includes/Database.php

   1 <?php
   2 /**
   3  * This file deals with MySQL interface functions
   4  * and query specifics/optimisations
   5  * @version # $Id$
   6  * @package MediaWiki
   7  */
   8
   9 /**
  10  * Depends on the CacheManager
  11  */
  12 require_once( 'CacheManager.php' );
  13
  14 /** @todo document */
  15 define( 'LIST_COMMA', 0 );
  16 /** @todo document */
  17 define( 'LIST_AND', 1 );
  18 /** @todo document */
  19 define( 'LIST_SET', 2 );
  20 /** @todo document */
  21 define( 'LIST_NAMES', 3);
  22
  23 /** Number of times to re-try an operation in case of deadlock */
  24 define( 'DEADLOCK_TRIES', 4 );
  25 /** Minimum time to wait before retry, in microseconds */
  26 define( 'DEADLOCK_DELAY_MIN', 500000 );
  27 /** Maximum time to wait before retry */
  28 define( 'DEADLOCK_DELAY_MAX', 1500000 );
  29
  30 /**
  31  * Database abstraction object
  32  * @package MediaWiki
  33  * @version # $Id$
  34  */
  35 class Database {
  36
  37 #------------------------------------------------------------------------------
  38 # Variables
  39 #------------------------------------------------------------------------------
  40         /**#@+
  41          * @access private
  42          */
  43         var $mLastQuery = '';
  44
  45         var $mServer, $mUser, $mPassword, $mConn, $mDBname;
  46         var $mOut, $mOpened = false;
  47
  48         var $mFailFunction;
  49         var $mTablePrefix;
  50         var $mFlags;
  51         var $mTrxLevel = 0;
  52         /**#@-*/
  53
  54 #------------------------------------------------------------------------------
  55 # Accessors
  56 #------------------------------------------------------------------------------
  57         # These optionally set a variable and return the previous state
  58
  59         /**
  60          * Fail function, takes a Database as a parameter
  61          * Set to false for default, 1 for ignore errors
  62          */
  63         function failFunction( $function = NULL ) {
  64                 return wfSetVar( $this->mFailFunction, $function );
  65         }
  66
  67         /**
  68          * Output page, used for reporting errors
  69          * FALSE means discard output
  70          */
  71         function &setOutputPage( &$out ) {
  72                 $this->mOut =& $out;
  73         }
  74
  75         /**
  76          * Boolean, controls output of large amounts of debug information
  77          */
  78         function debug( $debug = NULL ) {
  79                 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
  80         }
  81
  82         /**
  83          * Turns buffering of SQL result sets on (true) or off (false).
  84          * Default is "on" and it should not be changed without good reasons.
  85          */
  86         function bufferResults( $buffer = NULL ) {
  87                 if ( is_null( $buffer ) ) {
  88                         return !(bool)( $this->mFlags & DBO_NOBUFFER );
  89                 } else {
  90                         return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
  91                 }
  92         }
  93
  94         /**
  95          * Turns on (false) or off (true) the automatic generation and sending
  96          * of a "we're sorry, but there has been a database error" page on
  97          * database errors. Default is on (false). When turned off, the
  98          * code should use wfLastErrno() and wfLastError() to handle the
  99          * situation as appropriate.
 100          */
 101         function ignoreErrors( $ignoreErrors = NULL ) {
 102                 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
 103         }
 104
 105         /**
 106          * The current depth of nested transactions
 107          * @param integer $level
 108          */
 109         function trxLevel( $level = NULL ) {
 110                 return wfSetVar( $this->mTrxLevel, $level );
 111         }
 112
 113         /**#@+
 114          * Get function
 115          */
 116         function lastQuery() { return $this->mLastQuery; }
 117         function isOpen() { return $this->mOpened; }
 118         /**#@-*/
 119
 120 #------------------------------------------------------------------------------
 121 # Other functions
 122 #------------------------------------------------------------------------------
 123
 124         /**#@+
 125          * @param string $server database server host
 126          * @param string $user database user name
 127          * @param string $password database user password
 128          * @param string $dbname database name
 129          */
 130
 131         /**
 132          * @param failFunction
 133          * @param $flags
 134          * @param string $tablePrefix Database table prefixes. By default use the prefix gave in LocalSettings.php
 135          */
 136         function Database( $server = false, $user = false, $password = false, $dbName = false,
 137                 $failFunction = false, $flags = 0, $tablePrefix = 'get from global' ) {
 138
 139                 global $wgOut, $wgDBprefix, $wgCommandLineMode;
 140                 # Can't get a reference if it hasn't been set yet
 141                 if ( !isset( $wgOut ) ) {
 142                         $wgOut = NULL;
 143                 }
 144                 $this->mOut =& $wgOut;
 145
 146                 $this->mFailFunction = $failFunction;
 147                 $this->mFlags = $flags;
 148
 149                 if ( $this->mFlags & DBO_DEFAULT ) {
 150                         if ( $wgCommandLineMode ) {
 151                                 $this->mFlags &= ~DBO_TRX;
 152                         } else {
 153                                 $this->mFlags |= DBO_TRX;
 154                         }
 155                 }
 156
 157                 /** Get the default table prefix*/
 158                 if ( $tablePrefix == 'get from global' ) {
 159                         $this->mTablePrefix = $wgDBprefix;
 160                 } else {
 161                         $this->mTablePrefix = $tablePrefix;
 162                 }
 163
 164                 if ( $server ) {
 165                         $this->open( $server, $user, $password, $dbName );
 166                 }
 167         }
 168
 169         /**
 170          * @static
 171          * @param failFunction
 172          * @param $flags
 173          */
 174         function newFromParams( $server, $user, $password, $dbName,
 175                 $failFunction = false, $flags = 0 )
 176         {
 177                 return new Database( $server, $user, $password, $dbName, $failFunction, $flags );
 178         }
 179
 180         /**
 181          * Usually aborts on failure
 182          * If the failFunction is set to a non-zero integer, returns success
 183          */
 184         function open( $server, $user, $password, $dbName ) {
 185                 # Test for missing mysql.so
 186                 # Otherwise we get a suppressed fatal error, which is very hard to track down
 187                 if ( !function_exists( 'mysql_connect' ) ) {
 188                         die( "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
 189                 }
 190
 191                 $this->close();
 192                 $this->mServer = $server;
 193                 $this->mUser = $user;
 194                 $this->mPassword = $password;
 195                 $this->mDBname = $dbName;
 196
 197                 $success = false;
 198
 199                 @/**/$this->mConn = mysql_connect( $server, $user, $password );
 200                 if ( $dbName != '' ) {
 201                         if ( $this->mConn !== false ) {
 202                                 $success = @/**/mysql_select_db( $dbName, $this->mConn );
 203                                 if ( !$success ) {
 204                                         wfDebug( "Error selecting database \"$dbName\": " . $this->lastError() . "\n" );
 205                                 }
 206                         } else {
 207                                 wfDebug( "DB connection error\n" );
 208                                 wfDebug( "Server: $server, User: $user, Password: " .
 209                                         substr( $password, 0, 3 ) . "...\n" );
 210                                 $success = false;
 211                         }
 212                 } else {
 213                         # Delay USE query
 214                         $success = !!$this->mConn;
 215                 }
 216
 217                 if ( !$success ) {
 218                         $this->reportConnectionError();
 219                         $this->close();
 220                 }
 221                 $this->mOpened = $success;
 222                 return $success;
 223         }
 224         /**#@-*/
 225
 226         /**
 227          * Closes a database connection.
 228          * if it is open : commits any open transactions
 229          *
 230          * @return bool operation success. true if already closed.
 231          */
 232         function close()
 233         {
 234                 $this->mOpened = false;
 235                 if ( $this->mConn ) {
 236                         if ( $this->trxLevel() ) {
 237                                 $this->immediateCommit();
 238                         }
 239                         return mysql_close( $this->mConn );
 240                 } else {
 241                         return true;
 242                 }
 243         }
 244
 245         /**
 246          * @access private
 247          * @param string $msg error message ?
 248          * @todo parameter $msg is not used
 249          */
 250         function reportConnectionError( $msg = '') {
 251                 if ( $this->mFailFunction ) {
 252                         if ( !is_int( $this->mFailFunction ) ) {
 253                                 $ff = $this->mFailFunction;
 254                                 $ff( $this, mysql_error() );
 255                         }
 256                 } else {
 257                         wfEmergencyAbort( $this, mysql_error() );
 258                 }
 259         }
 260
 261         /**
 262          * Usually aborts on failure
 263          * If errors are explicitly ignored, returns success
 264          */
 265         function query( $sql, $fname = '', $tempIgnore = false ) {
 266                 global $wgProfiling, $wgCommandLineMode;
 267
 268                 if ( $wgProfiling ) {
 269                         # generalizeSQL will probably cut down the query to reasonable
 270                         # logging size most of the time. The substr is really just a sanity check.
 271                         $profName = 'query: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 272                         wfProfileIn( $profName );
 273                 }
 274
 275                 $this->mLastQuery = $sql;
 276
 277                 if ( $this->debug() ) {
 278                         $sqlx = substr( $sql, 0, 500 );
 279                         $sqlx = wordwrap(strtr($sqlx,"\t\n",'  '));
 280                         wfDebug( "SQL: $sqlx\n" );
 281                 }
 282                 # Add a comment for easy SHOW PROCESSLIST interpretation
 283                 if ( $fname ) {
 284                         $commentedSql = "/* $fname */ $sql";
 285                 } else {
 286                         $commentedSql = $sql;
 287                 }
 288
 289                 # If DBO_TRX is set, start a transaction
 290                 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() && $sql != 'BEGIN' ) {
 291                         $this->begin();
 292                 }
 293
 294                 # Do the query and handle errors
 295                 $ret = $this->doQuery( $commentedSql );
 296                 if ( false === $ret ) {
 297                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
 298                 }
 299
 300                 if ( $wgProfiling ) {
 301                         wfProfileOut( $profName );
 302                 }
 303                 return $ret;
 304         }
 305
 306         /**
 307          * The DBMS-dependent part of query()
 308          * @param string $sql SQL query.
 309          */
 310         function doQuery( $sql ) {
 311                 if( $this->bufferResults() ) {
 312                         $ret = mysql_query( $sql, $this->mConn );
 313                 } else {
 314                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 315                 }
 316                 return $ret;
 317         }
 318
 319         /**
 320          * @param $error
 321          * @param $errno
 322          * @param $sql
 323          * @param string $fname
 324          * @param bool $tempIgnore
 325          */
 326         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 327                 global $wgCommandLineMode, $wgFullyInitialised;
 328                 # Ignore errors during error handling to avoid infinite recursion
 329                 $ignore = $this->ignoreErrors( true );
 330
 331                 if( $ignore || $tempIgnore ) {
 332                         wfDebug("SQL ERROR (ignored): " . $error . "\n");
 333                 } else {
 334                         $sql1line = str_replace( "\n", "\\n", $sql );
 335                         wfLogDBError("$fname\t$errno\t$error\t$sql1line\n");
 336                         wfDebug("SQL ERROR: " . $error . "\n");
 337                         if ( $wgCommandLineMode || !$this->mOut || empty( $wgFullyInitialised ) ) {
 338                                 $message = "A database error has occurred\n" .
 339                                   "Query: $sql\n" .
 340                                   "Function: $fname\n" .
 341                                   "Error: $errno $error\n";
 342                                 if ( !$wgCommandLineMode ) {
 343                                         $message = nl2br( $message );
 344                                 }
 345                                 wfDebugDieBacktrace( $message );
 346                         } else {
 347                                 // this calls wfAbruptExit()
 348                                 $this->mOut->databaseError( $fname, $sql, $error, $errno );
 349                         }
 350                 }
 351                 $this->ignoreErrors( $ignore );
 352         }
 353
 354
 355         /**#@+
 356          * @param mixed $res A SQL result
 357          */
 358         /**
 359          * @todo document
 360          */
 361         function freeResult( $res ) {
 362                 if ( !@/**/mysql_free_result( $res ) ) {
 363                         wfDebugDieBacktrace( "Unable to free MySQL result\n" );
 364                 }
 365         }
 366
 367         /**
 368          * @todo FIXME: HACK HACK HACK HACK debug
 369          */
 370         function fetchObject( $res ) {
 371                 @/**/$row = mysql_fetch_object( $res );
 372                 # FIXME: HACK HACK HACK HACK debug
 373                 if( mysql_errno() ) {
 374                         wfDebugDieBacktrace( 'Error in fetchObject(): ' . htmlspecialchars( mysql_error() ) );
 375                 }
 376                 return $row;
 377         }
 378
 379         /**
 380          * @todo document
 381          */
 382         function fetchRow( $res ) {
 383                 @/**/$row = mysql_fetch_array( $res );
 384                 if (mysql_errno() ) {
 385                         wfDebugDieBacktrace( 'Error in fetchRow(): ' . htmlspecialchars( mysql_error() ) );
 386                 }
 387                 return $row;
 388         }
 389
 390         /**
 391          * @todo document
 392          */
 393         function numRows( $res ) {
 394                 @/**/$n = mysql_num_rows( $res );
 395                 if( mysql_errno() ) {
 396                         wfDebugDieBacktrace( 'Error in numRows(): ' . htmlspecialchars( mysql_error() ) );
 397                 }
 398                 return $n;
 399         }
 400
 401         /**
 402          * @todo document
 403          */
 404         function numFields( $res ) { return mysql_num_fields( $res ); }
 405
 406         /**
 407          * @todo document
 408          */
 409         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 410         /**
 411          * @todo document
 412          */
 413         function insertId() { return mysql_insert_id( $this->mConn ); }
 414         /**
 415          * @todo document
 416          */
 417         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 418         /**
 419          * @todo document
 420          */
 421         function lastErrno() { return mysql_errno(); }
 422         /**
 423          * @todo document
 424          */
 425         function lastError() { return mysql_error(); }
 426         /**
 427          * @todo document
 428          */
 429         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 430         /**#@-*/ // end of template : @param $result
 431
 432
 433         /**
 434          * Simple UPDATE wrapper
 435          * Usually aborts on failure
 436          * If errors are explicitly ignored, returns success
 437          */
 438         function set( $table, $var, $value, $cond, $fname = 'Database::set' )
 439         {
 440                 $table = $this->tableName( $table );
 441                 $sql = "UPDATE $table SET $var = '" .
 442                   $this->strencode( $value ) . "' WHERE ($cond)";
 443                 return !!$this->query( $sql, DB_MASTER, $fname );
 444         }
 445
 446         /**
 447          * @todo document
 448          */
 449         function getField( $table, $var, $cond='', $fname = 'Database::getField', $options = array() ) {
 450                 return $this->selectField( $table, $var, $cond, $fname = 'Database::get', $options = array() );
 451         }
 452
 453         /**
 454          * Simple SELECT wrapper, returns a single field, input must be encoded
 455          * Usually aborts on failure
 456          * If errors are explicitly ignored, returns FALSE on failure
 457          */
 458         function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
 459                 if ( !is_array( $options ) ) {
 460                         $options = array( $options );
 461                 }
 462                 $options['LIMIT'] = 1;
 463
 464                 $res = $this->select( $table, $var, $cond, $fname, $options );
 465                 if ( $res === false || !$this->numRows( $res ) ) {
 466                         return false;
 467                 }
 468                 $row = $this->fetchRow( $res );
 469                 if ( $row !== false ) {
 470                         $this->freeResult( $res );
 471                         return $row[0];
 472                 } else {
 473                         return false;
 474                 }
 475         }
 476
 477         /**
 478          * Returns an optional USE INDEX clause to go after the table, and a
 479          * string to go at the end of the query
 480          */
 481         function makeSelectOptions( $options ) {
 482                 if ( !is_array( $options ) ) {
 483                         $options = array( $options );
 484                 }
 485
 486                 $tailOpts = '';
 487
 488                 if ( isset( $options['ORDER BY'] ) ) {
 489                         $tailOpts .= " ORDER BY {$options['ORDER BY']}";
 490                 }
 491                 if ( isset( $options['LIMIT'] ) ) {
 492                         $tailOpts .= " LIMIT {$options['LIMIT']}";
 493                 }
 494
 495                 if ( is_numeric( array_search( 'FOR UPDATE', $options ) ) ) {
 496                         $tailOpts .= ' FOR UPDATE';
 497                 }
 498
 499                 if ( is_numeric( array_search( 'LOCK IN SHARE MODE', $options ) ) ) {
 500                         $tailOpts .= ' LOCK IN SHARE MODE';
 501                 }
 502
 503                 if ( isset( $options['USE INDEX'] ) ) {
 504                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
 505                 } else {
 506                         $useIndex = '';
 507                 }
 508                 return array( $useIndex, $tailOpts );
 509         }
 510
 511         /**
 512          * SELECT wrapper
 513          */
 514         function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array() )
 515         {
 516                 if ( is_array( $vars ) ) {
 517                         $vars = implode( ',', $vars );
 518                 }
 519                 if ($table!='')
 520                         $from = ' FROM ' .$this->tableName( $table );
 521                 else
 522                         $from = '';
 523
 524                 list( $useIndex, $tailOpts ) = $this->makeSelectOptions( $options );
 525
 526                 if ( $conds !== false && $conds != '' ) {
 527                         if ( is_array( $conds ) ) {
 528                                 $conds = $this->makeList( $conds, LIST_AND );
 529                         }
 530                         $sql = "SELECT $vars $from $useIndex WHERE $conds $tailOpts";
 531                 } else {
 532                         $sql = "SELECT $vars $from $useIndex $tailOpts";
 533                 }
 534                 return $this->query( $sql, $fname );
 535         }
 536
 537         /**
 538          * @todo document
 539          */
 540         function getArray( $table, $vars, $conds, $fname = 'Database::getArray', $options = array() ) {
 541                 return $this->selectRow( $table, $vars, $conds, $fname, $options );
 542         }
 543
 544
 545         /**
 546          * Single row SELECT wrapper
 547          * Aborts or returns FALSE on error
 548          *
 549          * $vars: the selected variables
 550          * $conds: a condition map, terms are ANDed together.
 551          *   Items with numeric keys are taken to be literal conditions
 552          * Takes an array of selected variables, and a condition map, which is ANDed
 553          * e.g. selectRow( "cur", array( "cur_id" ), array( "cur_namespace" => 0, "cur_title" => "Astronomy" ) )
 554          *   would return an object where $obj->cur_id is the ID of the Astronomy article
 555          *
 556          * @todo migrate documentation to phpdocumentor format
 557          */
 558         function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
 559                 $options['LIMIT'] = 1;
 560                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 561                 if ( $res === false || !$this->numRows( $res ) ) {
 562                         return false;
 563                 }
 564                 $obj = $this->fetchObject( $res );
 565                 $this->freeResult( $res );
 566                 return $obj;
 567
 568         }
 569
 570         /**
 571          * Removes most variables from an SQL query and replaces them with X or N for numbers.
 572          * It's only slightly flawed. Don't use for anything important.
 573          *
 574          * @param string $sql A SQL Query
 575          * @static
 576          */
 577         function generalizeSQL( $sql ) {
 578                 # This does the same as the regexp below would do, but in such a way
 579                 # as to avoid crashing php on some large strings.
 580                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
 581
 582                 $sql = str_replace ( "\\\\", '', $sql);
 583                 $sql = str_replace ( "\\'", '', $sql);
 584                 $sql = str_replace ( "\\\"", '', $sql);
 585                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
 586                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
 587
 588                 # All newlines, tabs, etc replaced by single space
 589                 $sql = preg_replace ( "/\s+/", ' ', $sql);
 590
 591                 # All numbers => N
 592                 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
 593
 594                 return $sql;
 595         }
 596
 597         /**
 598          * Determines whether a field exists in a table
 599          * Usually aborts on failure
 600          * If errors are explicitly ignored, returns NULL on failure
 601          */
 602         function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
 603                 $table = $this->tableName( $table );
 604                 $res = $this->query( 'DESCRIBE '.$table, DB_SLAVE, $fname );
 605                 if ( !$res ) {
 606                         return NULL;
 607                 }
 608
 609                 $found = false;
 610
 611                 while ( $row = $this->fetchObject( $res ) ) {
 612                         if ( $row->Field == $field ) {
 613                                 $found = true;
 614                                 break;
 615                         }
 616                 }
 617                 return $found;
 618         }
 619
 620         /**
 621          * Determines whether an index exists
 622          * Usually aborts on failure
 623          * If errors are explicitly ignored, returns NULL on failure
 624          */
 625         function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
 626                 $info = $this->indexInfo( $table, $index, $fname );
 627                 if ( is_null( $info ) ) {
 628                         return NULL;
 629                 } else {
 630                         return $info !== false;
 631                 }
 632         }
 633
 634
 635         /**
 636          * @todo document
 637          */
 638         function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
 639                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 640                 # SHOW INDEX should work for 3.x and up:
 641                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 642                 $table = $this->tableName( $table );
 643                 $sql = 'SHOW INDEX FROM '.$table;
 644                 $res = $this->query( $sql, $fname );
 645                 if ( !$res ) {
 646                         return NULL;
 647                 }
 648
 649                 while ( $row = $this->fetchObject( $res ) ) {
 650                         if ( $row->Key_name == $index ) {
 651                                 return $row;
 652                         }
 653                 }
 654                 return false;
 655         }
 656
 657         /**
 658          * @param $table
 659          * @todo document
 660          */
 661         function tableExists( $table ) {
 662                 $table = $this->tableName( $table );
 663                 $old = $this->ignoreErrors( true );
 664                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
 665                 $this->ignoreErrors( $old );
 666                 if( $res ) {
 667                         $this->freeResult( $res );
 668                         return true;
 669                 } else {
 670                         return false;
 671                 }
 672         }
 673
 674         /**
 675          * @param $table
 676          * @param $field
 677          * @todo document
 678          */
 679         function fieldInfo( $table, $field ) {
 680                 $table = $this->tableName( $table );
 681                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
 682                 $n = mysql_num_fields( $res );
 683                 for( $i = 0; $i < $n; $i++ ) {
 684                         $meta = mysql_fetch_field( $res, $i );
 685                         if( $field == $meta->name ) {
 686                                 return $meta;
 687                         }
 688                 }
 689                 return false;
 690         }
 691
 692         /**
 693          * @todo document
 694          */
 695         function fieldType( $res, $index ) {
 696                 return mysql_field_type( $res, $index );
 697         }
 698
 699         /**
 700          * @todo document
 701          */
 702         function indexUnique( $table, $index ) {
 703                 $indexInfo = $this->indexInfo( $table, $index );
 704                 if ( !$indexInfo ) {
 705                         return NULL;
 706                 }
 707                 return !$indexInfo->Non_unique;
 708         }
 709
 710         /**
 711          * @todo document
 712          */
 713         function insertArray( $table, $a, $fname = 'Database::insertArray', $options = array() ) {
 714                 return $this->insert( $table, $a, $fname = 'Database::insertArray', $options = array() );
 715         }
 716
 717         /**
 718          * INSERT wrapper, inserts an array into a table
 719          *
 720          * $a may be a single associative array, or an array of these with numeric keys, for
 721          * multi-row insert.
 722          *
 723          * Usually aborts on failure
 724          * If errors are explicitly ignored, returns success
 725          */
 726         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
 727                 # No rows to insert, easy just return now
 728                 if ( !count( $a ) ) {
 729                         return true;
 730                 }
 731
 732                 $table = $this->tableName( $table );
 733                 if ( !is_array( $options ) ) {
 734                         $options = array( $options );
 735                 }
 736                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
 737                         $multi = true;
 738                         $keys = array_keys( $a[0] );
 739                 } else {
 740                         $multi = false;
 741                         $keys = array_keys( $a );
 742                 }
 743
 744                 $sql = 'INSERT ' . implode( ' ', $options ) .
 745                         " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
 746
 747                 if ( $multi ) {
 748                         $first = true;
 749                         foreach ( $a as $row ) {
 750                                 if ( $first ) {
 751                                         $first = false;
 752                                 } else {
 753                                         $sql .= ',';
 754                                 }
 755                                 $sql .= '(' . $this->makeList( $row ) . ')';
 756                         }
 757                 } else {
 758                         $sql .= '(' . $this->makeList( $a ) . ')';
 759                 }
 760                 return !!$this->query( $sql, $fname );
 761         }
 762
 763         /**
 764          * @todo document
 765          */
 766         function updateArray( $table, $values, $conds, $fname = 'Database::updateArray' ) {
 767                 return $this->update( $table, $values, $conds, $fname );
 768         }
 769
 770         /**
 771          * UPDATE wrapper, takes a condition array and a SET array
 772          */
 773         function update( $table, $values, $conds, $fname = 'Database::update' ) {
 774                 $table = $this->tableName( $table );
 775                 $sql = "UPDATE $table SET " . $this->makeList( $values, LIST_SET );
 776                 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
 777                 $this->query( $sql, $fname );
 778         }
 779
 780         /**
 781          * Makes a wfStrencoded list from an array
 782          * $mode: LIST_COMMA         - comma separated, no field names
 783          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
 784          *        LIST_SET           - comma separated with field names, like a SET clause
 785          *        LIST_NAMES         - comma separated field names
 786          */
 787         function makeList( $a, $mode = LIST_COMMA ) {
 788                 if ( !is_array( $a ) ) {
 789                         wfDebugDieBacktrace( 'Database::makeList called with incorrect parameters' );
 790                 }
 791
 792                 $first = true;
 793                 $list = '';
 794                 foreach ( $a as $field => $value ) {
 795                         if ( !$first ) {
 796                                 if ( $mode == LIST_AND ) {
 797                                         $list .= ' AND ';
 798                                 } else {
 799                                         $list .= ',';
 800                                 }
 801                         } else {
 802                                 $first = false;
 803                         }
 804                         if ( $mode == LIST_AND && is_numeric( $field ) ) {
 805                                 $list .= "($value)";
 806                         } else {
 807                                 if ( $mode == LIST_AND || $mode == LIST_SET ) {
 808                                         $list .= $field.'=';
 809                                 }
 810                                 $list .= ($mode==LIST_NAMES?$value:$this->addQuotes( $value ));
 811                         }
 812                 }
 813                 return $list;
 814         }
 815
 816         /**
 817          * @todo document
 818          */
 819         function selectDB( $db ) {
 820                 $this->mDBname = $db;
 821                 mysql_select_db( $db, $this->mConn );
 822         }
 823
 824         /**
 825          * @todo document
 826          */
 827         function startTimer( $timeout ) {
 828                 global $IP;
 829                 if( function_exists( 'mysql_thread_id' ) ) {
 830                         # This will kill the query if it's still running after $timeout seconds.
 831                         $tid = mysql_thread_id( $this->mConn );
 832                         exec( "php $IP/killthread.php $timeout $tid &>/dev/null &" );
 833                 }
 834         }
 835
 836         /**
 837          * Does nothing at all
 838          * @todo document
 839          */
 840         function stopTimer() { }
 841
 842         /**
 843          * @param string $name database table name
 844          * @todo document
 845          */
 846         function tableName( $name ) {
 847                 global $wgSharedDB;
 848                 if ( $this->mTablePrefix !== '' ) {
 849                         if ( strpos( '.', $name ) === false ) {
 850                                 $name = $this->mTablePrefix . $name;
 851                         }
 852                 }
 853                 if ( isset( $wgSharedDB ) && 'user' == $name ) {
 854                         $name = $wgSharedDB . '.' . $name;
 855                 }
 856                 return $name;
 857         }
 858
 859         /**
 860          * @todo document
 861          */
 862         function tableNames() {
 863                 $inArray = func_get_args();
 864                 $retVal = array();
 865                 foreach ( $inArray as $name ) {
 866                         $retVal[$name] = $this->tableName( $name );
 867                 }
 868                 return $retVal;
 869         }
 870
 871         /**
 872          * Wrapper for addslashes()
 873          * @param string $s String to be slashed.
 874          * @return string slashed string.
 875          */
 876         function strencode( $s ) {
 877                 return addslashes( $s );
 878         }
 879
 880         /**
 881          * If it's a string, adds quotes and backslashes
 882          * Otherwise returns as-is
 883          */
 884         function addQuotes( $s ) {
 885                 if ( is_null( $s ) ) {
 886                         $s = 'NULL';
 887                 } else {
 888                         # This will also quote numeric values. This should be harmless,
 889                         # and protects against weird problems that occur when they really
 890                         # _are_ strings such as article titles and string->number->string
 891                         # conversion is not 1:1.
 892                         $s = "'" . $this->strencode( $s ) . "'";
 893                 }
 894                 return $s;
 895         }
 896
 897         /**
 898          * Returns an appropriately quoted sequence value for inserting a new row.
 899          * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
 900          * subclass will return an integer, and save the value for insertId()
 901          */
 902         function nextSequenceValue( $seqName ) {
 903                 return NULL;
 904         }
 905
 906         /**
 907          * USE INDEX clause
 908          * PostgreSQL doesn't have them and returns ""
 909          */
 910         function useIndexClause( $index ) {
 911                 return 'USE INDEX ('.$index.')';
 912         }
 913
 914         /**
 915          * REPLACE query wrapper
 916          * PostgreSQL simulates this with a DELETE followed by INSERT
 917          * $row is the row to insert, an associative array
 918          * $uniqueIndexes is an array of indexes. Each element may be either a
 919          * field name or an array of field names
 920          *
 921          * It may be more efficient to leave off unique indexes which are unlikely to collide.
 922          * However if you do this, you run the risk of encountering errors which wouldn't have
 923          * occurred in MySQL
 924          *
 925          * @todo migrate comment to phodocumentor format
 926          */
 927         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
 928                 $table = $this->tableName( $table );
 929
 930                 # Single row case
 931                 if ( !is_array( reset( $rows ) ) ) {
 932                         $rows = array( $rows );
 933                 }
 934
 935                 $sql = "REPLACE INTO $table (" . implode( ',', array_flip( $rows[0] ) ) .') VALUES ';
 936                 $first = true;
 937                 foreach ( $rows as $row ) {
 938                         if ( $first ) {
 939                                 $first = false;
 940                         } else {
 941                                 $sql .= ',';
 942                         }
 943                         $sql .= '(' . $this->makeList( $row ) . ')';
 944                 }
 945                 return $this->query( $sql, $fname );
 946         }
 947
 948         /**
 949          * DELETE where the condition is a join
 950          * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
 951          *
 952          * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
 953          * join condition matches, set $conds='*'
 954          *
 955          * DO NOT put the join condition in $conds
 956          *
 957          * @param string $delTable The table to delete from.
 958          * @param string $joinTable The other table.
 959          * @param string $delVar The variable to join on, in the first table.
 960          * @param string $joinVar The variable to join on, in the second table.
 961          * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
 962          */
 963         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
 964                 if ( !$conds ) {
 965                         wfDebugDieBacktrace( 'Database::deleteJoin() called with empty $conds' );
 966                 }
 967
 968                 $delTable = $this->tableName( $delTable );
 969                 $joinTable = $this->tableName( $joinTable );
 970                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
 971                 if ( $conds != '*' ) {
 972                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
 973                 }
 974
 975                 return $this->query( $sql, $fname );
 976         }
 977
 978         /**
 979          * Returns the size of a text field, or -1 for "unlimited"
 980          */
 981         function textFieldSize( $table, $field ) {
 982                 $table = $this->tableName( $table );
 983                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
 984                 $res = $this->query( $sql, 'Database::textFieldSize' );
 985                 $row = $this->fetchObject( $res );
 986                 $this->freeResult( $res );
 987
 988                 if ( preg_match( "/\((.*)\)/", $row->Type, $m ) ) {
 989                         $size = $m[1];
 990                 } else {
 991                         $size = -1;
 992                 }
 993                 return $size;
 994         }
 995
 996         /**
 997          * @return string Always return 'LOW_PRIORITY'
 998          */
 999         function lowPriorityOption() {
1000                 return 'LOW_PRIORITY';
1001         }
1002
1003         /**
1004          * Use $conds == "*" to delete all rows
1005          * @todo document
1006          */
1007         function delete( $table, $conds, $fname = 'Database::delete' ) {
1008                 if ( !$conds ) {
1009                         wfDebugDieBacktrace( 'Database::delete() called with no conditions' );
1010                 }
1011                 $table = $this->tableName( $table );
1012                 $sql = "DELETE FROM $table ";
1013                 if ( $conds != '*' ) {
1014                         $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
1015                 }
1016                 return $this->query( $sql, $fname );
1017         }
1018
1019         /**
1020          * INSERT SELECT wrapper
1021          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1022          * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1023          * $conds may be "*" to copy the whole table
1024          */
1025         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect' ) {
1026                 $destTable = $this->tableName( $destTable );
1027                 $srcTable = $this->tableName( $srcTable );
1028                 $sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1029                         ' SELECT ' . implode( ',', $varMap ) .
1030                         " FROM $srcTable";
1031                 if ( $conds != '*' ) {
1032                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1033                 }
1034                 return $this->query( $sql, $fname );
1035         }
1036
1037         /**
1038          * @todo document
1039          */
1040         function limitResult($limit,$offset) {
1041                 return ' LIMIT '.(is_numeric($offset)?"{$offset},":"")."{$limit} ";
1042         }
1043
1044         /**
1045          * @todo document
1046          */
1047         function wasDeadlock() {
1048                 return $this->lastErrno() == 1213;
1049         }
1050
1051         /**
1052          * @todo document
1053          */
1054         function deadlockLoop() {
1055                 $myFname = 'Database::deadlockLoop';
1056
1057                 $this->query( 'BEGIN', $myFname );
1058                 $args = func_get_args();
1059                 $function = array_shift( $args );
1060                 $oldIgnore = $dbw->ignoreErrors( true );
1061                 $tries = DEADLOCK_TRIES;
1062                 if ( is_array( $function ) ) {
1063                         $fname = $function[0];
1064                 } else {
1065                         $fname = $function;
1066                 }
1067                 do {
1068                         $retVal = call_user_func_array( $function, $args );
1069                         $error = $this->lastError();
1070                         $errno = $this->lastErrno();
1071                         $sql = $this->lastQuery();
1072
1073                         if ( $errno ) {
1074                                 if ( $dbw->wasDeadlock() ) {
1075                                         # Retry
1076                                         usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1077                                 } else {
1078                                         $dbw->reportQueryError( $error, $errno, $sql, $fname );
1079                                 }
1080                         }
1081                 } while( $dbw->wasDeadlock && --$tries > 0 );
1082                 $this->ignoreErrors( $oldIgnore );
1083                 if ( $tries <= 0 ) {
1084                         $this->query( 'ROLLBACK', $myFname );
1085                         $this->reportQueryError( $error, $errno, $sql, $fname );
1086                         return false;
1087                 } else {
1088                         $this->query( 'COMMIT', $myFname );
1089                         return $retVal;
1090                 }
1091         }
1092
1093         /**
1094          * Do a SELECT MASTER_POS_WAIT()
1095          * @todo document
1096          */
1097         function masterPosWait( $file, $pos, $timeout ) {
1098                 $encFile = $this->strencode( $file );
1099                 $sql = "SELECT MASTER_POS_WAIT('$encFile', $pos, $timeout)";
1100                 $res = $this->query( $sql, 'Database::masterPosWait' );
1101                 if ( $res && $row = $this->fetchRow( $res ) ) {
1102                         $this->freeResult( $res );
1103                         return $row[0];
1104                 } else {
1105                         return false;
1106                 }
1107         }
1108
1109         /**
1110          * Get the position of the master from SHOW SLAVE STATUS
1111          */
1112         function getSlavePos() {
1113                 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1114                 $row = $this->fetchObject( $res );
1115                 if ( $row ) {
1116                         return array( $row->Master_Log_File, $row->Read_Master_Log_Pos );
1117                 } else {
1118                         return array( false, false );
1119                 }
1120         }
1121
1122         /**
1123          * Get the position of the master from SHOW MASTER STATUS
1124          */
1125         function getMasterPos() {
1126                 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1127                 $row = $this->fetchObject( $res );
1128                 if ( $row ) {
1129                         return array( $row->File, $row->Position );
1130                 } else {
1131                         return array( false, false );
1132                 }
1133         }
1134
1135         /**
1136          * Begin a transaction, or if a transaction has already started, continue it
1137          */
1138         function begin( $fname = 'Database::begin' ) {
1139                 if ( !$this->mTrxLevel ) {
1140                         $this->immediateBegin( $fname );
1141                 } else {
1142                         $this->mTrxLevel++;
1143                 }
1144         }
1145
1146         /**
1147          * End a transaction, or decrement the nest level if transactions are nested
1148          */
1149         function commit( $fname = 'Database::commit' ) {
1150                 if ( $this->mTrxLevel ) {
1151                         $this->mTrxLevel--;
1152                 }
1153                 if ( !$this->mTrxLevel ) {
1154                         $this->immediateCommit( $fname );
1155                 }
1156         }
1157
1158         /**
1159          * Rollback a transaction
1160          */
1161         function rollback( $fname = 'Database::rollback' ) {
1162                 $this->query( 'ROLLBACK', $fname );
1163                 $this->mTrxLevel = 0;
1164         }
1165
1166         /**
1167          * Begin a transaction, committing any previously open transaction
1168          */
1169         function immediateBegin( $fname = 'Database::immediateBegin' ) {
1170                 $this->query( 'BEGIN', $fname );
1171                 $this->mTrxLevel = 1;
1172         }
1173
1174         /**
1175          * Commit transaction, if one is open
1176          */
1177         function immediateCommit( $fname = 'Database::immediateCommit' ) {
1178                 $this->query( 'COMMIT', $fname );
1179                 $this->mTrxLevel = 0;
1180         }
1181
1182         /**
1183          * Return MW-style timestamp used for MySQL schema
1184          */
1185         function timestamp( $ts=0 ) {
1186                 return wfTimestamp(TS_MW,$ts);
1187         }
1188
1189         /**
1190          * @todo document
1191          */
1192         function &resultObject( &$result ) {
1193                 if( empty( $result ) ) {
1194                         return NULL;
1195                 } else {
1196                         return new ResultWrapper( $this, $result );
1197                 }
1198         }
1199 }
1200
1201 /**
1202  * Database abstraction object for mySQL
1203  * Inherit all methods and properties of Database::Database()
1204  *
1205  * @package MediaWiki
1206  * @see Database
1207  * @version # $Id$
1208  */
1209 class DatabaseMysql extends Database {
1210         # Inherit all
1211 }
1212
1213
1214 /**
1215  * Result wrapper for grabbing data queried by someone else
1216  *
1217  * @package MediaWiki
1218  * @version # $Id$
1219  */
1220 class ResultWrapper {
1221         var $db, $result;
1222
1223         /**
1224          * @todo document
1225          */
1226         function ResultWrapper( $database, $result ) {
1227                 $this->db =& $database;
1228                 $this->result =& $result;
1229         }
1230
1231         /**
1232          * @todo document
1233          */
1234         function numRows() {
1235                 return $this->db->numRows( $this->result );
1236         }
1237
1238         /**
1239          * @todo document
1240          */
1241         function &fetchObject() {
1242                 return $this->db->fetchObject( $this->result );
1243         }
1244
1245         /**
1246          * @todo document
1247          */
1248         function &fetchRow() {
1249                 return $this->db->fetchRow( $this->result );
1250         }
1251
1252         /**
1253          * @todo document
1254          */
1255         function free() {
1256                 $this->db->freeResult( $this->result );
1257                 unset( $this->result );
1258                 unset( $this->db );
1259         }
1260 }
1261
1262 #------------------------------------------------------------------------------
1263 # Global functions
1264 #------------------------------------------------------------------------------
1265
1266 /**
1267  * Standard fail function, called by default when a connection cannot be
1268  * established.
1269  * Displays the file cache if possible
1270  */
1271 function wfEmergencyAbort( &$conn, $error ) {
1272         global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding, $wgSiteNotice, $wgOutputEncoding;
1273
1274         if( !headers_sent() ) {
1275                 header( 'HTTP/1.0 500 Internal Server Error' );
1276                 header( 'Content-type: text/html; charset='.$wgOutputEncoding );
1277                 /* Don't cache error pages!  They cause no end of trouble... */
1278                 header( 'Cache-control: none' );
1279                 header( 'Pragma: nocache' );
1280         }
1281         $msg = $wgSiteNotice;
1282         if($msg == '') $msg = wfMsgNoDB( 'noconnect', $error );
1283         $text = $msg;
1284
1285         if($wgUseFileCache) {
1286                 if($wgTitle) {
1287                         $t =& $wgTitle;
1288                 } else {
1289                         if($title) {
1290                                 $t = Title::newFromURL( $title );
1291                         } elseif (@/**/$_REQUEST['search']) {
1292                                 $search = $_REQUEST['search'];
1293                                 echo wfMsgNoDB( 'searchdisabled' );
1294                                 echo wfMsgNoDB( 'googlesearch', htmlspecialchars( $search ), $wgInputEncoding );
1295                                 wfErrorExit();
1296                         } else {
1297                                 $t = Title::newFromText( wfMsgNoDB( 'mainpage' ) );
1298                         }
1299                 }
1300
1301                 $cache = new CacheManager( $t );
1302                 if( $cache->isFileCached() ) {
1303                         $msg = '<p style="color: red"><b>'.$msg."<br />\n" .
1304                                 wfMsgNoDB( 'cachederror' ) . "</b></p>\n";
1305
1306                         $tag = '<div id="article">';
1307                         $text = str_replace(
1308                                 $tag,
1309                                 $tag . $msg,
1310                                 $cache->fetchPageText() );
1311                 }
1312         }
1313
1314         echo $text;
1315         wfErrorExit();
1316 }
1317
1318 ?>