includes/Database.php

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