includes/Database.php

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