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                                 // @todo, 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 does an implicit order by when the column has an index
 445          * For example: SELECT page_title FROM page LIMIT 1
 446          */
 447         function implicitOrderby() {
 448                 return true;
 449         }
 450
 451         /**
 452          * Returns true if this database can do a native search on IP columns
 453          * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
 454          */
 455         function searchableIPs() {
 456                 return false;
 457         }
 458
 459         /**
 460          * Returns true if this database can use functional indexes
 461          */
 462         function functionalIndexes() {
 463                 return false;
 464         }
 465
 466         /**#@+
 467          * Get function
 468          */
 469         function lastQuery() { return $this->mLastQuery; }
 470         function isOpen() { return $this->mOpened; }
 471         /**#@-*/
 472
 473         function setFlag( $flag ) {
 474                 $this->mFlags |= $flag;
 475         }
 476
 477         function clearFlag( $flag ) {
 478                 $this->mFlags &= ~$flag;
 479         }
 480
 481         function getFlag( $flag ) {
 482                 return !!($this->mFlags & $flag);
 483         }
 484
 485         /**
 486          * General read-only accessor
 487          */
 488         function getProperty( $name ) {
 489                 return $this->$name;
 490         }
 491
 492 #------------------------------------------------------------------------------
 493 # Other functions
 494 #------------------------------------------------------------------------------
 495
 496         /**@{{
 497          * Constructor.
 498          * @param string $server database server host
 499          * @param string $user database user name
 500          * @param string $password database user password
 501          * @param string $dbname database name
 502          * @param failFunction
 503          * @param $flags
 504          * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
 505          */
 506         function __construct( $server = false, $user = false, $password = false, $dbName = false,
 507                 $failFunction = false, $flags = 0, $tablePrefix = 'get from global' ) {
 508
 509                 global $wgOut, $wgDBprefix, $wgCommandLineMode;
 510                 # Can't get a reference if it hasn't been set yet
 511                 if ( !isset( $wgOut ) ) {
 512                         $wgOut = NULL;
 513                 }
 514                 $this->mOut =& $wgOut;
 515
 516                 $this->mFailFunction = $failFunction;
 517                 $this->mFlags = $flags;
 518
 519                 if ( $this->mFlags & DBO_DEFAULT ) {
 520                         if ( $wgCommandLineMode ) {
 521                                 $this->mFlags &= ~DBO_TRX;
 522                         } else {
 523                                 $this->mFlags |= DBO_TRX;
 524                         }
 525                 }
 526
 527                 /*
 528                 // Faster read-only access
 529                 if ( wfReadOnly() ) {
 530                         $this->mFlags |= DBO_PERSISTENT;
 531                         $this->mFlags &= ~DBO_TRX;
 532                 }*/
 533
 534                 /** Get the default table prefix*/
 535                 if ( $tablePrefix == 'get from global' ) {
 536                         $this->mTablePrefix = $wgDBprefix;
 537                 } else {
 538                         $this->mTablePrefix = $tablePrefix;
 539                 }
 540
 541                 if ( $server ) {
 542                         $this->open( $server, $user, $password, $dbName );
 543                 }
 544         }
 545
 546         /**
 547          * @static
 548          * @param failFunction
 549          * @param $flags
 550          */
 551         static function newFromParams( $server, $user, $password, $dbName, $failFunction = false, $flags = 0 )
 552         {
 553                 return new Database( $server, $user, $password, $dbName, $failFunction, $flags );
 554         }
 555
 556         /**
 557          * Usually aborts on failure
 558          * If the failFunction is set to a non-zero integer, returns success
 559          */
 560         function open( $server, $user, $password, $dbName ) {
 561                 global $wguname;
 562                 wfProfileIn( __METHOD__ );
 563
 564                 # Test for missing mysql.so
 565                 # First try to load it
 566                 if (!@extension_loaded('mysql')) {
 567                         @dl('mysql.so');
 568                 }
 569
 570                 # Fail now
 571                 # Otherwise we get a suppressed fatal error, which is very hard to track down
 572                 if ( !function_exists( 'mysql_connect' ) ) {
 573                         throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
 574                 }
 575
 576                 $this->close();
 577                 $this->mServer = $server;
 578                 $this->mUser = $user;
 579                 $this->mPassword = $password;
 580                 $this->mDBname = $dbName;
 581
 582                 $success = false;
 583
 584                 wfProfileIn("dbconnect-$server");
 585
 586                 # LIVE PATCH by Tim, ask Domas for why: retry loop
 587                 $this->mConn = false;
 588                 $max = 3;
 589                 for ( $i = 0; $i < $max && !$this->mConn; $i++ ) {
 590                         if ( $i > 1 ) {
 591                                 usleep( 1000 );
 592                         }
 593                         if ( $this->mFlags & DBO_PERSISTENT ) {
 594                                 @/**/$this->mConn = mysql_pconnect( $server, $user, $password );
 595                         } else {
 596                                 # Create a new connection...
 597                                 @/**/$this->mConn = mysql_connect( $server, $user, $password, true );
 598                         }
 599                         if ($this->mConn === false) {
 600                                 #$iplus = $i + 1;
 601                                 #wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
 602                         }
 603                 }
 604
 605                 wfProfileOut("dbconnect-$server");
 606
 607                 if ( $dbName != '' ) {
 608                         if ( $this->mConn !== false ) {
 609                                 $success = @/**/mysql_select_db( $dbName, $this->mConn );
 610                                 if ( !$success ) {
 611                                         $error = "Error selecting database $dbName on server {$this->mServer} " .
 612                                                 "from client host {$wguname['nodename']}\n";
 613                                         wfLogDBError(" Error selecting database $dbName on server {$this->mServer} \n");
 614                                         wfDebug( $error );
 615                                 }
 616                         } else {
 617                                 wfDebug( "DB connection error\n" );
 618                                 wfDebug( "Server: $server, User: $user, Password: " .
 619                                         substr( $password, 0, 3 ) . "..., error: " . mysql_error() . "\n" );
 620                                 $success = false;
 621                         }
 622                 } else {
 623                         # Delay USE query
 624                         $success = (bool)$this->mConn;
 625                 }
 626
 627                 if ( $success ) {
 628                         $version = $this->getServerVersion();
 629                         if ( version_compare( $version, '4.1' ) >= 0 ) {
 630                                 // Tell the server we're communicating with it in UTF-8.
 631                                 // This may engage various charset conversions.
 632                                 global $wgDBmysql5;
 633                                 if( $wgDBmysql5 ) {
 634                                         $this->query( 'SET NAMES utf8', __METHOD__ );
 635                                 }
 636                                 // Turn off strict mode
 637                                 $this->query( "SET sql_mode = ''", __METHOD__ );
 638                         }
 639
 640                         // Turn off strict mode if it is on
 641                 } else {
 642                         $this->reportConnectionError();
 643                 }
 644
 645                 $this->mOpened = $success;
 646                 wfProfileOut( __METHOD__ );
 647                 return $success;
 648         }
 649         /**@}}*/
 650
 651         /**
 652          * Closes a database connection.
 653          * if it is open : commits any open transactions
 654          *
 655          * @return bool operation success. true if already closed.
 656          */
 657         function close()
 658         {
 659                 $this->mOpened = false;
 660                 if ( $this->mConn ) {
 661                         if ( $this->trxLevel() ) {
 662                                 $this->immediateCommit();
 663                         }
 664                         return mysql_close( $this->mConn );
 665                 } else {
 666                         return true;
 667                 }
 668         }
 669
 670         /**
 671          * @param string $error fallback error message, used if none is given by MySQL
 672          */
 673         function reportConnectionError( $error = 'Unknown error' ) {
 674                 $myError = $this->lastError();
 675                 if ( $myError ) {
 676                         $error = $myError;
 677                 }
 678
 679                 if ( $this->mFailFunction ) {
 680                         # Legacy error handling method
 681                         if ( !is_int( $this->mFailFunction ) ) {
 682                                 $ff = $this->mFailFunction;
 683                                 $ff( $this, $error );
 684                         }
 685                 } else {
 686                         # New method
 687                         wfLogDBError( "Connection error: $error\n" );
 688                         throw new DBConnectionError( $this, $error );
 689                 }
 690         }
 691
 692         /**
 693          * Usually aborts on failure.  If errors are explicitly ignored, returns success.
 694          *
 695          * @param  $sql        String: SQL query
 696          * @param  $fname      String: Name of the calling function, for profiling/SHOW PROCESSLIST
 697          *     comment (you can use __METHOD__ or add some extra info)
 698          * @param  $tempIgnore Bool:   Whether to avoid throwing an exception on errors...
 699          *     maybe best to catch the exception instead?
 700          * @return true for a successful write query, ResultWrapper object for a successful read query,
 701          *     or false on failure if $tempIgnore set
 702          * @throws DBQueryError Thrown when the database returns an error of any kind
 703          */
 704         public function query( $sql, $fname = '', $tempIgnore = false ) {
 705                 global $wgProfiling;
 706
 707                 if ( $wgProfiling ) {
 708                         # generalizeSQL will probably cut down the query to reasonable
 709                         # logging size most of the time. The substr is really just a sanity check.
 710
 711                         # Who's been wasting my precious column space? -- TS
 712                         #$profName = 'query: ' . $fname . ' ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 713
 714                         if ( is_null( $this->getLBInfo( 'master' ) ) ) {
 715                                 $queryProf = 'query: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 716                                 $totalProf = 'Database::query';
 717                         } else {
 718                                 $queryProf = 'query-m: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 719                                 $totalProf = 'Database::query-master';
 720                         }
 721                         wfProfileIn( $totalProf );
 722                         wfProfileIn( $queryProf );
 723                 }
 724
 725                 $this->mLastQuery = $sql;
 726
 727                 # Add a comment for easy SHOW PROCESSLIST interpretation
 728                 #if ( $fname ) {
 729                         global $wgUser;
 730                         if ( is_object( $wgUser ) && !($wgUser instanceof StubObject) ) {
 731                                 $userName = $wgUser->getName();
 732                                 if ( strlen( $userName ) > 15 ) {
 733                                         $userName = substr( $userName, 0, 15 ) . '...';
 734                                 }
 735                                 $userName = str_replace( '/', '', $userName );
 736                         } else {
 737                                 $userName = '';
 738                         }
 739                         $commentedSql = preg_replace('/\s/', " /* $fname $userName */ ", $sql, 1);
 740                 #} else {
 741                 #       $commentedSql = $sql;
 742                 #}
 743
 744                 # If DBO_TRX is set, start a transaction
 745                 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
 746                         $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK'
 747                 ) {
 748                         $this->begin();
 749                 }
 750
 751                 if ( $this->debug() ) {
 752                         $sqlx = substr( $commentedSql, 0, 500 );
 753                         $sqlx = strtr( $sqlx, "\t\n", '  ' );
 754                         wfDebug( "SQL: $sqlx\n" );
 755                 }
 756
 757                 # Do the query and handle errors
 758                 $ret = $this->doQuery( $commentedSql );
 759
 760                 # Try reconnecting if the connection was lost
 761                 if ( false === $ret && ( $this->lastErrno() == 2013 || $this->lastErrno() == 2006 ) ) {
 762                         # Transaction is gone, like it or not
 763                         $this->mTrxLevel = 0;
 764                         wfDebug( "Connection lost, reconnecting...\n" );
 765                         if ( $this->ping() ) {
 766                                 wfDebug( "Reconnected\n" );
 767                                 $sqlx = substr( $commentedSql, 0, 500 );
 768                                 $sqlx = strtr( $sqlx, "\t\n", '  ' );
 769                                 global $wgRequestTime;
 770                                 $elapsed = round( microtime(true) - $wgRequestTime, 3 );
 771                                 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
 772                                 $ret = $this->doQuery( $commentedSql );
 773                         } else {
 774                                 wfDebug( "Failed\n" );
 775                         }
 776                 }
 777
 778                 if ( false === $ret ) {
 779                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
 780                 }
 781
 782                 if ( $wgProfiling ) {
 783                         wfProfileOut( $queryProf );
 784                         wfProfileOut( $totalProf );
 785                 }
 786                 return $this->resultObject( $ret );
 787         }
 788
 789         /**
 790          * The DBMS-dependent part of query()
 791          * @param  $sql String: SQL query.
 792          * @return Result object to feed to fetchObject, fetchRow, ...; or false on failure
 793          * @access private
 794          */
 795         /*private*/ function doQuery( $sql ) {
 796                 if( $this->bufferResults() ) {
 797                         $ret = mysql_query( $sql, $this->mConn );
 798                 } else {
 799                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 800                 }
 801                 return $ret;
 802         }
 803
 804         /**
 805          * @param $error
 806          * @param $errno
 807          * @param $sql
 808          * @param string $fname
 809          * @param bool $tempIgnore
 810          */
 811         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 812                 global $wgCommandLineMode;
 813                 # Ignore errors during error handling to avoid infinite recursion
 814                 $ignore = $this->ignoreErrors( true );
 815                 ++$this->mErrorCount;
 816
 817                 if( $ignore || $tempIgnore ) {
 818                         wfDebug("SQL ERROR (ignored): $error\n");
 819                         $this->ignoreErrors( $ignore );
 820                 } else {
 821                         $sql1line = str_replace( "\n", "\\n", $sql );
 822                         wfLogDBError("$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n");
 823                         wfDebug("SQL ERROR: " . $error . "\n");
 824                         throw new DBQueryError( $this, $error, $errno, $sql, $fname );
 825                 }
 826         }
 827
 828
 829         /**
 830          * Intended to be compatible with the PEAR::DB wrapper functions.
 831          * http://pear.php.net/manual/en/package.database.db.intro-execute.php
 832          *
 833          * ? = scalar value, quoted as necessary
 834          * ! = raw SQL bit (a function for instance)
 835          * & = filename; reads the file and inserts as a blob
 836          *     (we don't use this though...)
 837          */
 838         function prepare( $sql, $func = 'Database::prepare' ) {
 839                 /* MySQL doesn't support prepared statements (yet), so just
 840                    pack up the query for reference. We'll manually replace
 841                    the bits later. */
 842                 return array( 'query' => $sql, 'func' => $func );
 843         }
 844
 845         function freePrepared( $prepared ) {
 846                 /* No-op for MySQL */
 847         }
 848
 849         /**
 850          * Execute a prepared query with the various arguments
 851          * @param string $prepared the prepared sql
 852          * @param mixed $args Either an array here, or put scalars as varargs
 853          */
 854         function execute( $prepared, $args = null ) {
 855                 if( !is_array( $args ) ) {
 856                         # Pull the var args
 857                         $args = func_get_args();
 858                         array_shift( $args );
 859                 }
 860                 $sql = $this->fillPrepared( $prepared['query'], $args );
 861                 return $this->query( $sql, $prepared['func'] );
 862         }
 863
 864         /**
 865          * Prepare & execute an SQL statement, quoting and inserting arguments
 866          * in the appropriate places.
 867          * @param string $query
 868          * @param string $args ...
 869          */
 870         function safeQuery( $query, $args = null ) {
 871                 $prepared = $this->prepare( $query, 'Database::safeQuery' );
 872                 if( !is_array( $args ) ) {
 873                         # Pull the var args
 874                         $args = func_get_args();
 875                         array_shift( $args );
 876                 }
 877                 $retval = $this->execute( $prepared, $args );
 878                 $this->freePrepared( $prepared );
 879                 return $retval;
 880         }
 881
 882         /**
 883          * For faking prepared SQL statements on DBs that don't support
 884          * it directly.
 885          * @param string $preparedSql - a 'preparable' SQL statement
 886          * @param array $args - array of arguments to fill it with
 887          * @return string executable SQL
 888          */
 889         function fillPrepared( $preparedQuery, $args ) {
 890                 reset( $args );
 891                 $this->preparedArgs =& $args;
 892                 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
 893                         array( &$this, 'fillPreparedArg' ), $preparedQuery );
 894         }
 895
 896         /**
 897          * preg_callback func for fillPrepared()
 898          * The arguments should be in $this->preparedArgs and must not be touched
 899          * while we're doing this.
 900          *
 901          * @param array $matches
 902          * @return string
 903          * @private
 904          */
 905         function fillPreparedArg( $matches ) {
 906                 switch( $matches[1] ) {
 907                         case '\\?': return '?';
 908                         case '\\!': return '!';
 909                         case '\\&': return '&';
 910                 }
 911                 list( /* $n */ , $arg ) = each( $this->preparedArgs );
 912                 switch( $matches[1] ) {
 913                         case '?': return $this->addQuotes( $arg );
 914                         case '!': return $arg;
 915                         case '&':
 916                                 # return $this->addQuotes( file_get_contents( $arg ) );
 917                                 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
 918                         default:
 919                                 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
 920                 }
 921         }
 922
 923         /**#@+
 924          * @param mixed $res A SQL result
 925          */
 926         /**
 927          * Free a result object
 928          */
 929         function freeResult( $res ) {
 930                 if ( $res instanceof ResultWrapper ) {
 931                         $res = $res->result;
 932                 }
 933                 if ( !@/**/mysql_free_result( $res ) ) {
 934                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 935                 }
 936         }
 937
 938         /**
 939          * Fetch the next row from the given result object, in object form.
 940          * Fields can be retrieved with $row->fieldname, with fields acting like
 941          * member variables.
 942          *
 943          * @param $res SQL result object as returned from Database::query(), etc.
 944          * @return MySQL row object
 945          * @throws DBUnexpectedError Thrown if the database returns an error
 946          */
 947         function fetchObject( $res ) {
 948                 if ( $res instanceof ResultWrapper ) {
 949                         $res = $res->result;
 950                 }
 951                 @/**/$row = mysql_fetch_object( $res );
 952                 if( $this->lastErrno() ) {
 953                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 954                 }
 955                 return $row;
 956         }
 957
 958         /**
 959          * Fetch the next row from the given result object, in associative array
 960          * form.  Fields are retrieved with $row['fieldname'].
 961          *
 962          * @param $res SQL result object as returned from Database::query(), etc.
 963          * @return MySQL row object
 964          * @throws DBUnexpectedError Thrown if the database returns an error
 965          */
 966         function fetchRow( $res ) {
 967                 if ( $res instanceof ResultWrapper ) {
 968                         $res = $res->result;
 969                 }
 970                 @/**/$row = mysql_fetch_array( $res );
 971                 if ( $this->lastErrno() ) {
 972                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 973                 }
 974                 return $row;
 975         }
 976
 977         /**
 978          * Get the number of rows in a result object
 979          */
 980         function numRows( $res ) {
 981                 if ( $res instanceof ResultWrapper ) {
 982                         $res = $res->result;
 983                 }
 984                 @/**/$n = mysql_num_rows( $res );
 985                 if( $this->lastErrno() ) {
 986                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 987                 }
 988                 return $n;
 989         }
 990
 991         /**
 992          * Get the number of fields in a result object
 993          * See documentation for mysql_num_fields()
 994          */
 995         function numFields( $res ) {
 996                 if ( $res instanceof ResultWrapper ) {
 997                         $res = $res->result;
 998                 }
 999                 return mysql_num_fields( $res );
1000         }
1001
1002         /**
1003          * Get a field name in a result object
1004          * See documentation for mysql_field_name():
1005          * http://www.php.net/mysql_field_name
1006          */
1007         function fieldName( $res, $n ) {
1008                 if ( $res instanceof ResultWrapper ) {
1009                         $res = $res->result;
1010                 }
1011                 return mysql_field_name( $res, $n );
1012         }
1013
1014         /**
1015          * Get the inserted value of an auto-increment row
1016          *
1017          * The value inserted should be fetched from nextSequenceValue()
1018          *
1019          * Example:
1020          * $id = $dbw->nextSequenceValue('page_page_id_seq');
1021          * $dbw->insert('page',array('page_id' => $id));
1022          * $id = $dbw->insertId();
1023          */
1024         function insertId() { return mysql_insert_id( $this->mConn ); }
1025
1026         /**
1027          * Change the position of the cursor in a result object
1028          * See mysql_data_seek()
1029          */
1030         function dataSeek( $res, $row ) {
1031                 if ( $res instanceof ResultWrapper ) {
1032                         $res = $res->result;
1033                 }
1034                 return mysql_data_seek( $res, $row );
1035         }
1036
1037         /**
1038          * Get the last error number
1039          * See mysql_errno()
1040          */
1041         function lastErrno() {
1042                 if ( $this->mConn ) {
1043                         return mysql_errno( $this->mConn );
1044                 } else {
1045                         return mysql_errno();
1046                 }
1047         }
1048
1049         /**
1050          * Get a description of the last error
1051          * See mysql_error() for more details
1052          */
1053         function lastError() {
1054                 if ( $this->mConn ) {
1055                         # Even if it's non-zero, it can still be invalid
1056                         wfSuppressWarnings();
1057                         $error = mysql_error( $this->mConn );
1058                         if ( !$error ) {
1059                                 $error = mysql_error();
1060                         }
1061                         wfRestoreWarnings();
1062                 } else {
1063                         $error = mysql_error();
1064                 }
1065                 if( $error ) {
1066                         $error .= ' (' . $this->mServer . ')';
1067                 }
1068                 return $error;
1069         }
1070         /**
1071          * Get the number of rows affected by the last write query
1072          * See mysql_affected_rows() for more details
1073          */
1074         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
1075         /**#@-*/ // end of template : @param $result
1076
1077         /**
1078          * Simple UPDATE wrapper
1079          * Usually aborts on failure
1080          * If errors are explicitly ignored, returns success
1081          *
1082          * This function exists for historical reasons, Database::update() has a more standard
1083          * calling convention and feature set
1084          */
1085         function set( $table, $var, $value, $cond, $fname = 'Database::set' )
1086         {
1087                 $table = $this->tableName( $table );
1088                 $sql = "UPDATE $table SET $var = '" .
1089                   $this->strencode( $value ) . "' WHERE ($cond)";
1090                 return (bool)$this->query( $sql, $fname );
1091         }
1092
1093         /**
1094          * Simple SELECT wrapper, returns a single field, input must be encoded
1095          * Usually aborts on failure
1096          * If errors are explicitly ignored, returns FALSE on failure
1097          */
1098         function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
1099                 if ( !is_array( $options ) ) {
1100                         $options = array( $options );
1101                 }
1102                 $options['LIMIT'] = 1;
1103
1104                 $res = $this->select( $table, $var, $cond, $fname, $options );
1105                 if ( $res === false || !$this->numRows( $res ) ) {
1106                         return false;
1107                 }
1108                 $row = $this->fetchRow( $res );
1109                 if ( $row !== false ) {
1110                         $this->freeResult( $res );
1111                         return $row[0];
1112                 } else {
1113                         return false;
1114                 }
1115         }
1116
1117         /**
1118          * Returns an optional USE INDEX clause to go after the table, and a
1119          * string to go at the end of the query
1120          *
1121          * @private
1122          *
1123          * @param array $options an associative array of options to be turned into
1124          *              an SQL query, valid keys are listed in the function.
1125          * @return array
1126          */
1127         function makeSelectOptions( $options ) {
1128                 $preLimitTail = $postLimitTail = '';
1129                 $startOpts = '';
1130
1131                 $noKeyOptions = array();
1132                 foreach ( $options as $key => $option ) {
1133                         if ( is_numeric( $key ) ) {
1134                                 $noKeyOptions[$option] = true;
1135                         }
1136                 }
1137
1138                 if ( isset( $options['GROUP BY'] ) ) $preLimitTail .= " GROUP BY {$options['GROUP BY']}";
1139                 if ( isset( $options['HAVING'] ) ) $preLimitTail .= " HAVING {$options['HAVING']}";
1140                 if ( isset( $options['ORDER BY'] ) ) $preLimitTail .= " ORDER BY {$options['ORDER BY']}";
1141
1142                 //if (isset($options['LIMIT'])) {
1143                 //      $tailOpts .= $this->limitResult('', $options['LIMIT'],
1144                 //              isset($options['OFFSET']) ? $options['OFFSET']
1145                 //              : false);
1146                 //}
1147
1148                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $postLimitTail .= ' FOR UPDATE';
1149                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $postLimitTail .= ' LOCK IN SHARE MODE';
1150                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
1151
1152                 # Various MySQL extensions
1153                 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) $startOpts .= ' /*! STRAIGHT_JOIN */';
1154                 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) $startOpts .= ' HIGH_PRIORITY';
1155                 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) $startOpts .= ' SQL_BIG_RESULT';
1156                 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) $startOpts .= ' SQL_BUFFER_RESULT';
1157                 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) $startOpts .= ' SQL_SMALL_RESULT';
1158                 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) $startOpts .= ' SQL_CALC_FOUND_ROWS';
1159                 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) $startOpts .= ' SQL_CACHE';
1160                 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) $startOpts .= ' SQL_NO_CACHE';
1161
1162                 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
1163                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1164                 } else {
1165                         $useIndex = '';
1166                 }
1167
1168                 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1169         }
1170
1171         /**
1172          * SELECT wrapper
1173          *
1174          * @param mixed  $table   Array or string, table name(s) (prefix auto-added)
1175          * @param mixed  $vars    Array or string, field name(s) to be retrieved
1176          * @param mixed  $conds   Array or string, condition(s) for WHERE
1177          * @param string $fname   Calling function name (use __METHOD__) for logs/profiling
1178          * @param array  $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
1179          *                        see Database::makeSelectOptions code for list of supported stuff
1180          * @return mixed Database result resource (feed to Database::fetchObject or whatever), or false on failure
1181          */
1182         function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array() )
1183         {
1184                 if( is_array( $vars ) ) {
1185                         $vars = implode( ',', $vars );
1186                 }
1187                 if( !is_array( $options ) ) {
1188                         $options = array( $options );
1189                 }
1190                 if( is_array( $table ) ) {
1191                         if ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1192                                 $from = ' FROM ' . $this->tableNamesWithUseIndex( $table, $options['USE INDEX'] );
1193                         else
1194                                 $from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
1195                 } elseif ($table!='') {
1196                         if ($table{0}==' ') {
1197                                 $from = ' FROM ' . $table;
1198                         } else {
1199                                 $from = ' FROM ' . $this->tableName( $table );
1200                         }
1201                 } else {
1202                         $from = '';
1203                 }
1204
1205                 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
1206
1207                 if( !empty( $conds ) ) {
1208                         if ( is_array( $conds ) ) {
1209                                 $conds = $this->makeList( $conds, LIST_AND );
1210                         }
1211                         $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
1212                 } else {
1213                         $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
1214                 }
1215
1216                 if (isset($options['LIMIT']))
1217                         $sql = $this->limitResult($sql, $options['LIMIT'],
1218                                 isset($options['OFFSET']) ? $options['OFFSET'] : false);
1219                 $sql = "$sql $postLimitTail";
1220
1221                 if (isset($options['EXPLAIN'])) {
1222                         $sql = 'EXPLAIN ' . $sql;
1223                 }
1224                 return $this->query( $sql, $fname );
1225         }
1226
1227         /**
1228          * Single row SELECT wrapper
1229          * Aborts or returns FALSE on error
1230          *
1231          * $vars: the selected variables
1232          * $conds: a condition map, terms are ANDed together.
1233          *   Items with numeric keys are taken to be literal conditions
1234          * Takes an array of selected variables, and a condition map, which is ANDed
1235          * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
1236          * NS_MAIN, "page_title" => "Astronomy" ) )   would return an object where
1237          * $obj- >page_id is the ID of the Astronomy article
1238          *
1239          * @todo migrate documentation to phpdocumentor format
1240          */
1241         function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
1242                 $options['LIMIT'] = 1;
1243                 $res = $this->select( $table, $vars, $conds, $fname, $options );
1244                 if ( $res === false )
1245                         return false;
1246                 if ( !$this->numRows($res) ) {
1247                         $this->freeResult($res);
1248                         return false;
1249                 }
1250                 $obj = $this->fetchObject( $res );
1251                 $this->freeResult( $res );
1252                 return $obj;
1253
1254         }
1255
1256         /**
1257          * Estimate rows in dataset
1258          * Returns estimated count, based on EXPLAIN output
1259          * Takes same arguments as Database::select()
1260          */
1261
1262         function estimateRowCount( $table, $vars='*', $conds='', $fname = 'Database::estimateRowCount', $options = array() ) {
1263                 $options['EXPLAIN']=true;
1264                 $res = $this->select ($table, $vars, $conds, $fname, $options );
1265                 if ( $res === false )
1266                         return false;
1267                 if (!$this->numRows($res)) {
1268                         $this->freeResult($res);
1269                         return 0;
1270                 }
1271
1272                 $rows=1;
1273
1274                 while( $plan = $this->fetchObject( $res ) ) {
1275                         $rows *= ($plan->rows > 0)?$plan->rows:1; // avoid resetting to zero
1276                 }
1277
1278                 $this->freeResult($res);
1279                 return $rows;
1280         }
1281
1282
1283         /**
1284          * Removes most variables from an SQL query and replaces them with X or N for numbers.
1285          * It's only slightly flawed. Don't use for anything important.
1286          *
1287          * @param string $sql A SQL Query
1288          * @static
1289          */
1290         static function generalizeSQL( $sql ) {
1291                 # This does the same as the regexp below would do, but in such a way
1292                 # as to avoid crashing php on some large strings.
1293                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1294
1295                 $sql = str_replace ( "\\\\", '', $sql);
1296                 $sql = str_replace ( "\\'", '', $sql);
1297                 $sql = str_replace ( "\\\"", '', $sql);
1298                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
1299                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
1300
1301                 # All newlines, tabs, etc replaced by single space
1302                 $sql = preg_replace ( '/\s+/', ' ', $sql);
1303
1304                 # All numbers => N
1305                 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
1306
1307                 return $sql;
1308         }
1309
1310         /**
1311          * Determines whether a field exists in a table
1312          * Usually aborts on failure
1313          * If errors are explicitly ignored, returns NULL on failure
1314          */
1315         function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
1316                 $table = $this->tableName( $table );
1317                 $res = $this->query( 'DESCRIBE '.$table, $fname );
1318                 if ( !$res ) {
1319                         return NULL;
1320                 }
1321
1322                 $found = false;
1323
1324                 while ( $row = $this->fetchObject( $res ) ) {
1325                         if ( $row->Field == $field ) {
1326                                 $found = true;
1327                                 break;
1328                         }
1329                 }
1330                 return $found;
1331         }
1332
1333         /**
1334          * Determines whether an index exists
1335          * Usually aborts on failure
1336          * If errors are explicitly ignored, returns NULL on failure
1337          */
1338         function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
1339                 $info = $this->indexInfo( $table, $index, $fname );
1340                 if ( is_null( $info ) ) {
1341                         return NULL;
1342                 } else {
1343                         return $info !== false;
1344                 }
1345         }
1346
1347
1348         /**
1349          * Get information about an index into an object
1350          * Returns false if the index does not exist
1351          */
1352         function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
1353                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
1354                 # SHOW INDEX should work for 3.x and up:
1355                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
1356                 $table = $this->tableName( $table );
1357                 $sql = 'SHOW INDEX FROM '.$table;
1358                 $res = $this->query( $sql, $fname );
1359                 if ( !$res ) {
1360                         return NULL;
1361                 }
1362
1363                 $result = array();
1364                 while ( $row = $this->fetchObject( $res ) ) {
1365                         if ( $row->Key_name == $index ) {
1366                                 $result[] = $row;
1367                         }
1368                 }
1369                 $this->freeResult($res);
1370
1371                 return empty($result) ? false : $result;
1372         }
1373
1374         /**
1375          * Query whether a given table exists
1376          */
1377         function tableExists( $table ) {
1378                 $table = $this->tableName( $table );
1379                 $old = $this->ignoreErrors( true );
1380                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
1381                 $this->ignoreErrors( $old );
1382                 if( $res ) {
1383                         $this->freeResult( $res );
1384                         return true;
1385                 } else {
1386                         return false;
1387                 }
1388         }
1389
1390         /**
1391          * mysql_fetch_field() wrapper
1392          * Returns false if the field doesn't exist
1393          *
1394          * @param $table
1395          * @param $field
1396          */
1397         function fieldInfo( $table, $field ) {
1398                 $table = $this->tableName( $table );
1399                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
1400                 $n = mysql_num_fields( $res->result );
1401                 for( $i = 0; $i < $n; $i++ ) {
1402                         $meta = mysql_fetch_field( $res->result, $i );
1403                         if( $field == $meta->name ) {
1404                                 return new MySQLField($meta);
1405                         }
1406                 }
1407                 return false;
1408         }
1409
1410         /**
1411          * mysql_field_type() wrapper
1412          */
1413         function fieldType( $res, $index ) {
1414                 if ( $res instanceof ResultWrapper ) {
1415                         $res = $res->result;
1416                 }
1417                 return mysql_field_type( $res, $index );
1418         }
1419
1420         /**
1421          * Determines if a given index is unique
1422          */
1423         function indexUnique( $table, $index ) {
1424                 $indexInfo = $this->indexInfo( $table, $index );
1425                 if ( !$indexInfo ) {
1426                         return NULL;
1427                 }
1428                 return !$indexInfo[0]->Non_unique;
1429         }
1430
1431         /**
1432          * INSERT wrapper, inserts an array into a table
1433          *
1434          * $a may be a single associative array, or an array of these with numeric keys, for
1435          * multi-row insert.
1436          *
1437          * Usually aborts on failure
1438          * If errors are explicitly ignored, returns success
1439          */
1440         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
1441                 # No rows to insert, easy just return now
1442                 if ( !count( $a ) ) {
1443                         return true;
1444                 }
1445
1446                 $table = $this->tableName( $table );
1447                 if ( !is_array( $options ) ) {
1448                         $options = array( $options );
1449                 }
1450                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1451                         $multi = true;
1452                         $keys = array_keys( $a[0] );
1453                 } else {
1454                         $multi = false;
1455                         $keys = array_keys( $a );
1456                 }
1457
1458                 $sql = 'INSERT ' . implode( ' ', $options ) .
1459                         " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1460
1461                 if ( $multi ) {
1462                         $first = true;
1463                         foreach ( $a as $row ) {
1464                                 if ( $first ) {
1465                                         $first = false;
1466                                 } else {
1467                                         $sql .= ',';
1468                                 }
1469                                 $sql .= '(' . $this->makeList( $row ) . ')';
1470                         }
1471                 } else {
1472                         $sql .= '(' . $this->makeList( $a ) . ')';
1473                 }
1474                 return (bool)$this->query( $sql, $fname );
1475         }
1476
1477         /**
1478          * Make UPDATE options for the Database::update function
1479          *
1480          * @private
1481          * @param array $options The options passed to Database::update
1482          * @return string
1483          */
1484         function makeUpdateOptions( $options ) {
1485                 if( !is_array( $options ) ) {
1486                         $options = array( $options );
1487                 }
1488                 $opts = array();
1489                 if ( in_array( 'LOW_PRIORITY', $options ) )
1490                         $opts[] = $this->lowPriorityOption();
1491                 if ( in_array( 'IGNORE', $options ) )
1492                         $opts[] = 'IGNORE';
1493                 return implode(' ', $opts);
1494         }
1495
1496         /**
1497          * UPDATE wrapper, takes a condition array and a SET array
1498          *
1499          * @param string $table  The table to UPDATE
1500          * @param array  $values An array of values to SET
1501          * @param array  $conds  An array of conditions (WHERE). Use '*' to update all rows.
1502          * @param string $fname  The Class::Function calling this function
1503          *                       (for the log)
1504          * @param array  $options An array of UPDATE options, can be one or
1505          *                        more of IGNORE, LOW_PRIORITY
1506          * @return bool
1507          */
1508         function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
1509                 $table = $this->tableName( $table );
1510                 $opts = $this->makeUpdateOptions( $options );
1511                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1512                 if ( $conds != '*' ) {
1513                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1514                 }
1515                 return $this->query( $sql, $fname );
1516         }
1517
1518         /**
1519          * Makes an encoded list of strings from an array
1520          * $mode:
1521          *        LIST_COMMA         - comma separated, no field names
1522          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
1523          *        LIST_OR            - ORed WHERE clause (without the WHERE)
1524          *        LIST_SET           - comma separated with field names, like a SET clause
1525          *        LIST_NAMES         - comma separated field names
1526          */
1527         function makeList( $a, $mode = LIST_COMMA ) {
1528                 if ( !is_array( $a ) ) {
1529                         throw new DBUnexpectedError( $this, 'Database::makeList called with incorrect parameters' );
1530                 }
1531
1532                 $first = true;
1533                 $list = '';
1534                 foreach ( $a as $field => $value ) {
1535                         if ( !$first ) {
1536                                 if ( $mode == LIST_AND ) {
1537                                         $list .= ' AND ';
1538                                 } elseif($mode == LIST_OR) {
1539                                         $list .= ' OR ';
1540                                 } else {
1541                                         $list .= ',';
1542                                 }
1543                         } else {
1544                                 $first = false;
1545                         }
1546                         if ( ($mode == LIST_AND || $mode == LIST_OR) && is_numeric( $field ) ) {
1547                                 $list .= "($value)";
1548                         } elseif ( ($mode == LIST_SET) && is_numeric( $field ) ) {
1549                                 $list .= "$value";
1550                         } elseif ( ($mode == LIST_AND || $mode == LIST_OR) && is_array($value) ) {
1551                                 $list .= $field." IN (".$this->makeList($value).") ";
1552                         } elseif( is_null($value) ) {
1553                                 if ( $mode == LIST_AND || $mode == LIST_OR ) {
1554                                         $list .= "$field IS ";
1555                                 } elseif ( $mode == LIST_SET ) {
1556                                         $list .= "$field = ";
1557                                 }
1558                                 $list .= 'NULL';
1559                         } else {
1560                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1561                                         $list .= "$field = ";
1562                                 }
1563                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1564                         }
1565                 }
1566                 return $list;
1567         }
1568
1569         /**
1570          * Change the current database
1571          */
1572         function selectDB( $db ) {
1573                 $this->mDBname = $db;
1574                 return mysql_select_db( $db, $this->mConn );
1575         }
1576
1577         /**
1578          * Format a table name ready for use in constructing an SQL query
1579          *
1580          * This does two important things: it quotes table names which as necessary,
1581          * and it adds a table prefix if there is one.
1582          *
1583          * All functions of this object which require a table name call this function
1584          * themselves. Pass the canonical name to such functions. This is only needed
1585          * when calling query() directly.
1586          *
1587          * @param string $name database table name
1588          */
1589         function tableName( $name ) {
1590                 global $wgSharedDB;
1591                 # Skip quoted literals
1592                 if ( $name{0} != '`' ) {
1593                         if ( $this->mTablePrefix !== '' &&  strpos( $name, '.' ) === false ) {
1594                                 $name = "{$this->mTablePrefix}$name";
1595                         }
1596                         if ( isset( $wgSharedDB ) && "{$this->mTablePrefix}user" == $name ) {
1597                                 $name = "`$wgSharedDB`.`$name`";
1598                         } else {
1599                                 # Standard quoting
1600                                 $name = "`$name`";
1601                         }
1602                 }
1603                 return $name;
1604         }
1605
1606         /**
1607          * Fetch a number of table names into an array
1608          * This is handy when you need to construct SQL for joins
1609          *
1610          * Example:
1611          * extract($dbr->tableNames('user','watchlist'));
1612          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1613          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1614          */
1615         public function tableNames() {
1616                 $inArray = func_get_args();
1617                 $retVal = array();
1618                 foreach ( $inArray as $name ) {
1619                         $retVal[$name] = $this->tableName( $name );
1620                 }
1621                 return $retVal;
1622         }
1623
1624         /**
1625          * Fetch a number of table names into an zero-indexed numerical array
1626          * This is handy when you need to construct SQL for joins
1627          *
1628          * Example:
1629          * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
1630          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1631          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1632          */
1633         public function tableNamesN() {
1634                 $inArray = func_get_args();
1635                 $retVal = array();
1636                 foreach ( $inArray as $name ) {
1637                         $retVal[] = $this->tableName( $name );
1638                 }
1639                 return $retVal;
1640         }
1641
1642         /**
1643          * @private
1644          */
1645         function tableNamesWithUseIndex( $tables, $use_index ) {
1646                 $ret = array();
1647
1648                 foreach ( $tables as $table )
1649                         if ( @$use_index[$table] !== null )
1650                                 $ret[] = $this->tableName( $table ) . ' ' . $this->useIndexClause( implode( ',', (array)$use_index[$table] ) );
1651                         else
1652                                 $ret[] = $this->tableName( $table );
1653
1654                 return implode( ',', $ret );
1655         }
1656
1657         /**
1658          * Wrapper for addslashes()
1659          * @param string $s String to be slashed.
1660          * @return string slashed string.
1661          */
1662         function strencode( $s ) {
1663                 return mysql_real_escape_string( $s, $this->mConn );
1664         }
1665
1666         /**
1667          * If it's a string, adds quotes and backslashes
1668          * Otherwise returns as-is
1669          */
1670         function addQuotes( $s ) {
1671                 if ( is_null( $s ) ) {
1672                         return 'NULL';
1673                 } else {
1674                         # This will also quote numeric values. This should be harmless,
1675                         # and protects against weird problems that occur when they really
1676                         # _are_ strings such as article titles and string->number->string
1677                         # conversion is not 1:1.
1678                         return "'" . $this->strencode( $s ) . "'";
1679                 }
1680         }
1681
1682         /**
1683          * Escape string for safe LIKE usage
1684          */
1685         function escapeLike( $s ) {
1686                 $s=$this->strencode( $s );
1687                 $s=str_replace(array('%','_'),array('\%','\_'),$s);
1688                 return $s;
1689         }
1690
1691         /**
1692          * Returns an appropriately quoted sequence value for inserting a new row.
1693          * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1694          * subclass will return an integer, and save the value for insertId()
1695          */
1696         function nextSequenceValue( $seqName ) {
1697                 return NULL;
1698         }
1699
1700         /**
1701          * USE INDEX clause
1702          * PostgreSQL doesn't have them and returns ""
1703          */
1704         function useIndexClause( $index ) {
1705                 return "FORCE INDEX ($index)";
1706         }
1707
1708         /**
1709          * REPLACE query wrapper
1710          * PostgreSQL simulates this with a DELETE followed by INSERT
1711          * $row is the row to insert, an associative array
1712          * $uniqueIndexes is an array of indexes. Each element may be either a
1713          * field name or an array of field names
1714          *
1715          * It may be more efficient to leave off unique indexes which are unlikely to collide.
1716          * However if you do this, you run the risk of encountering errors which wouldn't have
1717          * occurred in MySQL
1718          *
1719          * @todo migrate comment to phodocumentor format
1720          */
1721         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
1722                 $table = $this->tableName( $table );
1723
1724                 # Single row case
1725                 if ( !is_array( reset( $rows ) ) ) {
1726                         $rows = array( $rows );
1727                 }
1728
1729                 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) .') VALUES ';
1730                 $first = true;
1731                 foreach ( $rows as $row ) {
1732                         if ( $first ) {
1733                                 $first = false;
1734                         } else {
1735                                 $sql .= ',';
1736                         }
1737                         $sql .= '(' . $this->makeList( $row ) . ')';
1738                 }
1739                 return $this->query( $sql, $fname );
1740         }
1741
1742         /**
1743          * DELETE where the condition is a join
1744          * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1745          *
1746          * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1747          * join condition matches, set $conds='*'
1748          *
1749          * DO NOT put the join condition in $conds
1750          *
1751          * @param string $delTable The table to delete from.
1752          * @param string $joinTable The other table.
1753          * @param string $delVar The variable to join on, in the first table.
1754          * @param string $joinVar The variable to join on, in the second table.
1755          * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
1756          */
1757         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
1758                 if ( !$conds ) {
1759                         throw new DBUnexpectedError( $this, 'Database::deleteJoin() called with empty $conds' );
1760                 }
1761
1762                 $delTable = $this->tableName( $delTable );
1763                 $joinTable = $this->tableName( $joinTable );
1764                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1765                 if ( $conds != '*' ) {
1766                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1767                 }
1768
1769                 return $this->query( $sql, $fname );
1770         }
1771
1772         /**
1773          * Returns the size of a text field, or -1 for "unlimited"
1774          */
1775         function textFieldSize( $table, $field ) {
1776                 $table = $this->tableName( $table );
1777                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1778                 $res = $this->query( $sql, 'Database::textFieldSize' );
1779                 $row = $this->fetchObject( $res );
1780                 $this->freeResult( $res );
1781
1782                 $m = array();
1783                 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
1784                         $size = $m[1];
1785                 } else {
1786                         $size = -1;
1787                 }
1788                 return $size;
1789         }
1790
1791         /**
1792          * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1793          */
1794         function lowPriorityOption() {
1795                 return 'LOW_PRIORITY';
1796         }
1797
1798         /**
1799          * DELETE query wrapper
1800          *
1801          * Use $conds == "*" to delete all rows
1802          */
1803         function delete( $table, $conds, $fname = 'Database::delete' ) {
1804                 if ( !$conds ) {
1805                         throw new DBUnexpectedError( $this, 'Database::delete() called with no conditions' );
1806                 }
1807                 $table = $this->tableName( $table );
1808                 $sql = "DELETE FROM $table";
1809                 if ( $conds != '*' ) {
1810                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1811                 }
1812                 return $this->query( $sql, $fname );
1813         }
1814
1815         /**
1816          * INSERT SELECT wrapper
1817          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1818          * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1819          * $conds may be "*" to copy the whole table
1820          * srcTable may be an array of tables.
1821          */
1822         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect',
1823                 $insertOptions = array(), $selectOptions = array() )
1824         {
1825                 $destTable = $this->tableName( $destTable );
1826                 if ( is_array( $insertOptions ) ) {
1827                         $insertOptions = implode( ' ', $insertOptions );
1828                 }
1829                 if( !is_array( $selectOptions ) ) {
1830                         $selectOptions = array( $selectOptions );
1831                 }
1832                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
1833                 if( is_array( $srcTable ) ) {
1834                         $srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
1835                 } else {
1836                         $srcTable = $this->tableName( $srcTable );
1837                 }
1838                 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1839                         " SELECT $startOpts " . implode( ',', $varMap ) .
1840                         " FROM $srcTable $useIndex ";
1841                 if ( $conds != '*' ) {
1842                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1843                 }
1844                 $sql .= " $tailOpts";
1845                 return $this->query( $sql, $fname );
1846         }
1847
1848         /**
1849          * Construct a LIMIT query with optional offset
1850          * This is used for query pages
1851          * $sql string SQL query we will append the limit too
1852          * $limit integer the SQL limit
1853          * $offset integer the SQL offset (default false)
1854          */
1855         function limitResult($sql, $limit, $offset=false) {
1856                 if( !is_numeric($limit) ) {
1857                         throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
1858                 }
1859                 return " $sql LIMIT "
1860                                 . ( (is_numeric($offset) && $offset != 0) ? "{$offset}," : "" )
1861                                 . "{$limit} ";
1862         }
1863         function limitResultForUpdate($sql, $num) {
1864                 return $this->limitResult($sql, $num, 0);
1865         }
1866
1867         /**
1868          * Returns an SQL expression for a simple conditional.
1869          * Uses IF on MySQL.
1870          *
1871          * @param string $cond SQL expression which will result in a boolean value
1872          * @param string $trueVal SQL expression to return if true
1873          * @param string $falseVal SQL expression to return if false
1874          * @return string SQL fragment
1875          */
1876         function conditional( $cond, $trueVal, $falseVal ) {
1877                 return " IF($cond, $trueVal, $falseVal) ";
1878         }
1879
1880         /**
1881          * Determines if the last failure was due to a deadlock
1882          */
1883         function wasDeadlock() {
1884                 return $this->lastErrno() == 1213;
1885         }
1886
1887         /**
1888          * Perform a deadlock-prone transaction.
1889          *
1890          * This function invokes a callback function to perform a set of write
1891          * queries. If a deadlock occurs during the processing, the transaction
1892          * will be rolled back and the callback function will be called again.
1893          *
1894          * Usage:
1895          *   $dbw->deadlockLoop( callback, ... );
1896          *
1897          * Extra arguments are passed through to the specified callback function.
1898          *
1899          * Returns whatever the callback function returned on its successful,
1900          * iteration, or false on error, for example if the retry limit was
1901          * reached.
1902          */
1903         function deadlockLoop() {
1904                 $myFname = 'Database::deadlockLoop';
1905
1906                 $this->begin();
1907                 $args = func_get_args();
1908                 $function = array_shift( $args );
1909                 $oldIgnore = $this->ignoreErrors( true );
1910                 $tries = DEADLOCK_TRIES;
1911                 if ( is_array( $function ) ) {
1912                         $fname = $function[0];
1913                 } else {
1914                         $fname = $function;
1915                 }
1916                 do {
1917                         $retVal = call_user_func_array( $function, $args );
1918                         $error = $this->lastError();
1919                         $errno = $this->lastErrno();
1920                         $sql = $this->lastQuery();
1921
1922                         if ( $errno ) {
1923                                 if ( $this->wasDeadlock() ) {
1924                                         # Retry
1925                                         usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1926                                 } else {
1927                                         $this->reportQueryError( $error, $errno, $sql, $fname );
1928                                 }
1929                         }
1930                 } while( $this->wasDeadlock() && --$tries > 0 );
1931                 $this->ignoreErrors( $oldIgnore );
1932                 if ( $tries <= 0 ) {
1933                         $this->query( 'ROLLBACK', $myFname );
1934                         $this->reportQueryError( $error, $errno, $sql, $fname );
1935                         return false;
1936                 } else {
1937                         $this->query( 'COMMIT', $myFname );
1938                         return $retVal;
1939                 }
1940         }
1941
1942         /**
1943          * Do a SELECT MASTER_POS_WAIT()
1944          *
1945          * @param string $file the binlog file
1946          * @param string $pos the binlog position
1947          * @param integer $timeout the maximum number of seconds to wait for synchronisation
1948          */
1949         function masterPosWait( $file, $pos, $timeout ) {
1950                 $fname = 'Database::masterPosWait';
1951                 wfProfileIn( $fname );
1952
1953
1954                 # Commit any open transactions
1955                 $this->immediateCommit();
1956
1957                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
1958                 $encFile = $this->strencode( $file );
1959                 $sql = "SELECT MASTER_POS_WAIT('$encFile', $pos, $timeout)";
1960                 $res = $this->doQuery( $sql );
1961                 if ( $res && $row = $this->fetchRow( $res ) ) {
1962                         $this->freeResult( $res );
1963                         wfProfileOut( $fname );
1964                         return $row[0];
1965                 } else {
1966                         wfProfileOut( $fname );
1967                         return false;
1968                 }
1969         }
1970
1971         /**
1972          * Get the position of the master from SHOW SLAVE STATUS
1973          */
1974         function getSlavePos() {
1975                 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1976                 $row = $this->fetchObject( $res );
1977                 if ( $row ) {
1978                         return array( $row->Master_Log_File, $row->Read_Master_Log_Pos );
1979                 } else {
1980                         return array( false, false );
1981                 }
1982         }
1983
1984         /**
1985          * Get the position of the master from SHOW MASTER STATUS
1986          */
1987         function getMasterPos() {
1988                 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1989                 $row = $this->fetchObject( $res );
1990                 if ( $row ) {
1991                         return array( $row->File, $row->Position );
1992                 } else {
1993                         return array( false, false );
1994                 }
1995         }
1996
1997         /**
1998          * Begin a transaction, committing any previously open transaction
1999          */
2000         function begin( $fname = 'Database::begin' ) {
2001                 $this->query( 'BEGIN', $fname );
2002                 $this->mTrxLevel = 1;
2003         }
2004
2005         /**
2006          * End a transaction
2007          */
2008         function commit( $fname = 'Database::commit' ) {
2009                 $this->query( 'COMMIT', $fname );
2010                 $this->mTrxLevel = 0;
2011         }
2012
2013         /**
2014          * Rollback a transaction
2015          */
2016         function rollback( $fname = 'Database::rollback' ) {
2017                 $this->query( 'ROLLBACK', $fname );
2018                 $this->mTrxLevel = 0;
2019         }
2020
2021         /**
2022          * Begin a transaction, committing any previously open transaction
2023          * @deprecated use begin()
2024          */
2025         function immediateBegin( $fname = 'Database::immediateBegin' ) {
2026                 $this->begin();
2027         }
2028
2029         /**
2030          * Commit transaction, if one is open
2031          * @deprecated use commit()
2032          */
2033         function immediateCommit( $fname = 'Database::immediateCommit' ) {
2034                 $this->commit();
2035         }
2036
2037         /**
2038          * Return MW-style timestamp used for MySQL schema
2039          */
2040         function timestamp( $ts=0 ) {
2041                 return wfTimestamp(TS_MW,$ts);
2042         }
2043
2044         /**
2045          * Local database timestamp format or null
2046          */
2047         function timestampOrNull( $ts = null ) {
2048                 if( is_null( $ts ) ) {
2049                         return null;
2050                 } else {
2051                         return $this->timestamp( $ts );
2052                 }
2053         }
2054
2055         /**
2056          * @todo document
2057          */
2058         function resultObject( $result ) {
2059                 if( empty( $result ) ) {
2060                         return false;
2061                 } elseif ( $result instanceof ResultWrapper ) {
2062                         return $result;
2063                 } elseif ( $result === true ) {
2064                         // Successful write query
2065                         return $result;
2066                 } else {
2067                         return new ResultWrapper( $this, $result );
2068                 }
2069         }
2070
2071         /**
2072          * Return aggregated value alias
2073          */
2074         function aggregateValue ($valuedata,$valuename='value') {
2075                 return $valuename;
2076         }
2077
2078         /**
2079          * @return string wikitext of a link to the server software's web site
2080          */
2081         function getSoftwareLink() {
2082                 return "[http://www.mysql.com/ MySQL]";
2083         }
2084
2085         /**
2086          * @return string Version information from the database
2087          */
2088         function getServerVersion() {
2089                 return mysql_get_server_info( $this->mConn );
2090         }
2091
2092         /**
2093          * Ping the server and try to reconnect if it there is no connection
2094          */
2095         function ping() {
2096                 if( function_exists( 'mysql_ping' ) ) {
2097                         return mysql_ping( $this->mConn );
2098                 } else {
2099                         wfDebug( "Tried to call mysql_ping but this is ancient PHP version. Faking it!\n" );
2100                         return true;
2101                 }
2102         }
2103
2104         /**
2105          * Get slave lag.
2106          * At the moment, this will only work if the DB user has the PROCESS privilege
2107          */
2108         function getLag() {
2109                 $res = $this->query( 'SHOW PROCESSLIST' );
2110                 # Find slave SQL thread
2111                 while ( $row = $this->fetchObject( $res ) ) {
2112                         /* This should work for most situations - when default db
2113                          * for thread is not specified, it had no events executed,
2114                          * and therefore it doesn't know yet how lagged it is.
2115                          *
2116                          * Relay log I/O thread does not select databases.
2117                          */
2118                         if ( $row->User == 'system user' &&
2119                                 $row->State != 'Waiting for master to send event' &&
2120                                 $row->State != 'Connecting to master' &&
2121                                 $row->State != 'Queueing master event to the relay log' &&
2122                                 $row->State != 'Waiting for master update' &&
2123                                 $row->State != 'Requesting binlog dump'
2124                                 ) {
2125                                 # This is it, return the time (except -ve)
2126                                 if ( $row->Time > 0x7fffffff ) {
2127                                         return false;
2128                                 } else {
2129                                         return $row->Time;
2130                                 }
2131                         }
2132                 }
2133                 return false;
2134         }
2135
2136         /**
2137          * Get status information from SHOW STATUS in an associative array
2138          */
2139         function getStatus($which="%") {
2140                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
2141                 $status = array();
2142                 while ( $row = $this->fetchObject( $res ) ) {
2143                         $status[$row->Variable_name] = $row->Value;
2144                 }
2145                 return $status;
2146         }
2147
2148         /**
2149          * Return the maximum number of items allowed in a list, or 0 for unlimited.
2150          */
2151         function maxListLen() {
2152                 return 0;
2153         }
2154
2155         function encodeBlob($b) {
2156                 return $b;
2157         }
2158
2159         function decodeBlob($b) {
2160                 return $b;
2161         }
2162
2163         /**
2164          * Override database's default connection timeout.
2165          * May be useful for very long batch queries such as
2166          * full-wiki dumps, where a single query reads out
2167          * over hours or days.
2168          * @param int $timeout in seconds
2169          */
2170         public function setTimeout( $timeout ) {
2171                 $this->query( "SET net_read_timeout=$timeout" );
2172                 $this->query( "SET net_write_timeout=$timeout" );
2173         }
2174
2175         /**
2176          * Read and execute SQL commands from a file.
2177          * Returns true on success, error string on failure
2178          * @param string $filename File name to open
2179          * @param callback $lineCallback Optional function called before reading each line
2180          * @param callback $resultCallback Optional function called for each MySQL result
2181          */
2182         function sourceFile( $filename, $lineCallback = false, $resultCallback = false ) {
2183                 $fp = fopen( $filename, 'r' );
2184                 if ( false === $fp ) {
2185                         return "Could not open \"{$filename}\".\n";
2186                 }
2187                 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback );
2188                 fclose( $fp );
2189                 return $error;
2190         }
2191
2192         /**
2193          * Read and execute commands from an open file handle
2194          * Returns true on success, error string on failure
2195          * @param string $fp File handle
2196          * @param callback $lineCallback Optional function called before reading each line
2197          * @param callback $resultCallback Optional function called for each MySQL result
2198          */
2199         function sourceStream( $fp, $lineCallback = false, $resultCallback = false ) {
2200                 $cmd = "";
2201                 $done = false;
2202                 $dollarquote = false;
2203
2204                 while ( ! feof( $fp ) ) {
2205                         if ( $lineCallback ) {
2206                                 call_user_func( $lineCallback );
2207                         }
2208                         $line = trim( fgets( $fp, 1024 ) );
2209                         $sl = strlen( $line ) - 1;
2210
2211                         if ( $sl < 0 ) { continue; }
2212                         if ( '-' == $line{0} && '-' == $line{1} ) { continue; }
2213
2214                         ## Allow dollar quoting for function declarations
2215                         if (substr($line,0,4) == '$mw$') {
2216                                 if ($dollarquote) {
2217                                         $dollarquote = false;
2218                                         $done = true;
2219                                 }
2220                                 else {
2221                                         $dollarquote = true;
2222                                 }
2223                         }
2224                         else if (!$dollarquote) {
2225                                 if ( ';' == $line{$sl} && ($sl < 2 || ';' != $line{$sl - 1})) {
2226                                         $done = true;
2227                                         $line = substr( $line, 0, $sl );
2228                                 }
2229                         }
2230
2231                         if ( '' != $cmd ) { $cmd .= ' '; }
2232                         $cmd .= "$line\n";
2233
2234                         if ( $done ) {
2235                                 $cmd = str_replace(';;', ";", $cmd);
2236                                 $cmd = $this->replaceVars( $cmd );
2237                                 $res = $this->query( $cmd, __METHOD__, true );
2238                                 if ( $resultCallback ) {
2239                                         call_user_func( $resultCallback, $res );
2240                                 }
2241
2242                                 if ( false === $res ) {
2243                                         $err = $this->lastError();
2244                                         return "Query \"{$cmd}\" failed with error code \"$err\".\n";
2245                                 }
2246
2247                                 $cmd = '';
2248                                 $done = false;
2249                         }
2250                 }
2251                 return true;
2252         }
2253
2254
2255         /**
2256          * Replace variables in sourced SQL
2257          */
2258         protected function replaceVars( $ins ) {
2259                 $varnames = array(
2260                         'wgDBserver', 'wgDBname', 'wgDBintlname', 'wgDBuser',
2261                         'wgDBpassword', 'wgDBsqluser', 'wgDBsqlpassword',
2262                         'wgDBadminuser', 'wgDBadminpassword', 'wgDBTableOptions',
2263                 );
2264
2265                 // Ordinary variables
2266                 foreach ( $varnames as $var ) {
2267                         if( isset( $GLOBALS[$var] ) ) {
2268                                 $val = addslashes( $GLOBALS[$var] ); // FIXME: safety check?
2269                                 $ins = str_replace( '{$' . $var . '}', $val, $ins );
2270                                 $ins = str_replace( '/*$' . $var . '*/`', '`' . $val, $ins );
2271                                 $ins = str_replace( '/*$' . $var . '*/', $val, $ins );
2272                         }
2273                 }
2274
2275                 // Table prefixes
2276                 $ins = preg_replace_callback( '/\/\*(?:\$wgDBprefix|_)\*\/([a-z_]*)/',
2277                         array( &$this, 'tableNameCallback' ), $ins );
2278                 return $ins;
2279         }
2280
2281         /**
2282          * Table name callback
2283          * @private
2284          */
2285         protected function tableNameCallback( $matches ) {
2286                 return $this->tableName( $matches[1] );
2287         }
2288
2289 }
2290
2291 /**
2292  * Database abstraction object for mySQL
2293  * Inherit all methods and properties of Database::Database()
2294  *
2295  * @addtogroup Database
2296  * @see Database
2297  */
2298 class DatabaseMysql extends Database {
2299         # Inherit all
2300 }
2301
2302
2303 /**
2304  * Result wrapper for grabbing data queried by someone else
2305  * @addtogroup Database
2306  */
2307 class ResultWrapper implements Iterator {
2308         var $db, $result, $pos = 0, $currentRow = null;
2309
2310         /**
2311          * Create a new result object from a result resource and a Database object
2312          */
2313         function ResultWrapper( $database, $result ) {
2314                 $this->db = $database;
2315                 if ( $result instanceof ResultWrapper ) {
2316                         $this->result = $result->result;
2317                 } else {
2318                         $this->result = $result;
2319                 }
2320         }
2321
2322         /**
2323          * Get the number of rows in a result object
2324          */
2325         function numRows() {
2326                 return $this->db->numRows( $this->result );
2327         }
2328
2329         /**
2330          * Fetch the next row from the given result object, in object form.
2331          * Fields can be retrieved with $row->fieldname, with fields acting like
2332          * member variables.
2333          *
2334          * @param $res SQL result object as returned from Database::query(), etc.
2335          * @return MySQL row object
2336          * @throws DBUnexpectedError Thrown if the database returns an error
2337          */
2338         function fetchObject() {
2339                 return $this->db->fetchObject( $this->result );
2340         }
2341
2342         /**
2343          * Fetch the next row from the given result object, in associative array
2344          * form.  Fields are retrieved with $row['fieldname'].
2345          *
2346          * @param $res SQL result object as returned from Database::query(), etc.
2347          * @return MySQL row object
2348          * @throws DBUnexpectedError Thrown if the database returns an error
2349          */
2350         function fetchRow() {
2351                 return $this->db->fetchRow( $this->result );
2352         }
2353
2354         /**
2355          * Free a result object
2356          */
2357         function free() {
2358                 $this->db->freeResult( $this->result );
2359                 unset( $this->result );
2360                 unset( $this->db );
2361         }
2362
2363         /**
2364          * Change the position of the cursor in a result object
2365          * See mysql_data_seek()
2366          */
2367         function seek( $row ) {
2368                 $this->db->dataSeek( $this->result, $row );
2369         }
2370
2371         /*********************
2372          * Iterator functions
2373          * Note that using these in combination with the non-iterator functions
2374          * above may cause rows to be skipped or repeated.
2375          */
2376
2377         function rewind() {
2378                 if ($this->numRows()) {
2379                         $this->db->dataSeek($this->result, 0);
2380                 }
2381                 $this->pos = 0;
2382                 $this->currentRow = null;
2383         }
2384
2385         function current() {
2386                 if ( is_null( $this->currentRow ) ) {
2387                         $this->next();
2388                 }
2389                 return $this->currentRow;
2390         }
2391
2392         function key() {
2393                 return $this->pos;
2394         }
2395
2396         function next() {
2397                 $this->pos++;
2398                 $this->currentRow = $this->fetchObject();
2399                 return $this->currentRow;
2400         }
2401
2402         function valid() {
2403                 return $this->current() !== false;
2404         }
2405 }
2406
2407