includes/Database.php

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