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