlx, "\t\n", '  ' );
 751                                 global $wgRequestTime;
 752                                 $elapsed = round( microtime(true) - $wgRequestTime, 3 );
 753                                 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
 754                                 $ret = $this->doQuery( $commentedSql );
 755                         } else {
 756                                 wfDebug( "Failed\n" );
 757                         }
 758                 }
 759
 760                 if ( false === $ret ) {
 761                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
 762                 }
 763
 764                 if ( $wgProfiling ) {
 765                         wfProfileOut( $queryProf );
 766                         wfProfileOut( $totalProf );
 767                 }
 768                 return $ret;
 769         }
 770
 771         /**
 772          * The DBMS-dependent part of query()
 773          * @param  $sql String: SQL query.
 774          * @return Result object to feed to fetchObject, fetchRow, ...; or false on failure
 775          * @access private
 776          */
 777         /*private*/ function doQuery( $sql ) {
 778                 if( $this->bufferResults() ) {
 779                         $ret = mysql_query( $sql, $this->mConn );
 780                 } else {
 781                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 782                 }
 783                 return $ret;
 784         }
 785
 786         /**
 787          * @param $error
 788          * @param $errno
 789          * @param $sql
 790          * @param string $fname
 791          * @param bool $tempIgnore
 792          */
 793         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 794                 global $wgCommandLineMode;
 795                 # Ignore errors during error handling to avoid infinite recursion
 796                 $ignore = $this->ignoreErrors( true );
 797                 ++$this->mErrorCount;
 798
 799                 if( $ignore || $tempIgnore ) {
 800                         wfDebug("SQL ERROR (ignored): $error\n");
 801                         $this->ignoreErrors( $ignore );
 802                 } else {
 803                         $sql1line = str_replace( "\n", "\\n", $sql );
 804                         wfLogDBError("$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n");
 805                         wfDebug("SQL ERROR: " . $error . "\n");
 806                         throw new DBQueryError( $this, $error, $errno, $sql, $fname );
 807                 }
 808         }
 809
 810
 811         /**
 812          * Intended to be compatible with the PEAR::DB wrapper functions.
 813          * http://pear.php.net/manual/en/package.database.db.intro-execute.php
 814          *
 815          * ? = scalar value, quoted as necessary
 816          * ! = raw SQL bit (a function for instance)
 817          * & = filename; reads the file and inserts as a blob
 818          *     (we don't use this though...)
 819          */
 820         function prepare( $sql, $func = 'Database::prepare' ) {
 821                 /* MySQL doesn't support prepared statements (yet), so just
 822                    pack up the query for reference. We'll manually replace
 823                    the bits later. */
 824                 return array( 'query' => $sql, 'func' => $func );
 825         }
 826
 827         function freePrepared( $prepared ) {
 828                 /* No-op for MySQL */
 829         }
 830
 831         /**
 832          * Execute a prepared query with the various arguments
 833          * @param string $prepared the prepared sql
 834          * @param mixed $args Either an array here, or put scalars as varargs
 835          */
 836         function execute( $prepared, $args = null ) {
 837                 if( !is_array( $args ) ) {
 838                         # Pull the var args
 839                         $args = func_get_args();
 840                         array_shift( $args );
 841                 }
 842                 $sql = $this->fillPrepared( $prepared['query'], $args );
 843                 return $this->query( $sql, $prepared['func'] );
 844         }
 845
 846         /**
 847          * Prepare & execute an SQL statement, quoting and inserting arguments
 848          * in the appropriate places.
 849          * @param string $query
 850          * @param string $args ...
 851          */
 852         function safeQuery( $query, $args = null ) {
 853                 $prepared = $this->prepare( $query, 'Database::safeQuery' );
 854                 if( !is_array( $args ) ) {
 855                         # Pull the var args
 856                         $args = func_get_args();
 857                         array_shift( $args );
 858                 }
 859                 $retval = $this->execute( $prepared, $args );
 860                 $this->freePrepared( $prepared );
 861                 return $retval;
 862         }
 863
 864         /**
 865          * For faking prepared SQL statements on DBs that don't support
 866          * it directly.
 867          * @param string $preparedSql - a 'preparable' SQL statement
 868          * @param array $args - array of arguments to fill it with
 869          * @return string executable SQL
 870          */
 871         function fillPrepared( $preparedQuery, $args ) {
 872                 reset( $args );
 873                 $this->preparedArgs =& $args;
 874                 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
 875                         array( &$this, 'fillPreparedArg' ), $preparedQuery );
 876         }
 877
 878         /**
 879          * preg_callback func for fillPrepared()
 880          * The arguments should be in $this->preparedArgs and must not be touched
 881          * while we're doing this.
 882          *
 883          * @param array $matches
 884          * @return string
 885          * @private
 886          */
 887         function fillPreparedArg( $matches ) {
 888                 switch( $matches[1] ) {
 889                         case '\\?': return '?';
 890                         case '\\!': return '!';
 891                         case '\\&': return '&';
 892                 }
 893                 list( /* $n */ , $arg ) = each( $this->preparedArgs );
 894                 switch( $matches[1] ) {
 895                         case '?': return $this->addQuotes( $arg );
 896                         case '!': return $arg;
 897                         case '&':
 898                                 # return $this->addQuotes( file_get_contents( $arg ) );
 899                                 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
 900                         default:
 901                                 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
 902                 }
 903         }
 904
 905         /**#@+
 906          * @param mixed $res A SQL result
 907          */
 908         /**
 909          * Free a result object
 910          */
 911         function freeResult( $res ) {
 912                 if ( !@/**/mysql_free_result( $res ) ) {
 913                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 914                 }
 915         }
 916
 917         /**
 918          * Fetch the next row from the given result object, in object form.
 919          * Fields can be retrieved with $row->fieldname, with fields acting like
 920          * member variables.
 921          *
 922          * @param $res SQL result object as returned from Database::query(), etc.
 923          * @return MySQL row object
 924          * @throws DBUnexpectedError Thrown if the database returns an error
 925          */
 926         function fetchObject( $res ) {
 927                 @/**/$row = mysql_fetch_object( $res );
 928                 if( $this->lastErrno() ) {
 929                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 930                 }
 931                 return $row;
 932         }
 933
 934         /**
 935          * Fetch the next row from the given result object, in associative array
 936          * form.  Fields are retrieved with $row['fieldname'].
 937          *
 938          * @param $res SQL result object as returned from Database::query(), etc.
 939          * @return MySQL row object
 940          * @throws DBUnexpectedError Thrown if the database returns an error
 941          */
 942         function fetchRow( $res ) {
 943                 @/**/$row = mysql_fetch_array( $res );
 944                 if ( $this->lastErrno() ) {
 945                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 946                 }
 947                 return $row;
 948         }
 949
 950         /**
 951          * Get the number of rows in a result object
 952          */
 953         function numRows( $res ) {
 954                 @/**/$n = mysql_num_rows( $res );
 955                 if( $this->lastErrno() ) {
 956                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 957                 }
 958                 return $n;
 959         }
 960
 961         /**
 962          * Get the number of fields in a result object
 963          * See documentation for mysql_num_fields()
 964          */
 965         function numFields( $res ) { return mysql_num_fields( $res ); }
 966
 967         /**
 968          * Get a field name in a result object
 969          * See documentation for mysql_field_name():
 970          * http://www.php.net/mysql_field_name
 971          */
 972         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 973
 974         /**
 975          * Get the inserted value of an auto-increment row
 976          *
 977          * The value inserted should be fetched from nextSequenceValue()
 978          *
 979          * Example:
 980          * $id = $dbw->nextSequenceValue('page_page_id_seq');
 981          * $dbw->insert('page',array('page_id' => $id));
 982          * $id = $dbw->insertId();
 983          */
 984         function insertId() { return mysql_insert_id( $this->mConn ); }
 985
 986         /**
 987          * Change the position of the cursor in a result object
 988          * See mysql_data_seek()
 989          */
 990         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 991
 992         /**
 993          * Get the last error number
 994          * See mysql_errno()
 995          */
 996         function lastErrno() {
 997                 if ( $this->mConn ) {
 998                         return mysql_errno( $this->mConn );
 999                 } else {
1000                         return mysql_errno();
1001                 }
1002         }
1003
1004         /**
1005          * Get a description of the last error
1006          * See mysql_error() for more details
1007          */
1008         function lastError() {
1009                 if ( $this->mConn ) {
1010                         # Even if it's non-zero, it can still be invalid
1011                         wfSuppressWarnings();
1012                         $error = mysql_error( $this->mConn );
1013                         if ( !$error ) {
1014                                 $error = mysql_error();
1015                         }
1016                         wfRestoreWarnings();
1017                 } else {
1018                         $error = mysql_error();
1019                 }
1020                 if( $error ) {
1021                         $error .= ' (' . $this->mServer . ')';
1022                 }
1023                 return $error;
1024         }
1025         /**
1026          * Get the number of rows affected by the last write query
1027          * See mysql_affected_rows() for more details
1028          */
1029         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
1030         /**#@-*/ // end of template : @param $result
1031
1032         /**
1033          * Simple UPDATE wrapper
1034          * Usually aborts on failure
1035          * If errors are explicitly ignored, returns success
1036          *
1037          * This function exists for historical reasons, Database::update() has a more standard
1038          * calling convention and feature set
1039          */
1040         function set( $table, $var, $value, $cond, $fname = 'Database::set' )
1041         {
1042                 $table = $this->tableName( $table );
1043                 $sql = "UPDATE $table SET $var = '" .
1044                   $this->strencode( $value ) . "' WHERE ($cond)";
1045                 return (bool)$this->query( $sql, $fname );
1046         }
1047
1048         /**
1049          * Simple SELECT wrapper, returns a single field, input must be encoded
1050          * Usually aborts on failure
1051          * If errors are explicitly ignored, returns FALSE on failure
1052          */
1053         function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
1054                 if ( !is_array( $options ) ) {
1055                         $options = array( $options );
1056                 }
1057                 $options['LIMIT'] = 1;
1058
1059                 $res = $this->select( $table, $var, $cond, $fname, $options );
1060                 if ( $res === false || !$this->numRows( $res ) ) {
1061                         return false;
1062                 }
1063                 $row = $this->fetchRow( $res );
1064                 if ( $row !== false ) {
1065                         $this->freeResult( $res );
1066                         return $row[0];
1067                 } else {
1068                         return false;
1069                 }
1070         }
1071
1072         /**
1073          * Returns an optional USE INDEX clause to go after the table, and a
1074          * string to go at the end of the query
1075          *
1076          * @private
1077          *
1078          * @param array $options an associative array of options to be turned into
1079          *              an SQL query, valid keys are listed in the function.
1080          * @return array
1081          */
1082         function makeSelectOptions( $options ) {
1083                 $preLimitTail = $postLimitTail = '';
1084                 $startOpts = '';
1085
1086                 $noKeyOptions = array();
1087                 foreach ( $options as $key => $option ) {
1088                         if ( is_numeric( $key ) ) {
1089                                 $noKeyOptions[$option] = true;
1090                         }
1091                 }
1092
1093                 if ( isset( $options['GROUP BY'] ) ) $preLimitTail .= " GROUP BY {$options['GROUP BY']}";
1094                 if ( isset( $options['HAVING'] ) ) $preLimitTail .= " HAVING {$options['HAVING']}";
1095                 if ( isset( $options['ORDER BY'] ) ) $preLimitTail .= " ORDER BY {$options['ORDER BY']}";
1096
1097                 //if (isset($options['LIMIT'])) {
1098                 //      $tailOpts .= $this->limitResult('', $options['LIMIT'],
1099                 //              isset($options['OFFSET']) ? $options['OFFSET']
1100                 //              : false);
1101                 //}
1102
1103                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $postLimitTail .= ' FOR UPDATE';
1104                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $postLimitTail .= ' LOCK IN SHARE MODE';
1105                 if ( isset( $noKeyOptions['DISTINCT'] ) && isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
1106
1107                 # Various MySQL extensions
1108                 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) $startOpts .= ' /*! STRAIGHT_JOIN */';
1109                 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) $startOpts .= ' HIGH_PRIORITY';
1110                 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) $startOpts .= ' SQL_BIG_RESULT';
1111                 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) $startOpts .= ' SQL_BUFFER_RESULT';
1112                 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) $startOpts .= ' SQL_SMALL_RESULT';
1113                 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) $startOpts .= ' SQL_CALC_FOUND_ROWS';
1114                 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) $startOpts .= ' SQL_CACHE';
1115                 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) $startOpts .= ' SQL_NO_CACHE';
1116
1117                 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1118                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1119                 } else {
1120                         $useIndex = '';
1121                 }
1122
1123                 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1124         }
1125
1126         /**
1127          * SELECT wrapper
1128          *
1129          * @param mixed  $table   Array or string, table name(s) (prefix auto-added)
1130          * @param mixed  $vars    Array or string, field name(s) to be retrieved
1131          * @param mixed  $conds   Array or string, condition(s) for WHERE
1132          * @param string $fname   Calling function name (use __METHOD__) for logs/profiling
1133          * @param array  $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
1134          *                        see Database::makeSelectOptions code for list of supported stuff
1135          * @return mixed Database result resource (feed to Database::fetchObject or whatever), or false on failure
1136          */
1137         function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array() )
1138         {
1139                 if( is_array( $vars ) ) {
1140                         $vars = implode( ',', $vars );
1141                 }
1142                 if( !is_array( $options ) ) {
1143                         $options = array( $options );
1144                 }
1145                 if( is_array( $table ) ) {
1146                         if ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1147                                 $from = ' FROM ' . $this->tableNamesWithUseIndex( $table, $options['USE INDEX'] );
1148                         else
1149                                 $from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
1150                 } elseif ($table!='') {
1151                         if ($table{0}==' ') {
1152                                 $from = ' FROM ' . $table;
1153                         } else {
1154                                 $from = ' FROM ' . $this->tableName( $table );
1155                         }
1156                 } else {
1157                         $from = '';
1158                 }
1159
1160                 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1161
1162                 if( !empty( $conds ) ) {
1163                         if ( is_array( $conds ) ) {
1164                                 $conds = $this->makeList( $conds, LIST_AND );
1165                         }
1166                         $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1167                 } else {
1168                         $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1169                 }
1170
1171                 if (isset($options['LIMIT']))
1172                         $sql = $this->limitResult($sql, $options['LIMIT'],
1173                                 isset($options['OFFSET']) ? $options['OFFSET'] : false);
1174                 $sql = "$sql $postLimitTail";
1175
1176                 if (isset($options['EXPLAIN'])) {
1177                         $sql = 'EXPLAIN ' . $sql;
1178                 }
1179                 return $this->query( $sql, $fname );
1180         }
1181
1182         /**
1183          * Single row SELECT wrapper
1184          * Aborts or returns FALSE on error
1185          *
1186          * $vars: the selected variables
1187          * $conds: a condition map, terms are ANDed together.
1188          *   Items with numeric keys are taken to be literal conditions
1189          * Takes an array of selected variables, and a condition map, which is ANDed
1190          * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
1191          * NS_MAIN, "page_title" => "Astronomy" ) )   would return an object where
1192          * $obj- >page_id is the ID of the Astronomy article
1193          *
1194          * @todo migrate documentation to phpdocumentor format
1195          */
1196         function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
1197                 $options['LIMIT'] = 1;
1198                 $res = $this->select( $table, $vars, $conds, $fname, $options );
1199                 if ( $res === false )
1200                         return false;
1201                 if ( !$this->numRows($res) ) {
1202                         $this->freeResult($res);
1203                         return false;
1204                 }
1205                 $obj = $this->fetchObject( $res );
1206                 $this->freeResult( $res );
1207                 return $obj;
1208
1209         }
1210
1211         /**
1212          * Estimate rows in dataset
1213          * Returns estimated count, based on EXPLAIN output
1214          * Takes same arguments as Database::select()
1215          */
1216
1217         function estimateRowCount( $table, $vars='*', $conds='', $fname = 'Database::estimateRowCount', $options = array() ) {
1218                 $options['EXPLAIN']=true;
1219                 $res = $this->select ($table, $vars, $conds, $fname, $options );
1220                 if ( $res === false )
1221                         return false;
1222                 if (!$this->numRows($res)) {
1223                         $this->freeResult($res);
1224                         return 0;
1225                 }
1226
1227                 $rows=1;
1228
1229                 while( $plan = $this->fetchObject( $res ) ) {
1230                         $rows *= ($plan->rows > 0)?$plan->rows:1; // avoid resetting to zero
1231                 }
1232
1233                 $this->freeResult($res);
1234                 return $rows;
1235         }
1236
1237
1238         /**
1239          * Removes most variables from an SQL query and replaces them with X or N for numbers.
1240          * It's only slightly flawed. Don't use for anything important.
1241          *
1242          * @param string $sql A SQL Query
1243          * @static
1244          */
1245         static function generalizeSQL( $sql ) {
1246                 # This does the same as the regexp below would do, but in such a way
1247                 # as to avoid crashing php on some large strings.
1248                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1249
1250                 $sql = str_replace ( "\\\\", '', $sql);
1251                 $sql = str_replace ( "\\'", '', $sql);
1252                 $sql = str_replace ( "\\\"", '', $sql);
1253                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
1254                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
1255
1256                 # All newlines, tabs, etc replaced by single space
1257                 $sql = preg_replace ( '/\s+/', ' ', $sql);
1258
1259                 # All numbers => N
1260                 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
1261
1262                 return $sql;
1263         }
1264
1265         /**
1266          * Determines whether a field exists in a table
1267          * Usually aborts on failure
1268          * If errors are explicitly ignored, returns NULL on failure
1269          */
1270         function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
1271                 $table = $this->tableName( $table );
1272                 $res = $this->query( 'DESCRIBE '.$table, $fname );
1273                 if ( !$res ) {
1274                         return NULL;
1275                 }
1276
1277                 $found = false;
1278
1279                 while ( $row = $this->fetchObject( $res ) ) {
1280                         if ( $row->Field == $field ) {
1281                                 $found = true;
1282                                 break;
1283                         }
1284                 }
1285                 return $found;
1286         }
1287
1288         /**
1289          * Determines whether an index exists
1290          * Usually aborts on failure
1291          * If errors are explicitly ignored, returns NULL on failure
1292          */
1293         function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
1294                 $info = $this->indexInfo( $table, $index, $fname );
1295                 if ( is_null( $info ) ) {
1296                         return NULL;
1297                 } else {
1298                         return $info !== false;
1299                 }
1300         }
1301
1302
1303         /**
1304          * Get information about an index into an object
1305          * Returns false if the index does not exist
1306          */
1307         function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
1308                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
1309                 # SHOW INDEX should work for 3.x and up:
1310                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
1311                 $table = $this->tableName( $table );
1312                 $sql = 'SHOW INDEX FROM '.$table;
1313                 $res = $this->query( $sql, $fname );
1314                 if ( !$res ) {
1315                         return NULL;
1316                 }
1317
1318                 $result = array();
1319                 while ( $row = $this->fetchObject( $res ) ) {
1320                         if ( $row->Key_name == $index ) {
1321                                 $result[] = $row;
1322                         }
1323                 }
1324                 $this->freeResult($res);
1325
1326                 return empty($result) ? false : $result;
1327         }
1328
1329         /**
1330          * Query whether a given table exists
1331          */
1332         function tableExists( $table ) {
1333                 $table = $this->tableName( $table );
1334                 $old = $this->ignoreErrors( true );
1335                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
1336                 $this->ignoreErrors( $old );
1337                 if( $res ) {
1338                         $this->freeResult( $res );
1339                         return true;
1340                 } else {
1341                         return false;
1342                 }
1343         }
1344
1345         /**
1346          * mysql_fetch_field() wrapper
1347          * Returns false if the field doesn't exist
1348          *
1349          * @param $table
1350          * @param $field
1351          */
1352         function fieldInfo( $table, $field ) {
1353                 $table = $this->tableName( $table );
1354                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
1355                 $n = mysql_num_fields( $res );
1356                 for( $i = 0; $i < $n; $i++ ) {
1357                         $meta = mysql_fetch_field( $res, $i );
1358                         if( $field == $meta->name ) {
1359                                 return new MySQLField($meta);
1360                         }
1361                 }
1362                 return false;
1363         }
1364
1365         /**
1366          * mysql_field_type() wrapper
1367          */
1368         function fieldType( $res, $index ) {
1369                 return mysql_field_type( $res, $index );
1370         }
1371
1372         /**
1373          * Determines if a given index is unique
1374          */
1375         function indexUnique( $table, $index ) {
1376                 $indexInfo = $this->indexInfo( $table, $index );
1377                 if ( !$indexInfo ) {
1378                         return NULL;
1379                 }
1380                 return !$indexInfo[0]->Non_unique;
1381         }
1382
1383         /**
1384          * INSERT wrapper, inserts an array into a table
1385          *
1386          * $a may be a single associative array, or an array of these with numeric keys, for
1387          * multi-row insert.
1388          *
1389          * Usually aborts on failure
1390          * If errors are explicitly ignored, returns success
1391          */
1392         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
1393                 # No rows to insert, easy just return now
1394                 if ( !count( $a ) ) {
1395                         return true;
1396                 }
1397
1398                 $table = $this->tableName( $table );
1399                 if ( !is_array( $options ) ) {
1400                         $options = array( $options );
1401                 }
1402                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1403                         $multi = true;
1404                         $keys = array_keys( $a[0] );
1405                 } else {
1406                         $multi = false;
1407                         $keys = array_keys( $a );
1408                 }
1409
1410                 $sql = 'INSERT ' . implode( ' ', $options ) .
1411                         " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1412
1413                 if ( $multi ) {
1414                         $first = true;
1415                         foreach ( $a as $row ) {
1416                                 if ( $first ) {
1417                                         $first = false;
1418                                 } else {
1419                                         $sql .= ',';
1420                                 }
1421                                 $sql .= '(' . $this->makeList( $row ) . ')';
1422                         }
1423                 } else {
1424                         $sql .= '(' . $this->makeList( $a ) . ')';
1425                 }
1426                 return (bool)$this->query( $sql, $fname );
1427         }
1428
1429         /**
1430          * Make UPDATE options for the Database::update function
1431          *
1432          * @private
1433          * @param array $options The options passed to Database::update
1434          * @return string
1435          */
1436         function makeUpdateOptions( $options ) {
1437                 if( !is_array( $options ) ) {
1438                         $options = array( $options );
1439                 }
1440                 $opts = array();
1441                 if ( in_array( 'LOW_PRIORITY', $options ) )
1442                         $opts[] = $this->lowPriorityOption();
1443                 if ( in_array( 'IGNORE', $options ) )
1444                         $opts[] = 'IGNORE';
1445                 return implode(' ', $opts);
1446         }
1447
1448         /**
1449          * UPDATE wrapper, takes a condition array and a SET array
1450          *
1451          * @param string $table  The table to UPDATE
1452          * @param array  $values An array of values to SET
1453          * @param array  $conds  An array of conditions (WHERE). Use '*' to update all rows.
1454          * @param string $fname  The Class::Function calling this function
1455          *                       (for the log)
1456          * @param array  $options An array of UPDATE options, can be one or
1457          *                        more of IGNORE, LOW_PRIORITY
1458          */
1459         function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
1460                 $table = $this->tableName( $table );
1461                 $opts = $this->makeUpdateOptions( $options );
1462                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1463                 if ( $conds != '*' ) {
1464                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1465                 }
1466                 $this->query( $sql, $fname );
1467         }
1468
1469         /**
1470          * Makes an encoded list of strings from an array
1471          * $mode:
1472          *        LIST_COMMA         - comma separated, no field names
1473          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
1474          *        LIST_OR            - ORed WHERE clause (without the WHERE)
1475          *        LIST_SET           - comma separated with field names, like a SET clause
1476          *        LIST_NAMES         - comma separated field names
1477          */
1478         function makeList( $a, $mode = LIST_COMMA ) {
1479                 if ( !is_array( $a ) ) {
1480                         throw new DBUnexpectedError( $this, 'Database::makeList called with incorrect parameters' );
1481                 }
1482
1483                 $first = true;
1484                 $list = '';
1485                 foreach ( $a as $field => $value ) {
1486                         if ( !$first ) {
1487                                 if ( $mode == LIST_AND ) {
1488                                         $list .= ' AND ';
1489                                 } elseif($mode == LIST_OR) {
1490                                         $list .= ' OR ';
1491                                 } else {
1492                                         $list .= ',';
1493                                 }
1494                         } else {
1495                                 $first = false;
1496                         }
1497                         if ( ($mode == LIST_AND || $mode == LIST_OR) && is_numeric( $field ) ) {
1498                                 $list .= "($value)";
1499                         } elseif ( ($mode == LIST_SET) && is_numeric( $field ) ) {
1500                                 $list .= "$value";
1501                         } elseif ( ($mode == LIST_AND || $mode == LIST_OR) && is_array ($value) ) {
1502                                 $list .= $field." IN (".$this->makeList($value).") ";
1503                         } else {
1504                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1505                                         $list .= "$field = ";
1506                                 }
1507                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1508                         }
1509                 }
1510                 return $list;
1511         }
1512
1513         /**
1514          * Change the current database
1515          */
1516         function selectDB( $db ) {
1517                 $this->mDBname = $db;
1518                 return mysql_select_db( $db, $this->mConn );
1519         }
1520
1521         /**
1522          * Format a table name ready for use in constructing an SQL query
1523          *
1524          * This does two important things: it quotes table names which as necessary,
1525          * and it adds a table prefix if there is one.
1526          *
1527          * All functions of this object which require a table name call this function
1528          * themselves. Pass the canonical name to such functions. This is only needed
1529          * when calling query() directly.
1530          *
1531          * @param string $name database table name
1532          */
1533         function tableName( $name ) {
1534                 global $wgSharedDB;
1535                 # Skip quoted literals
1536                 if ( $name{0} != '`' ) {
1537                         if ( $this->mTablePrefix !== '' &&  strpos( '.', $name ) === false ) {
1538                                 $name = "{$this->mTablePrefix}$name";
1539                         }
1540                         if ( isset( $wgSharedDB ) && "{$this->mTablePrefix}user" == $name ) {
1541                                 $name = "`$wgSharedDB`.`$name`";
1542                         } else {
1543                                 # Standard quoting
1544                                 $name = "`$name`";
1545                         }
1546                 }
1547                 return $name;
1548         }
1549
1550         /**
1551          * Fetch a number of table names into an array
1552          * This is handy when you need to construct SQL for joins
1553          *
1554          * Example:
1555          * extract($dbr->tableNames('user','watchlist'));
1556          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1557          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1558          */
1559         public function tableNames() {
1560                 $inArray = func_get_args();
1561                 $retVal = array();
1562                 foreach ( $inArray as $name ) {
1563                         $retVal[$name] = $this->tableName( $name );
1564                 }
1565                 return $retVal;
1566         }
1567
1568         /**
1569          * Fetch a number of table names into an zero-indexed numerical array
1570          * This is handy when you need to construct SQL for joins
1571          *
1572          * Example:
1573          * list( $user, $watchlist ) = $dbr->tableNames('user','watchlist');
1574          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1575          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1576          */
1577         public function tableNamesN() {
1578                 $inArray = func_get_args();
1579                 $retVal = array();
1580                 foreach ( $inArray as $name ) {
1581                         $retVal[] = $this->tableName( $name );
1582                 }
1583                 return $retVal;
1584         }
1585
1586         /**
1587          * @private
1588          */
1589         function tableNamesWithUseIndex( $tables, $use_index ) {
1590                 $ret = array();
1591
1592                 foreach ( $tables as $table )
1593                         if ( @$use_index[$table] !== null )
1594                                 $ret[] = $this->tableName( $table ) . ' ' . $this->useIndexClause( implode( ',', (array)$use_index[$table] ) );
1595                         else
1596                                 $ret[] = $this->tableName( $table );
1597
1598                 return implode( ',', $ret );
1599         }
1600
1601         /**
1602          * Wrapper for addslashes()
1603          * @param string $s String to be slashed.
1604          * @return string slashed string.
1605          */
1606         function strencode( $s ) {
1607                 return mysql_real_escape_string( $s, $this->mConn );
1608         }
1609
1610         /**
1611          * If it's a string, adds quotes and backslashes
1612          * Otherwise returns as-is
1613          */
1614         function addQuotes( $s ) {
1615                 if ( is_null( $s ) ) {
1616                         return 'NULL';
1617                 } else {
1618                         # This will also quote numeric values. This should be harmless,
1619                         # and protects against weird problems that occur when they really
1620                         # _are_ strings such as article titles and string->number->string
1621                         # conversion is not 1:1.
1622                         return "'" . $this->strencode( $s ) . "'";
1623                 }
1624         }
1625
1626         /**
1627          * Escape string for safe LIKE usage
1628          */
1629         function escapeLike( $s ) {
1630                 $s=$this->strencode( $s );
1631                 $s=str_replace(array('%','_'),array('\%','\_'),$s);
1632                 return $s;
1633         }
1634
1635         /**
1636          * Returns an appropriately quoted sequence value for inserting a new row.
1637          * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1638          * subclass will return an integer, and save the value for insertId()
1639          */
1640         function nextSequenceValue( $seqName ) {
1641                 return NULL;
1642         }
1643
1644         /**
1645          * USE INDEX clause
1646          * PostgreSQL doesn't have them and returns ""
1647          */
1648         function useIndexClause( $index ) {
1649                 return "FORCE INDEX ($index)";
1650         }
1651
1652         /**
1653          * REPLACE query wrapper
1654          * PostgreSQL simulates this with a DELETE followed by INSERT
1655          * $row is the row to insert, an associative array
1656          * $uniqueIndexes is an array of indexes. Each element may be either a
1657          * field name or an array of field names
1658          *
1659          * It may be more efficient to leave off unique indexes which are unlikely to collide.
1660          * However if you do this, you run the risk of encountering errors which wouldn't have
1661          * occurred in MySQL
1662          *
1663          * @todo migrate comment to phodocumentor format
1664          */
1665         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
1666                 $table = $this->tableName( $table );
1667
1668                 # Single row case
1669                 if ( !is_array( reset( $rows ) ) ) {
1670                         $rows = array( $rows );
1671                 }
1672
1673                 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) .') VALUES ';
1674                 $first = true;
1675                 foreach ( $rows as $row ) {
1676                         if ( $first ) {
1677                                 $first = false;
1678                         } else {
1679                                 $sql .= ',';
1680                         }
1681                         $sql .= '(' . $this->makeList( $row ) . ')';
1682                 }
1683                 return $this->query( $sql, $fname );
1684         }
1685
1686         /**
1687          * DELETE where the condition is a join
1688          * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1689          *
1690          * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1691          * join condition matches, set $conds='*'
1692          *
1693          * DO NOT put the join condition in $conds
1694          *
1695          * @param string $delTable The table to delete from.
1696          * @param string $joinTable The other table.
1697          * @param string $delVar The variable to join on, in the first table.
1698          * @param string $joinVar The variable to join on, in the second table.
1699          * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
1700          */
1701         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
1702                 if ( !$conds ) {
1703                         throw new DBUnexpectedError( $this, 'Database::deleteJoin() called with empty $conds' );
1704                 }
1705
1706                 $delTable = $this->tableName( $delTable );
1707                 $joinTable = $this->tableName( $joinTable );
1708                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1709                 if ( $conds != '*' ) {
1710                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1711                 }
1712
1713                 return $this->query( $sql, $fname );
1714         }
1715
1716         /**
1717          * Returns the size of a text field, or -1 for "unlimited"
1718          */
1719         function textFieldSize( $table, $field ) {
1720                 $table = $this->tableName( $table );
1721                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1722                 $res = $this->query( $sql, 'Database::textFieldSize' );
1723                 $row = $this->fetchObject( $res );
1724                 $this->freeResult( $res );
1725
1726                 $m = array();
1727                 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
1728                         $size = $m[1];
1729                 } else {
1730                         $size = -1;
1731                 }
1732                 return $size;
1733         }
1734
1735         /**
1736          * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1737          */
1738         function lowPriorityOption() {
1739                 return 'LOW_PRIORITY';
1740         }
1741
1742         /**
1743          * DELETE query wrapper
1744          *
1745          * Use $conds == "*" to delete all rows
1746          */
1747         function delete( $table, $conds, $fname = 'Database::delete' ) {
1748                 if ( !$conds ) {
1749                         throw new DBUnexpectedError( $this, 'Database::delete() called with no conditions' );
1750                 }
1751                 $table = $this->tableName( $table );
1752                 $sql = "DELETE FROM $table";
1753                 if ( $conds != '*' ) {
1754                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1755                 }
1756                 return $this->query( $sql, $fname );
1757         }
1758
1759         /**
1760          * INSERT SELECT wrapper
1761          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1762          * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1763          * $conds may be "*" to copy the whole table
1764          * srcTable may be an array of tables.
1765          */
1766         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect',
1767                 $insertOptions = array(), $selectOptions = array() )
1768         {
1769                 $destTable = $this->tableName( $destTable );
1770                 if ( is_array( $insertOptions ) ) {
1771                         $insertOptions = implode( ' ', $insertOptions );
1772                 }
1773                 if( !is_array( $selectOptions ) ) {
1774                         $selectOptions = array( $selectOptions );
1775                 }
1776                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
1777                 if( is_array( $srcTable ) ) {
1778                         $srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
1779                 } else {
1780                         $srcTable = $this->tableName( $srcTable );
1781                 }
1782                 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1783                         " SELECT $startOpts " . implode( ',', $varMap ) .
1784                         " FROM $srcTable $useIndex ";
1785                 if ( $conds != '*' ) {
1786                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1787                 }
1788                 $sql .= " $tailOpts";
1789                 return $this->query( $sql, $fname );
1790         }
1791
1792         /**
1793          * Construct a LIMIT query with optional offset
1794          * This is used for query pages
1795          * $sql string SQL query we will append the limit too
1796          * $limit integer the SQL limit
1797          * $offset integer the SQL offset (default false)
1798          */
1799         function limitResult($sql, $limit, $offset=false) {
1800                 if( !is_numeric($limit) ) {
1801                         throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
1802                 }
1803                 return " $sql LIMIT "
1804                                 . ( (is_numeric($offset) && $offset != 0) ? "{$offset}," : "" )
1805                                 . "{$limit} ";
1806         }
1807         function limitResultForUpdate($sql, $num) {
1808                 return $this->limitResult($sql, $num, 0);
1809         }
1810
1811         /**
1812          * Returns an SQL expression for a simple conditional.
1813          * Uses IF on MySQL.
1814          *
1815          * @param string $cond SQL expression which will result in a boolean value
1816          * @param string $trueVal SQL expression to return if true
1817          * @param string $falseVal SQL expression to return if false
1818          * @return string SQL fragment
1819          */
1820         function conditional( $cond, $trueVal, $falseVal ) {
1821                 return " IF($cond, $trueVal, $falseVal) ";
1822         }
1823
1824         /**
1825          * Determines if the last failure was due to a deadlock
1826          */
1827         function wasDeadlock() {
1828                 return $this->lastErrno() == 1213;
1829         }
1830
1831         /**
1832          * Perform a deadlock-prone transaction.
1833          *
1834          * This function invokes a callback function to perform a set of write
1835          * queries. If a deadlock occurs during the processing, the transaction
1836          * will be rolled back and the callback function will be called again.
1837          *
1838          * Usage:
1839          *   $dbw->deadlockLoop( callback, ... );
1840          *
1841          * Extra arguments are passed through to the specified callback function.
1842          *
1843          * Returns whatever the callback function returned on its successful,
1844          * iteration, or false on error, for example if the retry limit was
1845          * reached.
1846          */
1847         function deadlockLoop() {
1848                 $myFname = 'Database::deadlockLoop';
1849
1850                 $this->begin();
1851                 $args = func_get_args();
1852                 $function = array_shift( $args );
1853                 $oldIgnore = $this->ignoreErrors( true );
1854                 $tries = DEADLOCK_TRIES;
1855                 if ( is_array( $function ) ) {
1856                         $fname = $function[0];
1857                 } else {
1858                         $fname = $function;
1859                 }
1860                 do {
1861                         $retVal = call_user_func_array( $function, $args );
1862                         $error = $this->lastError();
1863                         $errno = $this->lastErrno();
1864                         $sql = $this->lastQuery();
1865
1866                         if ( $errno ) {
1867                                 if ( $this->wasDeadlock() ) {
1868                                         # Retry
1869                                         usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1870                                 } else {
1871                                         $this->reportQueryError( $error, $errno, $sql, $fname );
1872                                 }
1873                         }
1874                 } while( $this->wasDeadlock() && --$tries > 0 );
1875                 $this->ignoreErrors( $oldIgnore );
1876                 if ( $tries <= 0 ) {
1877                         $this->query( 'ROLLBACK', $myFname );
1878                         $this->reportQueryError( $error, $errno, $sql, $fname );
1879                         return false;
1880                 } else {
1881                         $this->query( 'COMMIT', $myFname );
1882                         return $retVal;
1883                 }
1884         }
1885
1886         /**
1887          * Do a SELECT MASTER_POS_WAIT()
1888          *
1889          * @param string $file the binlog file
1890          * @param string $pos the binlog position
1891          * @param integer $timeout the maximum number of seconds to wait for synchronisation
1892          */
1893         function masterPosWait( $file, $pos, $timeout ) {
1894                 $fname = 'Database::masterPosWait';
1895                 wfProfileIn( $fname );
1896
1897
1898                 # Commit any open transactions
1899                 $this->immediateCommit();
1900
1901                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
1902                 $encFile = $this->strencode( $file );
1903                 $sql = "SELECT MASTER_POS_WAIT('$encFile', $pos, $timeout)";
1904                 $res = $this->doQuery( $sql );
1905                 if ( $res && $row = $this->fetchRow( $res ) ) {
1906                         $this->freeResult( $res );
1907                         wfProfileOut( $fname );
1908                         return $row[0];
1909                 } else {
1910                         wfProfileOut( $fname );
1911                         return false;
1912                 }
1913         }
1914
1915         /**
1916          * Get the position of the master from SHOW SLAVE STATUS
1917          */
1918         function getSlavePos() {
1919                 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1920                 $row = $this->fetchObject( $res );
1921                 if ( $row ) {
1922                         return array( $row->Master_Log_File, $row->Read_Master_Log_Pos );
1923                 } else {
1924                         return array( false, false );
1925                 }
1926         }
1927
1928         /**
1929          * Get the position of the master from SHOW MASTER STATUS
1930          */
1931         function getMasterPos() {
1932                 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1933                 $row = $this->fetchObject( $res );
1934                 if ( $row ) {
1935                         return array( $row->File, $row->Position );
1936                 } else {
1937                         return array( false, false );
1938                 }
1939         }
1940
1941         /**
1942          * Begin a transaction, committing any previously open transaction
1943          */
1944         function begin( $fname = 'Database::begin' ) {
1945                 $this->query( 'BEGIN', $fname );
1946                 $this->mTrxLevel = 1;
1947         }
1948
1949         /**
1950          * End a transaction
1951          */
1952         function commit( $fname = 'Database::commit' ) {
1953                 $this->query( 'COMMIT', $fname );
1954                 $this->mTrxLevel = 0;
1955         }
1956
1957         /**
1958          * Rollback a transaction
1959          */
1960         function rollback( $fname = 'Database::rollback' ) {
1961                 $this->query( 'ROLLBACK', $fname );
1962                 $this->mTrxLevel = 0;
1963         }
1964
1965         /**
1966          * Begin a transaction, committing any previously open transaction
1967          * @deprecated use begin()
1968          */
1969         function immediateBegin( $fname = 'Database::immediateBegin' ) {
1970                 $this->begin();
1971         }
1972
1973         /**
1974          * Commit transaction, if one is open
1975          * @deprecated use commit()
1976          */
1977         function immediateCommit( $fname = 'Database::immediateCommit' ) {
1978                 $this->commit();
1979         }
1980
1981         /**
1982          * Return MW-style timestamp used for MySQL schema
1983          */
1984         function timestamp( $ts=0 ) {
1985                 return wfTimestamp(TS_MW,$ts);
1986         }
1987
1988         /**
1989          * Local database timestamp format or null
1990          */
1991         function timestampOrNull( $ts = null ) {
1992                 if( is_null( $ts ) ) {
1993                         return null;
1994                 } else {
1995                         return $this->timestamp( $ts );
1996                 }
1997         }
1998
1999         /**
2000          * @todo document
2001          */
2002         function resultObject( $result ) {
2003                 if( empty( $result ) ) {
2004                         return NULL;
2005                 } else {
2006                         return new ResultWrapper( $this, $result );
2007                 }
2008         }
2009
2010         /**
2011          * Return aggregated value alias
2012          */
2013         function aggregateValue ($valuedata,$valuename='value') {
2014                 return $valuename;
2015         }
2016
2017         /**
2018          * @return string wikitext of a link to the server software's web site
2019          */
2020         function getSoftwareLink() {
2021                 return "[http://www.mysql.com/ MySQL]";
2022         }
2023
2024         /**
2025          * @return string Version information from the database
2026          */
2027         function getServerVersion() {
2028                 return mysql_get_server_info( $this->mConn );
2029         }
2030
2031         /**
2032          * Ping the server and try to reconnect if it there is no connection
2033          */
2034         function ping() {
2035                 if( function_exists( 'mysql_ping' ) ) {
2036                         return mysql_ping( $this->mConn );
2037                 } else {
2038                         wfDebug( "Tried to call mysql_ping but this is ancient PHP version. Faking it!\n" );
2039                         return true;
2040                 }
2041         }
2042
2043         /**
2044          * Get slave lag.
2045          * At the moment, this will only work if the DB user has the PROCESS privilege
2046          */
2047         function getLag() {
2048                 $res = $this->query( 'SHOW PROCESSLIST' );
2049                 # Find slave SQL thread. Assumed to be the second one running, which is a bit
2050                 # dubious, but unfortunately there's no easy rigorous way
2051                 while ( $row = $this->fetchObject( $res ) ) {
2052                         /* This should work for most situations - when default db
2053                          * for thread is not specified, it had no events executed,
2054                          * and therefore it doesn't know yet how lagged it is.
2055                          *
2056                          * Relay log I/O thread does not select databases.
2057                          */
2058                         if ( $row->User == 'system user' &&
2059                                 $row->State != 'Waiting for master to send event' &&
2060                                 $row->State != 'Connecting to master' &&
2061                                 $row->State != 'Queueing master event to the relay log' &&
2062                                 $row->State != 'Waiting for master update' &&
2063                                 $row->State != 'Requesting binlog dump'
2064                                 ) {
2065                                 # This is it, return the time (except -ve)
2066                                 if ( $row->Time > 0x7fffffff ) {
2067                                         return false;
2068                                 } else {
2069                                         return $row->Time;
2070                                 }
2071                         }
2072                 }
2073                 return false;
2074         }
2075
2076         /**
2077          * Get status information from SHOW STATUS in an associative array
2078          */
2079         function getStatus($which="%") {
2080                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
2081                 $status = array();
2082                 while ( $row = $this->fetchObject( $res ) ) {
2083                         $status[$row->Variable_name] = $row->Value;
2084                 }
2085                 return $status;
2086         }
2087
2088         /**
2089          * Return the maximum number of items allowed in a list, or 0 for unlimited.
2090          */
2091         function maxListLen() {
2092                 return 0;
2093         }
2094
2095         function encodeBlob($b) {
2096                 return $b;
2097         }
2098
2099         function decodeBlob($b) {
2100                 return $b;
2101         }
2102
2103         /**
2104          * Override database's default connection timeout.
2105          * May be useful for very long batch queries such as
2106          * full-wiki dumps, where a single query reads out
2107          * over hours or days.
2108          * @param int $timeout in seconds
2109          */
2110         public function setTimeout( $timeout ) {
2111                 $this->query( "SET net_read_timeout=$timeout" );
2112                 $this->query( "SET net_write_timeout=$timeout" );
2113         }
2114
2115         /**
2116          * Read and execute SQL commands from a file.
2117          * Returns true on success, error string on failure
2118          * @param string $filename File name to open
2119          * @param callback $lineCallback Optional function called before reading each line
2120          * @param callback $resultCallback Optional function called for each MySQL result
2121          */
2122         function sourceFile( $filename, $lineCallback = false, $resultCallback = false ) {
2123                 $fp = fopen( $filename, 'r' );
2124                 if ( false === $fp ) {
2125                         return "Could not open \"{$filename}\".\n";
2126                 }
2127                 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback );
2128                 fclose( $fp );
2129                 return $error;
2130         }
2131
2132         /**
2133          * Read and execute commands from an open file handle
2134          * Returns true on success, error string on failure
2135          * @param string $fp File handle
2136          * @param callback $lineCallback Optional function called before reading each line
2137          * @param callback $resultCallback Optional function called for each MySQL result
2138          */
2139         function sourceStream( $fp, $lineCallback = false, $resultCallback = false ) {
2140                 $cmd = "";
2141                 $done = false;
2142                 $dollarquote = false;
2143
2144                 while ( ! feof( $fp ) ) {
2145                         if ( $lineCallback ) {
2146                                 call_user_func( $lineCallback );
2147                         }
2148                         $line = trim( fgets( $fp, 1024 ) );
2149                         $sl = strlen( $line ) - 1;
2150
2151                         if ( $sl < 0 ) { continue; }
2152                         if ( '-' == $line{0} && '-' == $line{1} ) { continue; }
2153
2154                         ## Allow dollar quoting for function declarations
2155                         if (substr($line,0,4) == '$mw$') {
2156                                 if ($dollarquote) {
2157                                         $dollarquote = false;
2158                                         $done = true;
2159                                 }
2160                                 else {
2161                                         $dollarquote = true;
2162                                 }
2163                         }
2164                         else if (!$dollarquote) {
2165                                 if ( ';' == $line{$sl} && ($sl < 2 || ';' != $line{$sl - 1})) {
2166                                         $done = true;
2167                                         $line = substr( $line, 0, $sl );
2168                                 }
2169                         }
2170
2171                         if ( '' != $cmd ) { $cmd .= ' '; }
2172                         $cmd .= "$line\n";
2173
2174                         if ( $done ) {
2175                                 $cmd = str_replace(';;', ";", $cmd);
2176                                 $cmd = $this->replaceVars( $cmd );
2177                                 $res = $this->query( $cmd, __METHOD__, true );
2178                                 if ( $resultCallback ) {
2179                                         call_user_func( $resultCallback, $this->resultObject( $res ) );
2180                                 }
2181
2182                                 if ( false === $res ) {
2183                                         $err = $this->lastError();
2184                                         return "Query \"{$cmd}\" failed with error code \"$err\".\n";
2185                                 }
2186
2187                                 $cmd = '';
2188                                 $done = false;
2189                         }
2190                 }
2191                 return true;
2192         }
2193
2194
2195         /**
2196          * Replace variables in sourced SQL
2197          */
2198         protected function replaceVars( $ins ) {
2199                 $varnames = array(
2200                         'wgDBserver', 'wgDBname', 'wgDBintlname', 'wgDBuser',
2201                         'wgDBpassword', 'wgDBsqluser', 'wgDBsqlpassword',
2202                         'wgDBadminuser', 'wgDBadminpassword', 'wgDBTableOptions',
2203                 );
2204
2205                 // Ordinary variables
2206                 foreach ( $varnames as $var ) {
2207                         if( isset( $GLOBALS[$var] ) ) {
2208                                 $val = addslashes( $GLOBALS[$var] ); // FIXME: safety check?
2209                                 $ins = str_replace( '{$' . $var . '}', $val, $ins );
2210                                 $ins = str_replace( '/*$' . $var . '*/`', '`' . $val, $ins );
2211                                 $ins = str_replace( '/*$' . $var . '*/', $val, $ins );
2212                         }
2213                 }
2214
2215                 // Table prefixes
2216                 $ins = preg_replace_callback( '/\/\*(?:\$wgDBprefix|_)\*\/([a-z_]*)/',
2217                         array( &$this, 'tableNameCallback' ), $ins );
2218                 return $ins;
2219         }
2220
2221         /**
2222          * Table name callback
2223          * @private
2224          */
2225         protected function tableNameCallback( $matches ) {
2226                 return $this->tableName( $matches[1] );
2227         }
2228
2229 }
2230
2231 /**
2232  * Database abstraction object for mySQL
2233  * Inherit all methods and properties of Database::Database()
2234  *
2235  * @addtogroup Database
2236  * @see Database
2237  */
2238 class DatabaseMysql extends Database {
2239         # Inherit all
2240 }
2241
2242
2243 /**
2244  * Result wrapper for grabbing data queried by someone else
2245  * @addtogroup Database
2246  */
2247 class ResultWrapper {
2248         var $db, $result;
2249
2250         /**
2251          * @todo document
2252          */
2253         function ResultWrapper( &$database, $result ) {
2254                 $this->db =& $database;
2255                 $this->result =& $result;
2256         }
2257
2258         /**
2259          * @todo document
2260          */
2261         function numRows() {
2262                 return $this->db->numRows( $this->result );
2263         }
2264
2265         /**
2266          * @todo document
2267          */
2268         function fetchObject() {
2269                 return $this->db->fetchObject( $this->result );
2270         }
2271
2272         /**
2273          * @todo document
2274          */
2275         function fetchRow() {
2276                 return $this->db->fetchRow( $this->result );
2277         }
2278
2279         /**
2280          * @todo document
2281          */
2282         function free() {
2283                 $this->db->freeResult( $this->result );
2284                 unset( $this->result );
2285                 unset( $this->db );
2286         }
2287
2288         function seek( $row ) {
2289                 $this->db->dataSeek( $this->result, $row );
2290         }
2291
2292         function rewind() {
2293                 if ($this->numRows()) {
2294                         $this->db->dataSeek($this->result, 0);
2295                 }
2296         }
2297
2298 }
2299
2300 ?>