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  * Database abstraction object
  16  * @addtogroup Database
  17  */
  18 class Database {
  19
  20 #------------------------------------------------------------------------------
  21 # Variables
  22 #------------------------------------------------------------------------------
  23
  24         protected $mLastQuery = '';
  25
  26         protected $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
  27         protected $mOut, $mOpened = false;
  28
  29         protected $mFailFunction;
  30         protected $mTablePrefix;
  31         protected $mFlags;
  32         protected $mTrxLevel = 0;
  33         protected $mErrorCount = 0;
  34         protected $mLBInfo = array();
  35         protected $mFakeSlaveLag = null, $mFakeMaster = false;
  36
  37 #------------------------------------------------------------------------------
  38 # Accessors
  39 #------------------------------------------------------------------------------
  40         # These optionally set a variable and return the previous state
  41
  42         /**
  43          * Fail function, takes a Database as a parameter
  44          * Set to false for default, 1 for ignore errors
  45          */
  46         function failFunction( $function = NULL ) {
  47                 return wfSetVar( $this->mFailFunction, $function );
  48         }
  49
  50         /**
  51          * Output page, used for reporting errors
  52          * FALSE means discard output
  53          */
  54         function setOutputPage( $out ) {
  55                 $this->mOut = $out;
  56         }
  57
  58         /**
  59          * Boolean, controls output of large amounts of debug information
  60          */
  61         function debug( $debug = NULL ) {
  62                 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
  63         }
  64
  65         /**
  66          * Turns buffering of SQL result sets on (true) or off (false).
  67          * Default is "on" and it should not be changed without good reasons.
  68          */
  69         function bufferResults( $buffer = NULL ) {
  70                 if ( is_null( $buffer ) ) {
  71                         return !(bool)( $this->mFlags & DBO_NOBUFFER );
  72                 } else {
  73                         return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
  74                 }
  75         }
  76
  77         /**
  78          * Turns on (false) or off (true) the automatic generation and sending
  79          * of a "we're sorry, but there has been a database error" page on
  80          * database errors. Default is on (false). When turned off, the
  81          * code should use lastErrno() and lastError() to handle the
  82          * situation as appropriate.
  83          */
  84         function ignoreErrors( $ignoreErrors = NULL ) {
  85                 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
  86         }
  87
  88         /**
  89          * The current depth of nested transactions
  90          * @param $level Integer: , default NULL.
  91          */
  92         function trxLevel( $level = NULL ) {
  93                 return wfSetVar( $this->mTrxLevel, $level );
  94         }
  95
  96         /**
  97          * Number of errors logged, only useful when errors are ignored
  98          */
  99         function errorCount( $count = NULL ) {
 100                 return wfSetVar( $this->mErrorCount, $count );
 101         }
 102
 103         function tablePrefix( $prefix = null ) {
 104                 return wfSetVar( $this->mTablePrefix, $prefix );
 105         }
 106
 107         /**
 108          * Properties passed down from the server info array of the load balancer
 109          */
 110         function getLBInfo( $name = NULL ) {
 111                 if ( is_null( $name ) ) {
 112                         return $this->mLBInfo;
 113                 } else {
 114                         if ( array_key_exists( $name, $this->mLBInfo ) ) {
 115                                 return $this->mLBInfo[$name];
 116                         } else {
 117                                 return NULL;
 118                         }
 119                 }
 120         }
 121
 122         function setLBInfo( $name, $value = NULL ) {
 123                 if ( is_null( $value ) ) {
 124                         $this->mLBInfo = $name;
 125                 } else {
 126                         $this->mLBInfo[$name] = $value;
 127                 }
 128         }
 129
 130         /**
 131          * Set lag time in seconds for a fake slave
 132          */
 133         function setFakeSlaveLag( $lag ) {
 134                 $this->mFakeSlaveLag = $lag;
 135         }
 136
 137         /**
 138          * Make this connection a fake master
 139          */
 140         function setFakeMaster( $enabled = true ) {
 141                 $this->mFakeMaster = $enabled;
 142         }
 143
 144         /**
 145          * Returns true if this database supports (and uses) cascading deletes
 146          */
 147         function cascadingDeletes() {
 148                 return false;
 149         }
 150
 151         /**
 152          * Returns true if this database supports (and uses) triggers (e.g. on the page table)
 153          */
 154         function cleanupTriggers() {
 155                 return false;
 156         }
 157
 158         /**
 159          * Returns true if this database is strict about what can be put into an IP field.
 160          * Specifically, it uses a NULL value instead of an empty string.
 161          */
 162         function strictIPs() {
 163                 return false;
 164         }
 165
 166         /**
 167          * Returns true if this database uses timestamps rather than integers
 168         */
 169         function realTimestamps() {
 170                 return false;
 171         }
 172
 173         /**
 174          * Returns true if this database does an implicit sort when doing GROUP BY
 175          */
 176         function implicitGroupby() {
 177                 return true;
 178         }
 179
 180         /**
 181          * Returns true if this database does an implicit order by when the column has an index
 182          * For example: SELECT page_title FROM page LIMIT 1
 183          */
 184         function implicitOrderby() {
 185                 return true;
 186         }
 187
 188         /**
 189          * Returns true if this database can do a native search on IP columns
 190          * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
 191          */
 192         function searchableIPs() {
 193                 return false;
 194         }
 195
 196         /**
 197          * Returns true if this database can use functional indexes
 198          */
 199         function functionalIndexes() {
 200                 return false;
 201         }
 202
 203         /**#@+
 204          * Get function
 205          */
 206         function lastQuery() { return $this->mLastQuery; }
 207         function isOpen() { return $this->mOpened; }
 208         /**#@-*/
 209
 210         function setFlag( $flag ) {
 211                 $this->mFlags |= $flag;
 212         }
 213
 214         function clearFlag( $flag ) {
 215                 $this->mFlags &= ~$flag;
 216         }
 217
 218         function getFlag( $flag ) {
 219                 return !!($this->mFlags & $flag);
 220         }
 221
 222         /**
 223          * General read-only accessor
 224          */
 225         function getProperty( $name ) {
 226                 return $this->$name;
 227         }
 228
 229         function getWikiID() {
 230                 if( $this->mTablePrefix ) {
 231                         return "{$this->mDBname}-{$this->mTablePrefix}";
 232                 } else {
 233                         return $this->mDBname;
 234                 }
 235         }
 236
 237 #------------------------------------------------------------------------------
 238 # Other functions
 239 #------------------------------------------------------------------------------
 240
 241         /**@{{
 242          * Constructor.
 243          * @param string $server database server host
 244          * @param string $user database user name
 245          * @param string $password database user password
 246          * @param string $dbname database name
 247          * @param failFunction
 248          * @param $flags
 249          * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
 250          */
 251         function __construct( $server = false, $user = false, $password = false, $dbName = false,
 252                 $failFunction = false, $flags = 0, $tablePrefix = 'get from global' ) {
 253
 254                 global $wgOut, $wgDBprefix, $wgCommandLineMode;
 255                 # Can't get a reference if it hasn't been set yet
 256                 if ( !isset( $wgOut ) ) {
 257                         $wgOut = NULL;
 258                 }
 259                 $this->mOut =& $wgOut;
 260
 261                 $this->mFailFunction = $failFunction;
 262                 $this->mFlags = $flags;
 263
 264                 if ( $this->mFlags & DBO_DEFAULT ) {
 265                         if ( $wgCommandLineMode ) {
 266                                 $this->mFlags &= ~DBO_TRX;
 267                         } else {
 268                                 $this->mFlags |= DBO_TRX;
 269                         }
 270                 }
 271
 272                 /*
 273                 // Faster read-only access
 274                 if ( wfReadOnly() ) {
 275                         $this->mFlags |= DBO_PERSISTENT;
 276                         $this->mFlags &= ~DBO_TRX;
 277                 }*/
 278
 279                 /** Get the default table prefix*/
 280                 if ( $tablePrefix == 'get from global' ) {
 281                         $this->mTablePrefix = $wgDBprefix;
 282                 } else {
 283                         $this->mTablePrefix = $tablePrefix;
 284                 }
 285
 286                 if ( $server ) {
 287                         $this->open( $server, $user, $password, $dbName );
 288                 }
 289         }
 290
 291         /**
 292          * @static
 293          * @param failFunction
 294          * @param $flags
 295          */
 296         static function newFromParams( $server, $user, $password, $dbName, $failFunction = false, $flags = 0 )
 297         {
 298                 return new Database( $server, $user, $password, $dbName, $failFunction, $flags );
 299         }
 300
 301         /**
 302          * Usually aborts on failure
 303          * If the failFunction is set to a non-zero integer, returns success
 304          */
 305         function open( $server, $user, $password, $dbName ) {
 306                 global $wguname, $wgAllDBsAreLocalhost;
 307                 wfProfileIn( __METHOD__ );
 308
 309                 # Test for missing mysql.so
 310                 # First try to load it
 311                 if (!@extension_loaded('mysql')) {
 312                         @dl('mysql.so');
 313                 }
 314
 315                 # Fail now
 316                 # Otherwise we get a suppressed fatal error, which is very hard to track down
 317                 if ( !function_exists( 'mysql_connect' ) ) {
 318                         throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
 319                 }
 320
 321                 # Debugging hack -- fake cluster
 322                 if ( $wgAllDBsAreLocalhost ) {
 323                         $realServer = 'localhost';
 324                 } else {
 325                         $realServer = $server;
 326                 }
 327                 $this->close();
 328                 $this->mServer = $server;
 329                 $this->mUser = $user;
 330                 $this->mPassword = $password;
 331                 $this->mDBname = $dbName;
 332
 333                 $success = false;
 334
 335                 wfProfileIn("dbconnect-$server");
 336
 337                 # Try to connect up to three times
 338                 # The kernel's default SYN retransmission period is far too slow for us,
 339                 # so we use a short timeout plus a manual retry.
 340                 $this->mConn = false;
 341                 $max = 3;
 342                 for ( $i = 0; $i < $max && !$this->mConn; $i++ ) {
 343                         if ( $i > 1 ) {
 344                                 usleep( 1000 );
 345                         }
 346                         if ( $this->mFlags & DBO_PERSISTENT ) {
 347                                 @/**/$this->mConn = mysql_pconnect( $realServer, $user, $password );
 348                         } else {
 349                                 # Create a new connection...
 350                                 @/**/$this->mConn = mysql_connect( $realServer, $user, $password, true );
 351                         }
 352                         if ($this->mConn === false) {
 353                                 #$iplus = $i + 1;
 354                                 #wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
 355                         }
 356                 }
 357
 358                 wfProfileOut("dbconnect-$server");
 359
 360                 if ( $dbName != '' ) {
 361                         if ( $this->mConn !== false ) {
 362                                 $success = @/**/mysql_select_db( $dbName, $this->mConn );
 363                                 if ( !$success ) {
 364                                         $error = "Error selecting database $dbName on server {$this->mServer} " .
 365                                                 "from client host {$wguname['nodename']}\n";
 366                                         wfLogDBError(" Error selecting database $dbName on server {$this->mServer} \n");
 367                                         wfDebug( $error );
 368                                 }
 369                         } else {
 370                                 wfDebug( "DB connection error\n" );
 371                                 wfDebug( "Server: $server, User: $user, Password: " .
 372                                         substr( $password, 0, 3 ) . "..., error: " . mysql_error() . "\n" );
 373                                 $success = false;
 374                         }
 375                 } else {
 376                         # Delay USE query
 377                         $success = (bool)$this->mConn;
 378                 }
 379
 380                 if ( $success ) {
 381                         $version = $this->getServerVersion();
 382                         if ( version_compare( $version, '4.1' ) >= 0 ) {
 383                                 // Tell the server we're communicating with it in UTF-8.
 384                                 // This may engage various charset conversions.
 385                                 global $wgDBmysql5;
 386                                 if( $wgDBmysql5 ) {
 387                                         $this->query( 'SET NAMES utf8', __METHOD__ );
 388                                 }
 389                                 // Turn off strict mode
 390                                 $this->query( "SET sql_mode = ''", __METHOD__ );
 391                         }
 392
 393                         // Turn off strict mode if it is on
 394                 } else {
 395                         $this->reportConnectionError();
 396                 }
 397
 398                 $this->mOpened = $success;
 399                 wfProfileOut( __METHOD__ );
 400                 return $success;
 401         }
 402         /**@}}*/
 403
 404         /**
 405          * Closes a database connection.
 406          * if it is open : commits any open transactions
 407          *
 408          * @return bool operation success. true if already closed.
 409          */
 410         function close()
 411         {
 412                 $this->mOpened = false;
 413                 if ( $this->mConn ) {
 414                         if ( $this->trxLevel() ) {
 415                                 $this->immediateCommit();
 416                         }
 417                         return mysql_close( $this->mConn );
 418                 } else {
 419                         return true;
 420                 }
 421         }
 422
 423         /**
 424          * @param string $error fallback error message, used if none is given by MySQL
 425          */
 426         function reportConnectionError( $error = 'Unknown error' ) {
 427                 $myError = $this->lastError();
 428                 if ( $myError ) {
 429                         $error = $myError;
 430                 }
 431
 432                 if ( $this->mFailFunction ) {
 433                         # Legacy error handling method
 434                         if ( !is_int( $this->mFailFunction ) ) {
 435                                 $ff = $this->mFailFunction;
 436                                 $ff( $this, $error );
 437                         }
 438                 } else {
 439                         # New method
 440                         wfLogDBError( "Connection error: $error\n" );
 441                         throw new DBConnectionError( $this, $error );
 442                 }
 443         }
 444
 445         /**
 446          * Usually aborts on failure.  If errors are explicitly ignored, returns success.
 447          *
 448          * @param  $sql        String: SQL query
 449          * @param  $fname      String: Name of the calling function, for profiling/SHOW PROCESSLIST
 450          *     comment (you can use __METHOD__ or add some extra info)
 451          * @param  $tempIgnore Bool:   Whether to avoid throwing an exception on errors...
 452          *     maybe best to catch the exception instead?
 453          * @return true for a successful write query, ResultWrapper object for a successful read query,
 454          *     or false on failure if $tempIgnore set
 455          * @throws DBQueryError Thrown when the database returns an error of any kind
 456          */
 457         public function query( $sql, $fname = '', $tempIgnore = false ) {
 458                 global $wgProfiler;
 459
 460                 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
 461                 if ( isset( $wgProfiler ) ) {
 462                         # generalizeSQL will probably cut down the query to reasonable
 463                         # logging size most of the time. The substr is really just a sanity check.
 464
 465                         # Who's been wasting my precious column space? -- TS
 466                         #$profName = 'query: ' . $fname . ' ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 467
 468                         if ( $isMaster ) {
 469                                 $queryProf = 'query-m: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 470                                 $totalProf = 'Database::query-master';
 471                         } else {
 472                                 $queryProf = 'query: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 473                                 $totalProf = 'Database::query';
 474                         }
 475                         wfProfileIn( $totalProf );
 476                         wfProfileIn( $queryProf );
 477                 }
 478
 479                 $this->mLastQuery = $sql;
 480
 481                 # Add a comment for easy SHOW PROCESSLIST interpretation
 482                 #if ( $fname ) {
 483                         global $wgUser;
 484                         if ( is_object( $wgUser ) && !($wgUser instanceof StubObject) ) {
 485                                 $userName = $wgUser->getName();
 486                                 if ( mb_strlen( $userName ) > 15 ) {
 487                                         $userName = mb_substr( $userName, 0, 15 ) . '...';
 488                                 }
 489                                 $userName = str_replace( '/', '', $userName );
 490                         } else {
 491                                 $userName = '';
 492                         }
 493                         $commentedSql = preg_replace('/\s/', " /* $fname $userName */ ", $sql, 1);
 494                 #} else {
 495                 #       $commentedSql = $sql;
 496                 #}
 497
 498                 # If DBO_TRX is set, start a transaction
 499                 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() &&
 500                         $sql != 'BEGIN' && $sql != 'COMMIT' && $sql != 'ROLLBACK') {
 501                         // avoid establishing transactions for SHOW and SET statements too -
 502                         // that would delay transaction initializations to once connection
 503                         // is really used by application
 504                         $sqlstart = substr($sql,0,10); // very much worth it, benchmark certified(tm)
 505                         if (strpos($sqlstart,"SHOW ")!==0 and strpos($sqlstart,"SET ")!==0)
 506                                 $this->begin();
 507                 }
 508
 509                 if ( $this->debug() ) {
 510                         $sqlx = substr( $commentedSql, 0, 500 );
 511                         $sqlx = strtr( $sqlx, "\t\n", '  ' );
 512                         if ( $isMaster ) {
 513                                 wfDebug( "SQL-master: $sqlx\n" );
 514                         } else {
 515                                 wfDebug( "SQL: $sqlx\n" );
 516                         }
 517                 }
 518
 519                 # Do the query and handle errors
 520                 $ret = $this->doQuery( $commentedSql );
 521
 522                 # Try reconnecting if the connection was lost
 523                 if ( false === $ret && ( $this->lastErrno() == 2013 || $this->lastErrno() == 2006 ) ) {
 524                         # Transaction is gone, like it or not
 525                         $this->mTrxLevel = 0;
 526                         wfDebug( "Connection lost, reconnecting...\n" );
 527                         if ( $this->ping() ) {
 528                                 wfDebug( "Reconnected\n" );
 529                                 $sqlx = substr( $commentedSql, 0, 500 );
 530                                 $sqlx = strtr( $sqlx, "\t\n", '  ' );
 531                                 global $wgRequestTime;
 532                                 $elapsed = round( microtime(true) - $wgRequestTime, 3 );
 533                                 wfLogDBError( "Connection lost and reconnected after {$elapsed}s, query: $sqlx\n" );
 534                                 $ret = $this->doQuery( $commentedSql );
 535                         } else {
 536                                 wfDebug( "Failed\n" );
 537                         }
 538                 }
 539
 540                 if ( false === $ret ) {
 541                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
 542                 }
 543
 544                 if ( isset( $wgProfiler ) ) {
 545                         wfProfileOut( $queryProf );
 546                         wfProfileOut( $totalProf );
 547                 }
 548                 return $this->resultObject( $ret );
 549         }
 550
 551         /**
 552          * The DBMS-dependent part of query()
 553          * @param  $sql String: SQL query.
 554          * @return Result object to feed to fetchObject, fetchRow, ...; or false on failure
 555          * @access private
 556          */
 557         /*private*/ function doQuery( $sql ) {
 558                 if( $this->bufferResults() ) {
 559                         $ret = mysql_query( $sql, $this->mConn );
 560                 } else {
 561                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 562                 }
 563                 return $ret;
 564         }
 565
 566         /**
 567          * @param $error
 568          * @param $errno
 569          * @param $sql
 570          * @param string $fname
 571          * @param bool $tempIgnore
 572          */
 573         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 574                 global $wgCommandLineMode;
 575                 # Ignore errors during error handling to avoid infinite recursion
 576                 $ignore = $this->ignoreErrors( true );
 577                 ++$this->mErrorCount;
 578
 579                 if( $ignore || $tempIgnore ) {
 580                         wfDebug("SQL ERROR (ignored): $error\n");
 581                         $this->ignoreErrors( $ignore );
 582                 } else {
 583                         $sql1line = str_replace( "\n", "\\n", $sql );
 584                         wfLogDBError("$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n");
 585                         wfDebug("SQL ERROR: " . $error . "\n");
 586                         throw new DBQueryError( $this, $error, $errno, $sql, $fname );
 587                 }
 588         }
 589
 590
 591         /**
 592          * Intended to be compatible with the PEAR::DB wrapper functions.
 593          * http://pear.php.net/manual/en/package.database.db.intro-execute.php
 594          *
 595          * ? = scalar value, quoted as necessary
 596          * ! = raw SQL bit (a function for instance)
 597          * & = filename; reads the file and inserts as a blob
 598          *     (we don't use this though...)
 599          */
 600         function prepare( $sql, $func = 'Database::prepare' ) {
 601                 /* MySQL doesn't support prepared statements (yet), so just
 602                    pack up the query for reference. We'll manually replace
 603                    the bits later. */
 604                 return array( 'query' => $sql, 'func' => $func );
 605         }
 606
 607         function freePrepared( $prepared ) {
 608                 /* No-op for MySQL */
 609         }
 610
 611         /**
 612          * Execute a prepared query with the various arguments
 613          * @param string $prepared the prepared sql
 614          * @param mixed $args Either an array here, or put scalars as varargs
 615          */
 616         function execute( $prepared, $args = null ) {
 617                 if( !is_array( $args ) ) {
 618                         # Pull the var args
 619                         $args = func_get_args();
 620                         array_shift( $args );
 621                 }
 622                 $sql = $this->fillPrepared( $prepared['query'], $args );
 623                 return $this->query( $sql, $prepared['func'] );
 624         }
 625
 626         /**
 627          * Prepare & execute an SQL statement, quoting and inserting arguments
 628          * in the appropriate places.
 629          * @param string $query
 630          * @param string $args ...
 631          */
 632         function safeQuery( $query, $args = null ) {
 633                 $prepared = $this->prepare( $query, 'Database::safeQuery' );
 634                 if( !is_array( $args ) ) {
 635                         # Pull the var args
 636                         $args = func_get_args();
 637                         array_shift( $args );
 638                 }
 639                 $retval = $this->execute( $prepared, $args );
 640                 $this->freePrepared( $prepared );
 641                 return $retval;
 642         }
 643
 644         /**
 645          * For faking prepared SQL statements on DBs that don't support
 646          * it directly.
 647          * @param string $preparedSql - a 'preparable' SQL statement
 648          * @param array $args - array of arguments to fill it with
 649          * @return string executable SQL
 650          */
 651         function fillPrepared( $preparedQuery, $args ) {
 652                 reset( $args );
 653                 $this->preparedArgs =& $args;
 654                 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
 655                         array( &$this, 'fillPreparedArg' ), $preparedQuery );
 656         }
 657
 658         /**
 659          * preg_callback func for fillPrepared()
 660          * The arguments should be in $this->preparedArgs and must not be touched
 661          * while we're doing this.
 662          *
 663          * @param array $matches
 664          * @return string
 665          * @private
 666          */
 667         function fillPreparedArg( $matches ) {
 668                 switch( $matches[1] ) {
 669                         case '\\?': return '?';
 670                         case '\\!': return '!';
 671                         case '\\&': return '&';
 672                 }
 673                 list( /* $n */ , $arg ) = each( $this->preparedArgs );
 674                 switch( $matches[1] ) {
 675                         case '?': return $this->addQuotes( $arg );
 676                         case '!': return $arg;
 677                         case '&':
 678                                 # return $this->addQuotes( file_get_contents( $arg ) );
 679                                 throw new DBUnexpectedError( $this, '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
 680                         default:
 681                                 throw new DBUnexpectedError( $this, 'Received invalid match. This should never happen!' );
 682                 }
 683         }
 684
 685         /**#@+
 686          * @param mixed $res A SQL result
 687          */
 688         /**
 689          * Free a result object
 690          */
 691         function freeResult( $res ) {
 692                 if ( $res instanceof ResultWrapper ) {
 693                         $res = $res->result;
 694                 }
 695                 if ( !@/**/mysql_free_result( $res ) ) {
 696                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 697                 }
 698         }
 699
 700         /**
 701          * Fetch the next row from the given result object, in object form.
 702          * Fields can be retrieved with $row->fieldname, with fields acting like
 703          * member variables.
 704          *
 705          * @param $res SQL result object as returned from Database::query(), etc.
 706          * @return MySQL row object
 707          * @throws DBUnexpectedError Thrown if the database returns an error
 708          */
 709         function fetchObject( $res ) {
 710                 if ( $res instanceof ResultWrapper ) {
 711                         $res = $res->result;
 712                 }
 713                 @/**/$row = mysql_fetch_object( $res );
 714                 if( $this->lastErrno() ) {
 715                         throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
 716                 }
 717                 return $row;
 718         }
 719
 720         /**
 721          * Fetch the next row from the given result object, in associative array
 722          * form.  Fields are retrieved with $row['fieldname'].
 723          *
 724          * @param $res SQL result object as returned from Database::query(), etc.
 725          * @return MySQL row object
 726          * @throws DBUnexpectedError Thrown if the database returns an error
 727          */
 728         function fetchRow( $res ) {
 729                 if ( $res instanceof ResultWrapper ) {
 730                         $res = $res->result;
 731                 }
 732                 @/**/$row = mysql_fetch_array( $res );
 733                 if ( $this->lastErrno() ) {
 734                         throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
 735                 }
 736                 return $row;
 737         }
 738
 739         /**
 740          * Get the number of rows in a result object
 741          */
 742         function numRows( $res ) {
 743                 if ( $res instanceof ResultWrapper ) {
 744                         $res = $res->result;
 745                 }
 746                 @/**/$n = mysql_num_rows( $res );
 747                 if( $this->lastErrno() ) {
 748                         throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
 749                 }
 750                 return $n;
 751         }
 752
 753         /**
 754          * Get the number of fields in a result object
 755          * See documentation for mysql_num_fields()
 756          */
 757         function numFields( $res ) {
 758                 if ( $res instanceof ResultWrapper ) {
 759                         $res = $res->result;
 760                 }
 761                 return mysql_num_fields( $res );
 762         }
 763
 764         /**
 765          * Get a field name in a result object
 766          * See documentation for mysql_field_name():
 767          * http://www.php.net/mysql_field_name
 768          */
 769         function fieldName( $res, $n ) {
 770                 if ( $res instanceof ResultWrapper ) {
 771                         $res = $res->result;
 772                 }
 773                 return mysql_field_name( $res, $n );
 774         }
 775
 776         /**
 777          * Get the inserted value of an auto-increment row
 778          *
 779          * The value inserted should be fetched from nextSequenceValue()
 780          *
 781          * Example:
 782          * $id = $dbw->nextSequenceValue('page_page_id_seq');
 783          * $dbw->insert('page',array('page_id' => $id));
 784          * $id = $dbw->insertId();
 785          */
 786         function insertId() { return mysql_insert_id( $this->mConn ); }
 787
 788         /**
 789          * Change the position of the cursor in a result object
 790          * See mysql_data_seek()
 791          */
 792         function dataSeek( $res, $row ) {
 793                 if ( $res instanceof ResultWrapper ) {
 794                         $res = $res->result;
 795                 }
 796                 return mysql_data_seek( $res, $row );
 797         }
 798
 799         /**
 800          * Get the last error number
 801          * See mysql_errno()
 802          */
 803         function lastErrno() {
 804                 if ( $this->mConn ) {
 805                         return mysql_errno( $this->mConn );
 806                 } else {
 807                         return mysql_errno();
 808                 }
 809         }
 810
 811         /**
 812          * Get a description of the last error
 813          * See mysql_error() for more details
 814          */
 815         function lastError() {
 816                 if ( $this->mConn ) {
 817                         # Even if it's non-zero, it can still be invalid
 818                         wfSuppressWarnings();
 819                         $error = mysql_error( $this->mConn );
 820                         if ( !$error ) {
 821                                 $error = mysql_error();
 822                         }
 823                         wfRestoreWarnings();
 824                 } else {
 825                         $error = mysql_error();
 826                 }
 827                 if( $error ) {
 828                         $error .= ' (' . $this->mServer . ')';
 829                 }
 830                 return $error;
 831         }
 832         /**
 833          * Get the number of rows affected by the last write query
 834          * See mysql_affected_rows() for more details
 835          */
 836         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 837         /**#@-*/ // end of template : @param $result
 838
 839         /**
 840          * Simple UPDATE wrapper
 841          * Usually aborts on failure
 842          * If errors are explicitly ignored, returns success
 843          *
 844          * This function exists for historical reasons, Database::update() has a more standard
 845          * calling convention and feature set
 846          */
 847         function set( $table, $var, $value, $cond, $fname = 'Database::set' )
 848         {
 849                 $table = $this->tableName( $table );
 850                 $sql = "UPDATE $table SET $var = '" .
 851                   $this->strencode( $value ) . "' WHERE ($cond)";
 852                 return (bool)$this->query( $sql, $fname );
 853         }
 854
 855         /**
 856          * Simple SELECT wrapper, returns a single field, input must be encoded
 857          * Usually aborts on failure
 858          * If errors are explicitly ignored, returns FALSE on failure
 859          */
 860         function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
 861                 if ( !is_array( $options ) ) {
 862                         $options = array( $options );
 863                 }
 864                 $options['LIMIT'] = 1;
 865
 866                 $res = $this->select( $table, $var, $cond, $fname, $options );
 867                 if ( $res === false || !$this->numRows( $res ) ) {
 868                         return false;
 869                 }
 870                 $row = $this->fetchRow( $res );
 871                 if ( $row !== false ) {
 872                         $this->freeResult( $res );
 873                         return $row[0];
 874                 } else {
 875                         return false;
 876                 }
 877         }
 878
 879         /**
 880          * Returns an optional USE INDEX clause to go after the table, and a
 881          * string to go at the end of the query
 882          *
 883          * @private
 884          *
 885          * @param array $options an associative array of options to be turned into
 886          *              an SQL query, valid keys are listed in the function.
 887          * @return array
 888          */
 889         function makeSelectOptions( $options ) {
 890                 $preLimitTail = $postLimitTail = '';
 891                 $startOpts = '';
 892
 893                 $noKeyOptions = array();
 894                 foreach ( $options as $key => $option ) {
 895                         if ( is_numeric( $key ) ) {
 896                                 $noKeyOptions[$option] = true;
 897                         }
 898                 }
 899
 900                 if ( isset( $options['GROUP BY'] ) ) $preLimitTail .= " GROUP BY {$options['GROUP BY']}";
 901                 if ( isset( $options['HAVING'] ) ) $preLimitTail .= " HAVING {$options['HAVING']}";
 902                 if ( isset( $options['ORDER BY'] ) ) $preLimitTail .= " ORDER BY {$options['ORDER BY']}";
 903
 904                 //if (isset($options['LIMIT'])) {
 905                 //      $tailOpts .= $this->limitResult('', $options['LIMIT'],
 906                 //              isset($options['OFFSET']) ? $options['OFFSET']
 907                 //              : false);
 908                 //}
 909
 910                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $postLimitTail .= ' FOR UPDATE';
 911                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $postLimitTail .= ' LOCK IN SHARE MODE';
 912                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
 913
 914                 # Various MySQL extensions
 915                 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) $startOpts .= ' /*! STRAIGHT_JOIN */';
 916                 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) $startOpts .= ' HIGH_PRIORITY';
 917                 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) $startOpts .= ' SQL_BIG_RESULT';
 918                 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) $startOpts .= ' SQL_BUFFER_RESULT';
 919                 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) $startOpts .= ' SQL_SMALL_RESULT';
 920                 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) $startOpts .= ' SQL_CALC_FOUND_ROWS';
 921                 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) $startOpts .= ' SQL_CACHE';
 922                 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) $startOpts .= ' SQL_NO_CACHE';
 923
 924                 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
 925                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
 926                 } else {
 927                         $useIndex = '';
 928                 }
 929
 930                 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
 931         }
 932
 933         /**
 934          * SELECT wrapper
 935          *
 936          * @param mixed  $table   Array or string, table name(s) (prefix auto-added)
 937          * @param mixed  $vars    Array or string, field name(s) to be retrieved
 938          * @param mixed  $conds   Array or string, condition(s) for WHERE
 939          * @param string $fname   Calling function name (use __METHOD__) for logs/profiling
 940          * @param array  $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
 941          *                        see Database::makeSelectOptions code for list of supported stuff
 942          * @param array $join_conds Associative array of table join conditions (optional)
 943          *                        (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
 944          * @return mixed Database result resource (feed to Database::fetchObject or whatever), or false on failure
 945          */
 946         function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array(), $join_conds = array() )
 947         {
 948                 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 949                 return $this->query( $sql, $fname );
 950         }
 951
 952         /**
 953          * SELECT wrapper
 954          *
 955          * @param mixed  $table   Array or string, table name(s) (prefix auto-added)
 956          * @param mixed  $vars    Array or string, field name(s) to be retrieved
 957          * @param mixed  $conds   Array or string, condition(s) for WHERE
 958          * @param string $fname   Calling function name (use __METHOD__) for logs/profiling
 959          * @param array  $options Associative array of options (e.g. array('GROUP BY' => 'page_title')),
 960          *                        see Database::makeSelectOptions code for list of supported stuff
 961          * @param array $join_conds Associative array of table join conditions (optional)
 962          *                        (e.g. array( 'page' => array('LEFT JOIN','page_latest=rev_id') )
 963          * @return string, the SQL text
 964          */
 965         function selectSQLText( $table, $vars, $conds='', $fname = 'Database::select', $options = array(), $join_conds = array() ) {
 966                 if( is_array( $vars ) ) {
 967                         $vars = implode( ',', $vars );
 968                 }
 969                 if( !is_array( $options ) ) {
 970                         $options = array( $options );
 971                 }
 972                 if( is_array( $table ) ) {
 973                         if ( !empty($join_conds) || is_array( @$options['USE INDEX'] ) )
 974                                 $from = ' FROM ' . $this->tableNamesWithUseIndexOrJOIN( $table, @$options['USE INDEX'], $join_conds );
 975                         else
 976                                 $from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
 977                 } elseif ($table!='') {
 978                         if ($table{0}==' ') {
 979                                 $from = ' FROM ' . $table;
 980                         } else {
 981                                 $from = ' FROM ' . $this->tableName( $table );
 982                         }
 983                 } else {
 984                         $from = '';
 985                 }
 986
 987                 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) = $this->makeSelectOptions( $options );
 988
 989                 if( !empty( $conds ) ) {
 990                         if ( is_array( $conds ) ) {
 991                                 $conds = $this->makeList( $conds, LIST_AND );
 992                         }
 993                         $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
 994                 } else {
 995                         $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
 996                 }
 997
 998                 if (isset($options['LIMIT']))
 999                         $sql = $this->limitResult($sql, $options['LIMIT'],
1000                                 isset($options['OFFSET']) ? $options['OFFSET'] : false);
1001                 $sql = "$sql $postLimitTail";
1002
1003                 if (isset($options['EXPLAIN'])) {
1004                         $sql = 'EXPLAIN ' . $sql;
1005                 }
1006                 return $sql;
1007         }
1008
1009         /**
1010          * Single row SELECT wrapper
1011          * Aborts or returns FALSE on error
1012          *
1013          * $vars: the selected variables
1014          * $conds: a condition map, terms are ANDed together.
1015          *   Items with numeric keys are taken to be literal conditions
1016          * Takes an array of selected variables, and a condition map, which is ANDed
1017          * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
1018          * NS_MAIN, "page_title" => "Astronomy" ) )   would return an object where
1019          * $obj- >page_id is the ID of the Astronomy article
1020          *
1021          * @todo migrate documentation to phpdocumentor format
1022          */
1023         function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
1024                 $options['LIMIT'] = 1;
1025                 $res = $this->select( $table, $vars, $conds, $fname, $options );
1026                 if ( $res === false )
1027                         return false;
1028                 if ( !$this->numRows($res) ) {
1029                         $this->freeResult($res);
1030                         return false;
1031                 }
1032                 $obj = $this->fetchObject( $res );
1033                 $this->freeResult( $res );
1034                 return $obj;
1035
1036         }
1037
1038         /**
1039          * Estimate rows in dataset
1040          * Returns estimated count, based on EXPLAIN output
1041          * Takes same arguments as Database::select()
1042          */
1043
1044         function estimateRowCount( $table, $vars='*', $conds='', $fname = 'Database::estimateRowCount', $options = array() ) {
1045                 $options['EXPLAIN']=true;
1046                 $res = $this->select ($table, $vars, $conds, $fname, $options );
1047                 if ( $res === false )
1048                         return false;
1049                 if (!$this->numRows($res)) {
1050                         $this->freeResult($res);
1051                         return 0;
1052                 }
1053
1054                 $rows=1;
1055
1056                 while( $plan = $this->fetchObject( $res ) ) {
1057                         $rows *= ($plan->rows > 0)?$plan->rows:1; // avoid resetting to zero
1058                 }
1059
1060                 $this->freeResult($res);
1061                 return $rows;
1062         }
1063
1064
1065         /**
1066          * Removes most variables from an SQL query and replaces them with X or N for numbers.
1067          * It's only slightly flawed. Don't use for anything important.
1068          *
1069          * @param string $sql A SQL Query
1070          * @static
1071          */
1072         static function generalizeSQL( $sql ) {
1073                 # This does the same as the regexp below would do, but in such a way
1074                 # as to avoid crashing php on some large strings.
1075                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
1076
1077                 $sql = str_replace ( "\\\\", '', $sql);
1078                 $sql = str_replace ( "\\'", '', $sql);
1079                 $sql = str_replace ( "\\\"", '', $sql);
1080                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
1081                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
1082
1083                 # All newlines, tabs, etc replaced by single space
1084                 $sql = preg_replace ( '/\s+/', ' ', $sql);
1085
1086                 # All numbers => N
1087                 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
1088
1089                 return $sql;
1090         }
1091
1092         /**
1093          * Determines whether a field exists in a table
1094          * Usually aborts on failure
1095          * If errors are explicitly ignored, returns NULL on failure
1096          */
1097         function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
1098                 $table = $this->tableName( $table );
1099                 $res = $this->query( 'DESCRIBE '.$table, $fname );
1100                 if ( !$res ) {
1101                         return NULL;
1102                 }
1103
1104                 $found = false;
1105
1106                 while ( $row = $this->fetchObject( $res ) ) {
1107                         if ( $row->Field == $field ) {
1108                                 $found = true;
1109                                 break;
1110                         }
1111                 }
1112                 return $found;
1113         }
1114
1115         /**
1116          * Determines whether an index exists
1117          * Usually aborts on failure
1118          * If errors are explicitly ignored, returns NULL on failure
1119          */
1120         function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
1121                 $info = $this->indexInfo( $table, $index, $fname );
1122                 if ( is_null( $info ) ) {
1123                         return NULL;
1124                 } else {
1125                         return $info !== false;
1126                 }
1127         }
1128
1129
1130         /**
1131          * Get information about an index into an object
1132          * Returns false if the index does not exist
1133          */
1134         function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
1135                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
1136                 # SHOW INDEX should work for 3.x and up:
1137                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
1138                 $table = $this->tableName( $table );
1139                 $sql = 'SHOW INDEX FROM '.$table;
1140                 $res = $this->query( $sql, $fname );
1141                 if ( !$res ) {
1142                         return NULL;
1143                 }
1144
1145                 $result = array();
1146                 while ( $row = $this->fetchObject( $res ) ) {
1147                         if ( $row->Key_name == $index ) {
1148                                 $result[] = $row;
1149                         }
1150                 }
1151                 $this->freeResult($res);
1152
1153                 return empty($result) ? false : $result;
1154         }
1155
1156         /**
1157          * Query whether a given table exists
1158          */
1159         function tableExists( $table ) {
1160                 $table = $this->tableName( $table );
1161                 $old = $this->ignoreErrors( true );
1162                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
1163                 $this->ignoreErrors( $old );
1164                 if( $res ) {
1165                         $this->freeResult( $res );
1166                         return true;
1167                 } else {
1168                         return false;
1169                 }
1170         }
1171
1172         /**
1173          * mysql_fetch_field() wrapper
1174          * Returns false if the field doesn't exist
1175          *
1176          * @param $table
1177          * @param $field
1178          */
1179         function fieldInfo( $table, $field ) {
1180                 $table = $this->tableName( $table );
1181                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
1182                 $n = mysql_num_fields( $res->result );
1183                 for( $i = 0; $i < $n; $i++ ) {
1184                         $meta = mysql_fetch_field( $res->result, $i );
1185                         if( $field == $meta->name ) {
1186                                 return new MySQLField($meta);
1187                         }
1188                 }
1189                 return false;
1190         }
1191
1192         /**
1193          * mysql_field_type() wrapper
1194          */
1195         function fieldType( $res, $index ) {
1196                 if ( $res instanceof ResultWrapper ) {
1197                         $res = $res->result;
1198                 }
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[0]->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          * @return bool
1289          */
1290         function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
1291                 $table = $this->tableName( $table );
1292                 $opts = $this->makeUpdateOptions( $options );
1293                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1294                 if ( $conds != '*' ) {
1295                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1296                 }
1297                 return $this->query( $sql, $fname );
1298         }
1299
1300         /**
1301          * Makes an encoded list of strings from an array
1302          * $mode:
1303          *        LIST_COMMA         - comma separated, no field names
1304          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
1305          *        LIST_OR            - ORed WHERE clause (without the WHERE)
1306          *        LIST_SET           - comma separated with field names, like a SET clause
1307          *        LIST_NAMES         - comma separated field names
1308          */
1309         function makeList( $a, $mode = LIST_COMMA ) {
1310                 if ( !is_array( $a ) ) {
1311                         throw new DBUnexpectedError( $this, 'Database::makeList called with incorrect parameters' );
1312                 }
1313
1314                 $first = true;
1315                 $list = '';
1316                 foreach ( $a as $field => $value ) {
1317                         if ( !$first ) {
1318                                 if ( $mode == LIST_AND ) {
1319                                         $list .= ' AND ';
1320                                 } elseif($mode == LIST_OR) {
1321                                         $list .= ' OR ';
1322                                 } else {
1323                                         $list .= ',';
1324                                 }
1325                         } else {
1326                                 $first = false;
1327                         }
1328                         if ( ($mode == LIST_AND || $mode == LIST_OR) && is_numeric( $field ) ) {
1329                                 $list .= "($value)";
1330                         } elseif ( ($mode == LIST_SET) && is_numeric( $field ) ) {
1331                                 $list .= "$value";
1332                         } elseif ( ($mode == LIST_AND || $mode == LIST_OR) && is_array($value) ) {
1333                                 if( count( $value ) == 0 ) {
1334                                         throw new MWException( __METHOD__.': empty input' );
1335                                 } elseif( count( $value ) == 1 ) {
1336                                         // Special-case single values, as IN isn't terribly efficient
1337                                         // Don't necessarily assume the single key is 0; we don't
1338                                         // enforce linear numeric ordering on other arrays here.
1339                                         $value = array_values( $value );
1340                                         $list .= $field." = ".$this->addQuotes( $value[0] );
1341                                 } else {
1342                                         $list .= $field." IN (".$this->makeList($value).") ";
1343                                 }
1344                         } elseif( is_null($value) ) {
1345                                 if ( $mode == LIST_AND || $mode == LIST_OR ) {
1346                                         $list .= "$field IS ";
1347                                 } elseif ( $mode == LIST_SET ) {
1348                                         $list .= "$field = ";
1349                                 }
1350                                 $list .= 'NULL';
1351                         } else {
1352                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1353                                         $list .= "$field = ";
1354                                 }
1355                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1356                         }
1357                 }
1358                 return $list;
1359         }
1360
1361         /**
1362          * Change the current database
1363          */
1364         function selectDB( $db ) {
1365                 $this->mDBname = $db;
1366                 return mysql_select_db( $db, $this->mConn );
1367         }
1368
1369         /**
1370          * Get the current DB name
1371          */
1372         function getDBname() {
1373                 return $this->mDBname;
1374         }
1375
1376         /**
1377          * Get the server hostname or IP address
1378          */
1379         function getServer() {
1380                 return $this->mServer;
1381         }
1382
1383         /**
1384          * Format a table name ready for use in constructing an SQL query
1385          *
1386          * This does two important things: it quotes the table names to clean them up,
1387          * and it adds a table prefix if only given a table name with no quotes.
1388          *
1389          * All functions of this object which require a table name call this function
1390          * themselves. Pass the canonical name to such functions. This is only needed
1391          * when calling query() directly.
1392          *
1393          * @param string $name database table name
1394          * @return string full database name
1395          */
1396         function tableName( $name ) {
1397                 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables;
1398                 # Skip the entire process when we have a string quoted on both ends.
1399                 # Note that we check the end so that we will still quote any use of
1400                 # use of `database`.table. But won't break things if someone wants
1401                 # to query a database table with a dot in the name.
1402                 if ( $name[0] == '`' && substr( $name, -1, 1 ) == '`' ) return $name;
1403
1404                 # Lets test for any bits of text that should never show up in a table
1405                 # name. Basically anything like JOIN or ON which are actually part of
1406                 # SQL queries, but may end up inside of the table value to combine
1407                 # sql. Such as how the API is doing.
1408                 # Note that we use a whitespace test rather than a \b test to avoid
1409                 # any remote case where a word like on may be inside of a table name
1410                 # surrounded by symbols which may be considered word breaks.
1411                 if( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) return $name;
1412
1413                 # Split database and table into proper variables.
1414                 # We reverse the explode so that database.table and table both output
1415                 # the correct table.
1416                 @list( $table, $database ) = array_reverse( explode( '.', $name, 2 ) );
1417                 $prefix = $this->mTablePrefix; # Default prefix
1418
1419                 # A database name has been specified in input. Quote the table name
1420                 # because we don't want any prefixes added.
1421                 if( isset($database) ) $table = ( $table[0] == '`' ? $table : "`{$table}`" );
1422
1423                 # Note that we use the long format because php will complain in in_array if
1424                 # the input is not an array, and will complain in is_array if it is not set.
1425                 if( !isset( $database ) # Don't use shared database if pre selected.
1426                  && isset( $wgSharedDB ) # We have a shared database
1427                  && $table[0] != '`' # Paranoia check to prevent shared tables listing '`table`'
1428                  && isset( $wgSharedTables )
1429                  && is_array( $wgSharedTables )
1430                  && in_array( $table, $wgSharedTables ) ) { # A shared table is selected
1431                         $database = $wgSharedDB;
1432                         $prefix   = isset( $wgSharedprefix ) ? $wgSharedprefix : $prefix;
1433                 }
1434
1435                 # Quote the $database and $table and apply the prefix if not quoted.
1436                 if( isset($database) ) $database = ( $database[0] == '`' ? $database : "`{$database}`" );
1437                 $table = ( $table[0] == '`' ? $table : "`{$prefix}{$table}`" );
1438
1439                 # Merge our database and table into our final table name.
1440                 $tableName = ( isset($database) ? "{$database}.{$table}" : "{$table}" );
1441
1442                 # We're finished, return.
1443                 return $tableName;
1444         }
1445
1446         /**
1447          * Fetch a number of table names into an array
1448          * This is handy when you need to construct SQL for joins
1449          *
1450          * Example:
1451          * extract($dbr->tableNames('user','watchlist'));
1452          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1453          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1454          */
1455         public function tableNames() {
1456                 $inArray = func_get_args();
1457                 $retVal = array();
1458                 foreach ( $inArray as $name ) {
1459                         $retVal[$name] = $this->tableName( $name );
1460                 }
1461                 return $retVal;
1462         }
1463
1464         /**
1465          * Fetch a number of table names into an zero-indexed numerical array
1466          * This is handy when you need to construct SQL for joins
1467          *
1468          * Example:
1469          * list( $user, $watchlist ) = $dbr->tableNamesN('user','watchlist');
1470          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1471          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1472          */
1473         public function tableNamesN() {
1474                 $inArray = func_get_args();
1475                 $retVal = array();
1476                 foreach ( $inArray as $name ) {
1477                         $retVal[] = $this->tableName( $name );
1478                 }
1479                 return $retVal;
1480         }
1481
1482         /**
1483          * @private
1484          */
1485         function tableNamesWithUseIndexOrJOIN( $tables, $use_index = array(), $join_conds = array() ) {
1486                 $ret = array();
1487                 $retJOIN = array();
1488                 $use_index_safe = is_array($use_index) ? $use_index : array();
1489                 $join_conds_safe = is_array($join_conds) ? $join_conds : array();
1490                 foreach ( $tables as $table ) {
1491                         // Is there a JOIN and INDEX clause for this table?
1492                         if ( isset($join_conds_safe[$table]) && isset($use_index_safe[$table]) ) {
1493                                 $tableClause = $join_conds_safe[$table][0] . ' ' . $this->tableName( $table );
1494                                 $tableClause .= ' ' . $this->useIndexClause( implode( ',', (array)$use_index_safe[$table] ) );
1495                                 $tableClause .= ' ON (' . $this->makeList((array)$join_conds_safe[$table][1], LIST_AND) . ')';
1496                                 $retJOIN[] = $tableClause;
1497                         // Is there an INDEX clause?
1498                         } else if ( isset($use_index_safe[$table]) ) {
1499                                 $tableClause = $this->tableName( $table );
1500                                 $tableClause .= ' ' . $this->useIndexClause( implode( ',', (array)$use_index_safe[$table] ) );
1501                                 $ret[] = $tableClause;
1502                         // Is there a JOIN clause?
1503                         } else if ( isset($join_conds_safe[$table]) ) {
1504                                 $tableClause = $join_conds_safe[$table][0] . ' ' . $this->tableName( $table );
1505                                 $tableClause .= ' ON (' . $this->makeList((array)$join_conds_safe[$table][1], LIST_AND) . ')';
1506                                 $retJOIN[] = $tableClause;
1507                         } else {
1508                                 $tableClause = $this->tableName( $table );
1509                                 $ret[] = $tableClause;
1510                         }
1511                 }
1512                 // We can't separate explicit JOIN clauses with ',', use ' ' for those
1513                 $straightJoins = !empty($ret) ? implode( ',', $ret ) : "";
1514                 $otherJoins = !empty($retJOIN) ? implode( ' ', $retJOIN ) : "";
1515                 // Compile our final table clause
1516                 return implode(' ',array($straightJoins,$otherJoins) );
1517         }
1518
1519         /**
1520          * Wrapper for addslashes()
1521          * @param string $s String to be slashed.
1522          * @return string slashed string.
1523          */
1524         function strencode( $s ) {
1525                 return mysql_real_escape_string( $s, $this->mConn );
1526         }
1527
1528         /**
1529          * If it's a string, adds quotes and backslashes
1530          * Otherwise returns as-is
1531          */
1532         function addQuotes( $s ) {
1533                 if ( is_null( $s ) ) {
1534                         return 'NULL';
1535                 } else {
1536                         # This will also quote numeric values. This should be harmless,
1537                         # and protects against weird problems that occur when they really
1538                         # _are_ strings such as article titles and string->number->string
1539                         # conversion is not 1:1.
1540                         return "'" . $this->strencode( $s ) . "'";
1541                 }
1542         }
1543
1544         /**
1545          * Escape string for safe LIKE usage
1546          */
1547         function escapeLike( $s ) {
1548                 $s=$this->strencode( $s );
1549                 $s=str_replace(array('%','_'),array('\%','\_'),$s);
1550                 return $s;
1551         }
1552
1553         /**
1554          * Returns an appropriately quoted sequence value for inserting a new row.
1555          * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1556          * subclass will return an integer, and save the value for insertId()
1557          */
1558         function nextSequenceValue( $seqName ) {
1559                 return NULL;
1560         }
1561
1562         /**
1563          * USE INDEX clause
1564          * PostgreSQL doesn't have them and returns ""
1565          */
1566         function useIndexClause( $index ) {
1567                 return "FORCE INDEX ($index)";
1568         }
1569
1570         /**
1571          * REPLACE query wrapper
1572          * PostgreSQL simulates this with a DELETE followed by INSERT
1573          * $row is the row to insert, an associative array
1574          * $uniqueIndexes is an array of indexes. Each element may be either a
1575          * field name or an array of field names
1576          *
1577          * It may be more efficient to leave off unique indexes which are unlikely to collide.
1578          * However if you do this, you run the risk of encountering errors which wouldn't have
1579          * occurred in MySQL
1580          *
1581          * @todo migrate comment to phodocumentor format
1582          */
1583         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
1584                 $table = $this->tableName( $table );
1585
1586                 # Single row case
1587                 if ( !is_array( reset( $rows ) ) ) {
1588                         $rows = array( $rows );
1589                 }
1590
1591                 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) .') VALUES ';
1592                 $first = true;
1593                 foreach ( $rows as $row ) {
1594                         if ( $first ) {
1595                                 $first = false;
1596                         } else {
1597                                 $sql .= ',';
1598                         }
1599                         $sql .= '(' . $this->makeList( $row ) . ')';
1600                 }
1601                 return $this->query( $sql, $fname );
1602         }
1603
1604         /**
1605          * DELETE where the condition is a join
1606          * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1607          *
1608          * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1609          * join condition matches, set $conds='*'
1610          *
1611          * DO NOT put the join condition in $conds
1612          *
1613          * @param string $delTable The table to delete from.
1614          * @param string $joinTable The other table.
1615          * @param string $delVar The variable to join on, in the first table.
1616          * @param string $joinVar The variable to join on, in the second table.
1617          * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
1618          */
1619         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
1620                 if ( !$conds ) {
1621                         throw new DBUnexpectedError( $this, 'Database::deleteJoin() called with empty $conds' );
1622                 }
1623
1624                 $delTable = $this->tableName( $delTable );
1625                 $joinTable = $this->tableName( $joinTable );
1626                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1627                 if ( $conds != '*' ) {
1628                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1629                 }
1630
1631                 return $this->query( $sql, $fname );
1632         }
1633
1634         /**
1635          * Returns the size of a text field, or -1 for "unlimited"
1636          */
1637         function textFieldSize( $table, $field ) {
1638                 $table = $this->tableName( $table );
1639                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1640                 $res = $this->query( $sql, 'Database::textFieldSize' );
1641                 $row = $this->fetchObject( $res );
1642                 $this->freeResult( $res );
1643
1644                 $m = array();
1645                 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
1646                         $size = $m[1];
1647                 } else {
1648                         $size = -1;
1649                 }
1650                 return $size;
1651         }
1652
1653         /**
1654          * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1655          */
1656         function lowPriorityOption() {
1657                 return 'LOW_PRIORITY';
1658         }
1659
1660         /**
1661          * DELETE query wrapper
1662          *
1663          * Use $conds == "*" to delete all rows
1664          */
1665         function delete( $table, $conds, $fname = 'Database::delete' ) {
1666                 if ( !$conds ) {
1667                         throw new DBUnexpectedError( $this, 'Database::delete() called with no conditions' );
1668                 }
1669                 $table = $this->tableName( $table );
1670                 $sql = "DELETE FROM $table";
1671                 if ( $conds != '*' ) {
1672                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1673                 }
1674                 return $this->query( $sql, $fname );
1675         }
1676
1677         /**
1678          * INSERT SELECT wrapper
1679          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1680          * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1681          * $conds may be "*" to copy the whole table
1682          * srcTable may be an array of tables.
1683          */
1684         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect',
1685                 $insertOptions = array(), $selectOptions = array() )
1686         {
1687                 $destTable = $this->tableName( $destTable );
1688                 if ( is_array( $insertOptions ) ) {
1689                         $insertOptions = implode( ' ', $insertOptions );
1690                 }
1691                 if( !is_array( $selectOptions ) ) {
1692                         $selectOptions = array( $selectOptions );
1693                 }
1694                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
1695                 if( is_array( $srcTable ) ) {
1696                         $srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
1697                 } else {
1698                         $srcTable = $this->tableName( $srcTable );
1699                 }
1700                 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1701                         " SELECT $startOpts " . implode( ',', $varMap ) .
1702                         " FROM $srcTable $useIndex ";
1703                 if ( $conds != '*' ) {
1704                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1705                 }
1706                 $sql .= " $tailOpts";
1707                 return $this->query( $sql, $fname );
1708         }
1709
1710         /**
1711          * Construct a LIMIT query with optional offset
1712          * This is used for query pages
1713          * $sql string SQL query we will append the limit too
1714          * $limit integer the SQL limit
1715          * $offset integer the SQL offset (default false)
1716          */
1717         function limitResult($sql, $limit, $offset=false) {
1718                 if( !is_numeric($limit) ) {
1719                         throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
1720                 }
1721                 return "$sql LIMIT "
1722                                 . ( (is_numeric($offset) && $offset != 0) ? "{$offset}," : "" )
1723                                 . "{$limit} ";
1724         }
1725         function limitResultForUpdate($sql, $num) {
1726                 return $this->limitResult($sql, $num, 0);
1727         }
1728
1729         /**
1730          * Returns an SQL expression for a simple conditional.
1731          * Uses IF on MySQL.
1732          *
1733          * @param string $cond SQL expression which will result in a boolean value
1734          * @param string $trueVal SQL expression to return if true
1735          * @param string $falseVal SQL expression to return if false
1736          * @return string SQL fragment
1737          */
1738         function conditional( $cond, $trueVal, $falseVal ) {
1739                 return " IF($cond, $trueVal, $falseVal) ";
1740         }
1741
1742         /**
1743          * Returns a comand for str_replace function in SQL query.
1744          * Uses REPLACE() in MySQL
1745          *
1746          * @param string $orig String or column to modify
1747          * @param string $old String or column to seek
1748          * @param string $new String or column to replace with
1749          */
1750         function strreplace( $orig, $old, $new ) {
1751                 return "REPLACE({$orig}, {$old}, {$new})";
1752         }
1753
1754         /**
1755          * Determines if the last failure was due to a deadlock
1756          */
1757         function wasDeadlock() {
1758                 return $this->lastErrno() == 1213;
1759         }
1760
1761         /**
1762          * Perform a deadlock-prone transaction.
1763          *
1764          * This function invokes a callback function to perform a set of write
1765          * queries. If a deadlock occurs during the processing, the transaction
1766          * will be rolled back and the callback function will be called again.
1767          *
1768          * Usage:
1769          *   $dbw->deadlockLoop( callback, ... );
1770          *
1771          * Extra arguments are passed through to the specified callback function.
1772          *
1773          * Returns whatever the callback function returned on its successful,
1774          * iteration, or false on error, for example if the retry limit was
1775          * reached.
1776          */
1777         function deadlockLoop() {
1778                 $myFname = 'Database::deadlockLoop';
1779
1780                 $this->begin();
1781                 $args = func_get_args();
1782                 $function = array_shift( $args );
1783                 $oldIgnore = $this->ignoreErrors( true );
1784                 $tries = DEADLOCK_TRIES;
1785                 if ( is_array( $function ) ) {
1786                         $fname = $function[0];
1787                 } else {
1788                         $fname = $function;
1789                 }
1790                 do {
1791                         $retVal = call_user_func_array( $function, $args );
1792                         $error = $this->lastError();
1793                         $errno = $this->lastErrno();
1794                         $sql = $this->lastQuery();
1795
1796                         if ( $errno ) {
1797                                 if ( $this->wasDeadlock() ) {
1798                                         # Retry
1799                                         usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1800                                 } else {
1801                                         $this->reportQueryError( $error, $errno, $sql, $fname );
1802                                 }
1803                         }
1804                 } while( $this->wasDeadlock() && --$tries > 0 );
1805                 $this->ignoreErrors( $oldIgnore );
1806                 if ( $tries <= 0 ) {
1807                         $this->query( 'ROLLBACK', $myFname );
1808                         $this->reportQueryError( $error, $errno, $sql, $fname );
1809                         return false;
1810                 } else {
1811                         $this->query( 'COMMIT', $myFname );
1812                         return $retVal;
1813                 }
1814         }
1815
1816         /**
1817          * Do a SELECT MASTER_POS_WAIT()
1818          *
1819          * @param string $file the binlog file
1820          * @param string $pos the binlog position
1821          * @param integer $timeout the maximum number of seconds to wait for synchronisation
1822          */
1823         function masterPosWait( MySQLMasterPos $pos, $timeout ) {
1824                 $fname = 'Database::masterPosWait';
1825                 wfProfileIn( $fname );
1826
1827                 # Commit any open transactions
1828                 if ( $this->mTrxLevel ) {
1829                         $this->immediateCommit();
1830                 }
1831
1832                 if ( !is_null( $this->mFakeSlaveLag ) ) {
1833                         $wait = intval( ( $pos->pos - microtime(true) + $this->mFakeSlaveLag ) * 1e6 );
1834                         if ( $wait > $timeout * 1e6 ) {
1835                                 wfDebug( "Fake slave timed out waiting for $pos ($wait us)\n" );
1836                                 wfProfileOut( $fname );
1837                                 return -1;
1838                         } elseif ( $wait > 0 ) {
1839                                 wfDebug( "Fake slave waiting $wait us\n" );
1840                                 usleep( $wait );
1841                                 wfProfileOut( $fname );
1842                                 return 1;
1843                         } else {
1844                                 wfDebug( "Fake slave up to date ($wait us)\n" );
1845                                 wfProfileOut( $fname );
1846                                 return 0;
1847                         }
1848                 }
1849
1850                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
1851                 $encFile = $this->addQuotes( $pos->file );
1852                 $encPos = intval( $pos->pos );
1853                 $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
1854                 $res = $this->doQuery( $sql );
1855                 if ( $res && $row = $this->fetchRow( $res ) ) {
1856                         $this->freeResult( $res );
1857                         wfProfileOut( $fname );
1858                         return $row[0];
1859                 } else {
1860                         wfProfileOut( $fname );
1861                         return false;
1862                 }
1863         }
1864
1865         /**
1866          * Get the position of the master from SHOW SLAVE STATUS
1867          */
1868         function getSlavePos() {
1869                 if ( !is_null( $this->mFakeSlaveLag ) ) {
1870                         $pos = new MySQLMasterPos( 'fake', microtime(true) - $this->mFakeSlaveLag );
1871                         wfDebug( __METHOD__.": fake slave pos = $pos\n" );
1872                         return $pos;
1873                 }
1874                 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1875                 $row = $this->fetchObject( $res );
1876                 if ( $row ) {
1877                         return new MySQLMasterPos( $row->Master_Log_File, $row->Read_Master_Log_Pos );
1878                 } else {
1879                         return false;
1880                 }
1881         }
1882
1883         /**
1884          * Get the position of the master from SHOW MASTER STATUS
1885          */
1886         function getMasterPos() {
1887                 if ( $this->mFakeMaster ) {
1888                         return new MySQLMasterPos( 'fake', microtime( true ) );
1889                 }
1890                 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1891                 $row = $this->fetchObject( $res );
1892                 if ( $row ) {
1893                         return new MySQLMasterPos( $row->File, $row->Position );
1894                 } else {
1895                         return false;
1896                 }
1897         }
1898
1899         /**
1900          * Begin a transaction, committing any previously open transaction
1901          */
1902         function begin( $fname = 'Database::begin' ) {
1903                 $this->query( 'BEGIN', $fname );
1904                 $this->mTrxLevel = 1;
1905         }
1906
1907         /**
1908          * End a transaction
1909          */
1910         function commit( $fname = 'Database::commit' ) {
1911                 $this->query( 'COMMIT', $fname );
1912                 $this->mTrxLevel = 0;
1913         }
1914
1915         /**
1916          * Rollback a transaction.
1917          * No-op on non-transactional databases.
1918          */
1919         function rollback( $fname = 'Database::rollback' ) {
1920                 $this->query( 'ROLLBACK', $fname, true );
1921                 $this->mTrxLevel = 0;
1922         }
1923
1924         /**
1925          * Begin a transaction, committing any previously open transaction
1926          * @deprecated use begin()
1927          */
1928         function immediateBegin( $fname = 'Database::immediateBegin' ) {
1929                 $this->begin();
1930         }
1931
1932         /**
1933          * Commit transaction, if one is open
1934          * @deprecated use commit()
1935          */
1936         function immediateCommit( $fname = 'Database::immediateCommit' ) {
1937                 $this->commit();
1938         }
1939
1940         /**
1941          * Return MW-style timestamp used for MySQL schema
1942          */
1943         function timestamp( $ts=0 ) {
1944                 return wfTimestamp(TS_MW,$ts);
1945         }
1946
1947         /**
1948          * Local database timestamp format or null
1949          */
1950         function timestampOrNull( $ts = null ) {
1951                 if( is_null( $ts ) ) {
1952                         return null;
1953                 } else {
1954                         return $this->timestamp( $ts );
1955                 }
1956         }
1957
1958         /**
1959          * @todo document
1960          */
1961         function resultObject( $result ) {
1962                 if( empty( $result ) ) {
1963                         return false;
1964                 } elseif ( $result instanceof ResultWrapper ) {
1965                         return $result;
1966                 } elseif ( $result === true ) {
1967                         // Successful write query
1968                         return $result;
1969                 } else {
1970                         return new ResultWrapper( $this, $result );
1971                 }
1972         }
1973
1974         /**
1975          * Return aggregated value alias
1976          */
1977         function aggregateValue ($valuedata,$valuename='value') {
1978                 return $valuename;
1979         }
1980
1981         /**
1982          * @return string wikitext of a link to the server software's web site
1983          */
1984         function getSoftwareLink() {
1985                 return "[http://www.mysql.com/ MySQL]";
1986         }
1987
1988         /**
1989          * @return string Version information from the database
1990          */
1991         function getServerVersion() {
1992                 return mysql_get_server_info( $this->mConn );
1993         }
1994
1995         /**
1996          * Ping the server and try to reconnect if it there is no connection
1997          */
1998         function ping() {
1999                 if( !function_exists( 'mysql_ping' ) ) {
2000                         wfDebug( "Tried to call mysql_ping but this is ancient PHP version. Faking it!\n" );
2001                         return true;
2002                 }
2003                 $ping = mysql_ping( $this->mConn );
2004                 if ( $ping ) {
2005                         return true;
2006                 }
2007
2008                 // Need to reconnect manually in MySQL client 5.0.13+
2009                 if ( version_compare( mysql_get_client_info(), '5.0.13', '>=' ) ) {
2010                         mysql_close( $this->mConn );
2011                         $this->mOpened = false;
2012                         $this->mConn = false;
2013                         $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
2014                         return true;
2015                 }
2016                 return false;
2017         }
2018
2019         /**
2020          * Get slave lag.
2021          * At the moment, this will only work if the DB user has the PROCESS privilege
2022          */
2023         function getLag() {
2024                 if ( !is_null( $this->mFakeSlaveLag ) ) {
2025                         wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
2026                         return $this->mFakeSlaveLag;
2027                 }
2028                 $res = $this->query( 'SHOW PROCESSLIST' );
2029                 # Find slave SQL thread
2030                 while ( $row = $this->fetchObject( $res ) ) {
2031                         /* This should work for most situations - when default db
2032                          * for thread is not specified, it had no events executed,
2033                          * and therefore it doesn't know yet how lagged it is.
2034                          *
2035                          * Relay log I/O thread does not select databases.
2036                          */
2037                         if ( $row->User == 'system user' &&
2038                                 $row->State != 'Waiting for master to send event' &&
2039                                 $row->State != 'Connecting to master' &&
2040                                 $row->State != 'Queueing master event to the relay log' &&
2041                                 $row->State != 'Waiting for master update' &&
2042                                 $row->State != 'Requesting binlog dump'
2043                                 ) {
2044                                 # This is it, return the time (except -ve)
2045                                 if ( $row->Time > 0x7fffffff ) {
2046                                         return false;
2047                                 } else {
2048                                         return $row->Time;
2049                                 }
2050                         }
2051                 }
2052                 return false;
2053         }
2054
2055         /**
2056          * Get status information from SHOW STATUS in an associative array
2057          */
2058         function getStatus($which="%") {
2059                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
2060                 $status = array();
2061                 while ( $row = $this->fetchObject( $res ) ) {
2062                         $status[$row->Variable_name] = $row->Value;
2063                 }
2064                 return $status;
2065         }
2066
2067         /**
2068          * Return the maximum number of items allowed in a list, or 0 for unlimited.
2069          */
2070         function maxListLen() {
2071                 return 0;
2072         }
2073
2074         function encodeBlob($b) {
2075                 return $b;
2076         }
2077
2078         function decodeBlob($b) {
2079                 return $b;
2080         }
2081
2082         /**
2083          * Override database's default connection timeout.
2084          * May be useful for very long batch queries such as
2085          * full-wiki dumps, where a single query reads out
2086          * over hours or days.
2087          * @param int $timeout in seconds
2088          */
2089         public function setTimeout( $timeout ) {
2090                 $this->query( "SET net_read_timeout=$timeout" );
2091                 $this->query( "SET net_write_timeout=$timeout" );
2092         }
2093
2094         /**
2095          * Read and execute SQL commands from a file.
2096          * Returns true on success, error string on failure
2097          * @param string $filename File name to open
2098          * @param callback $lineCallback Optional function called before reading each line
2099          * @param callback $resultCallback Optional function called for each MySQL result
2100          */
2101         function sourceFile( $filename, $lineCallback = false, $resultCallback = false ) {
2102                 $fp = fopen( $filename, 'r' );
2103                 if ( false === $fp ) {
2104                         return "Could not open \"{$filename}\".\n";
2105                 }
2106                 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback );
2107                 fclose( $fp );
2108                 return $error;
2109         }
2110
2111         /**
2112          * Read and execute commands from an open file handle
2113          * Returns true on success, error string on failure
2114          * @param string $fp File handle
2115          * @param callback $lineCallback Optional function called before reading each line
2116          * @param callback $resultCallback Optional function called for each MySQL result
2117          */
2118         function sourceStream( $fp, $lineCallback = false, $resultCallback = false ) {
2119                 $cmd = "";
2120                 $done = false;
2121                 $dollarquote = false;
2122
2123                 while ( ! feof( $fp ) ) {
2124                         if ( $lineCallback ) {
2125                                 call_user_func( $lineCallback );
2126                         }
2127                         $line = trim( fgets( $fp, 1024 ) );
2128                         $sl = strlen( $line ) - 1;
2129
2130                         if ( $sl < 0 ) { continue; }
2131                         if ( '-' == $line{0} && '-' == $line{1} ) { continue; }
2132
2133                         ## Allow dollar quoting for function declarations
2134                         if (substr($line,0,4) == '$mw$') {
2135                                 if ($dollarquote) {
2136                                         $dollarquote = false;
2137                                         $done = true;
2138                                 }
2139                                 else {
2140                                         $dollarquote = true;
2141                                 }
2142                         }
2143                         else if (!$dollarquote) {
2144                                 if ( ';' == $line{$sl} && ($sl < 2 || ';' != $line{$sl - 1})) {
2145                                         $done = true;
2146                                         $line = substr( $line, 0, $sl );
2147                                 }
2148                         }
2149
2150                         if ( '' != $cmd ) { $cmd .= ' '; }
2151                         $cmd .= "$line\n";
2152
2153                         if ( $done ) {
2154                                 $cmd = str_replace(';;', ";", $cmd);
2155                                 $cmd = $this->replaceVars( $cmd );
2156                                 $res = $this->query( $cmd, __METHOD__, true );
2157                                 if ( $resultCallback ) {
2158                                         call_user_func( $resultCallback, $res );
2159                                 }
2160
2161                                 if ( false === $res ) {
2162                                         $err = $this->lastError();
2163                                         return "Query \"{$cmd}\" failed with error code \"$err\".\n";
2164                                 }
2165
2166                                 $cmd = '';
2167                                 $done = false;
2168                         }
2169                 }
2170                 return true;
2171         }
2172
2173
2174         /**
2175          * Replace variables in sourced SQL
2176          */
2177         protected function replaceVars( $ins ) {
2178                 $varnames = array(
2179                         'wgDBserver', 'wgDBname', 'wgDBintlname', 'wgDBuser',
2180                         'wgDBpassword', 'wgDBsqluser', 'wgDBsqlpassword',
2181                         'wgDBadminuser', 'wgDBadminpassword', 'wgDBTableOptions',
2182                 );
2183
2184                 // Ordinary variables
2185                 foreach ( $varnames as $var ) {
2186                         if( isset( $GLOBALS[$var] ) ) {
2187                                 $val = addslashes( $GLOBALS[$var] ); // FIXME: safety check?
2188                                 $ins = str_replace( '{$' . $var . '}', $val, $ins );
2189                                 $ins = str_replace( '/*$' . $var . '*/`', '`' . $val, $ins );
2190                                 $ins = str_replace( '/*$' . $var . '*/', $val, $ins );
2191                         }
2192                 }
2193
2194                 // Table prefixes
2195                 $ins = preg_replace_callback( '/\/\*(?:\$wgDBprefix|_)\*\/([a-z_]*)/',
2196                         array( &$this, 'tableNameCallback' ), $ins );
2197                 return $ins;
2198         }
2199
2200         /**
2201          * Table name callback
2202          * @private
2203          */
2204         protected function tableNameCallback( $matches ) {
2205                 return $this->tableName( $matches[1] );
2206         }
2207
2208         /*
2209          * Build a concatenation list to feed into a SQL query
2210         */
2211         function buildConcat( $stringList ) {
2212                 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2213         }
2214
2215 }
2216
2217 /**
2218  * Database abstraction object for mySQL
2219  * Inherit all methods and properties of Database::Database()
2220  *
2221  * @addtogroup Database
2222  * @see Database
2223  */
2224 class DatabaseMysql extends Database {
2225         # Inherit all
2226 }
2227
2228 /******************************************************************************
2229  * Utility classes
2230  *****************************************************************************/
2231
2232 /**
2233  * Utility class.
2234  * @addtogroup Database
2235  */
2236 class DBObject {
2237         public $mData;
2238
2239         function DBObject($data) {
2240                 $this->mData = $data;
2241         }
2242
2243         function isLOB() {
2244                 return false;
2245         }
2246
2247         function data() {
2248                 return $this->mData;
2249         }
2250 }
2251
2252 /**
2253  * Utility class
2254  * @addtogroup Database
2255  *
2256  * This allows us to distinguish a blob from a normal string and an array of strings
2257  */
2258 class Blob {
2259         private $mData;
2260         function __construct($data) {
2261                 $this->mData = $data;
2262         }
2263         function fetch() {
2264                 return $this->mData;
2265         }
2266 }
2267
2268 /**
2269  * Utility class.
2270  * @addtogroup Database
2271  */
2272 class MySQLField {
2273         private $name, $tablename, $default, $max_length, $nullable,
2274                 $is_pk, $is_unique, $is_multiple, $is_key, $type;
2275         function __construct ($info) {
2276                 $this->name = $info->name;
2277                 $this->tablename = $info->table;
2278                 $this->default = $info->def;
2279                 $this->max_length = $info->max_length;
2280                 $this->nullable = !$info->not_null;
2281                 $this->is_pk = $info->primary_key;
2282                 $this->is_unique = $info->unique_key;
2283                 $this->is_multiple = $info->multiple_key;
2284                 $this->is_key = ($this->is_pk || $this->is_unique || $this->is_multiple);
2285                 $this->type = $info->type;
2286         }
2287
2288         function name() {
2289                 return $this->name;
2290         }
2291
2292         function tableName() {
2293                 return $this->tableName;
2294         }
2295
2296         function defaultValue() {
2297                 return $this->default;
2298         }
2299
2300         function maxLength() {
2301                 return $this->max_length;
2302         }
2303
2304         function nullable() {
2305                 return $this->nullable;
2306         }
2307
2308         function isKey() {
2309                 return $this->is_key;
2310         }
2311
2312         function isMultipleKey() {
2313                 return $this->is_multiple;
2314         }
2315
2316         function type() {
2317                 return $this->type;
2318         }
2319 }
2320
2321 /******************************************************************************
2322  * Error classes
2323  *****************************************************************************/
2324
2325 /**
2326  * Database error base class
2327  * @addtogroup Database
2328  */
2329 class DBError extends MWException {
2330         public $db;
2331
2332         /**
2333          * Construct a database error
2334          * @param Database $db The database object which threw the error
2335          * @param string $error A simple error message to be used for debugging
2336          */
2337         function __construct( Database &$db, $error ) {
2338                 $this->db =& $db;
2339                 parent::__construct( $error );
2340         }
2341 }
2342
2343 /**
2344  * @addtogroup Database
2345  */
2346 class DBConnectionError extends DBError {
2347         public $error;
2348
2349         function __construct( Database &$db, $error = 'unknown error' ) {
2350                 $msg = 'DB connection error';
2351                 if ( trim( $error ) != '' ) {
2352                         $msg .= ": $error";
2353                 }
2354                 $this->error = $error;
2355                 parent::__construct( $db, $msg );
2356         }
2357
2358         function useOutputPage() {
2359                 // Not likely to work
2360                 return false;
2361         }
2362
2363         function useMessageCache() {
2364                 // Not likely to work
2365                 return false;
2366         }
2367
2368         function getText() {
2369                 return $this->getMessage() . "\n";
2370         }
2371
2372         function getLogMessage() {
2373                 # Don't send to the exception log
2374                 return false;
2375         }
2376
2377         function getPageTitle() {
2378                 global $wgSitename;
2379                 return "$wgSitename has a problem";
2380         }
2381
2382         function getHTML() {
2383                 global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding;
2384                 global $wgSitename, $wgServer, $wgMessageCache;
2385
2386                 # I give up, Brion is right. Getting the message cache to work when there is no DB is tricky.
2387                 # Hard coding strings instead.
2388
2389                 $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>";
2390                 $mainpage = 'Main Page';
2391                 $searchdisabled = <<<EOT
2392 <p style="margin: 1.5em 2em 1em">$wgSitename search is disabled for performance reasons. You can search via Google in the meantime.
2393 <span style="font-size: 89%; display: block; margin-left: .2em">Note that their indexes of $wgSitename content may be out of date.</span></p>',
2394 EOT;
2395
2396                 $googlesearch = "
2397 <!-- SiteSearch Google -->
2398 <FORM method=GET action=\"http://www.google.com/search\">
2399 <TABLE bgcolor=\"#FFFFFF\"><tr><td>
2400 <A HREF=\"http://www.google.com/\">
2401 <IMG SRC=\"http://www.google.com/logos/Logo_40wht.gif\"
2402 border=\"0\" ALT=\"Google\"></A>
2403 </td>
2404 <td>
2405 <INPUT TYPE=text name=q size=31 maxlength=255 value=\"$1\">
2406 <INPUT type=submit name=btnG VALUE=\"Google Search\">
2407 <font size=-1>
2408 <input type=hidden name=domains value=\"$wgServer\"><br /><input type=radio name=sitesearch value=\"\"> WWW <input type=radio name=sitesearch value=\"$wgServer\" checked> $wgServer <br />
2409 <input type='hidden' name='ie' value='$2'>
2410 <input type='hidden' name='oe' value='$2'>
2411 </font>
2412 </td></tr></TABLE>
2413 </FORM>
2414 <!-- SiteSearch Google -->";
2415                 $cachederror = "The following is a cached copy of the requested page, and may not be up to date. ";
2416
2417                 # No database access
2418                 if ( is_object( $wgMessageCache ) ) {
2419                         $wgMessageCache->disable();
2420                 }
2421
2422                 if ( trim( $this->error ) == '' ) {
2423                         $this->error = $this->db->getProperty('mServer');
2424                 }
2425
2426                 $text = str_replace( '$1', $this->error, $noconnect );
2427                 $text .= wfGetSiteNotice();
2428
2429                 if($wgUseFileCache) {
2430                         if($wgTitle) {
2431                                 $t =& $wgTitle;
2432                         } else {
2433                                 if($title) {
2434                                         $t = Title::newFromURL( $title );
2435                                 } elseif (@/**/$_REQUEST['search']) {
2436                                         $search = $_REQUEST['search'];
2437                                         return $searchdisabled .
2438                                           str_replace( array( '$1', '$2' ), array( htmlspecialchars( $search ),
2439                                           $wgInputEncoding ), $googlesearch );
2440                                 } else {
2441                                         $t = Title::newFromText( $mainpage );
2442                                 }
2443                         }
2444
2445                         $cache = new HTMLFileCache( $t );
2446                         if( $cache->isFileCached() ) {
2447                                 // @todo, FIXME: $msg is not defined on the next line.
2448                                 $msg = '<p style="color: red"><b>'.$msg."<br />\n" .
2449                                         $cachederror . "</b></p>\n";
2450
2451                                 $tag = '<div id="article">';
2452                                 $text = str_replace(
2453                                         $tag,
2454                                         $tag . $msg,
2455                                         $cache->fetchPageText() );
2456                         }
2457                 }
2458
2459                 return $text;
2460         }
2461 }
2462
2463 /**
2464  * @addtogroup Database
2465  */
2466 class DBQueryError extends DBError {
2467         public $error, $errno, $sql, $fname;
2468
2469         function __construct( Database &$db, $error, $errno, $sql, $fname ) {
2470                 $message = "A database error has occurred\n" .
2471                   "Query: $sql\n" .
2472                   "Function: $fname\n" .
2473                   "Error: $errno $error\n";
2474
2475                 parent::__construct( $db, $message );
2476                 $this->error = $error;
2477                 $this->errno = $errno;
2478                 $this->sql = $sql;
2479                 $this->fname = $fname;
2480         }
2481
2482         function getText() {
2483                 if ( $this->useMessageCache() ) {
2484                         return wfMsg( 'dberrortextcl', htmlspecialchars( $this->getSQL() ),
2485                           htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) ) . "\n";
2486                 } else {
2487                         return $this->getMessage();
2488                 }
2489         }
2490
2491         function getSQL() {
2492                 global $wgShowSQLErrors;
2493                 if( !$wgShowSQLErrors ) {
2494                         return $this->msg( 'sqlhidden', 'SQL hidden' );
2495                 } else {
2496                         return $this->sql;
2497                 }
2498         }
2499
2500         function getLogMessage() {
2501                 # Don't send to the exception log
2502                 return false;
2503         }
2504
2505         function getPageTitle() {
2506                 return $this->msg( 'databaseerror', 'Database error' );
2507         }
2508
2509         function getHTML() {
2510                 if ( $this->useMessageCache() ) {
2511                         return wfMsgNoDB( 'dberrortext', htmlspecialchars( $this->getSQL() ),
2512                           htmlspecialchars( $this->fname ), $this->errno, htmlspecialchars( $this->error ) );
2513                 } else {
2514                         return nl2br( htmlspecialchars( $this->getMessage() ) );
2515                 }
2516         }
2517 }
2518
2519 /**
2520  * @addtogroup Database
2521  */
2522 class DBUnexpectedError extends DBError {}
2523
2524
2525 /**
2526  * Result wrapper for grabbing data queried by someone else
2527  * @addtogroup Database
2528  */
2529 class ResultWrapper implements Iterator {
2530         var $db, $result, $pos = 0, $currentRow = null;
2531
2532         /**
2533          * Create a new result object from a result resource and a Database object
2534          */
2535         function ResultWrapper( $database, $result ) {
2536                 $this->db = $database;
2537                 if ( $result instanceof ResultWrapper ) {
2538                         $this->result = $result->result;
2539                 } else {
2540                         $this->result = $result;
2541                 }
2542         }
2543
2544         /**
2545          * Get the number of rows in a result object
2546          */
2547         function numRows() {
2548                 return $this->db->numRows( $this->result );
2549         }
2550
2551         /**
2552          * Fetch the next row from the given result object, in object form.
2553          * Fields can be retrieved with $row->fieldname, with fields acting like
2554          * member variables.
2555          *
2556          * @param $res SQL result object as returned from Database::query(), etc.
2557          * @return MySQL row object
2558          * @throws DBUnexpectedError Thrown if the database returns an error
2559          */
2560         function fetchObject() {
2561                 return $this->db->fetchObject( $this->result );
2562         }
2563
2564         /**
2565          * Fetch the next row from the given result object, in associative array
2566          * form.  Fields are retrieved with $row['fieldname'].
2567          *
2568          * @param $res SQL result object as returned from Database::query(), etc.
2569          * @return MySQL row object
2570          * @throws DBUnexpectedError Thrown if the database returns an error
2571          */
2572         function fetchRow() {
2573                 return $this->db->fetchRow( $this->result );
2574         }
2575
2576         /**
2577          * Free a result object
2578          */
2579         function free() {
2580                 $this->db->freeResult( $this->result );
2581                 unset( $this->result );
2582                 unset( $this->db );
2583         }
2584
2585         /**
2586          * Change the position of the cursor in a result object
2587          * See mysql_data_seek()
2588          */
2589         function seek( $row ) {
2590                 $this->db->dataSeek( $this->result, $row );
2591         }
2592
2593         /*********************
2594          * Iterator functions
2595          * Note that using these in combination with the non-iterator functions
2596          * above may cause rows to be skipped or repeated.
2597          */
2598
2599         function rewind() {
2600                 if ($this->numRows()) {
2601                         $this->db->dataSeek($this->result, 0);
2602                 }
2603                 $this->pos = 0;
2604                 $this->currentRow = null;
2605         }
2606
2607         function current() {
2608                 if ( is_null( $this->currentRow ) ) {
2609                         $this->next();
2610                 }
2611                 return $this->currentRow;
2612         }
2613
2614         function key() {
2615                 return $this->pos;
2616         }
2617
2618         function next() {
2619                 $this->pos++;
2620                 $this->currentRow = $this->fetchObject();
2621                 return $this->currentRow;
2622         }
2623
2624         function valid() {
2625                 return $this->current() !== false;
2626         }
2627 }
2628
2629 class MySQLMasterPos {
2630         var $file, $pos;
2631
2632         function __construct( $file, $pos ) {
2633                 $this->file = $file;
2634                 $this->pos = $pos;
2635         }
2636
2637         function __toString() {
2638                 return "{$this->file}/{$this->pos}";
2639         }
2640 }