includes/Database.php

   1 <?php
   2 /**
   3  * This file deals with MySQL interface functions
   4  * and query specifics/optimisations
   5  * @package MediaWiki
   6  */
   7
   8 /**
   9  * Depends on the CacheManager
  10  */
  11 require_once( 'CacheManager.php' );
  12
  13 /** See Database::makeList() */
  14 define( 'LIST_COMMA', 0 );
  15 define( 'LIST_AND', 1 );
  16 define( 'LIST_SET', 2 );
  17 define( 'LIST_NAMES', 3);
  18 define( 'LIST_OR', 4);
  19
  20 /** Number of times to re-try an operation in case of deadlock */
  21 define( 'DEADLOCK_TRIES', 4 );
  22 /** Minimum time to wait before retry, in microseconds */
  23 define( 'DEADLOCK_DELAY_MIN', 500000 );
  24 /** Maximum time to wait before retry */
  25 define( 'DEADLOCK_DELAY_MAX', 1500000 );
  26
  27 class DBObject {
  28         var $mData;
  29
  30         function DBObject($data) {
  31                 $this->mData = $data;
  32         }
  33
  34         function isLOB() {
  35                 return false;
  36         }
  37
  38         function data() {
  39                 return $this->mData;
  40         }
  41 };
  42
  43 /**
  44  * Database abstraction object
  45  * @package MediaWiki
  46  */
  47 class Database {
  48
  49 #------------------------------------------------------------------------------
  50 # Variables
  51 #------------------------------------------------------------------------------
  52         /**#@+
  53          * @private
  54          */
  55         var $mLastQuery = '';
  56
  57         var $mServer, $mUser, $mPassword, $mConn = null, $mDBname;
  58         var $mOut, $mOpened = false;
  59
  60         var $mFailFunction;
  61         var $mTablePrefix;
  62         var $mFlags;
  63         var $mTrxLevel = 0;
  64         var $mErrorCount = 0;
  65         var $mLBInfo = array();
  66         /**#@-*/
  67
  68 #------------------------------------------------------------------------------
  69 # Accessors
  70 #------------------------------------------------------------------------------
  71         # These optionally set a variable and return the previous state
  72
  73         /**
  74          * Fail function, takes a Database as a parameter
  75          * Set to false for default, 1 for ignore errors
  76          */
  77         function failFunction( $function = NULL ) {
  78                 return wfSetVar( $this->mFailFunction, $function );
  79         }
  80
  81         /**
  82          * Output page, used for reporting errors
  83          * FALSE means discard output
  84          */
  85         function &setOutputPage( &$out ) {
  86                 $this->mOut =& $out;
  87         }
  88
  89         /**
  90          * Boolean, controls output of large amounts of debug information
  91          */
  92         function debug( $debug = NULL ) {
  93                 return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
  94         }
  95
  96         /**
  97          * Turns buffering of SQL result sets on (true) or off (false).
  98          * Default is "on" and it should not be changed without good reasons.
  99          */
 100         function bufferResults( $buffer = NULL ) {
 101                 if ( is_null( $buffer ) ) {
 102                         return !(bool)( $this->mFlags & DBO_NOBUFFER );
 103                 } else {
 104                         return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
 105                 }
 106         }
 107
 108         /**
 109          * Turns on (false) or off (true) the automatic generation and sending
 110          * of a "we're sorry, but there has been a database error" page on
 111          * database errors. Default is on (false). When turned off, the
 112          * code should use wfLastErrno() and wfLastError() to handle the
 113          * situation as appropriate.
 114          */
 115         function ignoreErrors( $ignoreErrors = NULL ) {
 116                 return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
 117         }
 118
 119         /**
 120          * The current depth of nested transactions
 121          * @param $level Integer: , default NULL.
 122          */
 123         function trxLevel( $level = NULL ) {
 124                 return wfSetVar( $this->mTrxLevel, $level );
 125         }
 126
 127         /**
 128          * Number of errors logged, only useful when errors are ignored
 129          */
 130         function errorCount( $count = NULL ) {
 131                 return wfSetVar( $this->mErrorCount, $count );
 132         }
 133
 134         /**
 135          * Properties passed down from the server info array of the load balancer
 136          */
 137         function getLBInfo( $name = NULL ) {
 138                 if ( is_null( $name ) ) {
 139                         return $this->mLBInfo;
 140                 } else {
 141                         if ( array_key_exists( $name, $this->mLBInfo ) ) {
 142                                 return $this->mLBInfo[$name];
 143                         } else {
 144                                 return NULL;
 145                         }
 146                 }
 147         }
 148
 149         function setLBInfo( $name, $value = NULL ) {
 150                 if ( is_null( $value ) ) {
 151                         $this->mLBInfo = $name;
 152                 } else {
 153                         $this->mLBInfo[$name] = $value;
 154                 }
 155         }
 156
 157         /**#@+
 158          * Get function
 159          */
 160         function lastQuery() { return $this->mLastQuery; }
 161         function isOpen() { return $this->mOpened; }
 162         /**#@-*/
 163
 164         function setFlag( $flag ) {
 165                 $this->mFlags |= $flag;
 166         }
 167
 168         function clearFlag( $flag ) {
 169                 $this->mFlags &= ~$flag;
 170         }
 171
 172         function getFlag( $flag ) {
 173                 return !!($this->mFlags & $flag);
 174         }
 175
 176 #------------------------------------------------------------------------------
 177 # Other functions
 178 #------------------------------------------------------------------------------
 179
 180         /**@{{
 181          * @param string $server database server host
 182          * @param string $user database user name
 183          * @param string $password database user password
 184          * @param string $dbname database name
 185          */
 186
 187         /**
 188          * @param failFunction
 189          * @param $flags
 190          * @param $tablePrefix String: database table prefixes. By default use the prefix gave in LocalSettings.php
 191          */
 192         function Database( $server = false, $user = false, $password = false, $dbName = false,
 193                 $failFunction = false, $flags = 0, $tablePrefix = 'get from global' ) {
 194
 195                 global $wgOut, $wgDBprefix, $wgCommandLineMode;
 196                 # Can't get a reference if it hasn't been set yet
 197                 if ( !isset( $wgOut ) ) {
 198                         $wgOut = NULL;
 199                 }
 200                 $this->mOut =& $wgOut;
 201
 202                 $this->mFailFunction = $failFunction;
 203                 $this->mFlags = $flags;
 204
 205                 if ( $this->mFlags & DBO_DEFAULT ) {
 206                         if ( $wgCommandLineMode ) {
 207                                 $this->mFlags &= ~DBO_TRX;
 208                         } else {
 209                                 $this->mFlags |= DBO_TRX;
 210                         }
 211                 }
 212
 213                 /*
 214                 // Faster read-only access
 215                 if ( wfReadOnly() ) {
 216                         $this->mFlags |= DBO_PERSISTENT;
 217                         $this->mFlags &= ~DBO_TRX;
 218                 }*/
 219
 220                 /** Get the default table prefix*/
 221                 if ( $tablePrefix == 'get from global' ) {
 222                         $this->mTablePrefix = $wgDBprefix;
 223                 } else {
 224                         $this->mTablePrefix = $tablePrefix;
 225                 }
 226
 227                 if ( $server ) {
 228                         $this->open( $server, $user, $password, $dbName );
 229                 }
 230         }
 231
 232         /**
 233          * @static
 234          * @param failFunction
 235          * @param $flags
 236          */
 237         function newFromParams( $server, $user, $password, $dbName,
 238                 $failFunction = false, $flags = 0 )
 239         {
 240                 return new Database( $server, $user, $password, $dbName, $failFunction, $flags );
 241         }
 242
 243         /**
 244          * Usually aborts on failure
 245          * If the failFunction is set to a non-zero integer, returns success
 246          */
 247         function open( $server, $user, $password, $dbName ) {
 248                 global $wguname;
 249
 250                 # Test for missing mysql.so
 251                 # First try to load it
 252                 if (!@extension_loaded('mysql')) {
 253                         @dl('mysql.so');
 254                 }
 255
 256                 # Otherwise we get a suppressed fatal error, which is very hard to track down
 257                 if ( !function_exists( 'mysql_connect' ) ) {
 258                         wfDie( "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
 259                 }
 260
 261                 $this->close();
 262                 $this->mServer = $server;
 263                 $this->mUser = $user;
 264                 $this->mPassword = $password;
 265                 $this->mDBname = $dbName;
 266
 267                 $success = false;
 268
 269                 if ( $this->mFlags & DBO_PERSISTENT ) {
 270                         @/**/$this->mConn = mysql_pconnect( $server, $user, $password );
 271                 } else {
 272                         # Create a new connection...
 273                         if( version_compare( PHP_VERSION, '4.2.0', 'ge' ) ) {
 274                                 @/**/$this->mConn = mysql_connect( $server, $user, $password, true );
 275                         } else {
 276                                 # On PHP 4.1 the new_link parameter is not available. We cannot
 277                                 # guarantee that we'll actually get a new connection, and this
 278                                 # may cause some operations to fail possibly.
 279                                 @/**/$this->mConn = mysql_connect( $server, $user, $password );
 280                         }
 281                 }
 282
 283                 if ( $dbName != '' ) {
 284                         if ( $this->mConn !== false ) {
 285                                 $success = @/**/mysql_select_db( $dbName, $this->mConn );
 286                                 if ( !$success ) {
 287                                         $error = "Error selecting database $dbName on server {$this->mServer} " .
 288                                                 "from client host {$wguname['nodename']}\n";
 289                                         wfDebug( $error );
 290                                 }
 291                         } else {
 292                                 wfDebug( "DB connection error\n" );
 293                                 wfDebug( "Server: $server, User: $user, Password: " .
 294                                         substr( $password, 0, 3 ) . "..., error: " . mysql_error() . "\n" );
 295                                 $success = false;
 296                         }
 297                 } else {
 298                         # Delay USE query
 299                         $success = (bool)$this->mConn;
 300                 }
 301
 302                 if ( !$success ) {
 303                         $this->reportConnectionError();
 304                 }
 305
 306                 global $wgDBmysql5;
 307                 if( $wgDBmysql5 ) {
 308                         // Tell the server we're communicating with it in UTF-8.
 309                         // This may engage various charset conversions.
 310                         $this->query( 'SET NAMES utf8' );
 311                 }
 312
 313                 $this->mOpened = $success;
 314                 return $success;
 315         }
 316         /**@}}*/
 317
 318         /**
 319          * Closes a database connection.
 320          * if it is open : commits any open transactions
 321          *
 322          * @return bool operation success. true if already closed.
 323          */
 324         function close()
 325         {
 326                 $this->mOpened = false;
 327                 if ( $this->mConn ) {
 328                         if ( $this->trxLevel() ) {
 329                                 $this->immediateCommit();
 330                         }
 331                         return mysql_close( $this->mConn );
 332                 } else {
 333                         return true;
 334                 }
 335         }
 336
 337         /**
 338          * @private
 339          * @param string $error fallback error message, used if none is given by MySQL
 340          */
 341         function reportConnectionError( $error = 'Unknown error' ) {
 342                 $myError = $this->lastError();
 343                 if ( $myError ) {
 344                         $error = $myError;
 345                 }
 346
 347                 if ( $this->mFailFunction ) {
 348                         if ( !is_int( $this->mFailFunction ) ) {
 349                                 $ff = $this->mFailFunction;
 350                                 $ff( $this, $error );
 351                         }
 352                 } else {
 353                         wfEmergencyAbort( $this, $error );
 354                 }
 355         }
 356
 357         /**
 358          * Usually aborts on failure
 359          * If errors are explicitly ignored, returns success
 360          */
 361         function query( $sql, $fname = '', $tempIgnore = false ) {
 362                 global $wgProfiling;
 363
 364                 if ( $wgProfiling ) {
 365                         # generalizeSQL will probably cut down the query to reasonable
 366                         # logging size most of the time. The substr is really just a sanity check.
 367
 368                         # Who's been wasting my precious column space? -- TS
 369                         #$profName = 'query: ' . $fname . ' ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 370
 371                         if ( is_null( $this->getLBInfo( 'master' ) ) ) {
 372                                 $queryProf = 'query: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 373                                 $totalProf = 'Database::query';
 374                         } else {
 375                                 $queryProf = 'query-m: ' . substr( Database::generalizeSQL( $sql ), 0, 255 );
 376                                 $totalProf = 'Database::query-master';
 377                         }
 378                         wfProfileIn( $totalProf );
 379                         wfProfileIn( $queryProf );
 380                 }
 381
 382                 $this->mLastQuery = $sql;
 383
 384                 # Add a comment for easy SHOW PROCESSLIST interpretation
 385                 if ( $fname ) {
 386                         $commentedSql = preg_replace("/\s/", " /* $fname */ ", $sql, 1);
 387                 } else {
 388                         $commentedSql = $sql;
 389                 }
 390
 391                 # If DBO_TRX is set, start a transaction
 392                 if ( ( $this->mFlags & DBO_TRX ) && !$this->trxLevel() && $sql != 'BEGIN' ) {
 393                         $this->begin();
 394                 }
 395
 396                 if ( $this->debug() ) {
 397                         $sqlx = substr( $commentedSql, 0, 500 );
 398                         $sqlx = strtr( $sqlx, "\t\n", '  ' );
 399                         wfDebug( "SQL: $sqlx\n" );
 400                 }
 401
 402                 # Do the query and handle errors
 403                 $ret = $this->doQuery( $commentedSql );
 404
 405                 # Try reconnecting if the connection was lost
 406                 if ( false === $ret && ( $this->lastErrno() == 2013 || $this->lastErrno() == 2006 ) ) {
 407                         # Transaction is gone, like it or not
 408                         $this->mTrxLevel = 0;
 409                         wfDebug( "Connection lost, reconnecting...\n" );
 410                         if ( $this->ping() ) {
 411                                 wfDebug( "Reconnected\n" );
 412                                 $ret = $this->doQuery( $commentedSql );
 413                         } else {
 414                                 wfDebug( "Failed\n" );
 415                         }
 416                 }
 417
 418                 if ( false === $ret ) {
 419                         $this->reportQueryError( $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
 420                 }
 421
 422                 if ( $wgProfiling ) {
 423                         wfProfileOut( $queryProf );
 424                         wfProfileOut( $totalProf );
 425                 }
 426                 return $ret;
 427         }
 428
 429         /**
 430          * The DBMS-dependent part of query()
 431          * @param string $sql SQL query.
 432          */
 433         function doQuery( $sql ) {
 434                 if( $this->bufferResults() ) {
 435                         $ret = mysql_query( $sql, $this->mConn );
 436                 } else {
 437                         $ret = mysql_unbuffered_query( $sql, $this->mConn );
 438                 }
 439                 return $ret;
 440         }
 441
 442         /**
 443          * @param $error
 444          * @param $errno
 445          * @param $sql
 446          * @param string $fname
 447          * @param bool $tempIgnore
 448          */
 449         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 450                 global $wgCommandLineMode, $wgFullyInitialised, $wgColorErrors;
 451                 # Ignore errors during error handling to avoid infinite recursion
 452                 $ignore = $this->ignoreErrors( true );
 453                 ++$this->mErrorCount;
 454
 455                 if( $ignore || $tempIgnore ) {
 456                         wfDebug("SQL ERROR (ignored): $error\n");
 457                 } else {
 458                         $sql1line = str_replace( "\n", "\\n", $sql );
 459                         wfLogDBError("$fname\t{$this->mServer}\t$errno\t$error\t$sql1line\n");
 460                         wfDebug("SQL ERROR: " . $error . "\n");
 461                         if ( $wgCommandLineMode || !$this->mOut || empty( $wgFullyInitialised ) ) {
 462                                 $message = "A database error has occurred\n" .
 463                                   "Query: $sql\n" .
 464                                   "Function: $fname\n" .
 465                                   "Error: $errno $error\n";
 466                                 if ( !$wgCommandLineMode ) {
 467                                         $message = nl2br( $message );
 468                                 }
 469                                 if( $wgCommandLineMode && $wgColorErrors && !wfIsWindows() && posix_isatty(1) ) {
 470                                         $color = 31; // bright red!
 471                                         $message = "\x1b[1;{$color}m{$message}\x1b[0m";
 472                                 }
 473                                 wfDebugDieBacktrace( $message );
 474                         } else {
 475                                 // this calls wfAbruptExit()
 476                                 $this->mOut->databaseError( $fname, $sql, $error, $errno );
 477                         }
 478                 }
 479                 $this->ignoreErrors( $ignore );
 480         }
 481
 482
 483         /**
 484          * Intended to be compatible with the PEAR::DB wrapper functions.
 485          * http://pear.php.net/manual/en/package.database.db.intro-execute.php
 486          *
 487          * ? = scalar value, quoted as necessary
 488          * ! = raw SQL bit (a function for instance)
 489          * & = filename; reads the file and inserts as a blob
 490          *     (we don't use this though...)
 491          */
 492         function prepare( $sql, $func = 'Database::prepare' ) {
 493                 /* MySQL doesn't support prepared statements (yet), so just
 494                    pack up the query for reference. We'll manually replace
 495                    the bits later. */
 496                 return array( 'query' => $sql, 'func' => $func );
 497         }
 498
 499         function freePrepared( $prepared ) {
 500                 /* No-op for MySQL */
 501         }
 502
 503         /**
 504          * Execute a prepared query with the various arguments
 505          * @param string $prepared the prepared sql
 506          * @param mixed $args Either an array here, or put scalars as varargs
 507          */
 508         function execute( $prepared, $args = null ) {
 509                 if( !is_array( $args ) ) {
 510                         # Pull the var args
 511                         $args = func_get_args();
 512                         array_shift( $args );
 513                 }
 514                 $sql = $this->fillPrepared( $prepared['query'], $args );
 515                 return $this->query( $sql, $prepared['func'] );
 516         }
 517
 518         /**
 519          * Prepare & execute an SQL statement, quoting and inserting arguments
 520          * in the appropriate places.
 521          * @param string $query
 522          * @param string $args ...
 523          */
 524         function safeQuery( $query, $args = null ) {
 525                 $prepared = $this->prepare( $query, 'Database::safeQuery' );
 526                 if( !is_array( $args ) ) {
 527                         # Pull the var args
 528                         $args = func_get_args();
 529                         array_shift( $args );
 530                 }
 531                 $retval = $this->execute( $prepared, $args );
 532                 $this->freePrepared( $prepared );
 533                 return $retval;
 534         }
 535
 536         /**
 537          * For faking prepared SQL statements on DBs that don't support
 538          * it directly.
 539          * @param string $preparedSql - a 'preparable' SQL statement
 540          * @param array $args - array of arguments to fill it with
 541          * @return string executable SQL
 542          */
 543         function fillPrepared( $preparedQuery, $args ) {
 544                 $n = 0;
 545                 reset( $args );
 546                 $this->preparedArgs =& $args;
 547                 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
 548                         array( &$this, 'fillPreparedArg' ), $preparedQuery );
 549         }
 550
 551         /**
 552          * preg_callback func for fillPrepared()
 553          * The arguments should be in $this->preparedArgs and must not be touched
 554          * while we're doing this.
 555          *
 556          * @param array $matches
 557          * @return string
 558          * @private
 559          */
 560         function fillPreparedArg( $matches ) {
 561                 switch( $matches[1] ) {
 562                         case '\\?': return '?';
 563                         case '\\!': return '!';
 564                         case '\\&': return '&';
 565                 }
 566                 list( $n, $arg ) = each( $this->preparedArgs );
 567                 switch( $matches[1] ) {
 568                         case '?': return $this->addQuotes( $arg );
 569                         case '!': return $arg;
 570                         case '&':
 571                                 # return $this->addQuotes( file_get_contents( $arg ) );
 572                                 wfDebugDieBacktrace( '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
 573                         default:
 574                                 wfDebugDieBacktrace( 'Received invalid match. This should never happen!' );
 575                 }
 576         }
 577
 578         /**#@+
 579          * @param mixed $res A SQL result
 580          */
 581         /**
 582          * Free a result object
 583          */
 584         function freeResult( $res ) {
 585                 if ( !@/**/mysql_free_result( $res ) ) {
 586                         wfDebugDieBacktrace( "Unable to free MySQL result\n" );
 587                 }
 588         }
 589
 590         /**
 591          * Fetch the next row from the given result object, in object form
 592          */
 593         function fetchObject( $res ) {
 594                 @/**/$row = mysql_fetch_object( $res );
 595                 if( mysql_errno() ) {
 596                         wfDebugDieBacktrace( 'Error in fetchObject(): ' . htmlspecialchars( mysql_error() ) );
 597                 }
 598                 return $row;
 599         }
 600
 601         /**
 602          * Fetch the next row from the given result object
 603          * Returns an array
 604          */
 605         function fetchRow( $res ) {
 606                 @/**/$row = mysql_fetch_array( $res );
 607                 if (mysql_errno() ) {
 608                         wfDebugDieBacktrace( 'Error in fetchRow(): ' . htmlspecialchars( mysql_error() ) );
 609                 }
 610                 return $row;
 611         }
 612
 613         /**
 614          * Get the number of rows in a result object
 615          */
 616         function numRows( $res ) {
 617                 @/**/$n = mysql_num_rows( $res );
 618                 if( mysql_errno() ) {
 619                         wfDebugDieBacktrace( 'Error in numRows(): ' . htmlspecialchars( mysql_error() ) );
 620                 }
 621                 return $n;
 622         }
 623
 624         /**
 625          * Get the number of fields in a result object
 626          * See documentation for mysql_num_fields()
 627          */
 628         function numFields( $res ) { return mysql_num_fields( $res ); }
 629
 630         /**
 631          * Get a field name in a result object
 632          * See documentation for mysql_field_name():
 633          * http://www.php.net/mysql_field_name
 634          */
 635         function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }
 636
 637         /**
 638          * Get the inserted value of an auto-increment row
 639          *
 640          * The value inserted should be fetched from nextSequenceValue()
 641          *
 642          * Example:
 643          * $id = $dbw->nextSequenceValue('page_page_id_seq');
 644          * $dbw->insert('page',array('page_id' => $id));
 645          * $id = $dbw->insertId();
 646          */
 647         function insertId() { return mysql_insert_id( $this->mConn ); }
 648
 649         /**
 650          * Change the position of the cursor in a result object
 651          * See mysql_data_seek()
 652          */
 653         function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }
 654
 655         /**
 656          * Get the last error number
 657          * See mysql_errno()
 658          */
 659         function lastErrno() {
 660                 if ( $this->mConn ) {
 661                         return mysql_errno( $this->mConn );
 662                 } else {
 663                         return mysql_errno();
 664                 }
 665         }
 666
 667         /**
 668          * Get a description of the last error
 669          * See mysql_error() for more details
 670          */
 671         function lastError() {
 672                 if ( $this->mConn ) {
 673                         # Even if it's non-zero, it can still be invalid
 674                         wfSuppressWarnings();
 675                         $error = mysql_error( $this->mConn );
 676                         if ( !$error ) {
 677                                 $error = mysql_error();
 678                         }
 679                         wfRestoreWarnings();
 680                 } else {
 681                         $error = mysql_error();
 682                 }
 683                 if( $error ) {
 684                         $error .= ' (' . $this->mServer . ')';
 685                 }
 686                 return $error;
 687         }
 688         /**
 689          * Get the number of rows affected by the last write query
 690          * See mysql_affected_rows() for more details
 691          */
 692         function affectedRows() { return mysql_affected_rows( $this->mConn ); }
 693         /**#@-*/ // end of template : @param $result
 694
 695         /**
 696          * Simple UPDATE wrapper
 697          * Usually aborts on failure
 698          * If errors are explicitly ignored, returns success
 699          *
 700          * This function exists for historical reasons, Database::update() has a more standard
 701          * calling convention and feature set
 702          */
 703         function set( $table, $var, $value, $cond, $fname = 'Database::set' )
 704         {
 705                 $table = $this->tableName( $table );
 706                 $sql = "UPDATE $table SET $var = '" .
 707                   $this->strencode( $value ) . "' WHERE ($cond)";
 708                 return (bool)$this->query( $sql, $fname );
 709         }
 710
 711         /**
 712          * Simple SELECT wrapper, returns a single field, input must be encoded
 713          * Usually aborts on failure
 714          * If errors are explicitly ignored, returns FALSE on failure
 715          */
 716         function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
 717                 if ( !is_array( $options ) ) {
 718                         $options = array( $options );
 719                 }
 720                 $options['LIMIT'] = 1;
 721
 722                 $res = $this->select( $table, $var, $cond, $fname, $options );
 723                 if ( $res === false || !$this->numRows( $res ) ) {
 724                         return false;
 725                 }
 726                 $row = $this->fetchRow( $res );
 727                 if ( $row !== false ) {
 728                         $this->freeResult( $res );
 729                         return $row[0];
 730                 } else {
 731                         return false;
 732                 }
 733         }
 734
 735         /**
 736          * Returns an optional USE INDEX clause to go after the table, and a
 737          * string to go at the end of the query
 738          *
 739          * @private
 740          *
 741          * @param array $options an associative array of options to be turned into
 742          *              an SQL query, valid keys are listed in the function.
 743          * @return array
 744          */
 745         function makeSelectOptions( $options ) {
 746                 $tailOpts = '';
 747                 $startOpts = '';
 748
 749                 $noKeyOptions = array();
 750                 foreach ( $options as $key => $option ) {
 751                         if ( is_numeric( $key ) ) {
 752                                 $noKeyOptions[$option] = true;
 753                         }
 754                 }
 755
 756                 if ( isset( $options['GROUP BY'] ) ) $tailOpts .= " GROUP BY {$options['GROUP BY']}";
 757                 if ( isset( $options['ORDER BY'] ) ) $tailOpts .= " ORDER BY {$options['ORDER BY']}";
 758
 759                 if (isset($options['LIMIT'])) {
 760                         $tailOpts .= $this->limitResult('', $options['LIMIT'],
 761                                 isset($options['OFFSET']) ? $options['OFFSET'] : false);
 762                 }
 763
 764                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) $tailOpts .= ' FOR UPDATE';
 765                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) $tailOpts .= ' LOCK IN SHARE MODE';
 766                 if ( isset( $noKeyOptions['DISTINCT'] ) && isset( $noKeyOptions['DISTINCTROW'] ) ) $startOpts .= 'DISTINCT';
 767
 768                 # Various MySQL extensions
 769                 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) $startOpts .= ' HIGH_PRIORITY';
 770                 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) $startOpts .= ' SQL_BIG_RESULT';
 771                 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) $startOpts .= ' SQL_BUFFER_RESULT';
 772                 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) $startOpts .= ' SQL_SMALL_RESULT';
 773                 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) $startOpts .= ' SQL_CALC_FOUND_ROWS';
 774                 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) $startOpts .= ' SQL_CACHE';
 775                 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) $startOpts .= ' SQL_NO_CACHE';
 776
 777                 if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
 778                         $useIndex = $this->useIndexClause( $options['USE INDEX'] );
 779                 } else {
 780                         $useIndex = '';
 781                 }
 782
 783                 return array( $startOpts, $useIndex, $tailOpts );
 784         }
 785
 786         /**
 787          * SELECT wrapper
 788          */
 789         function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array() )
 790         {
 791                 if( is_array( $vars ) ) {
 792                         $vars = implode( ',', $vars );
 793                 }
 794                 if( !is_array( $options ) ) {
 795                         $options = array( $options );
 796                 }
 797                 if( is_array( $table ) ) {
 798                         if ( @is_array( $options['USE INDEX'] ) )
 799                                 $from = ' FROM ' . $this->tableNamesWithUseIndex( $table, $options['USE INDEX'] );
 800                         else
 801                                 $from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
 802                 } elseif ($table!='') {
 803                         $from = ' FROM ' . $this->tableName( $table );
 804                 } else {
 805                         $from = '';
 806                 }
 807
 808                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $options );
 809
 810                 if( !empty( $conds ) ) {
 811                         if ( is_array( $conds ) ) {
 812                                 $conds = $this->makeList( $conds, LIST_AND );
 813                         }
 814                         $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $tailOpts";
 815                 } else {
 816                         $sql = "SELECT $startOpts $vars $from $useIndex $tailOpts";
 817                 }
 818
 819                 return $this->query( $sql, $fname );
 820         }
 821
 822         /**
 823          * Single row SELECT wrapper
 824          * Aborts or returns FALSE on error
 825          *
 826          * $vars: the selected variables
 827          * $conds: a condition map, terms are ANDed together.
 828          *   Items with numeric keys are taken to be literal conditions
 829          * Takes an array of selected variables, and a condition map, which is ANDed
 830          * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
 831          * NS_MAIN, "page_title" => "Astronomy" ) )   would return an object where
 832          * $obj- >page_id is the ID of the Astronomy article
 833          *
 834          * @todo migrate documentation to phpdocumentor format
 835          */
 836         function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
 837                 $options['LIMIT'] = 1;
 838                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 839                 if ( $res === false )
 840                         return false;
 841                 if ( !$this->numRows($res) ) {
 842                         $this->freeResult($res);
 843                         return false;
 844                 }
 845                 $obj = $this->fetchObject( $res );
 846                 $this->freeResult( $res );
 847                 return $obj;
 848
 849         }
 850
 851         /**
 852          * Removes most variables from an SQL query and replaces them with X or N for numbers.
 853          * It's only slightly flawed. Don't use for anything important.
 854          *
 855          * @param string $sql A SQL Query
 856          * @static
 857          */
 858         function generalizeSQL( $sql ) {
 859                 # This does the same as the regexp below would do, but in such a way
 860                 # as to avoid crashing php on some large strings.
 861                 # $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);
 862
 863                 $sql = str_replace ( "\\\\", '', $sql);
 864                 $sql = str_replace ( "\\'", '', $sql);
 865                 $sql = str_replace ( "\\\"", '', $sql);
 866                 $sql = preg_replace ("/'.*'/s", "'X'", $sql);
 867                 $sql = preg_replace ('/".*"/s', "'X'", $sql);
 868
 869                 # All newlines, tabs, etc replaced by single space
 870                 $sql = preg_replace ( "/\s+/", ' ', $sql);
 871
 872                 # All numbers => N
 873                 $sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);
 874
 875                 return $sql;
 876         }
 877
 878         /**
 879          * Determines whether a field exists in a table
 880          * Usually aborts on failure
 881          * If errors are explicitly ignored, returns NULL on failure
 882          */
 883         function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
 884                 $table = $this->tableName( $table );
 885                 $res = $this->query( 'DESCRIBE '.$table, $fname );
 886                 if ( !$res ) {
 887                         return NULL;
 888                 }
 889
 890                 $found = false;
 891
 892                 while ( $row = $this->fetchObject( $res ) ) {
 893                         if ( $row->Field == $field ) {
 894                                 $found = true;
 895                                 break;
 896                         }
 897                 }
 898                 return $found;
 899         }
 900
 901         /**
 902          * Determines whether an index exists
 903          * Usually aborts on failure
 904          * If errors are explicitly ignored, returns NULL on failure
 905          */
 906         function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
 907                 $info = $this->indexInfo( $table, $index, $fname );
 908                 if ( is_null( $info ) ) {
 909                         return NULL;
 910                 } else {
 911                         return $info !== false;
 912                 }
 913         }
 914
 915
 916         /**
 917          * Get information about an index into an object
 918          * Returns false if the index does not exist
 919          */
 920         function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
 921                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 922                 # SHOW INDEX should work for 3.x and up:
 923                 # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 924                 $table = $this->tableName( $table );
 925                 $sql = 'SHOW INDEX FROM '.$table;
 926                 $res = $this->query( $sql, $fname );
 927                 if ( !$res ) {
 928                         return NULL;
 929                 }
 930
 931                 while ( $row = $this->fetchObject( $res ) ) {
 932                         if ( $row->Key_name == $index ) {
 933                                 return $row;
 934                         }
 935                 }
 936                 return false;
 937         }
 938
 939         /**
 940          * Query whether a given table exists
 941          */
 942         function tableExists( $table ) {
 943                 $table = $this->tableName( $table );
 944                 $old = $this->ignoreErrors( true );
 945                 $res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
 946                 $this->ignoreErrors( $old );
 947                 if( $res ) {
 948                         $this->freeResult( $res );
 949                         return true;
 950                 } else {
 951                         return false;
 952                 }
 953         }
 954
 955         /**
 956          * mysql_fetch_field() wrapper
 957          * Returns false if the field doesn't exist
 958          *
 959          * @param $table
 960          * @param $field
 961          */
 962         function fieldInfo( $table, $field ) {
 963                 $table = $this->tableName( $table );
 964                 $res = $this->query( "SELECT * FROM $table LIMIT 1" );
 965                 $n = mysql_num_fields( $res );
 966                 for( $i = 0; $i < $n; $i++ ) {
 967                         $meta = mysql_fetch_field( $res, $i );
 968                         if( $field == $meta->name ) {
 969                                 return $meta;
 970                         }
 971                 }
 972                 return false;
 973         }
 974
 975         /**
 976          * mysql_field_type() wrapper
 977          */
 978         function fieldType( $res, $index ) {
 979                 return mysql_field_type( $res, $index );
 980         }
 981
 982         /**
 983          * Determines if a given index is unique
 984          */
 985         function indexUnique( $table, $index ) {
 986                 $indexInfo = $this->indexInfo( $table, $index );
 987                 if ( !$indexInfo ) {
 988                         return NULL;
 989                 }
 990                 return !$indexInfo->Non_unique;
 991         }
 992
 993         /**
 994          * INSERT wrapper, inserts an array into a table
 995          *
 996          * $a may be a single associative array, or an array of these with numeric keys, for
 997          * multi-row insert.
 998          *
 999          * Usually aborts on failure
1000          * If errors are explicitly ignored, returns success
1001          */
1002         function insert( $table, $a, $fname = 'Database::insert', $options = array() ) {
1003                 # No rows to insert, easy just return now
1004                 if ( !count( $a ) ) {
1005                         return true;
1006                 }
1007
1008                 $table = $this->tableName( $table );
1009                 if ( !is_array( $options ) ) {
1010                         $options = array( $options );
1011                 }
1012                 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1013                         $multi = true;
1014                         $keys = array_keys( $a[0] );
1015                 } else {
1016                         $multi = false;
1017                         $keys = array_keys( $a );
1018                 }
1019
1020                 $sql = 'INSERT ' . implode( ' ', $options ) .
1021                         " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1022
1023                 if ( $multi ) {
1024                         $first = true;
1025                         foreach ( $a as $row ) {
1026                                 if ( $first ) {
1027                                         $first = false;
1028                                 } else {
1029                                         $sql .= ',';
1030                                 }
1031                                 $sql .= '(' . $this->makeList( $row ) . ')';
1032                         }
1033                 } else {
1034                         $sql .= '(' . $this->makeList( $a ) . ')';
1035                 }
1036                 return (bool)$this->query( $sql, $fname );
1037         }
1038
1039         /**
1040          * Make UPDATE options for the Database::update function
1041          *
1042          * @private
1043          * @param array $options The options passed to Database::update
1044          * @return string
1045          */
1046         function makeUpdateOptions( $options ) {
1047                 if( !is_array( $options ) ) {
1048                         $options = array( $options );
1049                 }
1050                 $opts = array();
1051                 if ( in_array( 'LOW_PRIORITY', $options ) )
1052                         $opts[] = $this->lowPriorityOption();
1053                 if ( in_array( 'IGNORE', $options ) )
1054                         $opts[] = 'IGNORE';
1055                 return implode(' ', $opts);
1056         }
1057
1058         /**
1059          * UPDATE wrapper, takes a condition array and a SET array
1060          *
1061          * @param string $table  The table to UPDATE
1062          * @param array  $values An array of values to SET
1063          * @param array  $conds  An array of conditions (WHERE). Use '*' to update all rows.
1064          * @param string $fname  The Class::Function calling this function
1065          *                       (for the log)
1066          * @param array  $options An array of UPDATE options, can be one or
1067          *                        more of IGNORE, LOW_PRIORITY
1068          */
1069         function update( $table, $values, $conds, $fname = 'Database::update', $options = array() ) {
1070                 $table = $this->tableName( $table );
1071                 $opts = $this->makeUpdateOptions( $options );
1072                 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
1073                 if ( $conds != '*' ) {
1074                         $sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
1075                 }
1076                 $this->query( $sql, $fname );
1077         }
1078
1079         /**
1080          * Makes a wfStrencoded list from an array
1081          * $mode:
1082          *        LIST_COMMA         - comma separated, no field names
1083          *        LIST_AND           - ANDed WHERE clause (without the WHERE)
1084          *        LIST_OR            - ORed WHERE clause (without the WHERE)
1085          *        LIST_SET           - comma separated with field names, like a SET clause
1086          *        LIST_NAMES         - comma separated field names
1087          */
1088         function makeList( $a, $mode = LIST_COMMA ) {
1089                 if ( !is_array( $a ) ) {
1090                         wfDebugDieBacktrace( 'Database::makeList called with incorrect parameters' );
1091                 }
1092
1093                 $first = true;
1094                 $list = '';
1095                 foreach ( $a as $field => $value ) {
1096                         if ( !$first ) {
1097                                 if ( $mode == LIST_AND ) {
1098                                         $list .= ' AND ';
1099                                 } elseif($mode == LIST_OR) {
1100                                         $list .= ' OR ';
1101                                 } else {
1102                                         $list .= ',';
1103                                 }
1104                         } else {
1105                                 $first = false;
1106                         }
1107                         if ( ($mode == LIST_AND || $mode == LIST_OR) && is_numeric( $field ) ) {
1108                                 $list .= "($value)";
1109                         } elseif ( ($mode == LIST_AND || $mode == LIST_OR) && is_array ($value) ) {
1110                                 $list .= $field." IN (".$this->makeList($value).") ";
1111                         } else {
1112                                 if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
1113                                         $list .= "$field = ";
1114                                 }
1115                                 $list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
1116                         }
1117                 }
1118                 return $list;
1119         }
1120
1121         /**
1122          * Change the current database
1123          */
1124         function selectDB( $db ) {
1125                 $this->mDBname = $db;
1126                 return mysql_select_db( $db, $this->mConn );
1127         }
1128
1129         /**
1130          * Format a table name ready for use in constructing an SQL query
1131          *
1132          * This does two important things: it quotes table names which as necessary,
1133          * and it adds a table prefix if there is one.
1134          *
1135          * All functions of this object which require a table name call this function
1136          * themselves. Pass the canonical name to such functions. This is only needed
1137          * when calling query() directly.
1138          *
1139          * @param string $name database table name
1140          */
1141         function tableName( $name ) {
1142                 global $wgSharedDB;
1143                 # Skip quoted literals
1144                 if ( $name{0} != '`' ) {
1145                         if ( $this->mTablePrefix !== '' &&  strpos( '.', $name ) === false ) {
1146                                 $name = "{$this->mTablePrefix}$name";
1147                         }
1148                         if ( isset( $wgSharedDB ) && "{$this->mTablePrefix}user" == $name ) {
1149                                 $name = "`$wgSharedDB`.`$name`";
1150                         } else {
1151                                 # Standard quoting
1152                                 $name = "`$name`";
1153                         }
1154                 }
1155                 return $name;
1156         }
1157
1158         /**
1159          * Fetch a number of table names into an array
1160          * This is handy when you need to construct SQL for joins
1161          *
1162          * Example:
1163          * extract($dbr->tableNames('user','watchlist'));
1164          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1165          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1166          */
1167         function tableNames() {
1168                 $inArray = func_get_args();
1169                 $retVal = array();
1170                 foreach ( $inArray as $name ) {
1171                         $retVal[$name] = $this->tableName( $name );
1172                 }
1173                 return $retVal;
1174         }
1175
1176         /**
1177          * @private
1178          */
1179         function tableNamesWithUseIndex( $tables, $use_index ) {
1180                 $ret = array();
1181
1182                 foreach ( $tables as $table )
1183                         if ( @$use_index[$table] !== null )
1184                                 $ret[] = $this->tableName( $table ) . ' ' . $this->useIndexClause( implode( ',', (array)$use_index[$table] ) );
1185                         else
1186                                 $ret[] = $this->tableName( $table );
1187
1188                 return implode( ',', $ret );
1189         }
1190
1191         /**
1192          * Wrapper for addslashes()
1193          * @param string $s String to be slashed.
1194          * @return string slashed string.
1195          */
1196         function strencode( $s ) {
1197                 return addslashes( $s );
1198         }
1199
1200         /**
1201          * If it's a string, adds quotes and backslashes
1202          * Otherwise returns as-is
1203          */
1204         function addQuotes( $s ) {
1205                 if ( is_null( $s ) ) {
1206                         return 'NULL';
1207                 } else {
1208                         # This will also quote numeric values. This should be harmless,
1209                         # and protects against weird problems that occur when they really
1210                         # _are_ strings such as article titles and string->number->string
1211                         # conversion is not 1:1.
1212                         return "'" . $this->strencode( $s ) . "'";
1213                 }
1214         }
1215
1216         /**
1217          * Escape string for safe LIKE usage
1218          */
1219         function escapeLike( $s ) {
1220                 $s=$this->strencode( $s );
1221                 $s=str_replace(array('%','_'),array('\%','\_'),$s);
1222                 return $s;
1223         }
1224
1225         /**
1226          * Returns an appropriately quoted sequence value for inserting a new row.
1227          * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
1228          * subclass will return an integer, and save the value for insertId()
1229          */
1230         function nextSequenceValue( $seqName ) {
1231                 return NULL;
1232         }
1233
1234         /**
1235          * USE INDEX clause
1236          * PostgreSQL doesn't have them and returns ""
1237          */
1238         function useIndexClause( $index ) {
1239                 return "FORCE INDEX ($index)";
1240         }
1241
1242         /**
1243          * REPLACE query wrapper
1244          * PostgreSQL simulates this with a DELETE followed by INSERT
1245          * $row is the row to insert, an associative array
1246          * $uniqueIndexes is an array of indexes. Each element may be either a
1247          * field name or an array of field names
1248          *
1249          * It may be more efficient to leave off unique indexes which are unlikely to collide.
1250          * However if you do this, you run the risk of encountering errors which wouldn't have
1251          * occurred in MySQL
1252          *
1253          * @todo migrate comment to phodocumentor format
1254          */
1255         function replace( $table, $uniqueIndexes, $rows, $fname = 'Database::replace' ) {
1256                 $table = $this->tableName( $table );
1257
1258                 # Single row case
1259                 if ( !is_array( reset( $rows ) ) ) {
1260                         $rows = array( $rows );
1261                 }
1262
1263                 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) .') VALUES ';
1264                 $first = true;
1265                 foreach ( $rows as $row ) {
1266                         if ( $first ) {
1267                                 $first = false;
1268                         } else {
1269                                 $sql .= ',';
1270                         }
1271                         $sql .= '(' . $this->makeList( $row ) . ')';
1272                 }
1273                 return $this->query( $sql, $fname );
1274         }
1275
1276         /**
1277          * DELETE where the condition is a join
1278          * MySQL does this with a multi-table DELETE syntax, PostgreSQL does it with sub-selects
1279          *
1280          * For safety, an empty $conds will not delete everything. If you want to delete all rows where the
1281          * join condition matches, set $conds='*'
1282          *
1283          * DO NOT put the join condition in $conds
1284          *
1285          * @param string $delTable The table to delete from.
1286          * @param string $joinTable The other table.
1287          * @param string $delVar The variable to join on, in the first table.
1288          * @param string $joinVar The variable to join on, in the second table.
1289          * @param array $conds Condition array of field names mapped to variables, ANDed together in the WHERE clause
1290          */
1291         function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'Database::deleteJoin' ) {
1292                 if ( !$conds ) {
1293                         wfDebugDieBacktrace( 'Database::deleteJoin() called with empty $conds' );
1294                 }
1295
1296                 $delTable = $this->tableName( $delTable );
1297                 $joinTable = $this->tableName( $joinTable );
1298                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1299                 if ( $conds != '*' ) {
1300                         $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
1301                 }
1302
1303                 return $this->query( $sql, $fname );
1304         }
1305
1306         /**
1307          * Returns the size of a text field, or -1 for "unlimited"
1308          */
1309         function textFieldSize( $table, $field ) {
1310                 $table = $this->tableName( $table );
1311                 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
1312                 $res = $this->query( $sql, 'Database::textFieldSize' );
1313                 $row = $this->fetchObject( $res );
1314                 $this->freeResult( $res );
1315
1316                 if ( preg_match( "/\((.*)\)/", $row->Type, $m ) ) {
1317                         $size = $m[1];
1318                 } else {
1319                         $size = -1;
1320                 }
1321                 return $size;
1322         }
1323
1324         /**
1325          * @return string Returns the text of the low priority option if it is supported, or a blank string otherwise
1326          */
1327         function lowPriorityOption() {
1328                 return 'LOW_PRIORITY';
1329         }
1330
1331         /**
1332          * DELETE query wrapper
1333          *
1334          * Use $conds == "*" to delete all rows
1335          */
1336         function delete( $table, $conds, $fname = 'Database::delete' ) {
1337                 if ( !$conds ) {
1338                         wfDebugDieBacktrace( 'Database::delete() called with no conditions' );
1339                 }
1340                 $table = $this->tableName( $table );
1341                 $sql = "DELETE FROM $table";
1342                 if ( $conds != '*' ) {
1343                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1344                 }
1345                 return $this->query( $sql, $fname );
1346         }
1347
1348         /**
1349          * INSERT SELECT wrapper
1350          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
1351          * Source items may be literals rather than field names, but strings should be quoted with Database::addQuotes()
1352          * $conds may be "*" to copy the whole table
1353          * srcTable may be an array of tables.
1354          */
1355         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'Database::insertSelect',
1356                 $insertOptions = array(), $selectOptions = array() )
1357         {
1358                 $destTable = $this->tableName( $destTable );
1359                 if ( is_array( $insertOptions ) ) {
1360                         $insertOptions = implode( ' ', $insertOptions );
1361                 }
1362                 if( !is_array( $selectOptions ) ) {
1363                         $selectOptions = array( $selectOptions );
1364                 }
1365                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
1366                 if( is_array( $srcTable ) ) {
1367                         $srcTable =  implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
1368                 } else {
1369                         $srcTable = $this->tableName( $srcTable );
1370                 }
1371                 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
1372                         " SELECT $startOpts " . implode( ',', $varMap ) .
1373                         " FROM $srcTable $useIndex ";
1374                 if ( $conds != '*' ) {
1375                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
1376                 }
1377                 $sql .= " $tailOpts";
1378                 return $this->query( $sql, $fname );
1379         }
1380
1381         /**
1382          * Construct a LIMIT query with optional offset
1383          * This is used for query pages
1384          * $sql string SQL query we will append the limit too
1385          * $limit integer the SQL limit
1386          * $offset integer the SQL offset (default false)
1387          */
1388         function limitResult($sql, $limit, $offset=false) {
1389                 if( !is_numeric($limit) ) {
1390                         wfDie( "Invalid non-numeric limit passed to limitResult()\n" );
1391                 }
1392                 return " $sql LIMIT "
1393                                 . ( (is_numeric($offset) && $offset != 0) ? "{$offset}," : "" )
1394                                 . "{$limit} ";
1395         }
1396         function limitResultForUpdate($sql, $num) {
1397                 return $this->limitResult($sql, $num, 0);
1398         }
1399
1400         /**
1401          * Returns an SQL expression for a simple conditional.
1402          * Uses IF on MySQL.
1403          *
1404          * @param string $cond SQL expression which will result in a boolean value
1405          * @param string $trueVal SQL expression to return if true
1406          * @param string $falseVal SQL expression to return if false
1407          * @return string SQL fragment
1408          */
1409         function conditional( $cond, $trueVal, $falseVal ) {
1410                 return " IF($cond, $trueVal, $falseVal) ";
1411         }
1412
1413         /**
1414          * Determines if the last failure was due to a deadlock
1415          */
1416         function wasDeadlock() {
1417                 return $this->lastErrno() == 1213;
1418         }
1419
1420         /**
1421          * Perform a deadlock-prone transaction.
1422          *
1423          * This function invokes a callback function to perform a set of write
1424          * queries. If a deadlock occurs during the processing, the transaction
1425          * will be rolled back and the callback function will be called again.
1426          *
1427          * Usage:
1428          *   $dbw->deadlockLoop( callback, ... );
1429          *
1430          * Extra arguments are passed through to the specified callback function.
1431          *
1432          * Returns whatever the callback function returned on its successful,
1433          * iteration, or false on error, for example if the retry limit was
1434          * reached.
1435          */
1436         function deadlockLoop() {
1437                 $myFname = 'Database::deadlockLoop';
1438
1439                 $this->begin();
1440                 $args = func_get_args();
1441                 $function = array_shift( $args );
1442                 $oldIgnore = $this->ignoreErrors( true );
1443                 $tries = DEADLOCK_TRIES;
1444                 if ( is_array( $function ) ) {
1445                         $fname = $function[0];
1446                 } else {
1447                         $fname = $function;
1448                 }
1449                 do {
1450                         $retVal = call_user_func_array( $function, $args );
1451                         $error = $this->lastError();
1452                         $errno = $this->lastErrno();
1453                         $sql = $this->lastQuery();
1454
1455                         if ( $errno ) {
1456                                 if ( $this->wasDeadlock() ) {
1457                                         # Retry
1458                                         usleep( mt_rand( DEADLOCK_DELAY_MIN, DEADLOCK_DELAY_MAX ) );
1459                                 } else {
1460                                         $this->reportQueryError( $error, $errno, $sql, $fname );
1461                                 }
1462                         }
1463                 } while( $this->wasDeadlock() && --$tries > 0 );
1464                 $this->ignoreErrors( $oldIgnore );
1465                 if ( $tries <= 0 ) {
1466                         $this->query( 'ROLLBACK', $myFname );
1467                         $this->reportQueryError( $error, $errno, $sql, $fname );
1468                         return false;
1469                 } else {
1470                         $this->query( 'COMMIT', $myFname );
1471                         return $retVal;
1472                 }
1473         }
1474
1475         /**
1476          * Do a SELECT MASTER_POS_WAIT()
1477          *
1478          * @param string $file the binlog file
1479          * @param string $pos the binlog position
1480          * @param integer $timeout the maximum number of seconds to wait for synchronisation
1481          */
1482         function masterPosWait( $file, $pos, $timeout ) {
1483                 $fname = 'Database::masterPosWait';
1484                 wfProfileIn( $fname );
1485
1486
1487                 # Commit any open transactions
1488                 $this->immediateCommit();
1489
1490                 # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
1491                 $encFile = $this->strencode( $file );
1492                 $sql = "SELECT MASTER_POS_WAIT('$encFile', $pos, $timeout)";
1493                 $res = $this->doQuery( $sql );
1494                 if ( $res && $row = $this->fetchRow( $res ) ) {
1495                         $this->freeResult( $res );
1496                         wfProfileOut( $fname );
1497                         return $row[0];
1498                 } else {
1499                         wfProfileOut( $fname );
1500                         return false;
1501                 }
1502         }
1503
1504         /**
1505          * Get the position of the master from SHOW SLAVE STATUS
1506          */
1507         function getSlavePos() {
1508                 $res = $this->query( 'SHOW SLAVE STATUS', 'Database::getSlavePos' );
1509                 $row = $this->fetchObject( $res );
1510                 if ( $row ) {
1511                         return array( $row->Master_Log_File, $row->Read_Master_Log_Pos );
1512                 } else {
1513                         return array( false, false );
1514                 }
1515         }
1516
1517         /**
1518          * Get the position of the master from SHOW MASTER STATUS
1519          */
1520         function getMasterPos() {
1521                 $res = $this->query( 'SHOW MASTER STATUS', 'Database::getMasterPos' );
1522                 $row = $this->fetchObject( $res );
1523                 if ( $row ) {
1524                         return array( $row->File, $row->Position );
1525                 } else {
1526                         return array( false, false );
1527                 }
1528         }
1529
1530         /**
1531          * Begin a transaction, or if a transaction has already started, continue it
1532          */
1533         function begin( $fname = 'Database::begin' ) {
1534                 if ( !$this->mTrxLevel ) {
1535                         $this->immediateBegin( $fname );
1536                 } else {
1537                         $this->mTrxLevel++;
1538                 }
1539         }
1540
1541         /**
1542          * End a transaction, or decrement the nest level if transactions are nested
1543          */
1544         function commit( $fname = 'Database::commit' ) {
1545                 if ( $this->mTrxLevel ) {
1546                         $this->mTrxLevel--;
1547                 }
1548                 if ( !$this->mTrxLevel ) {
1549                         $this->immediateCommit( $fname );
1550                 }
1551         }
1552
1553         /**
1554          * Rollback a transaction
1555          */
1556         function rollback( $fname = 'Database::rollback' ) {
1557                 $this->query( 'ROLLBACK', $fname );
1558                 $this->mTrxLevel = 0;
1559         }
1560
1561         /**
1562          * Begin a transaction, committing any previously open transaction
1563          */
1564         function immediateBegin( $fname = 'Database::immediateBegin' ) {
1565                 $this->query( 'BEGIN', $fname );
1566                 $this->mTrxLevel = 1;
1567         }
1568
1569         /**
1570          * Commit transaction, if one is open
1571          */
1572         function immediateCommit( $fname = 'Database::immediateCommit' ) {
1573                 $this->query( 'COMMIT', $fname );
1574                 $this->mTrxLevel = 0;
1575         }
1576
1577         /**
1578          * Return MW-style timestamp used for MySQL schema
1579          */
1580         function timestamp( $ts=0 ) {
1581                 return wfTimestamp(TS_MW,$ts);
1582         }
1583
1584         /**
1585          * Local database timestamp format or null
1586          */
1587         function timestampOrNull( $ts = null ) {
1588                 if( is_null( $ts ) ) {
1589                         return null;
1590                 } else {
1591                         return $this->timestamp( $ts );
1592                 }
1593         }
1594
1595         /**
1596          * @todo document
1597          */
1598         function resultObject( $result ) {
1599                 if( empty( $result ) ) {
1600                         return NULL;
1601                 } else {
1602                         return new ResultWrapper( $this, $result );
1603                 }
1604         }
1605
1606         /**
1607          * Return aggregated value alias
1608          */
1609         function aggregateValue ($valuedata,$valuename='value') {
1610                 return $valuename;
1611         }
1612
1613         /**
1614          * @return string wikitext of a link to the server software's web site
1615          */
1616         function getSoftwareLink() {
1617                 return "[http://www.mysql.com/ MySQL]";
1618         }
1619
1620         /**
1621          * @return string Version information from the database
1622          */
1623         function getServerVersion() {
1624                 return mysql_get_server_info();
1625         }
1626
1627         /**
1628          * Ping the server and try to reconnect if it there is no connection
1629          */
1630         function ping() {
1631                 if( function_exists( 'mysql_ping' ) ) {
1632                         return mysql_ping( $this->mConn );
1633                 } else {
1634                         wfDebug( "Tried to call mysql_ping but this is ancient PHP version. Faking it!\n" );
1635                         return true;
1636                 }
1637         }
1638
1639         /**
1640          * Get slave lag.
1641          * At the moment, this will only work if the DB user has the PROCESS privilege
1642          */
1643         function getLag() {
1644                 $res = $this->query( 'SHOW PROCESSLIST' );
1645                 # Find slave SQL thread. Assumed to be the second one running, which is a bit
1646                 # dubious, but unfortunately there's no easy rigorous way
1647                 $slaveThreads = 0;
1648                 while ( $row = $this->fetchObject( $res ) ) {
1649                         if ( $row->User == 'system user' ) {
1650                                 if ( ++$slaveThreads == 2 ) {
1651                                         # This is it, return the time (except -ve)
1652                                         if ( $row->Time > 0x7fffffff ) {
1653                                                 return false;
1654                                         } else {
1655                                                 return $row->Time;
1656                                         }
1657                                 }
1658                         }
1659                 }
1660                 return false;
1661         }
1662
1663         /**
1664          * Get status information from SHOW STATUS in an associative array
1665          */
1666         function getStatus($which="%") {
1667                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1668                 $status = array();
1669                 while ( $row = $this->fetchObject( $res ) ) {
1670                         $status[$row->Variable_name] = $row->Value;
1671                 }
1672                 return $status;
1673         }
1674
1675         /**
1676          * Return the maximum number of items allowed in a list, or 0 for unlimited.
1677          */
1678         function maxListLen() {
1679                 return 0;
1680         }
1681
1682         function encodeBlob($b) {
1683                 return $b;
1684         }
1685
1686         /**
1687          * Read and execute SQL commands from a file.
1688          * Returns true on success, error string on failure
1689          */
1690         function sourceFile( $filename ) {
1691                 $fp = fopen( $filename, 'r' );
1692                 if ( false === $fp ) {
1693                         return "Could not open \"{$fname}\".\n";
1694                 }
1695
1696                 $cmd = "";
1697                 $done = false;
1698                 $dollarquote = false;
1699
1700                 while ( ! feof( $fp ) ) {
1701                         $line = trim( fgets( $fp, 1024 ) );
1702                         $sl = strlen( $line ) - 1;
1703
1704                         if ( $sl < 0 ) { continue; }
1705                         if ( '-' == $line{0} && '-' == $line{1} ) { continue; }
1706
1707                         ## Allow dollar quoting for function declarations
1708                         if (substr($line,0,4) == '$mw$') {
1709                                 if ($dollarquote) {
1710                                         $dollarquote = false;
1711                                         $done = true;
1712                                 }
1713                                 else {
1714                                         $dollarquote = true;
1715                                 }
1716                         }
1717                         else if (!$dollarquote) {
1718                                 if ( ';' == $line{$sl} && ($sl < 2 || ';' != $line{$sl - 1})) {
1719                                         $done = true;
1720                                         $line = substr( $line, 0, $sl );
1721                                 }
1722                         }
1723
1724                         if ( '' != $cmd ) { $cmd .= ' '; }
1725                         $cmd .= "$line\n";
1726
1727                         if ( $done ) {
1728                                 $cmd = str_replace(';;', ";", $cmd);
1729                                 $cmd = $this->replaceVars( $cmd );
1730                                 $res = $this->query( $cmd, 'dbsource', true );
1731
1732                                 if ( false === $res ) {
1733                                         $err = $this->lastError();
1734                                         return "Query \"{$cmd}\" failed with error code \"$err\".\n";
1735                                 }
1736
1737                                 $cmd = '';
1738                                 $done = false;
1739                         }
1740                 }
1741                 fclose( $fp );
1742                 return true;
1743         }
1744
1745         /**
1746          * Replace variables in sourced SQL
1747          */
1748         function replaceVars( $ins ) {
1749                 $varnames = array(
1750                         'wgDBserver', 'wgDBname', 'wgDBintlname', 'wgDBuser',
1751                         'wgDBpassword', 'wgDBsqluser', 'wgDBsqlpassword',
1752                         'wgDBadminuser', 'wgDBadminpassword',
1753                 );
1754
1755                 // Ordinary variables
1756                 foreach ( $varnames as $var ) {
1757                         if( isset( $GLOBALS[$var] ) ) {
1758                                 $val = addslashes( $GLOBALS[$var] );
1759                                 $ins = str_replace( '{$' . $var . '}', $val, $ins );
1760                                 $ins = str_replace( '/*$' . $var . '*/`', '`' . $val, $ins );
1761                                 $ins = str_replace( '/*$' . $var . '*/', $val, $ins );
1762                         }
1763                 }
1764
1765                 // Table prefixes
1766                 $ins = preg_replace_callback( '/\/\*(?:\$wgDBprefix|_)\*\/([a-z_]*)/',
1767                         array( &$this, 'tableNameCallback' ), $ins );
1768                 return $ins;
1769         }
1770
1771         /**
1772          * Table name callback
1773          * @private
1774          */
1775         function tableNameCallback( $matches ) {
1776                 return $this->tableName( $matches[1] );
1777         }
1778
1779 }
1780
1781 /**
1782  * Database abstraction object for mySQL
1783  * Inherit all methods and properties of Database::Database()
1784  *
1785  * @package MediaWiki
1786  * @see Database
1787  */
1788 class DatabaseMysql extends Database {
1789         # Inherit all
1790 }
1791
1792
1793 /**
1794  * Result wrapper for grabbing data queried by someone else
1795  *
1796  * @package MediaWiki
1797  */
1798 class ResultWrapper {
1799         var $db, $result;
1800
1801         /**
1802          * @todo document
1803          */
1804         function ResultWrapper( &$database, $result ) {
1805                 $this->db =& $database;
1806                 $this->result =& $result;
1807         }
1808
1809         /**
1810          * @todo document
1811          */
1812         function numRows() {
1813                 return $this->db->numRows( $this->result );
1814         }
1815
1816         /**
1817          * @todo document
1818          */
1819         function fetchObject() {
1820                 return $this->db->fetchObject( $this->result );
1821         }
1822
1823         /**
1824          * @todo document
1825          */
1826         function &fetchRow() {
1827                 return $this->db->fetchRow( $this->result );
1828         }
1829
1830         /**
1831          * @todo document
1832          */
1833         function free() {
1834                 $this->db->freeResult( $this->result );
1835                 unset( $this->result );
1836                 unset( $this->db );
1837         }
1838
1839         function seek( $row ) {
1840                 $this->db->dataSeek( $this->result, $row );
1841         }
1842
1843 }
1844
1845
1846 #------------------------------------------------------------------------------
1847 # Global functions
1848 #------------------------------------------------------------------------------
1849
1850 /**
1851  * Standard fail function, called by default when a connection cannot be
1852  * established.
1853  * Displays the file cache if possible
1854  */
1855 function wfEmergencyAbort( &$conn, $error ) {
1856         global $wgTitle, $wgUseFileCache, $title, $wgInputEncoding, $wgOutputEncoding;
1857         global $wgSitename, $wgServer, $wgMessageCache, $wgLogo;
1858
1859         # I give up, Brion is right. Getting the message cache to work when there is no DB is tricky.
1860         # Hard coding strings instead.
1861
1862         $noconnect = "<h1><img src='$wgLogo' style='float:left;margin-right:1em' alt=''>$wgSitename has a problem</h1><p><strong>Sorry! This site is experiencing technical difficulties.</strong></p><p>Try waiting a few minutes and reloading.</p><p><small>(Can't contact the database server: $1)</small></p>";
1863         $mainpage = 'Main Page';
1864         $searchdisabled = <<<EOT
1865 <p style="margin: 1.5em 2em 1em">$wgSitename search is disabled for performance reasons. You can search via Google in the meantime.
1866 <span style="font-size: 89%; display: block; margin-left: .2em">Note that their indexes of $wgSitename content may be out of date.</span></p>',
1867 EOT;
1868
1869         $googlesearch = "
1870 <!-- SiteSearch Google -->
1871 <FORM method=GET action=\"http://www.google.com/search\">
1872 <TABLE bgcolor=\"#FFFFFF\"><tr><td>
1873 <A HREF=\"http://www.google.com/\">
1874 <IMG SRC=\"http://www.google.com/logos/Logo_40wht.gif\"
1875 border=\"0\" ALT=\"Google\"></A>
1876 </td>
1877 <td>
1878 <INPUT TYPE=text name=q size=31 maxlength=255 value=\"$1\">
1879 <INPUT type=submit name=btnG VALUE=\"Google Search\">
1880 <font size=-1>
1881 <input type=hidden name=domains value=\"$wgServer\"><br /><input type=radio name=sitesearch value=\"\"> WWW <input type=radio name=sitesearch value=\"$wgServer\" checked> $wgServer <br />
1882 <input type='hidden' name='ie' value='$2'>
1883 <input type='hidden' name='oe' value='$2'>
1884 </font>
1885 </td></tr></TABLE>
1886 </FORM>
1887 <!-- SiteSearch Google -->";
1888         $cachederror = "The following is a cached copy of the requested page, and may not be up to date. ";
1889
1890
1891         if( !headers_sent() ) {
1892                 header( 'HTTP/1.0 500 Internal Server Error' );
1893                 header( 'Content-type: text/html; charset='.$wgOutputEncoding );
1894                 /* Don't cache error pages!  They cause no end of trouble... */
1895                 header( 'Cache-control: none' );
1896                 header( 'Pragma: nocache' );
1897         }
1898
1899         # No database access
1900         if ( is_object( $wgMessageCache ) ) {
1901                 $wgMessageCache->disable();
1902         }
1903
1904         if ( trim( $error ) == '' ) {
1905                 $error = $this->mServer;
1906         }
1907
1908         wfLogDBError( "Connection error: $error\n" );
1909
1910         $text = str_replace( '$1', $error, $noconnect );
1911         $text .= wfGetSiteNotice();
1912
1913         if($wgUseFileCache) {
1914                 if($wgTitle) {
1915                         $t =& $wgTitle;
1916                 } else {
1917                         if($title) {
1918                                 $t = Title::newFromURL( $title );
1919                         } elseif (@/**/$_REQUEST['search']) {
1920                                 $search = $_REQUEST['search'];
1921                                 echo $searchdisabled;
1922                                 echo str_replace( array( '$1', '$2' ), array( htmlspecialchars( $search ),
1923                                   $wgInputEncoding ), $googlesearch );
1924                                 wfErrorExit();
1925                         } else {
1926                                 $t = Title::newFromText( $mainpage );
1927                         }
1928                 }
1929
1930                 $cache = new CacheManager( $t );
1931                 if( $cache->isFileCached() ) {
1932                         $msg = '<p style="color: red"><b>'.$msg."<br />\n" .
1933                                 $cachederror . "</b></p>\n";
1934
1935                         $tag = '<div id="article">';
1936                         $text = str_replace(
1937                                 $tag,
1938                                 $tag . $msg,
1939                                 $cache->fetchPageText() );
1940                 }
1941         }
1942
1943         echo $text;
1944         wfErrorExit();
1945 }
1946
1947 ?>