includes/Database.php

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