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
 682          *     comment (you can use __METHOD__ or add some extra info)
 683          * @param  $tempIgnore Bool:   Whether to avoid throwing an exception on errors...
 684          *     maybe best to catch the exception instead?
 685          * @return true for a successful write query, ResultWrapper object for a successful read query,
 686          *     or false on failure if $tempIgnore set
 687          * @throws DBQueryError Thrown when the database returns an error of any kind
 688          */
 689         public function query( $sql, $fname = '', $tempIgnore = false ) {
 690                 global $wgProfiling;
 691
 692                 if ( $wgProfiling ) {
 693                         # generalizeSQL will probably cut down the query to reasonable
 694                         # logging size most of the time. The substr is really just a sanity check.
 695
 696                         # Who's been wasting my precious column space? -- TS
 697                         #$profName = 'query: ' . $fname . ' ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 698
 699                         if ( is_null( $this->getLBInfo( 'master' ) ) ) {
 700                                 $queryProf = 'query: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 701                                 $totalProf = 'Database::query';
 702                         } else {
 703                                 $queryProf = 'query-m: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 704                                 $totalProf = 'Database::query-master';
 705                         }
 706                         wfProfileIn( $totalProf );
 707                         wfProfileIn( $queryProf );
 708                 }
 709
 710                 $this->mLastQuery = $sql;
 711
 712                 # Add a comment for easy SHOW PROCESSLIST interpretation
 713                 #if ( $fname ) {
 714                         global $wgUser;
 715                         if ( is_object( $wgUser ) && !($wgUser instanceof StubObject) ) {
 716                                 $userName = $wgUser->getName();
 717                                 if ( strlen( $userName ) > 15 ) {
 718                                         $userName = substr( $userName, 0, 15 ) . '...';
 719                                 }
 720                                 $userName = str_replace( '/', '', $userName );
 721                         } else {
 722                                 $userName = '';
 723                         }
 724                         $commentedSql = preg_replace('/\s/', " /* $fname $userName */ ", $sql, 1);
 725                 #} else {
 726                 #       $commentedSql = $sql;
 727                 #}
 728
 729                 # If DBO_TRX is set, start a transaction
 730                 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
 731                         $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK'
 732                 ) {
 733                         $this->begin();
 734                 }
 735
 736                 if ( $this->debug() ) {
 737                         $sqlx = substr( $commentedSql, 0, 500 );
 738                         $sqlx = strtr( $sqlx, "\t\n", '  ' );
 739                         wfDebug( "SQL: $sqlx\n" );
 740                 }
 741
 742                 # Do the query and handle errors
 743                 $ret = $this->doQuery( $commentedSql );
 744
 745                 # Try reconnecting if the connection was lost
 746                 if ( false === $ret && ( $this->lastErrno() == 2013 || $this->lastErrno() == 2006 ) ) {
 747                         # Transaction is gone, like it or not
 748                         $this->mTrxLevel = 0;
 749                         wfDebug( "Connection lost, reconnecting...\n" );
 750                         if ( $this->ping() ) {
 751                                 wfDebug( "Reconnected\n" );
 752                                 $sqlx = substr( $commentedSql, 0, 500 );
 753                                 $sqlx = strtr( $sqlx, "\t\n", '  ' );
 754                                 global $wgRequestTime;
 755                                 $elapsed = round( microtime(true) - $wgRequestTime, 3 );
 756                                 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
 757                                 $ret = $this->doQuery( $commentedSql );
 758                         } else {
 759                                 wfDebug( "Failed\n" );
 760                         }
 761                 }
 762
 763                 if ( false === $ret ) {
 764                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
 765                 }
 766
 767                 if ( $wgProfiling ) {
 768                         wfProfileOut( $queryProf );
 769                         wfProfileOut( $totalProf );
 770                 }
 771                 return $this->resultObject( $ret );
 772         }
 773
 774         /**
 775          * The DBMS-dependent part of query()
 776          * @param  $sql String: SQL query.
 777          * @return Result object to feed to fetchObject, fetchRow, ...; or false on failure
 778          * @access private
 779          */
 780         /*private*/ function doQuery( $sql ) {
 781                 if( $this->bufferResults() ) {
 782                         $ret = mysql_query( $sql, $this->mConn );
 783                 } else {
 784                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 785                 }
 786                 return $ret;
 787         }
 788
 789         /**
 790          * @param $error
 791          * @param $errno
 792          * @param $sql
 793          * @param string $fname
 794          * @param bool $tempIgnore
 795          */
 796         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 797                 global $wgCommandLineMode;
 798                 # Ignore errors during error handling to avoid infinite recursion
 799                 $ignore = $this->ignoreErrors( true );
 800                 ++$this->mErrorCount;
 801
 802                 if( $ignore || $tempIgnore ) {
 803                         wfDebug("SQL ERROR (ignored): $error\n");
 804                         $this->ignoreErrors( $ignore );
 805                 } else {
 806                         $sql1line = str_replace( "\n", "\\n", $sql );
 807                         wfLogDBError("$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n");
 808                         wfDebug("SQL ERROR: " . $error . "\n");
 809                         throw new DBQueryError( $this, $error, $errno, $sql, $fname );
 810                 }
 811         }
 812
 813
 814         /**
 815          * Intended to be compatible with the PEAR::DB wrapper functions.
 816          * http://pear.php.net/manual/en/package.database.db.intro-execute.php
 817          *
 818          * ? = scalar value, quoted as necessary
 819          * ! = raw SQL bit (a function for instance)
 820          * & = filename; reads the file and inserts as a blob
 821          *     (we don't use this though...)
 822          */
 823         function prepare( $sql, $func = 'Database::prepare' ) {
 824                 /* MySQL doesn't support prepared statements (yet), so just
 825                    pack up the query for reference. We'll manually replace
 826                    the bits later. */
 827                 return array( 'query' => $sql, 'func' => $func );
 828         }
 829
 830         function freePrepared( $prepared ) {
 831                 /* No-op for MySQL */
 832         }
 833
 834         /**
 835          * Execute a prepared query with the various arguments
 836          * @param string $prepared the prepared sql
 837          * @param mixed $args Either an array here, or put scalars as varargs
 838          */
 839         function execute( $prepared, $args = null ) {
 840                 if( !is_array( $args ) ) {
 841                         # Pull the var args
 842                         $args = func_get_args();
 843                         array_shift( $args );
 844                 }
 845                 $sql = $this->fillPrepared( $prepared['query'], $args );
 846                 return $this->query( $sql, $prepared['func'] );
 847         }
 848
 849         /**
 850          * Prepare & execute an SQL statement, quoting and inserting arguments
 851          * in the appropriate places.
 852          * @param string $query
 853          * @param string $args ...
 854          */
 855         function safeQuery( $query, $args = null ) {
 856                 $prepared = $this->prepare( $query, 'Database::safeQuery' );
 857                 if( !is_array( $args ) ) {
 858                         # Pull the var args
 859                         $args = func_get_args();
 860                         array_shift( $args );
 861                 }
 862                 $retval = $this->execute( $prepared, $args );
 863                 $this->freePrepared( $prepared );
 864                 return $retval;
 865         }
 866
 867         /**
 868          * For faking prepared SQL statements on DBs that don't support
 869          * it directly.
 870          * @param string $preparedSql - a 'preparable' SQL statement
 871          * @param array $args - array of arguments to fill it with
 872          * @return string executable SQL
 873          */
 874         function fillPrepared( $preparedQuery, $args ) {
 875                 reset( $args );
 876                 $this->preparedArgs =& $args;
 877                 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
 878                         array( &$this, 'fillPreparedArg' ), $preparedQuery );
 879         }
 880
 881         /**
 882          * preg_callback func for fillPrepared()
 883          * The arguments should be in $this->preparedArgs and must not be touched
 884          * while we're doing this.
 885          *
 886          * @param array $matches
 887          * @return string
 888          * @private
 889          */
 890         function fillPreparedArg( $matches ) {
 891                 switch( $matches[1] ) {
 892                         case '\\?': return '?';
 893                         case '\\!': return '!';
 894                         case '\\&': return '&';
 895                 }
 896                 list( /* $n */ , $arg ) = each( $this->preparedArgs );
 897                 switch( $matches[1] ) {
 898                         case '?': return $this->addQuotes( $arg );
 899                         case '!': return $arg;
 900                         case '&':
 901                                 # return $this->addQuotes( file_get_contents( $arg ) );
 902                                 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
 903                         default:
 904                                 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
 905                 }
 906         }
 907
 908         /**#@+
 909          * @param mixed $res A SQL result
 910          */
 911         /**
 912          * Free a result object
 913          */
 914         function freeResult( $res ) {
 915                 if ( $res instanceof ResultWrapper ) {
 916                         $res = $res->result;
 917                 }
 918                 if ( !@/**/mysql_free_result( $res ) ) {
 919                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 920                 }
 921         }
 922
 923         /**
 924          * Fetch the next row from the given result object, in object form.
 925          * Fields can be retrieved with $row->fieldname, with fields acting like
 926          * member variables.
 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 fetchObject( $res ) {
 933                 if ( $res instanceof ResultWrapper ) {
 934                         $res = $res->result;
 935                 }
 936                 @/**/$row = mysql_fetch_object( $res );
 937                 if( $this->lastErrno() ) {
 938                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 939                 }
 940                 return $row;
 941         }
 942
 943         /**
 944          * Fetch the next row from the given result object, in associative array
 945          * form.  Fields are retrieved with $row['fieldname'].
 946          *
 947          * @param $res SQL result object as returned from Database::query(), etc.
 948          * @return MySQL row object
 949          * @throws DBUnexpectedError Thrown if the database returns an error
 950          */
 951         function fetchRow( $res ) {
 952                 if ( $res instanceof ResultWrapper ) {
 953                         $res = $res->result;
 954                 }
 955                 @/**/$row = mysql_fetch_array( $res );
 956                 if ( $this->lastErrno() ) {
 957                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 958                 }
 959                 return $row;
 960         }
 961
 962         /**
 963          * Get the number of rows in a result object
 964          */
 965         function numRows( $res ) {
 966                 if ( $res instanceof ResultWrapper ) {
 967                         $res = $res->result;
 968                 }
 969                 @/**/$n = mysql_num_rows( $res );
 970                 if( $this->lastErrno() ) {
 971                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 972                 }
 973                 return $n;
 974         }
 975
 976         /**
 977          * Get the number of fields in a result object
 978          * See documentation for mysql_num_fields()
 979          */
 980         function numFields( $res ) {
 981                 if ( $res instanceof ResultWrapper ) {
 982                         $res = $res->result;
 983                 }
 984                 return mysql_num_fields( $res );
 985         }
 986
 987         /**
 988          * Get a field name in a result object
 989          * See documentation for mysql_field_name():
 990          * http://www.php.net/mysql_field_name
 991          */
 992         function fieldName( $res, $n ) {
 993                 if ( $res instanceof ResultWrapper ) {
 994                         $res = $res->result;
 995                 }
 996                 return mysql_field_name( $res, $n );
 997         }
 998
 999         /**
1000          * Get the inserted value of an auto-increment row
1001          *
1002          * The value inserted should be fetched from nextSequenceValue()
1003          *
1004          * Example:
1005          * $id = $dbw->nextSequenceValue('page_page_id_seq');
1006          * $dbw->insert('page',array('page_id' => $id));
1007          * $id = $dbw->insertId();
1008          */
1009         function insertId() { return mysql_insert_id( $this->mConn ); }
1010
1011         /**
1012          * Change the position of the cursor in a result object
1013          * See mysql_data_seek()
1014          */
1015         function dataSeek( $res, $row ) {
1016                 if ( $res instanceof ResultWrapper ) {
1017                         $res = $res->result;
1018                 }
1019                 return mysql_data_seek( $res, $row );
1020         }
1021
1022         /**
1023          * Get the last error number
1024          * See mysql_errno()
1025          */
1026         function lastErrno() {
1027                 if ( $this->mConn ) {
1028                         return mysql_errno( $this->mConn );
1029                 } else {
1030                         return mysql_errno();
1031                 }
1032         }
1033
1034         /**
1035          * Get a description of the last error
1036          * See mysql_error() for more details
1037          */
1038         function lastError() {
1039                 if ( $this->mConn ) {
1040                         # Even if it's non-zero, it can still be invalid
1041                         wfSuppressWarnings();
1042                         $error = mysql_error( $this->mConn );
1043                         if ( !$error ) {
1044                                 $error = mysql_error();
1045                         }
1046                         wfRestoreWarnings();
1047                 } else {
1048                         $error = mysql_error();
1049                 }
1050                 if( $error ) {
1051                         $error .= ' (' . $this->mServer . ')';
1052                 }
1053                 return $error;
1054         }
1055         /**
1056          * Get the number of rows affected by the last write query
1057          * See mysql_affected_rows() for more details
1058          */
1059         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
1060         /**#@-*/ // end of template : @param $result
1061
1062         /**
1063          * Simple UPDATE wrapper
1064          * Usually aborts on failure
1065          * If errors are explicitly ignored, returns success
1066          *
1067          * This function exists for historical reasons, Database::update() has a more standard
1068          * calling convention and feature set
1069          */
1070         function set( $table, $var, $value, $cond, $fname = 'Database::set' )
1071         {
1072                 $table = $this->tableName( $table );
1073                 $sql = "UPDATE $table SET $var = '" .
1074                   $this->strencode( $value ) . "' WHERE ($cond)";
1075                 return (bool)$this->query( $sql, $fname );
1076         }
1077
1078         /**
1079          * Simple SELECT wrapper, returns a single field, input must be encoded
1080          * Usually aborts on failure
1081          * If errors are explicitly ignored, returns FALSE on failure
1082          */
1083         function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
1084                 if ( !is_array( $options ) ) {
1085                         $options = array( $options );
1086                 }
1087                 $options['LIMIT'] = 1;
1088
1089                 $res = $this->select( $table, $var, $cond, $fname, $options );
1090                 if ( $res === false || !$this->numRows( $res ) ) {
1091                         return false;
1092                 }
1093                 $row = $this->fetchRow( $res );
1094                 if ( $row !== false ) {
1095                         $this->freeResult( $res );
1096                         return $row[0];
1097                 } else {
1098                         return false;
1099                 }
1100         }
1101
1102         /**
1103          * Returns an optional USE INDEX clause to go after the table, and a
1104          * string to go at the end of the query
1105          *
1106          * @private
1107          *
1108          * @param array $options an associative array of options to be turned into
1109          *              an SQL query, valid keys are listed in the function.
1110          * @return array
1111          */
1112         function makeSelectOptions( $options ) {
1113                 $preLimitTail = $postLimitTail = '';
1114                 $startOpts = '';
1115
1116                 $noKeyOptions = array();
1117                 foreach ( $options as $key => $option ) {
1118                         if ( is_numeric( $key ) ) {
1119                                 $noKeyOptions[$option] = true;
1120                         }
1121                 }
1122
1123                 if ( isset( $options['GROUP BY'] ) ) $preLimitTail .= " GROUP BY {$options['GROUP BY']}";
1124                 if ( isset( $options['HAVING'] ) ) $preLimitTail .= " HAVING {$options['HAVING']}";
1125                 if ( isset( $options['ORDER BY'] ) ) $preLimitTail .= " ORDER BY {$options['ORDER BY']}";
1126
1127                 //if (isset($options['LIMIT'])) {
1128                 //      $tailOpts .= $this->limitResult('', $options['LIMIT'],
1129                 //              isset($options['OFFSET']) ? $options['OFFSET']
1130                 //              : false);
1131                 //}
1132
1133                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $postLimitTail .= ' FOR UPDATE';
1134                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $postLimitTail .= ' LOCK IN SHARE MODE';
1135                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
1136
1137                 # Various MySQL extensions
1138                 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) $startOpts .= ' /*! STRAIGHT_JOIN */';
1139                 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) $startOpts .= ' HIGH_PRIORITY';
1140                 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) $startOpts .= ' SQL_BIG_RESULT';
1141                 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) $startOpts .= ' SQL_BUFFER_RESULT';
1142                 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) $startOpts .= ' SQL_SMALL_RESULT';
1143                 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) $startOpts .= ' SQL_CALC_FOUND_ROWS';
1144                 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) $startOpts .= ' SQL_CACHE';
1145                 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) $startOpts .= ' SQL_NO_CACHE';
1146
1147                 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1148                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1149                 } else {
1150                         $useIndex = '';
1151                 }
1152
1153                 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1154         }
1155
1156         /**
1157          * SELECT wrapper
1158          *
1159          * @param mixed  $table   Array or string, table name(s) (prefix auto-added)
1160          * @param mixed  $vars    Array or string, field name(s) to be retrieved
1161          * @param mixed  $conds   Array or string, condition(s) for WHERE
1162          * @param string $fname   Calling function name (use __METHOD__) for logs/profiling
1163          * @param array  $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
1164          *                        see Database::makeSelectOptions code for list of supported stuff
1165          * @return mixed Database result resource (feed to Database::fetchObject or whatever), or false on failure
1166          */
1167         function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array() )
1168         {
1169                 if( is_array( $vars ) ) {
1170                         $vars = implode( ',', $vars );
1171                 }
1172                 if( !is_array( $options ) ) {
1173                         $options = array( $options );
1174                 }
1175                 if( is_array( $table ) ) {
1176                         if ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1177                                 $from = ' FROM ' . $this->tableNamesWithUseIndex( $table, $options['USE INDEX'] );
1178                         else
1179                                 $from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
1180                 } elseif ($table!='') {
1181                         if ($table{0}==' ') {
1182                                 $from = ' FROM ' . $table;
1183                         } else {
1184                                 $from = ' FROM ' . $this->tableName( $table );
1185                         }
1186                 } else {
1187                         $from = '';
1188                 }
1189
1190                 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1191
1192                 if( !empty( $conds ) ) {
1193                         if ( is_array( $conds ) ) {
1194                                 $conds = $this->makeList( $conds, LIST_AND );
1195                         }
1196                         $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1197                 } else {
1198                         $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1199                 }
1200
1201                 if (isset($options['LIMIT']))
1202                         $sql = $this->limitResult($sql, $options['LIMIT'],
1203                                 isset($options['OFFSET']) ? $options['OFFSET'] : false);
1204                 $sql = "$sql $postLimitTail";
1205
1206                 if (isset($options['EXPLAIN'])) {
1207                         $sql = 'EXPLAIN ' . $sql;
1208                 }
1209                 return $this->query( $sql, $fname );
1210         }
1211
1212         /**
1213          * Single row SELECT wrapper
1214          * Aborts or returns FALSE on error
1215          *
1216          * $vars: the selected variables
1217          * $conds: a condition map, terms are ANDed together.
1218          *   Items with numeric keys are taken to be literal conditions
1219          * Takes an array of selected variables, and a condition map, which is ANDed
1220          * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
1221          * NS_MAIN, "page_title" => "Astronomy" ) )   would return an object where
1222          * $obj- >page_id is the ID of the Astronomy article
1223          *
1224          * @todo migrate documentation to phpdocumentor format
1225          */
1226         function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
1227                 $options['LIMIT'] = 1;
1228                 $res = $this->select( $table, $vars, $conds, $fname, $options );
1229                 if ( $res === false )
1230                         return false;
1231                 if ( !$this->numRows($res) ) {
1232                         $this->freeResult($res);
1233                         return false;
1234                 }
1235                 $obj = $this->fetchObject( $res );
1236                 $this->freeResult( $res );
1237                 return $obj;
1238
1239         }
1240
1241         /**
1242          * Estimate rows in dataset
1243          * Returns estimated count, based on EXPLAIN output
1244          * Takes same arguments as Database::select()
1245          */
1246
1247         function estimateRowCount( $table, $vars='*', $conds='', $fname = 'Database::estimateRowCount', $options = array() ) {
1248                 $options['EXPLAIN']=true;
1249                 $res = $this->select ($table, $vars, $conds, $fname, $options );
1250                 if ( $res === false )
1251                         return false;
1252                 if (!$this->numRows($res)) {
1253                         $this->freeResult($res);
1254                         return 0;
1255                 }
1256
1257                 $rows=1;
1258
1259                 while( $plan = $this->fetchObject( $res ) ) {
1260                         $rows *= ($plan->rows > 0)?$plan->rows:1; // avoid resetting to zero
1261                 }
1262
1263                 $this->freeResult($res);
1264                 return $rows;
1265         }
1266
1267
1268         /**
1269          * Removes most variables from an SQL query and replaces them with X or N for numbers.
1270          * It's only slightly flawed. Don't use for anything important.
1271          *
1272          * @param string $sql A SQL Query
1273          * @static
1274          */
1275         static function generalizeSQL( $sql ) {
1276                 # This does the same as the regexp below would do, but in such a way
1277                 # as to avoid crashing php on some large strings.
1278                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1279
1280                 $sql = str_replace ( "\\\\", '', $sql);
1281                 $sql = str_replace ( "\\'", '', $sql);
1282                 $sql = str_replace ( "\\\"", '', $sql);
1283                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
1284                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
1285
1286                 # All newlines, tabs, etc replaced by single space
1287                 $sql = preg_replace ( '/\s+/', ' ', $sql);
1288
1289                 # All numbers => N
1290                 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
1291
1292                 return $sql;
1293         }
1294
1295         /**
1296          * Determines whether a field exists in a table
1297          * Usually aborts on failure
1298          * If errors are explicitly ignored, returns NULL on failure
1299          */
1300         function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
1301                 $table = $this->tableName( $table );
1302                 $res = $this->query( 'DESCRIBE '.$table, $fname );
1303                 if ( !$res ) {
1304                         return NULL;
1305                 }
1306
1307                 $found = false;
1308
1309                 while ( $row = $this->fetchObject( $res ) ) {
1310                         if ( $row->Field == $field ) {
1311                                 $found = true;
1312                                 break;
1313                         }
1314                 }
1315                 return $found;
1316         }
1317
1318         /**
1319          * Determines whether an index exists
1320          * Usually aborts on failure
1321          * If errors are explicitly ignored, returns NULL on failure
1322          */
1323         function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
1324                 $info = $this->indexInfo( $table, $index, $fname );
1325                 if ( is_null( $info ) ) {
1326                         return NULL;
1327                 } else {
1328                         return $info !== false;
1329                 }
1330         }
1331
1332
1333         /**
1334          * Get information about an index into an object
1335          * Returns false if the index does not exist
1336          */
1337         function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
1338                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
1339                 # SHOW INDEX should work for 3.x and up:
1340                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
1341                 $table = $this->tableName( $table );
1342                 $sql = 'SHOW INDEX FROM '.$table;
1343                 $res = $this->query( $sql, $fname );
1344                 if ( !$res ) {
1345                         return NULL;
1346                 }
1347
1348                 $result = array();
1349                 while ( $row = $this->fetchObject( $res ) ) {
1350                         if ( $row->Key_name == $index ) {
1351                                 $result[] = $row;
1352                         }
1353                 }
1354                 $this->freeResult($res);
1355
1356                 return empty($result) ? false : $result;
1357         }
1358
1359         /**
1360          * Query whether a given table exists
1361          */
1362         function tableExists( $table ) {
1363                 $table = $this->tableName( $table );
1364                 $old = $this->ignoreErrors( true );
1365                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
1366                 $this->ignoreErrors( $old );
1367                 if( $res ) {
1368                         $this->freeResult( $res );
1369                         return true;
1370                 } else {
1371                         return false;
1372                 }
1373         }
1374
1375         /**
1376          * mysql_fetch_field() wrapper
1377          * Returns false if the field doesn't exist
1378          *
1379          * @param $table
1380          * @param $field
1381          */
1382         function fieldInfo( $table, $field ) {
1383                 $table = $this->tableName( $table );
1384                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
1385                 $n = mysql_num_fields( $res->result );
1386                 for( $i = 0; $i < $n; $i++ ) {
1387                         $meta = mysql_fetch_field( $res->result, $i );
1388                         if( $field == $meta->name ) {
1389                                 return new MySQLField($meta);
1390                         }
1391                 }
1392                 return false;
1393         }
1394
1395         /**
1396          * mysql_field_type() wrapper
1397          */
1398         function fieldType( $res, $index ) {
1399                 if ( $res instanceof ResultWrapper ) {
1400                         $res = $res->result;
1401                 }
1402                 return mysql_field_type( $res, $index );
1403         }
1404
1405         /**
1406          * Determines if a given index is unique
1407          */
1408         function indexUnique( $table, $index ) {
1409                 $indexInfo = $this->indexInfo( $table, $index );
1410                 if ( !$indexInfo ) {
1411                         return NULL;
1412                 }
1413                 return !$indexInfo[0]->Non_unique;
1414         }
1415
1416         /**
1417          * INSERT wrapper, inserts an array into a table
1418          *
1419          * $a may be a single associative array, or an array of these with numeric keys, for
1420          * multi-row insert.
1421          *
1422          * Usually aborts on failure
1423          * If errors are explicitly ignored, returns success
1424          */
1425         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
1426                 # No rows to insert, easy just return now
1427                 if ( !count( $a ) ) {
1428                         return true;
1429                 }
1430
1431                 $table = $this->tableName( $table );
1432                 if ( !is_array( $options ) ) {
1433                         $options = array( $options );
1434                 }
1435                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1436                         $multi = true;
1437                         $keys = array_keys( $a[0] );
1438                 } else {
1439                         $multi = false;
1440                         $keys = array_keys( $a );
1441                 }
1442
1443                 $sql = 'INSERT ' . implode( ' ', $options ) .
1444                         " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1445
1446                 if ( $multi ) {
1447                         $first = true;
1448                         foreach ( $a as $row ) {
1449                                 if ( $first ) {
1450                                         $first = false;
1451                                 } else {
1452                                         $sql .= ',';
1453                                 }
1454                                 $sql .= '(' . $this->makeList( $row ) . ')';
1455                         }
1456                 } else {
1457                         $sql .= '(' . $this->makeList( $a ) . ')';
1458                 }
1459                 return (bool)$this->query( $sql, $fname );
1460         }
1461
1462         /**
1463          * Make UPDATE options for the Database::update function
1464          *
1465          * @private
1466          * @param array $options The options passed to Database::update
1467          * @return string
1468          */
1469         function makeUpdateOptions( $options ) {
1470                 if( !is_array( $options ) ) {
1471                         $options = array( $options );
1472                 }
1473                 $opts = array();
1474                 if ( in_array( 'LOW_PRIORITY', $options ) )
1475                         $opts[] = $this->lowPriorityOption();
1476                 if ( in_array( 'IGNORE', $options ) )
1477                         $opts[] = 'IGNORE';
1478                 return implode(' ', $opts);
1479         }
1480
1481         /**
1482          * UPDATE wrapper, takes a condition array and a SET array
1483          *
1484          * @param string $table  The table to UPDATE
1485          * @param array  $values An array of values to SET
1486          * @param array  $conds  An array of conditions (WHERE). Use '*' to update all rows.
1487          * @param string $fname  The Class::Function calling this function
1488          *                       (for the log)
1489          * @param array  $options An array of UPDATE options, can be one or
1490          *                        more of IGNORE, LOW_PRIORITY
1491          */
1492         function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
1493                 $table = $this->tableName( $table );
1494                 $opts = $this->makeUpdateOptions( $options );
1495                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1496                 if ( $conds != '*' ) {
1497                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1498                 }
1499                 $this->query( $sql, $fname );
1500         }
1501
1502         /**
1503          * Makes an encoded list of strings from an array
1504          * $mode:
1505          *        LIST_COMMA         - comma separated, no field names
1506          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
1507          *        LIST_OR            - ORed WHERE clause (without the WHERE)
1508          *        LIST_SET           - comma separated with field names, like a SET clause
1509          *        LIST_NAMES         - comma separated field names
1510          */
1511         function makeList( $a, $mode = LIST_COMMA ) {
1512                 if ( !is_array( $a ) ) {
1513                         throw new DBUnexpectedError( $this, 'Database::makeList called with incorrect parameters' );
1514                 }
1515
1516                 $first = true;
1517                 $list = '';
1518                 foreach ( $a as $field => $value ) {
1519                         if ( !$first ) {
1520                                 if ( $mode == LIST_AND ) {
1521                                         $list .= ' AND ';
1522                                 } elseif($mode == LIST_OR) {
1523                                         $list .= ' OR ';
1524                                 } else {
1525                                         $list .= ',';
1526                                 }
1527                         } else {
1528                                 $first = false;
1529                         }
1530                         if ( ($mode == LIST_AND || $mode == LIST_OR) && is_numeric( $field ) ) {
1531                                 $list .= "($value)";
1532                         } elseif ( ($mode == LIST_SET) && is_numeric( $field ) ) {
1533                                 $list .= "$value";
1534                         } elseif ( ($mode == LIST_AND || $mode == LIST_OR) && is_array ($value) ) {
1535                                 $list .= $field." IN (".$this->makeList($value).") ";
1536                         } else {
1537                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1538                                         $list .= "$field = ";
1539                                 }
1540                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1541                         }
1542                 }
1543                 return $list;
1544         }
1545
1546         /**
1547          * Change the current database
1548          */
1549         function selectDB( $db ) {
1550                 $this->mDBname = $db;
1551                 return mysql_select_db( $db, $this->mConn );
1552         }
1553
1554         /**
1555          * Format a table name ready for use in constructing an SQL query
1556          *
1557          * This does two important things: it quotes table names which as necessary,
1558          * and it adds a table prefix if there is one.
1559          *
1560          * All functions of this object which require a table name call this function
1561          * themselves. Pass the canonical name to such functions. This is only needed
1562          * when calling query() directly.
1563          *
1564          * @param string $name database table name
1565          */
1566         function tableName( $name ) {
1567                 global $wgSharedDB;
1568                 # Skip quoted literals
1569                 if ( $name{0} != '`' ) {
1570                         if ( $this->mTablePrefix !== '' &&  strpos( '.', $name ) === false ) {
1571                                 $name = "{$this->mTablePrefix}$name";
1572                         }
1573                         if ( isset( $wgSharedDB ) && "{$this->mTablePrefix}user" == $name ) {
1574                                 $name = "`$wgSharedDB`.`$name`";
1575                         } else {
1576                                 # Standard quoting
1577                                 $name = "`$name`";
1578                         }
1579                 }
1580                 return $name;
1581         }
1582
1583         /**
1584          * Fetch a number of table names into an array
1585          * This is handy when you need to construct SQL for joins
1586          *
1587          * Example:
1588          * extract($dbr->tableNames('user','watchlist'));
1589          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1590          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1591          */
1592         public function tableNames() {
1593                 $inArray = func_get_args();
1594                 $retVal = array();
1595                 foreach ( $inArray as $name ) {
1596                         $retVal[$name] = $this->tableName( $name );
1597                 }
1598                 return $retVal;
1599         }
1600
1601         /**
1602          * Fetch a number of table names into an zero-indexed numerical array
1603          * This is handy when you need to construct SQL for joins
1604          *
1605          * Example:
1606          * list( $user, $watchlist ) = $dbr->tableNames('user','watchlist');
1607          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1608          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1609          */
1610         public function tableNamesN() {
1611                 $inArray = func_get_args();
1612                 $retVal = array();
1613                 foreach ( $inArray as $name ) {
1614                         $retVal[] = $this->tableName( $name );
1615                 }
1616                 return $retVal;
1617         }
1618
1619         /**
1620          * @private
1621          */
1622         function tableNamesWithUseIndex( $tables, $use_index ) {
1623                 $ret = array();
1624
1625                 foreach ( $tables as $table )
1626                         if ( @$use_index[$table] !== null )
1627                                 $ret[] = $this->tableName( $table ) . ' ' . $this->useIndexClause( implode( ',', (array)$use_index[$table] ) );
1628                         else
1629                                 $ret[] = $this->tableName( $table );
1630
1631                 return implode( ',', $ret );
1632         }
1633
1634         /**
1635          * Wrapper for addslashes()
1636          * @param string $s String to be slashed.
1637          * @return string slashed string.
1638          */
1639         function strencode( $s ) {
1640                 return mysql_real_escape_string( $s, $this->mConn );
1641         }
1642
1643         /**
1644          * If it's a string, adds quotes and backslashes
1645          * Otherwise returns as-is
1646          */
1647         function addQuotes( $s ) {
1648                 if ( is_null( $s ) ) {
1649                         return 'NULL';
1650                 } else {
1651                         # This will also quote numeric values. This should be harmless,
1652                         # and protects against weird problems that occur when they really
1653                         # _are_ strings such as article titles and string->number->string
1654                         # conversion is not 1:1.
1655                         return "'" . $this->strencode( $s ) . "'";
1656                 }
1657         }
1658
1659         /**
1660          * Escape string for safe LIKE usage
1661          */
1662         function escapeLike( $s ) {
1663                 $s=$this->strencode( $s );
1664                 $s=str_replace(array('%','_'),array('\%','\_'),$s);
1665                 return $s;
1666         }
1667
1668         /**
1669          * Returns an appropriately quoted sequence value for inserting a new row.
1670          * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1671          * subclass will return an integer, and save the value for insertId()
1672          */
1673         function nextSequenceValue( $seqName ) {
1674                 return NULL;
1675         }
1676
1677         /**
1678          * USE INDEX clause
1679          * PostgreSQL doesn't have them and returns ""
1680          */
1681         function useIndexClause( $index ) {
1682                 return "FORCE INDEX ($index)";
1683         }
1684
1685         /**
1686          * REPLACE query wrapper
1687          * PostgreSQL simulates this with a DELETE followed by INSERT
1688          * $row is the row to insert, an associative array
1689          * $uniqueIndexes is an array of indexes. Each element may be either a
1690          * field name or an array of field names
1691          *
1692          * It may be more efficient to leave off unique indexes which are unlikely to collide.
1693          * However if you do this, you run the risk of encountering errors which wouldn't have
1694          * occurred in MySQL
1695          *
1696          * @todo migrate comment to phodocumentor format
1697          */
1698         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
1699                 $table = $this->tableName( $table );
1700
1701                 # Single row case
1702                 if ( !is_array( reset( $rows ) ) ) {
1703                         $rows = array( $rows );
1704                 }
1705
1706                 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) .') VALUES ';
1707                 $first = true;
1708                 foreach ( $rows as $row ) {
1709                         if ( $first ) {
1710                                 $first = false;
1711                         } else {
1712                                 $sql .= ',';
1713                         }
1714                         $sql .= '(' . $this->makeList( $row ) . ')';
1715                 }
1716                 return $this->query( $sql, $fname );
1717         }
1718
1719         /**
1720          * DELETE where the condition is a join
1721          * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1722          *
1723          * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1724          * join condition matches, set $conds='*'
1725          *
1726          * DO NOT put the join condition in $conds
1727          *
1728          * @param string $delTable The table to delete from.
1729          * @param string $joinTable The other table.
1730          * @param string $delVar The variable to join on, in the first table.
1731          * @param string $joinVar The variable to join on, in the second table.
1732          * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
1733          */
1734         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
1735                 if ( !$conds ) {
1736                         throw new DBUnexpectedError( $this, 'Database::deleteJoin() called with empty $conds' );
1737                 }
1738
1739                 $delTable = $this->tableName( $delTable );
1740                 $joinTable = $this->tableName( $joinTable );
1741                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1742                 if ( $conds != '*' ) {
1743                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1744                 }
1745
1746                 return $this->query( $sql, $fname );
1747         }
1748
1749         /**
1750          * Returns the size of a text field, or -1 for "unlimited"
1751          */
1752         function textFieldSize( $table, $field ) {
1753                 $table = $this->tableName( $table );
1754                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1755                 $res = $this->query( $sql, 'Database::textFieldSize' );
1756                 $row = $this->fetchObject( $res );
1757                 $this->freeResult( $res );
1758
1759                 $m = array();
1760                 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
1761                         $size = $m[1];
1762                 } else {
1763                         $size = -1;
1764                 }
1765                 return $size;
1766         }
1767
1768         /**
1769          * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1770          */
1771         function lowPriorityOption() {
1772                 return 'LOW_PRIORITY';
1773         }
1774
1775         /**
1776          * DELETE query wrapper
1777          *
1778          * Use $conds == "*" to delete all rows
1779          */
1780         function delete( $table, $conds, $fname = 'Database::delete' ) {
1781                 if ( !$conds ) {
1782                         throw new DBUnexpectedError( $this, 'Database::delete() called with no conditions' );
1783                 }
1784                 $table = $this->tableName( $table );
1785                 $sql = "DELETE FROM $table";
1786                 if ( $conds != '*' ) {
1787                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1788                 }
1789                 return $this->query( $sql, $fname );
1790         }
1791
1792         /**
1793          * INSERT SELECT wrapper
1794          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1795          * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1796          * $conds may be "*" to copy the whole table
1797          * srcTable may be an array of tables.
1798          */
1799         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect',
1800                 $insertOptions = array(), $selectOptions = array() )
1801         {
1802                 $destTable = $this->tableName( $destTable );
1803                 if ( is_array( $insertOptions ) ) {
1804                         $insertOptions = implode( ' ', $insertOptions );
1805                 }
1806                 if( !is_array( $selectOptions ) ) {
1807                         $selectOptions = array( $selectOptions );
1808                 }
1809                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
1810                 if( is_array( $srcTable ) ) {
1811                         $srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
1812                 } else {
1813                         $srcTable = $this->tableName( $srcTable );
1814                 }
1815                 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1816                         " SELECT $startOpts " . implode( ',', $varMap ) .
1817                         " FROM $srcTable $useIndex ";
1818                 if ( $conds != '*' ) {
1819                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1820                 }
1821                 $sql .= " $tailOpts";
1822                 return $this->query( $sql, $fname );
1823         }
1824
1825         /**
1826          * Construct a LIMIT query with optional offset
1827          * This is used for query pages
1828          * $sql string SQL query we will append the limit too
1829          * $limit integer the SQL limit
1830          * $offset integer the SQL offset (default false)
1831          */
1832         function limitResult($sql, $limit, $offset=false) {
1833                 if( !is_numeric($limit) ) {
1834                         throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
1835                 }
1836                 return " $sql LIMIT "
1837                                 . ( (is_numeric($offset) && $offset != 0) ? "{$offset}," : "" )
1838                                 . "{$limit} ";
1839         }
1840         function limitResultForUpdate($sql, $num) {
1841                 return $this->limitResult($sql, $num, 0);
1842         }
1843
1844         /**
1845          * Returns an SQL expression for a simple conditional.
1846          * Uses IF on MySQL.
1847          *
1848          * @param string $cond SQL expression which will result in a boolean value
1849          * @param string $trueVal SQL expression to return if true
1850          * @param string $falseVal SQL expression to return if false
1851          * @return string SQL fragment
1852          */
1853         function conditional( $cond, $trueVal, $falseVal ) {
1854                 return " IF($cond, $trueVal, $falseVal) ";
1855         }
1856
1857         /**
1858          * Determines if the last failure was due to a deadlock
1859          */
1860         function wasDeadlock() {
1861                 return $this->lastErrno() == 1213;
1862         }
1863
1864         /**
1865          * Perform a deadlock-prone transaction.
1866          *
1867          * This function invokes a callback function to perform a set of write
1868          * queries. If a deadlock occurs during the processing, the transaction
1869          * will be rolled back and the callback function will be called again.
1870          *
1871          * Usage:
1872          *   $dbw->deadlockLoop( callback, ... );
1873          *
1874          * Extra arguments are passed through to the specified callback function.
1875          *
1876          * Returns whatever the callback function returned on its successful,
1877          * iteration, or false on error, for example if the retry limit was
1878          * reached.
1879          */
1880         function deadlockLoop() {
1881                 $myFname = 'Database::deadlockLoop';
1882
1883                 $this->begin();
1884                 $args = func_get_args();
1885                 $function = array_shift( $args );
1886                 $oldIgnore = $this->ignoreErrors( true );
1887                 $tries = DEADLOCK_TRIES;
1888                 if ( is_array( $function ) ) {
1889                         $fname = $function[0];
1890                 } else {
1891                         $fname = $function;
1892                 }
1893                 do {
1894                         $retVal = call_user_func_array( $function, $args );
1895                         $error = $this->lastError();
1896                         $errno = $this->lastErrno();
1897                         $sql = $this->lastQuery();
1898
1899                         if ( $errno ) {
1900                                 if ( $this->wasDeadlock() ) {
1901                                         # Retry
1902                                         usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1903                                 } else {
1904                                         $this->reportQueryError( $error, $errno, $sql, $fname );
1905                                 }
1906                         }
1907                 } while( $this->wasDeadlock() && --$tries > 0 );
1908                 $this->ignoreErrors( $oldIgnore );
1909                 if ( $tries <= 0 ) {
1910                         $this->query( 'ROLLBACK', $myFname );
1911                         $this->reportQueryError( $error, $errno, $sql, $fname );
1912                         return false;
1913                 } else {
1914                         $this->query( 'COMMIT', $myFname );
1915                         return $retVal;
1916                 }
1917         }
1918
1919         /**
1920          * Do a SELECT MASTER_POS_WAIT()
1921          *
1922          * @param string $file the binlog file
1923          * @param string $pos the binlog position
1924          * @param integer $timeout the maximum number of seconds to wait for synchronisation
1925          */
1926         function masterPosWait( $file, $pos, $timeout ) {
1927                 $fname = 'Database::masterPosWait';
1928                 wfProfileIn( $fname );
1929
1930
1931                 # Commit any open transactions
1932                 $this->immediateCommit();
1933
1934                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
1935                 $encFile = $this->strencode( $file );
1936                 $sql = "SELECT MASTER_POS_WAIT('$encFile', $pos, $timeout)";
1937                 $res = $this->doQuery( $sql );
1938                 if ( $res && $row = $this->fetchRow( $res ) ) {
1939                         $this->freeResult( $res );
1940                         wfProfileOut( $fname );
1941                         return $row[0];
1942                 } else {
1943                         wfProfileOut( $fname );
1944                         return false;
1945                 }
1946         }
1947
1948         /**
1949          * Get the position of the master from SHOW SLAVE STATUS
1950          */
1951         function getSlavePos() {
1952                 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1953                 $row = $this->fetchObject( $res );
1954                 if ( $row ) {
1955                         return array( $row->Master_Log_File, $row->Read_Master_Log_Pos );
1956                 } else {
1957                         return array( false, false );
1958                 }
1959         }
1960
1961         /**
1962          * Get the position of the master from SHOW MASTER STATUS
1963          */
1964         function getMasterPos() {
1965                 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1966                 $row = $this->fetchObject( $res );
1967                 if ( $row ) {
1968                         return array( $row->File, $row->Position );
1969                 } else {
1970                         return array( false, false );
1971                 }
1972         }
1973
1974         /**
1975          * Begin a transaction, committing any previously open transaction
1976          */
1977         function begin( $fname = 'Database::begin' ) {
1978                 $this->query( 'BEGIN', $fname );
1979                 $this->mTrxLevel = 1;
1980         }
1981
1982         /**
1983          * End a transaction
1984          */
1985         function commit( $fname = 'Database::commit' ) {
1986                 $this->query( 'COMMIT', $fname );
1987                 $this->mTrxLevel = 0;
1988         }
1989
1990         /**
1991          * Rollback a transaction
1992          */
1993         function rollback( $fname = 'Database::rollback' ) {
1994                 $this->query( 'ROLLBACK', $fname );
1995                 $this->mTrxLevel = 0;
1996         }
1997
1998         /**
1999          * Begin a transaction, committing any previously open transaction
2000          * @deprecated use begin()
2001          */
2002         function immediateBegin( $fname = 'Database::immediateBegin' ) {
2003                 $this->begin();
2004         }
2005
2006         /**
2007          * Commit transaction, if one is open
2008          * @deprecated use commit()
2009          */
2010         function immediateCommit( $fname = 'Database::immediateCommit' ) {
2011                 $this->commit();
2012         }
2013
2014         /**
2015          * Return MW-style timestamp used for MySQL schema
2016          */
2017         function timestamp( $ts=0 ) {
2018                 return wfTimestamp(TS_MW,$ts);
2019         }
2020
2021         /**
2022          * Local database timestamp format or null
2023          */
2024         function timestampOrNull( $ts = null ) {
2025                 if( is_null( $ts ) ) {
2026                         return null;
2027                 } else {
2028                         return $this->timestamp( $ts );
2029                 }
2030         }
2031
2032         /**
2033          * @todo document
2034          */
2035         function resultObject( $result ) {
2036                 if( empty( $result ) ) {
2037                         return false;
2038                 } elseif ( $result instanceof ResultWrapper ) {
2039                         return $result;
2040                 } elseif ( $result === true ) {
2041                         // Successful write query
2042                         return $result;
2043                 } else {
2044                         return new ResultWrapper( $this, $result );
2045                 }
2046         }
2047
2048         /**
2049          * Return aggregated value alias
2050          */
2051         function aggregateValue ($valuedata,$valuename='value') {
2052                 return $valuename;
2053         }
2054
2055         /**
2056          * @return string wikitext of a link to the server software's web site
2057          */
2058         function getSoftwareLink() {
2059                 return "[http://www.mysql.com/ MySQL]";
2060         }
2061
2062         /**
2063          * @return string Version information from the database
2064          */
2065         function getServerVersion() {
2066                 return mysql_get_server_info( $this->mConn );
2067         }
2068
2069         /**
2070          * Ping the server and try to reconnect if it there is no connection
2071          */
2072         function ping() {
2073                 if( function_exists( 'mysql_ping' ) ) {
2074                         return mysql_ping( $this->mConn );
2075                 } else {
2076                         wfDebug( "Tried to call mysql_ping but this is ancient PHP version. Faking it!\n" );
2077                         return true;
2078                 }
2079         }
2080
2081         /**
2082          * Get slave lag.
2083          * At the moment, this will only work if the DB user has the PROCESS privilege
2084          */
2085         function getLag() {
2086                 $res = $this->query( 'SHOW PROCESSLIST' );
2087                 # Find slave SQL thread. Assumed to be the second one running, which is a bit
2088                 # dubious, but unfortunately there's no easy rigorous way
2089                 while ( $row = $this->fetchObject( $res ) ) {
2090                         /* This should work for most situations - when default db
2091                          * for thread is not specified, it had no events executed,
2092                          * and therefore it doesn't know yet how lagged it is.
2093                          *
2094                          * Relay log I/O thread does not select databases.
2095                          */
2096                         if ( $row->User == 'system user' &&
2097                                 $row->State != 'Waiting for master to send event' &&
2098                                 $row->State != 'Connecting to master' &&
2099                                 $row->State != 'Queueing master event to the relay log' &&
2100                                 $row->State != 'Waiting for master update' &&
2101                                 $row->State != 'Requesting binlog dump'
2102                                 ) {
2103                                 # This is it, return the time (except -ve)
2104                                 if ( $row->Time > 0x7fffffff ) {
2105                                         return false;
2106                                 } else {
2107                                         return $row->Time;
2108                                 }
2109                         }
2110                 }
2111                 return false;
2112         }
2113
2114         /**
2115          * Get status information from SHOW STATUS in an associative array
2116          */
2117         function getStatus($which="%") {
2118                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
2119                 $status = array();
2120                 while ( $row = $this->fetchObject( $res ) ) {
2121                         $status[$row->Variable_name] = $row->Value;
2122                 }
2123                 return $status;
2124         }
2125
2126         /**
2127          * Return the maximum number of items allowed in a list, or 0 for unlimited.
2128          */
2129         function maxListLen() {
2130                 return 0;
2131         }
2132
2133         function encodeBlob($b) {
2134                 return $b;
2135         }
2136
2137         function decodeBlob($b) {
2138                 return $b;
2139         }
2140
2141         /**
2142          * Override database's default connection timeout.
2143          * May be useful for very long batch queries such as
2144          * full-wiki dumps, where a single query reads out
2145          * over hours or days.
2146          * @param int $timeout in seconds
2147          */
2148         public function setTimeout( $timeout ) {
2149                 $this->query( "SET net_read_timeout=$timeout" );
2150                 $this->query( "SET net_write_timeout=$timeout" );
2151         }
2152
2153         /**
2154          * Read and execute SQL commands from a file.
2155          * Returns true on success, error string on failure
2156          * @param string $filename File name to open
2157          * @param callback $lineCallback Optional function called before reading each line
2158          * @param callback $resultCallback Optional function called for each MySQL result
2159          */
2160         function sourceFile( $filename, $lineCallback = false, $resultCallback = false ) {
2161                 $fp = fopen( $filename, 'r' );
2162                 if ( false === $fp ) {
2163                         return "Could not open \"{$filename}\".\n";
2164                 }
2165                 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback );
2166                 fclose( $fp );
2167                 return $error;
2168         }
2169
2170         /**
2171          * Read and execute commands from an open file handle
2172          * Returns true on success, error string on failure
2173          * @param string $fp File handle
2174          * @param callback $lineCallback Optional function called before reading each line
2175          * @param callback $resultCallback Optional function called for each MySQL result
2176          */
2177         function sourceStream( $fp, $lineCallback = false, $resultCallback = false ) {
2178                 $cmd = "";
2179                 $done = false;
2180                 $dollarquote = false;
2181
2182                 while ( ! feof( $fp ) ) {
2183                         if ( $lineCallback ) {
2184                                 call_user_func( $lineCallback );
2185                         }
2186                         $line = trim( fgets( $fp, 1024 ) );
2187                         $sl = strlen( $line ) - 1;
2188
2189                         if ( $sl < 0 ) { continue; }
2190                         if ( '-' == $line{0} && '-' == $line{1} ) { continue; }
2191
2192                         ## Allow dollar quoting for function declarations
2193                         if (substr($line,0,4) == '$mw$') {
2194                                 if ($dollarquote) {
2195                                         $dollarquote = false;
2196                                         $done = true;
2197                                 }
2198                                 else {
2199                                         $dollarquote = true;
2200                                 }
2201                         }
2202                         else if (!$dollarquote) {
2203                                 if ( ';' == $line{$sl} && ($sl < 2 || ';' != $line{$sl - 1})) {
2204                                         $done = true;
2205                                         $line = substr( $line, 0, $sl );
2206                                 }
2207                         }
2208
2209                         if ( '' != $cmd ) { $cmd .= ' '; }
2210                         $cmd .= "$line\n";
2211
2212                         if ( $done ) {
2213                                 $cmd = str_replace(';;', ";", $cmd);
2214                                 $cmd = $this->replaceVars( $cmd );
2215                                 $res = $this->query( $cmd, __METHOD__, true );
2216                                 if ( $resultCallback ) {
2217                                         call_user_func( $resultCallback, $res );
2218                                 }
2219
2220                                 if ( false === $res ) {
2221                                         $err = $this->lastError();
2222                                         return "Query \"{$cmd}\" failed with error code \"$err\".\n";
2223                                 }
2224
2225                                 $cmd = '';
2226                                 $done = false;
2227                         }
2228                 }
2229                 return true;
2230         }
2231
2232
2233         /**
2234          * Replace variables in sourced SQL
2235          */
2236         protected function replaceVars( $ins ) {
2237                 $varnames = array(
2238                         'wgDBserver', 'wgDBname', 'wgDBintlname', 'wgDBuser',
2239                         'wgDBpassword', 'wgDBsqluser', 'wgDBsqlpassword',
2240                         'wgDBadminuser', 'wgDBadminpassword', 'wgDBTableOptions',
2241                 );
2242
2243                 // Ordinary variables
2244                 foreach ( $varnames as $var ) {
2245                         if( isset( $GLOBALS[$var] ) ) {
2246                                 $val = addslashes( $GLOBALS[$var] ); // FIXME: safety check?
2247                                 $ins = str_replace( '{$' . $var . '}', $val, $ins );
2248                                 $ins = str_replace( '/*$' . $var . '*/`', '`' . $val, $ins );
2249                                 $ins = str_replace( '/*$' . $var . '*/', $val, $ins );
2250                         }
2251                 }
2252
2253                 // Table prefixes
2254                 $ins = preg_replace_callback( '/\/\*(?:\$wgDBprefix|_)\*\/([a-z_]*)/',
2255                         array( &$this, 'tableNameCallback' ), $ins );
2256                 return $ins;
2257         }
2258
2259         /**
2260          * Table name callback
2261          * @private
2262          */
2263         protected function tableNameCallback( $matches ) {
2264                 return $this->tableName( $matches[1] );
2265         }
2266
2267 }
2268
2269 /**
2270  * Database abstraction object for mySQL
2271  * Inherit all methods and properties of Database::Database()
2272  *
2273  * @addtogroup Database
2274  * @see Database
2275  */
2276 class DatabaseMysql extends Database {
2277         # Inherit all
2278 }
2279
2280
2281 /**
2282  * Result wrapper for grabbing data queried by someone else
2283  * @addtogroup Database
2284  */
2285 class ResultWrapper {
2286         var $db, $result;
2287
2288         /**
2289          * Create a new result object from a result resource and a Database object
2290          */
2291         function ResultWrapper( $database, $result ) {
2292                 $this->db = $database;
2293                 if ( $result instanceof ResultWrapper ) {
2294                         $this->result = $result->result;
2295                 } else {
2296                         $this->result = $result;
2297                 }
2298         }
2299
2300         /**
2301          * Get the number of rows in a result object
2302          */
2303         function numRows() {
2304                 return $this->db->numRows( $this->result );
2305         }
2306
2307         /**
2308          * Fetch the next row from the given result object, in object form.
2309          * Fields can be retrieved with $row->fieldname, with fields acting like
2310          * member variables.
2311          *
2312          * @param $res SQL result object as returned from Database::query(), etc.
2313          * @return MySQL row object
2314          * @throws DBUnexpectedError Thrown if the database returns an error
2315          */
2316         function fetchObject() {
2317                 return $this->db->fetchObject( $this->result );
2318         }
2319
2320         /**
2321          * Fetch the next row from the given result object, in associative array
2322          * form.  Fields are retrieved with $row['fieldname'].
2323          *
2324          * @param $res SQL result object as returned from Database::query(), etc.
2325          * @return MySQL row object
2326          * @throws DBUnexpectedError Thrown if the database returns an error
2327          */
2328         function fetchRow() {
2329                 return $this->db->fetchRow( $this->result );
2330         }
2331
2332         /**
2333          * Free a result object
2334          */
2335         function free() {
2336                 $this->db->freeResult( $this->result );
2337                 unset( $this->result );
2338                 unset( $this->db );
2339         }
2340
2341         /**
2342          * Change the position of the cursor in a result object
2343          * See mysql_data_seek()
2344          */
2345         function seek( $row ) {
2346                 $this->db->dataSeek( $this->result, $row );
2347         }
2348
2349         /**
2350          * Reset the cursor to the start of the result set
2351          */
2352         function rewind() {
2353                 if ($this->numRows()) {
2354                         $this->db->dataSeek($this->result, 0);
2355                 }
2356         }
2357
2358 }
2359
2360