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                         $commentedSql = preg_replace('/\s/', " /* $fname */ ", $sql, 1);
 712                 } else {
 713                         $commentedSql = $sql;
 714                 }
 715
 716                 # If DBO_TRX is set, start a transaction
 717                 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
 718                         $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK'
 719                 ) {
 720                         $this->begin();
 721                 }
 722
 723                 if ( $this->debug() ) {
 724                         $sqlx = substr( $commentedSql, 0, 500 );
 725                         $sqlx = strtr( $sqlx, "\t\n", '  ' );
 726                         wfDebug( "SQL: $sqlx\n" );
 727                 }
 728
 729                 # Do the query and handle errors
 730                 $ret = $this->doQuery( $commentedSql );
 731
 732                 # Try reconnecting if the connection was lost
 733                 if ( false === $ret && ( $this->lastErrno() == 2013 || $this->lastErrno() == 2006 ) ) {
 734                         # Transaction is gone, like it or not
 735                         $this->mTrxLevel = 0;
 736                         wfDebug( "Connection lost, reconnecting...\n" );
 737                         if ( $this->ping() ) {
 738                                 wfDebug( "Reconnected\n" );
 739                                 $sqlx = substr( $commentedSql, 0, 500 );
 740                                 $sqlx = strtr( $sqlx, "\t\n", '  ' );
 741                                 global $wgRequestTime;
 742                                 $elapsed = round( microtime(true) - $wgRequestTime, 3 );
 743                                 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
 744                                 $ret = $this->doQuery( $commentedSql );
 745                         } else {
 746                                 wfDebug( "Failed\n" );
 747                         }
 748                 }
 749
 750                 if ( false === $ret ) {
 751                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
 752                 }
 753
 754                 if ( $wgProfiling ) {
 755                         wfProfileOut( $queryProf );
 756                         wfProfileOut( $totalProf );
 757                 }
 758                 return $ret;
 759         }
 760
 761         /**
 762          * The DBMS-dependent part of query()
 763          * @param  $sql String: SQL query.
 764          * @return Result object to feed to fetchObject, fetchRow, ...; or false on failure
 765          * @access private
 766          */
 767         /*private*/ function doQuery( $sql ) {
 768                 if( $this->bufferResults() ) {
 769                         $ret = mysql_query( $sql, $this->mConn );
 770                 } else {
 771                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 772                 }
 773                 return $ret;
 774         }
 775
 776         /**
 777          * @param $error
 778          * @param $errno
 779          * @param $sql
 780          * @param string $fname
 781          * @param bool $tempIgnore
 782          */
 783         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 784                 global $wgCommandLineMode;
 785                 # Ignore errors during error handling to avoid infinite recursion
 786                 $ignore = $this->ignoreErrors( true );
 787                 ++$this->mErrorCount;
 788
 789                 if( $ignore || $tempIgnore ) {
 790                         wfDebug("SQL ERROR (ignored): $error\n");
 791                         $this->ignoreErrors( $ignore );
 792                 } else {
 793                         $sql1line = str_replace( "\n", "\\n", $sql );
 794                         wfLogDBError("$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n");
 795                         wfDebug("SQL ERROR: " . $error . "\n");
 796                         throw new DBQueryError( $this, $error, $errno, $sql, $fname );
 797                 }
 798         }
 799
 800
 801         /**
 802          * Intended to be compatible with the PEAR::DB wrapper functions.
 803          * http://pear.php.net/manual/en/package.database.db.intro-execute.php
 804          *
 805          * ? = scalar value, quoted as necessary
 806          * ! = raw SQL bit (a function for instance)
 807          * & = filename; reads the file and inserts as a blob
 808          *     (we don't use this though...)
 809          */
 810         function prepare( $sql, $func = 'Database::prepare' ) {
 811                 /* MySQL doesn't support prepared statements (yet), so just
 812                    pack up the query for reference. We'll manually replace
 813                    the bits later. */
 814                 return array( 'query' => $sql, 'func' => $func );
 815         }
 816
 817         function freePrepared( $prepared ) {
 818                 /* No-op for MySQL */
 819         }
 820
 821         /**
 822          * Execute a prepared query with the various arguments
 823          * @param string $prepared the prepared sql
 824          * @param mixed $args Either an array here, or put scalars as varargs
 825          */
 826         function execute( $prepared, $args = null ) {
 827                 if( !is_array( $args ) ) {
 828                         # Pull the var args
 829                         $args = func_get_args();
 830                         array_shift( $args );
 831                 }
 832                 $sql = $this->fillPrepared( $prepared['query'], $args );
 833                 return $this->query( $sql, $prepared['func'] );
 834         }
 835
 836         /**
 837          * Prepare & execute an SQL statement, quoting and inserting arguments
 838          * in the appropriate places.
 839          * @param string $query
 840          * @param string $args ...
 841          */
 842         function safeQuery( $query, $args = null ) {
 843                 $prepared = $this->prepare( $query, 'Database::safeQuery' );
 844                 if( !is_array( $args ) ) {
 845                         # Pull the var args
 846                         $args = func_get_args();
 847                         array_shift( $args );
 848                 }
 849                 $retval = $this->execute( $prepared, $args );
 850                 $this->freePrepared( $prepared );
 851                 return $retval;
 852         }
 853
 854         /**
 855          * For faking prepared SQL statements on DBs that don't support
 856          * it directly.
 857          * @param string $preparedSql - a 'preparable' SQL statement
 858          * @param array $args - array of arguments to fill it with
 859          * @return string executable SQL
 860          */
 861         function fillPrepared( $preparedQuery, $args ) {
 862                 reset( $args );
 863                 $this->preparedArgs =& $args;
 864                 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
 865                         array( &$this, 'fillPreparedArg' ), $preparedQuery );
 866         }
 867
 868         /**
 869          * preg_callback func for fillPrepared()
 870          * The arguments should be in $this->preparedArgs and must not be touched
 871          * while we're doing this.
 872          *
 873          * @param array $matches
 874          * @return string
 875          * @private
 876          */
 877         function fillPreparedArg( $matches ) {
 878                 switch( $matches[1] ) {
 879                         case '\\?': return '?';
 880                         case '\\!': return '!';
 881                         case '\\&': return '&';
 882                 }
 883                 list( /* $n */ , $arg ) = each( $this->preparedArgs );
 884                 switch( $matches[1] ) {
 885                         case '?': return $this->addQuotes( $arg );
 886                         case '!': return $arg;
 887                         case '&':
 888                                 # return $this->addQuotes( file_get_contents( $arg ) );
 889                                 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
 890                         default:
 891                                 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
 892                 }
 893         }
 894
 895         /**#@+
 896          * @param mixed $res A SQL result
 897          */
 898         /**
 899          * Free a result object
 900          */
 901         function freeResult( $res ) {
 902                 if ( !@/**/mysql_free_result( $res ) ) {
 903                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 904                 }
 905         }
 906
 907         /**
 908          * Fetch the next row from the given result object, in object form.
 909          * Fields can be retrieved with $row->fieldname, with fields acting like
 910          * member variables.
 911          *
 912          * @param $res SQL result object as returned from Database::query(), etc.
 913          * @return MySQL row object
 914          * @throws DBUnexpectedError Thrown if the database returns an error
 915          */
 916         function fetchObject( $res ) {
 917                 @/**/$row = mysql_fetch_object( $res );
 918                 if( $this->lastErrno() ) {
 919                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 920                 }
 921                 return $row;
 922         }
 923
 924         /**
 925          * Fetch the next row from the given result object, in associative array
 926          * form.  Fields are retrieved with $row['fieldname'].
 927          *
 928          * @param $res SQL result object as returned from Database::query(), etc.
 929          * @return MySQL row object
 930          * @throws DBUnexpectedError Thrown if the database returns an error
 931          */
 932         function fetchRow( $res ) {
 933                 @/**/$row = mysql_fetch_array( $res );
 934                 if ( $this->lastErrno() ) {
 935                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 936                 }
 937                 return $row;
 938         }
 939
 940         /**
 941          * Get the number of rows in a result object
 942          */
 943         function numRows( $res ) {
 944                 @/**/$n = mysql_num_rows( $res );
 945                 if( $this->lastErrno() ) {
 946                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 947                 }
 948                 return $n;
 949         }
 950
 951         /**
 952          * Get the number of fields in a result object
 953          * See documentation for mysql_num_fields()
 954          */
 955         function numFields( $res ) { return mysql_num_fields( $res ); }
 956
 957         /**
 958          * Get a field name in a result object
 959          * See documentation for mysql_field_name():
 960          * http://www.php.net/mysql_field_name
 961          */
 962         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 963
 964         /**
 965          * Get the inserted value of an auto-increment row
 966          *
 967          * The value inserted should be fetched from nextSequenceValue()
 968          *
 969          * Example:
 970          * $id = $dbw->nextSequenceValue('page_page_id_seq');
 971          * $dbw->insert('page',array('page_id' => $id));
 972          * $id = $dbw->insertId();
 973          */
 974         function insertId() { return mysql_insert_id( $this->mConn ); }
 975
 976         /**
 977          * Change the position of the cursor in a result object
 978          * See mysql_data_seek()
 979          */
 980         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 981
 982         /**
 983          * Get the last error number
 984          * See mysql_errno()
 985          */
 986         function lastErrno() {
 987                 if ( $this->mConn ) {
 988                         return mysql_errno( $this->mConn );
 989                 } else {
 990                         return mysql_errno();
 991                 }
 992         }
 993
 994         /**
 995          * Get a description of the last error
 996          * See mysql_error() for more details
 997          */
 998         function lastError() {
 999                 if ( $this->mConn ) {
1000                         # Even if it's non-zero, it can still be invalid
1001                         wfSuppressWarnings();
1002                         $error = mysql_error( $this->mConn );
1003                         if ( !$error ) {
1004                                 $error = mysql_error();
1005                         }
1006                         wfRestoreWarnings();
1007                 } else {
1008                         $error = mysql_error();
1009                 }
1010                 if( $error ) {
1011                         $error .= ' (' . $this->mServer . ')';
1012                 }
1013                 return $error;
1014         }
1015         /**
1016          * Get the number of rows affected by the last write query
1017          * See mysql_affected_rows() for more details
1018          */
1019         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
1020         /**#@-*/ // end of template : @param $result
1021
1022         /**
1023          * Simple UPDATE wrapper
1024          * Usually aborts on failure
1025          * If errors are explicitly ignored, returns success
1026          *
1027          * This function exists for historical reasons, Database::update() has a more standard
1028          * calling convention and feature set
1029          */
1030         function set( $table, $var, $value, $cond, $fname = 'Database::set' )
1031         {
1032                 $table = $this->tableName( $table );
1033                 $sql = "UPDATE $table SET $var = '" .
1034                   $this->strencode( $value ) . "' WHERE ($cond)";
1035                 return (bool)$this->query( $sql, $fname );
1036         }
1037
1038         /**
1039          * Simple SELECT wrapper, returns a single field, input must be encoded
1040          * Usually aborts on failure
1041          * If errors are explicitly ignored, returns FALSE on failure
1042          */
1043         function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
1044                 if ( !is_array( $options ) ) {
1045                         $options = array( $options );
1046                 }
1047                 $options['LIMIT'] = 1;
1048
1049                 $res = $this->select( $table, $var, $cond, $fname, $options );
1050                 if ( $res === false || !$this->numRows( $res ) ) {
1051                         return false;
1052                 }
1053                 $row = $this->fetchRow( $res );
1054                 if ( $row !== false ) {
1055                         $this->freeResult( $res );
1056                         return $row[0];
1057                 } else {
1058                         return false;
1059                 }
1060         }
1061
1062         /**
1063          * Returns an optional USE INDEX clause to go after the table, and a
1064          * string to go at the end of the query
1065          *
1066          * @private
1067          *
1068          * @param array $options an associative array of options to be turned into
1069          *              an SQL query, valid keys are listed in the function.
1070          * @return array
1071          */
1072         function makeSelectOptions( $options ) {
1073                 $preLimitTail = $postLimitTail = '';
1074                 $startOpts = '';
1075
1076                 $noKeyOptions = array();
1077                 foreach ( $options as $key => $option ) {
1078                         if ( is_numeric( $key ) ) {
1079                                 $noKeyOptions[$option] = true;
1080                         }
1081                 }
1082
1083                 if ( isset( $options['GROUP BY'] ) ) $preLimitTail .= " GROUP BY {$options['GROUP BY']}";
1084                 if ( isset( $options['ORDER BY'] ) ) $preLimitTail .= " ORDER BY {$options['ORDER BY']}";
1085
1086                 //if (isset($options['LIMIT'])) {
1087                 //      $tailOpts .= $this->limitResult('', $options['LIMIT'],
1088                 //              isset($options['OFFSET']) ? $options['OFFSET']
1089                 //              : false);
1090                 //}
1091
1092                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $postLimitTail .= ' FOR UPDATE';
1093                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $postLimitTail .= ' LOCK IN SHARE MODE';
1094                 if ( isset( $noKeyOptions['DISTINCT'] ) && isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
1095
1096                 # Various MySQL extensions
1097                 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) $startOpts .= ' /*! STRAIGHT_JOIN */';
1098                 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) $startOpts .= ' HIGH_PRIORITY';
1099                 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) $startOpts .= ' SQL_BIG_RESULT';
1100                 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) $startOpts .= ' SQL_BUFFER_RESULT';
1101                 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) $startOpts .= ' SQL_SMALL_RESULT';
1102                 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) $startOpts .= ' SQL_CALC_FOUND_ROWS';
1103                 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) $startOpts .= ' SQL_CACHE';
1104                 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) $startOpts .= ' SQL_NO_CACHE';
1105
1106                 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1107                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1108                 } else {
1109                         $useIndex = '';
1110                 }
1111
1112                 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1113         }
1114
1115         /**
1116          * SELECT wrapper
1117          *
1118          * @param mixed  $table   Array or string, table name(s) (prefix auto-added)
1119          * @param mixed  $vars    Array or string, field name(s) to be retrieved
1120          * @param mixed  $conds   Array or string, condition(s) for WHERE
1121          * @param string $fname   Calling function name (use __METHOD__) for logs/profiling
1122          * @param array  $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
1123          *                        see Database::makeSelectOptions code for list of supported stuff
1124          * @return mixed Database result resource (feed to Database::fetchObject or whatever), or false on failure
1125          */
1126         function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array() )
1127         {
1128                 if( is_array( $vars ) ) {
1129                         $vars = implode( ',', $vars );
1130                 }
1131                 if( !is_array( $options ) ) {
1132                         $options = array( $options );
1133                 }
1134                 if( is_array( $table ) ) {
1135                         if ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1136                                 $from = ' FROM ' . $this->tableNamesWithUseIndex( $table, $options['USE INDEX'] );
1137                         else
1138                                 $from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
1139                 } elseif ($table!='') {
1140                         if ($table{0}==' ') {
1141                                 $from = ' FROM ' . $table;
1142                         } else {
1143                                 $from = ' FROM ' . $this->tableName( $table );
1144                         }
1145                 } else {
1146                         $from = '';
1147                 }
1148
1149                 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1150
1151                 if( !empty( $conds ) ) {
1152                         if ( is_array( $conds ) ) {
1153                                 $conds = $this->makeList( $conds, LIST_AND );
1154                         }
1155                         $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1156                 } else {
1157                         $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1158                 }
1159
1160                 if (isset($options['LIMIT']))
1161                         $sql = $this->limitResult($sql, $options['LIMIT'],
1162                                 isset($options['OFFSET']) ? $options['OFFSET'] : false);
1163                 $sql = "$sql $postLimitTail";
1164
1165                 if (isset($options['EXPLAIN'])) {
1166                         $sql = 'EXPLAIN ' . $sql;
1167                 }
1168
1169                 return $this->query( $sql, $fname );
1170         }
1171
1172         /**
1173          * Single row SELECT wrapper
1174          * Aborts or returns FALSE on error
1175          *
1176          * $vars: the selected variables
1177          * $conds: a condition map, terms are ANDed together.
1178          *   Items with numeric keys are taken to be literal conditions
1179          * Takes an array of selected variables, and a condition map, which is ANDed
1180          * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
1181          * NS_MAIN, "page_title" => "Astronomy" ) )   would return an object where
1182          * $obj- >page_id is the ID of the Astronomy article
1183          *
1184          * @todo migrate documentation to phpdocumentor format
1185          */
1186         function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
1187                 $options['LIMIT'] = 1;
1188                 $res = $this->select( $table, $vars, $conds, $fname, $options );
1189                 if ( $res === false )
1190                         return false;
1191                 if ( !$this->numRows($res) ) {
1192                         $this->freeResult($res);
1193                         return false;
1194                 }
1195                 $obj = $this->fetchObject( $res );
1196                 $this->freeResult( $res );
1197                 return $obj;
1198
1199         }
1200
1201         /**
1202          * Estimate rows in dataset
1203          * Returns estimated count, based on EXPLAIN output
1204          * Takes same arguments as Database::select()
1205          */
1206
1207         function estimateRowCount( $table, $vars='*', $conds='', $fname = 'Database::estimateRowCount', $options = array() ) {
1208                 $options['EXPLAIN']=true;
1209                 $res = $this->select ($table, $vars, $conds, $fname, $options );
1210                 if ( $res === false )
1211                         return false;
1212                 if (!$this->numRows($res)) {
1213                         $this->freeResult($res);
1214                         return 0;
1215                 }
1216
1217                 $rows=1;
1218
1219                 while( $plan = $this->fetchObject( $res ) ) {
1220                         $rows *= ($plan->rows > 0)?$plan->rows:1; // avoid resetting to zero
1221                 }
1222
1223                 $this->freeResult($res);
1224                 return $rows;
1225         }
1226
1227
1228         /**
1229          * Removes most variables from an SQL query and replaces them with X or N for numbers.
1230          * It's only slightly flawed. Don't use for anything important.
1231          *
1232          * @param string $sql A SQL Query
1233          * @static
1234          */
1235         static function generalizeSQL( $sql ) {
1236                 # This does the same as the regexp below would do, but in such a way
1237                 # as to avoid crashing php on some large strings.
1238                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1239
1240                 $sql = str_replace ( "\\\\", '', $sql);
1241                 $sql = str_replace ( "\\'", '', $sql);
1242                 $sql = str_replace ( "\\\"", '', $sql);
1243                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
1244                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
1245
1246                 # All newlines, tabs, etc replaced by single space
1247                 $sql = preg_replace ( '/\s+/', ' ', $sql);
1248
1249                 # All numbers => N
1250                 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
1251
1252                 return $sql;
1253         }
1254
1255         /**
1256          * Determines whether a field exists in a table
1257          * Usually aborts on failure
1258          * If errors are explicitly ignored, returns NULL on failure
1259          */
1260         function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
1261                 $table = $this->tableName( $table );
1262                 $res = $this->query( 'DESCRIBE '.$table, $fname );
1263                 if ( !$res ) {
1264                         return NULL;
1265                 }
1266
1267                 $found = false;
1268
1269                 while ( $row = $this->fetchObject( $res ) ) {
1270                         if ( $row->Field == $field ) {
1271                                 $found = true;
1272                                 break;
1273                         }
1274                 }
1275                 return $found;
1276         }
1277
1278         /**
1279          * Determines whether an index exists
1280          * Usually aborts on failure
1281          * If errors are explicitly ignored, returns NULL on failure
1282          */
1283         function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
1284                 $info = $this->indexInfo( $table, $index, $fname );
1285                 if ( is_null( $info ) ) {
1286                         return NULL;
1287                 } else {
1288                         return $info !== false;
1289                 }
1290         }
1291
1292
1293         /**
1294          * Get information about an index into an object
1295          * Returns false if the index does not exist
1296          */
1297         function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
1298                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
1299                 # SHOW INDEX should work for 3.x and up:
1300                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
1301                 $table = $this->tableName( $table );
1302                 $sql = 'SHOW INDEX FROM '.$table;
1303                 $res = $this->query( $sql, $fname );
1304                 if ( !$res ) {
1305                         return NULL;
1306                 }
1307
1308                 $result = array();
1309                 while ( $row = $this->fetchObject( $res ) ) {
1310                         if ( $row->Key_name == $index ) {
1311                                 $result[] = $row;
1312                         }
1313                 }
1314                 $this->freeResult($res);
1315
1316                 return empty($result) ? false : $result;
1317         }
1318
1319         /**
1320          * Query whether a given table exists
1321          */
1322         function tableExists( $table ) {
1323                 $table = $this->tableName( $table );
1324                 $old = $this->ignoreErrors( true );
1325                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
1326                 $this->ignoreErrors( $old );
1327                 if( $res ) {
1328                         $this->freeResult( $res );
1329                         return true;
1330                 } else {
1331                         return false;
1332                 }
1333         }
1334
1335         /**
1336          * mysql_fetch_field() wrapper
1337          * Returns false if the field doesn't exist
1338          *
1339          * @param $table
1340          * @param $field
1341          */
1342         function fieldInfo( $table, $field ) {
1343                 $table = $this->tableName( $table );
1344                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
1345                 $n = mysql_num_fields( $res );
1346                 for( $i = 0; $i < $n; $i++ ) {
1347                         $meta = mysql_fetch_field( $res, $i );
1348                         if( $field == $meta->name ) {
1349                                 return new MySQLField($meta);
1350                         }
1351                 }
1352                 return false;
1353         }
1354
1355         /**
1356          * mysql_field_type() wrapper
1357          */
1358         function fieldType( $res, $index ) {
1359                 return mysql_field_type( $res, $index );
1360         }
1361
1362         /**
1363          * Determines if a given index is unique
1364          */
1365         function indexUnique( $table, $index ) {
1366                 $indexInfo = $this->indexInfo( $table, $index );
1367                 if ( !$indexInfo ) {
1368                         return NULL;
1369                 }
1370                 return !$indexInfo[0]->Non_unique;
1371         }
1372
1373         /**
1374          * INSERT wrapper, inserts an array into a table
1375          *
1376          * $a may be a single associative array, or an array of these with numeric keys, for
1377          * multi-row insert.
1378          *
1379          * Usually aborts on failure
1380          * If errors are explicitly ignored, returns success
1381          */
1382         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
1383                 # No rows to insert, easy just return now
1384                 if ( !count( $a ) ) {
1385                         return true;
1386                 }
1387
1388                 $table = $this->tableName( $table );
1389                 if ( !is_array( $options ) ) {
1390                         $options = array( $options );
1391                 }
1392                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1393                         $multi = true;
1394                         $keys = array_keys( $a[0] );
1395                 } else {
1396                         $multi = false;
1397                         $keys = array_keys( $a );
1398                 }
1399
1400                 $sql = 'INSERT ' . implode( ' ', $options ) .
1401                         " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1402
1403                 if ( $multi ) {
1404                         $first = true;
1405                         foreach ( $a as $row ) {
1406                                 if ( $first ) {
1407                                         $first = false;
1408                                 } else {
1409                                         $sql .= ',';
1410                                 }
1411                                 $sql .= '(' . $this->makeList( $row ) . ')';
1412                         }
1413                 } else {
1414                         $sql .= '(' . $this->makeList( $a ) . ')';
1415                 }
1416                 return (bool)$this->query( $sql, $fname );
1417         }
1418
1419         /**
1420          * Make UPDATE options for the Database::update function
1421          *
1422          * @private
1423          * @param array $options The options passed to Database::update
1424          * @return string
1425          */
1426         function makeUpdateOptions( $options ) {
1427                 if( !is_array( $options ) ) {
1428                         $options = array( $options );
1429                 }
1430                 $opts = array();
1431                 if ( in_array( 'LOW_PRIORITY', $options ) )
1432                         $opts[] = $this->lowPriorityOption();
1433                 if ( in_array( 'IGNORE', $options ) )
1434                         $opts[] = 'IGNORE';
1435                 return implode(' ', $opts);
1436         }
1437
1438         /**
1439          * UPDATE wrapper, takes a condition array and a SET array
1440          *
1441          * @param string $table  The table to UPDATE
1442          * @param array  $values An array of values to SET
1443          * @param array  $conds  An array of conditions (WHERE). Use '*' to update all rows.
1444          * @param string $fname  The Class::Function calling this function
1445          *                       (for the log)
1446          * @param array  $options An array of UPDATE options, can be one or
1447          *                        more of IGNORE, LOW_PRIORITY
1448          */
1449         function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
1450                 $table = $this->tableName( $table );
1451                 $opts = $this->makeUpdateOptions( $options );
1452                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1453                 if ( $conds != '*' ) {
1454                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1455                 }
1456                 $this->query( $sql, $fname );
1457         }
1458
1459         /**
1460          * Makes an encoded list of strings from an array
1461          * $mode:
1462          *        LIST_COMMA         - comma separated, no field names
1463          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
1464          *        LIST_OR            - ORed WHERE clause (without the WHERE)
1465          *        LIST_SET           - comma separated with field names, like a SET clause
1466          *        LIST_NAMES         - comma separated field names
1467          */
1468         function makeList( $a, $mode = LIST_COMMA ) {
1469                 if ( !is_array( $a ) ) {
1470                         throw new DBUnexpectedError( $this, 'Database::makeList called with incorrect parameters' );
1471                 }
1472
1473                 $first = true;
1474                 $list = '';
1475                 foreach ( $a as $field => $value ) {
1476                         if ( !$first ) {
1477                                 if ( $mode == LIST_AND ) {
1478                                         $list .= ' AND ';
1479                                 } elseif($mode == LIST_OR) {
1480                                         $list .= ' OR ';
1481                                 } else {
1482                                         $list .= ',';
1483                                 }
1484                         } else {
1485                                 $first = false;
1486                         }
1487                         if ( ($mode == LIST_AND || $mode == LIST_OR) && is_numeric( $field ) ) {
1488                                 $list .= "($value)";
1489                         } elseif ( ($mode == LIST_SET) && is_numeric( $field ) ) {
1490                                 $list .= "$value";
1491                         } elseif ( ($mode == LIST_AND || $mode == LIST_OR) && is_array ($value) ) {
1492                                 $list .= $field." IN (".$this->makeList($value).") ";
1493                         } else {
1494                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1495                                         $list .= "$field = ";
1496                                 }
1497                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1498                         }
1499                 }
1500                 return $list;
1501         }
1502
1503         /**
1504          * Change the current database
1505          */
1506         function selectDB( $db ) {
1507                 $this->mDBname = $db;
1508                 return mysql_select_db( $db, $this->mConn );
1509         }
1510
1511         /**
1512          * Format a table name ready for use in constructing an SQL query
1513          *
1514          * This does two important things: it quotes table names which as necessary,
1515          * and it adds a table prefix if there is one.
1516          *
1517          * All functions of this object which require a table name call this function
1518          * themselves. Pass the canonical name to such functions. This is only needed
1519          * when calling query() directly.
1520          *
1521          * @param string $name database table name
1522          */
1523         function tableName( $name ) {
1524                 global $wgSharedDB;
1525                 # Skip quoted literals
1526                 if ( $name{0} != '`' ) {
1527                         if ( $this->mTablePrefix !== '' &&  strpos( '.', $name ) === false ) {
1528                                 $name = "{$this->mTablePrefix}$name";
1529                         }
1530                         if ( isset( $wgSharedDB ) && "{$this->mTablePrefix}user" == $name ) {
1531                                 $name = "`$wgSharedDB`.`$name`";
1532                         } else {
1533                                 # Standard quoting
1534                                 $name = "`$name`";
1535                         }
1536                 }
1537                 return $name;
1538         }
1539
1540         /**
1541          * Fetch a number of table names into an array
1542          * This is handy when you need to construct SQL for joins
1543          *
1544          * Example:
1545          * extract($dbr->tableNames('user','watchlist'));
1546          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1547          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1548          */
1549         public function tableNames() {
1550                 $inArray = func_get_args();
1551                 $retVal = array();
1552                 foreach ( $inArray as $name ) {
1553                         $retVal[$name] = $this->tableName( $name );
1554                 }
1555                 return $retVal;
1556         }
1557
1558         /**
1559          * Fetch a number of table names into an zero-indexed numerical array
1560          * This is handy when you need to construct SQL for joins
1561          *
1562          * Example:
1563          * list( $user, $watchlist ) = $dbr->tableNames('user','watchlist');
1564          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1565          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1566          */
1567         public function tableNamesN() {
1568                 $inArray = func_get_args();
1569                 $retVal = array();
1570                 foreach ( $inArray as $name ) {
1571                         $retVal[] = $this->tableName( $name );
1572                 }
1573                 return $retVal;
1574         }
1575
1576         /**
1577          * @private
1578          */
1579         function tableNamesWithUseIndex( $tables, $use_index ) {
1580                 $ret = array();
1581
1582                 foreach ( $tables as $table )
1583                         if ( @$use_index[$table] !== null )
1584                                 $ret[] = $this->tableName( $table ) . ' ' . $this->useIndexClause( implode( ',', (array)$use_index[$table] ) );
1585                         else
1586                                 $ret[] = $this->tableName( $table );
1587
1588                 return implode( ',', $ret );
1589         }
1590
1591         /**
1592          * Wrapper for addslashes()
1593          * @param string $s String to be slashed.
1594          * @return string slashed string.
1595          */
1596         function strencode( $s ) {
1597                 return mysql_real_escape_string( $s, $this->mConn );
1598         }
1599
1600         /**
1601          * If it's a string, adds quotes and backslashes
1602          * Otherwise returns as-is
1603          */
1604         function addQuotes( $s ) {
1605                 if ( is_null( $s ) ) {
1606                         return 'NULL';
1607                 } else {
1608                         # This will also quote numeric values. This should be harmless,
1609                         # and protects against weird problems that occur when they really
1610                         # _are_ strings such as article titles and string->number->string
1611                         # conversion is not 1:1.
1612                         return "'" . $this->strencode( $s ) . "'";
1613                 }
1614         }
1615
1616         /**
1617          * Escape string for safe LIKE usage
1618          */
1619         function escapeLike( $s ) {
1620                 $s=$this->strencode( $s );
1621                 $s=str_replace(array('%','_'),array('\%','\_'),$s);
1622                 return $s;
1623         }
1624
1625         /**
1626          * Returns an appropriately quoted sequence value for inserting a new row.
1627          * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1628          * subclass will return an integer, and save the value for insertId()
1629          */
1630         function nextSequenceValue( $seqName ) {
1631                 return NULL;
1632         }
1633
1634         /**
1635          * USE INDEX clause
1636          * PostgreSQL doesn't have them and returns ""
1637          */
1638         function useIndexClause( $index ) {
1639                 return "FORCE INDEX ($index)";
1640         }
1641
1642         /**
1643          * REPLACE query wrapper
1644          * PostgreSQL simulates this with a DELETE followed by INSERT
1645          * $row is the row to insert, an associative array
1646          * $uniqueIndexes is an array of indexes. Each element may be either a
1647          * field name or an array of field names
1648          *
1649          * It may be more efficient to leave off unique indexes which are unlikely to collide.
1650          * However if you do this, you run the risk of encountering errors which wouldn't have
1651          * occurred in MySQL
1652          *
1653          * @todo migrate comment to phodocumentor format
1654          */
1655         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
1656                 $table = $this->tableName( $table );
1657
1658                 # Single row case
1659                 if ( !is_array( reset( $rows ) ) ) {
1660                         $rows = array( $rows );
1661                 }
1662
1663                 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) .') VALUES ';
1664                 $first = true;
1665                 foreach ( $rows as $row ) {
1666                         if ( $first ) {
1667                                 $first = false;
1668                         } else {
1669                                 $sql .= ',';
1670                         }
1671                         $sql .= '(' . $this->makeList( $row ) . ')';
1672                 }
1673                 return $this->query( $sql, $fname );
1674         }
1675
1676         /**
1677          * DELETE where the condition is a join
1678          * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1679          *
1680          * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1681          * join condition matches, set $conds='*'
1682          *
1683          * DO NOT put the join condition in $conds
1684          *
1685          * @param string $delTable The table to delete from.
1686          * @param string $joinTable The other table.
1687          * @param string $delVar The variable to join on, in the first table.
1688          * @param string $joinVar The variable to join on, in the second table.
1689          * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
1690          */
1691         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
1692                 if ( !$conds ) {
1693                         throw new DBUnexpectedError( $this, 'Database::deleteJoin() called with empty $conds' );
1694                 }
1695
1696                 $delTable = $this->tableName( $delTable );
1697                 $joinTable = $this->tableName( $joinTable );
1698                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1699                 if ( $conds != '*' ) {
1700                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1701                 }
1702
1703                 return $this->query( $sql, $fname );
1704         }
1705
1706         /**
1707          * Returns the size of a text field, or -1 for "unlimited"
1708          */
1709         function textFieldSize( $table, $field ) {
1710                 $table = $this->tableName( $table );
1711                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1712                 $res = $this->query( $sql, 'Database::textFieldSize' );
1713                 $row = $this->fetchObject( $res );
1714                 $this->freeResult( $res );
1715
1716                 $m = array();
1717                 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
1718                         $size = $m[1];
1719                 } else {
1720                         $size = -1;
1721                 }
1722                 return $size;
1723         }
1724
1725         /**
1726          * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1727          */
1728         function lowPriorityOption() {
1729                 return 'LOW_PRIORITY';
1730         }
1731
1732         /**
1733          * DELETE query wrapper
1734          *
1735          * Use $conds == "*" to delete all rows
1736          */
1737         function delete( $table, $conds, $fname = 'Database::delete' ) {
1738                 if ( !$conds ) {
1739                         throw new DBUnexpectedError( $this, 'Database::delete() called with no conditions' );
1740                 }
1741                 $table = $this->tableName( $table );
1742                 $sql = "DELETE FROM $table";
1743                 if ( $conds != '*' ) {
1744                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1745                 }
1746                 return $this->query( $sql, $fname );
1747         }
1748
1749         /**
1750          * INSERT SELECT wrapper
1751          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1752          * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1753          * $conds may be "*" to copy the whole table
1754          * srcTable may be an array of tables.
1755          */
1756         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect',
1757                 $insertOptions = array(), $selectOptions = array() )
1758         {
1759                 $destTable = $this->tableName( $destTable );
1760                 if ( is_array( $insertOptions ) ) {
1761                         $insertOptions = implode( ' ', $insertOptions );
1762                 }
1763                 if( !is_array( $selectOptions ) ) {
1764                         $selectOptions = array( $selectOptions );
1765                 }
1766                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
1767                 if( is_array( $srcTable ) ) {
1768                         $srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
1769                 } else {
1770                         $srcTable = $this->tableName( $srcTable );
1771                 }
1772                 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1773                         " SELECT $startOpts " . implode( ',', $varMap ) .
1774                         " FROM $srcTable $useIndex ";
1775                 if ( $conds != '*' ) {
1776                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1777                 }
1778                 $sql .= " $tailOpts";
1779                 return $this->query( $sql, $fname );
1780         }
1781
1782         /**
1783          * Construct a LIMIT query with optional offset
1784          * This is used for query pages
1785          * $sql string SQL query we will append the limit too
1786          * $limit integer the SQL limit
1787          * $offset integer the SQL offset (default false)
1788          */
1789         function limitResult($sql, $limit, $offset=false) {
1790                 if( !is_numeric($limit) ) {
1791                         throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
1792                 }
1793                 return " $sql LIMIT "
1794                                 . ( (is_numeric($offset) && $offset != 0) ? "{$offset}," : "" )
1795                                 . "{$limit} ";
1796         }
1797         function limitResultForUpdate($sql, $num) {
1798                 return $this->limitResult($sql, $num, 0);
1799         }
1800
1801         /**
1802          * Returns an SQL expression for a simple conditional.
1803          * Uses IF on MySQL.
1804          *
1805          * @param string $cond SQL expression which will result in a boolean value
1806          * @param string $trueVal SQL expression to return if true
1807          * @param string $falseVal SQL expression to return if false
1808          * @return string SQL fragment
1809          */
1810         function conditional( $cond, $trueVal, $falseVal ) {
1811                 return " IF($cond, $trueVal, $falseVal) ";
1812         }
1813
1814         /**
1815          * Determines if the last failure was due to a deadlock
1816          */
1817         function wasDeadlock() {
1818                 return $this->lastErrno() == 1213;
1819         }
1820
1821         /**
1822          * Perform a deadlock-prone transaction.
1823          *
1824          * This function invokes a callback function to perform a set of write
1825          * queries. If a deadlock occurs during the processing, the transaction
1826          * will be rolled back and the callback function will be called again.
1827          *
1828          * Usage:
1829          *   $dbw->deadlockLoop( callback, ... );
1830          *
1831          * Extra arguments are passed through to the specified callback function.
1832          *
1833          * Returns whatever the callback function returned on its successful,
1834          * iteration, or false on error, for example if the retry limit was
1835          * reached.
1836          */
1837         function deadlockLoop() {
1838                 $myFname = 'Database::deadlockLoop';
1839
1840                 $this->begin();
1841                 $args = func_get_args();
1842                 $function = array_shift( $args );
1843                 $oldIgnore = $this->ignoreErrors( true );
1844                 $tries = DEADLOCK_TRIES;
1845                 if ( is_array( $function ) ) {
1846                         $fname = $function[0];
1847                 } else {
1848                         $fname = $function;
1849                 }
1850                 do {
1851                         $retVal = call_user_func_array( $function, $args );
1852                         $error = $this->lastError();
1853                         $errno = $this->lastErrno();
1854                         $sql = $this->lastQuery();
1855
1856                         if ( $errno ) {
1857                                 if ( $this->wasDeadlock() ) {
1858                                         # Retry
1859                                         usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1860                                 } else {
1861                                         $this->reportQueryError( $error, $errno, $sql, $fname );
1862                                 }
1863                         }
1864                 } while( $this->wasDeadlock() && --$tries > 0 );
1865                 $this->ignoreErrors( $oldIgnore );
1866                 if ( $tries <= 0 ) {
1867                         $this->query( 'ROLLBACK', $myFname );
1868                         $this->reportQueryError( $error, $errno, $sql, $fname );
1869                         return false;
1870                 } else {
1871                         $this->query( 'COMMIT', $myFname );
1872                         return $retVal;
1873                 }
1874         }
1875
1876         /**
1877          * Do a SELECT MASTER_POS_WAIT()
1878          *
1879          * @param string $file the binlog file
1880          * @param string $pos the binlog position
1881          * @param integer $timeout the maximum number of seconds to wait for synchronisation
1882          */
1883         function masterPosWait( $file, $pos, $timeout ) {
1884                 $fname = 'Database::masterPosWait';
1885                 wfProfileIn( $fname );
1886
1887
1888                 # Commit any open transactions
1889                 $this->immediateCommit();
1890
1891                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
1892                 $encFile = $this->strencode( $file );
1893                 $sql = "SELECT MASTER_POS_WAIT('$encFile', $pos, $timeout)";
1894                 $res = $this->doQuery( $sql );
1895                 if ( $res && $row = $this->fetchRow( $res ) ) {
1896                         $this->freeResult( $res );
1897                         wfProfileOut( $fname );
1898                         return $row[0];
1899                 } else {
1900                         wfProfileOut( $fname );
1901                         return false;
1902                 }
1903         }
1904
1905         /**
1906          * Get the position of the master from SHOW SLAVE STATUS
1907          */
1908         function getSlavePos() {
1909                 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1910                 $row = $this->fetchObject( $res );
1911                 if ( $row ) {
1912                         return array( $row->Master_Log_File, $row->Read_Master_Log_Pos );
1913                 } else {
1914                         return array( false, false );
1915                 }
1916         }
1917
1918         /**
1919          * Get the position of the master from SHOW MASTER STATUS
1920          */
1921         function getMasterPos() {
1922                 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1923                 $row = $this->fetchObject( $res );
1924                 if ( $row ) {
1925                         return array( $row->File, $row->Position );
1926                 } else {
1927                         return array( false, false );
1928                 }
1929         }
1930
1931         /**
1932          * Begin a transaction, committing any previously open transaction
1933          */
1934         function begin( $fname = 'Database::begin' ) {
1935                 $this->query( 'BEGIN', $fname );
1936                 $this->mTrxLevel = 1;
1937         }
1938
1939         /**
1940          * End a transaction
1941          */
1942         function commit( $fname = 'Database::commit' ) {
1943                 $this->query( 'COMMIT', $fname );
1944                 $this->mTrxLevel = 0;
1945         }
1946
1947         /**
1948          * Rollback a transaction
1949          */
1950         function rollback( $fname = 'Database::rollback' ) {
1951                 $this->query( 'ROLLBACK', $fname );
1952                 $this->mTrxLevel = 0;
1953         }
1954
1955         /**
1956          * Begin a transaction, committing any previously open transaction
1957          * @deprecated use begin()
1958          */
1959         function immediateBegin( $fname = 'Database::immediateBegin' ) {
1960                 $this->begin();
1961         }
1962
1963         /**
1964          * Commit transaction, if one is open
1965          * @deprecated use commit()
1966          */
1967         function immediateCommit( $fname = 'Database::immediateCommit' ) {
1968                 $this->commit();
1969         }
1970
1971         /**
1972          * Return MW-style timestamp used for MySQL schema
1973          */
1974         function timestamp( $ts=0 ) {
1975                 return wfTimestamp(TS_MW,$ts);
1976         }
1977
1978         /**
1979          * Local database timestamp format or null
1980          */
1981         function timestampOrNull( $ts = null ) {
1982                 if( is_null( $ts ) ) {
1983                         return null;
1984                 } else {
1985                         return $this->timestamp( $ts );
1986                 }
1987         }
1988
1989         /**
1990          * @todo document
1991          */
1992         function resultObject( $result ) {
1993                 if( empty( $result ) ) {
1994                         return NULL;
1995                 } else {
1996                         return new ResultWrapper( $this, $result );
1997                 }
1998         }
1999
2000         /**
2001          * Return aggregated value alias
2002          */
2003         function aggregateValue ($valuedata,$valuename='value') {
2004                 return $valuename;
2005         }
2006
2007         /**
2008          * @return string wikitext of a link to the server software's web site
2009          */
2010         function getSoftwareLink() {
2011                 return "[http://www.mysql.com/ MySQL]";
2012         }
2013
2014         /**
2015          * @return string Version information from the database
2016          */
2017         function getServerVersion() {
2018                 return mysql_get_server_info( $this->mConn );
2019         }
2020
2021         /**
2022          * Ping the server and try to reconnect if it there is no connection
2023          */
2024         function ping() {
2025                 if( function_exists( 'mysql_ping' ) ) {
2026                         return mysql_ping( $this->mConn );
2027                 } else {
2028                         wfDebug( "Tried to call mysql_ping but this is ancient PHP version. Faking it!\n" );
2029                         return true;
2030                 }
2031         }
2032
2033         /**
2034          * Get slave lag.
2035          * At the moment, this will only work if the DB user has the PROCESS privilege
2036          */
2037         function getLag() {
2038                 $res = $this->query( 'SHOW PROCESSLIST' );
2039                 # Find slave SQL thread. Assumed to be the second one running, which is a bit
2040                 # dubious, but unfortunately there's no easy rigorous way
2041                 while ( $row = $this->fetchObject( $res ) ) {
2042                         /* This should work for most situations - when default db
2043                          * for thread is not specified, it had no events executed,
2044                          * and therefore it doesn't know yet how lagged it is.
2045                          *
2046                          * Relay log I/O thread does not select databases.
2047                          */
2048                         if ( $row->User == 'system user' &&
2049                                 $row->State != 'Waiting for master to send event' &&
2050                                 $row->State != 'Connecting to master' &&
2051                                 $row->State != 'Queueing master event to the relay log' &&
2052                                 $row->State != 'Waiting for master update' &&
2053                                 $row->State != 'Requesting binlog dump'
2054                                 ) {
2055                                 # This is it, return the time (except -ve)
2056                                 if ( $row->Time > 0x7fffffff ) {
2057                                         return false;
2058                                 } else {
2059                                         return $row->Time;
2060                                 }
2061                         }
2062                 }
2063                 return false;
2064         }
2065
2066         /**
2067          * Get status information from SHOW STATUS in an associative array
2068          */
2069         function getStatus($which="%") {
2070                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
2071                 $status = array();
2072                 while ( $row = $this->fetchObject( $res ) ) {
2073                         $status[$row->Variable_name] = $row->Value;
2074                 }
2075                 return $status;
2076         }
2077
2078         /**
2079          * Return the maximum number of items allowed in a list, or 0 for unlimited.
2080          */
2081         function maxListLen() {
2082                 return 0;
2083         }
2084
2085         function encodeBlob($b) {
2086                 return $b;
2087         }
2088
2089         function decodeBlob($b) {
2090                 return $b;
2091         }
2092
2093         /**
2094          * Override database's default connection timeout.
2095          * May be useful for very long batch queries such as
2096          * full-wiki dumps, where a single query reads out
2097          * over hours or days.
2098          * @param int $timeout in seconds
2099          */
2100         public function setTimeout( $timeout ) {
2101                 $this->query( "SET net_read_timeout=$timeout" );
2102                 $this->query( "SET net_write_timeout=$timeout" );
2103         }
2104
2105         /**
2106          * Read and execute SQL commands from a file.
2107          * Returns true on success, error string on failure
2108          * @param string $filename File name to open
2109          * @param callback $lineCallback Optional function called before reading each line
2110          * @param callback $resultCallback Optional function called for each MySQL result
2111          */
2112         function sourceFile( $filename, $lineCallback = false, $resultCallback = false ) {
2113                 $fp = fopen( $filename, 'r' );
2114                 if ( false === $fp ) {
2115                         return "Could not open \"{$filename}\".\n";
2116                 }
2117                 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback );
2118                 fclose( $fp );
2119                 return $error;
2120         }
2121
2122         /**
2123          * Read and execute commands from an open file handle
2124          * Returns true on success, error string on failure
2125          * @param string $fp File handle
2126          * @param callback $lineCallback Optional function called before reading each line
2127          * @param callback $resultCallback Optional function called for each MySQL result
2128          */
2129         function sourceStream( $fp, $lineCallback = false, $resultCallback = false ) {
2130                 $cmd = "";
2131                 $done = false;
2132                 $dollarquote = false;
2133
2134                 while ( ! feof( $fp ) ) {
2135                         if ( $lineCallback ) {
2136                                 call_user_func( $lineCallback );
2137                         }
2138                         $line = trim( fgets( $fp, 1024 ) );
2139                         $sl = strlen( $line ) - 1;
2140
2141                         if ( $sl < 0 ) { continue; }
2142                         if ( '-' == $line{0} && '-' == $line{1} ) { continue; }
2143
2144                         ## Allow dollar quoting for function declarations
2145                         if (substr($line,0,4) == '$mw$') {
2146                                 if ($dollarquote) {
2147                                         $dollarquote = false;
2148                                         $done = true;
2149                                 }
2150                                 else {
2151                                         $dollarquote = true;
2152                                 }
2153                         }
2154                         else if (!$dollarquote) {
2155                                 if ( ';' == $line{$sl} && ($sl < 2 || ';' != $line{$sl - 1})) {
2156                                         $done = true;
2157                                         $line = substr( $line, 0, $sl );
2158                                 }
2159                         }
2160
2161                         if ( '' != $cmd ) { $cmd .= ' '; }
2162                         $cmd .= "$line\n";
2163
2164                         if ( $done ) {
2165                                 $cmd = str_replace(';;', ";", $cmd);
2166                                 $cmd = $this->replaceVars( $cmd );
2167                                 $res = $this->query( $cmd, __METHOD__, true );
2168                                 if ( $resultCallback ) {
2169                                         call_user_func( $resultCallback, $this->resultObject( $res ) );
2170                                 }
2171
2172                                 if ( false === $res ) {
2173                                         $err = $this->lastError();
2174                                         return "Query \"{$cmd}\" failed with error code \"$err\".\n";
2175                                 }
2176
2177                                 $cmd = '';
2178                                 $done = false;
2179                         }
2180                 }
2181                 return true;
2182         }
2183
2184
2185         /**
2186          * Replace variables in sourced SQL
2187          */
2188         protected function replaceVars( $ins ) {
2189                 $varnames = array(
2190                         'wgDBserver', 'wgDBname', 'wgDBintlname', 'wgDBuser',
2191                         'wgDBpassword', 'wgDBsqluser', 'wgDBsqlpassword',
2192                         'wgDBadminuser', 'wgDBadminpassword', 'wgDBTableOptions',
2193                 );
2194
2195                 // Ordinary variables
2196                 foreach ( $varnames as $var ) {
2197                         if( isset( $GLOBALS[$var] ) ) {
2198                                 $val = addslashes( $GLOBALS[$var] ); // FIXME: safety check?
2199                                 $ins = str_replace( '{$' . $var . '}', $val, $ins );
2200                                 $ins = str_replace( '/*$' . $var . '*/`', '`' . $val, $ins );
2201                                 $ins = str_replace( '/*$' . $var . '*/', $val, $ins );
2202                         }
2203                 }
2204
2205                 // Table prefixes
2206                 $ins = preg_replace_callback( '/\/\*(?:\$wgDBprefix|_)\*\/([a-z_]*)/',
2207                         array( &$this, 'tableNameCallback' ), $ins );
2208                 return $ins;
2209         }
2210
2211         /**
2212          * Table name callback
2213          * @private
2214          */
2215         protected function tableNameCallback( $matches ) {
2216                 return $this->tableName( $matches[1] );
2217         }
2218
2219 }
2220
2221 /**
2222  * Database abstraction object for mySQL
2223  * Inherit all methods and properties of Database::Database()
2224  *
2225  * @addtogroup Database
2226  * @see Database
2227  */
2228 class DatabaseMysql extends Database {
2229         # Inherit all
2230 }
2231
2232
2233 /**
2234  * Result wrapper for grabbing data queried by someone else
2235  * @addtogroup Database
2236  */
2237 class ResultWrapper {
2238         var $db, $result;
2239
2240         /**
2241          * @todo document
2242          */
2243         function ResultWrapper( &$database, $result ) {
2244                 $this->db =& $database;
2245                 $this->result =& $result;
2246         }
2247
2248         /**
2249          * @todo document
2250          */
2251         function numRows() {
2252                 return $this->db->numRows( $this->result );
2253         }
2254
2255         /**
2256          * @todo document
2257          */
2258         function fetchObject() {
2259                 return $this->db->fetchObject( $this->result );
2260         }
2261
2262         /**
2263          * @todo document
2264          */
2265         function fetchRow() {
2266                 return $this->db->fetchRow( $this->result );
2267         }
2268
2269         /**
2270          * @todo document
2271          */
2272         function free() {
2273                 $this->db->freeResult( $this->result );
2274                 unset( $this->result );
2275                 unset( $this->db );
2276         }
2277
2278         function seek( $row ) {
2279                 $this->db->dataSeek( $this->result, $row );
2280         }
2281
2282         function rewind() {
2283                 if ($this->numRows()) {
2284                         $this->db->dataSeek($this->result, 0);
2285                 }
2286         }
2287
2288 }
2289
2290 ?>