databasec.php

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				if ( !$wgCommandLineMode ) {
					$message = nl2br( $message );
				}
				if( $wgCommandLineMode && $wgColorErrors && !wfIsWindows() && posix_isatty(1) ) {
					$color = 31; // bright red!
					$message = "\x1b[1;{$color}m{$message}\x1b[0m";
				}
				wfDebugDieBacktrace( $message );
			} else {
				// this calls wfAbruptExit()
				$this->mOut->databaseError( $fname, $sql, $error, $errno );
			}
		}
		$this->ignoreErrors( $ignore );
	}


	/**
	 * Intended to be compatible with the PEAR::DB wrapper functions.
	 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
	 *
	 * ? = scalar value, quoted as necessary
	 * ! = raw SQL bit (a function for instance)
	 * & = filename; reads the file and inserts as a blob
	 *     (we don't use this though...)
	 */
	function prepare( $sql, $func = 'Database::prepare' ) {
		/* MySQL doesn't support prepared statements (yet), so just
		   pack up the query for reference. We'll manually replace
		   the bits later. */
		return array( 'query' => $sql, 'func' => $func );
	}

	function freePrepared( $prepared ) {
		/* No-op for MySQL */
	}

	/**
	 * Execute a prepared query with the various arguments
	 * @param string $prepared the prepared sql
	 * @param mixed $args Either an array here, or put scalars as varargs
	 */
	function execute( $prepared, $args = null ) {
		if( !is_array( $args ) ) {
			# Pull the var args
			$args = func_get_args();
			array_shift( $args );
		}
		$sql = $this->fillPrepared( $prepared['query'], $args );
		return $this->query( $sql, $prepared['func'] );
	}

	/**
	 * Prepare & execute an SQL statement, quoting and inserting arguments
	 * in the appropriate places.
	 * @param string $query
	 * @param string $args ...
	 */
	function safeQuery( $query, $args = null ) {
		$prepared = $this->prepare( $query, 'Database::safeQuery' );
		if( !is_array( $args ) ) {
			# Pull the var args
			$args = func_get_args();
			array_shift( $args );
		}
		$retval = $this->execute( $prepared, $args );
		$this->freePrepared( $prepared );
		return $retval;
	}

	/**
	 * For faking prepared SQL statements on DBs that don't support
	 * it directly.
	 * @param string $preparedSql - a 'preparable' SQL statement
	 * @param array $args - array of arguments to fill it with
	 * @return string executable SQL
	 */
	function fillPrepared( $preparedQuery, $args ) {
		$n = 0;
		reset( $args );
		$this->preparedArgs =& $args;
		return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
			array( &$this, 'fillPreparedArg' ), $preparedQuery );
	}

	/**
	 * preg_callback func for fillPrepared()
	 * The arguments should be in $this->preparedArgs and must not be touched
	 * while we're doing this.
	 *
	 * @param array $matches
	 * @return string
	 * @access private
	 */
	function fillPreparedArg( $matches ) {
		switch( $matches[1] ) {
			case '\\?': return '?';
			case '\\!': return '!';
			case '\\&': return '&';
		}
		list( $n, $arg ) = each( $this->preparedArgs );
		switch( $matches[1] ) {
			case '?': return $this->addQuotes( $arg );
			case '!': return $arg;
			case '&':
				# return $this->addQuotes( file_get_contents( $arg ) );
				wfDebugDieBacktrace( '& mode is not implemented. If it\'s really needed, uncomment the line above.' );
			default:
				wfDebugDieBacktrace( 'Received invalid match. This should never happen!' );
		}
	}

	/**#@+
	 * @param mixed $res A SQL result
	 */
	/**
	 * Free a result object
	 */
	function freeResult( $res ) {
		if ( !@/**/mysql_free_result( $res ) ) {
			wfDebugDieBacktrace( "Unable to free MySQL result\n" );
		}
	}

	/**
	 * Fetch the next row from the given result object, in object form
	 */
	function fetchObject( $res ) {
		@/**/$row = mysql_fetch_object( $res );
		if( mysql_errno() ) {
			wfDebugDieBacktrace( 'Error in fetchObject(): ' . htmlspecialchars( mysql_error() ) );
		}
		return $row;
	}

	/**
	 * Fetch the next row from the given result object
	 * Returns an array
	 */
 	function fetchRow( $res ) {
		@/**/$row = mysql_fetch_array( $res );
		if (mysql_errno() ) {
			wfDebugDieBacktrace( 'Error in fetchRow(): ' . htmlspecialchars( mysql_error() ) );
		}
		return $row;
	}

	/**
	 * Get the number of rows in a result object
	 */
	function numRows( $res ) {
		@/**/$n = mysql_num_rows( $res );
		if( mysql_errno() ) {
			wfDebugDieBacktrace( 'Error in numRows(): ' . htmlspecialchars( mysql_error() ) );
		}
		return $n;
	}

	/**
	 * Get the number of fields in a result object
	 * See documentation for mysql_num_fields()
	 */
	function numFields( $res ) { return mysql_num_fields( $res ); }

	/**
	 * Get a field name in a result object
	 * See documentation for mysql_field_name()
	 */
	function fieldName( $res, $n ) { return mysql_field_name( $res, $n ); }

	/**
	 * Get the inserted value of an auto-increment row
	 *
	 * The value inserted should be fetched from nextSequenceValue()
	 *
	 * Example:
	 * $id = $dbw->nextSequenceValue('page_page_id_seq');
	 * $dbw->insert('page',array('page_id' => $id));
	 * $id = $dbw->insertId();
	 */
	function insertId() { return mysql_insert_id( $this->mConn ); }

	/**
	 * Change the position of the cursor in a result object
	 * See mysql_data_seek()
	 */
	function dataSeek( $res, $row ) { return mysql_data_seek( $res, $row ); }

	/**
	 * Get the last error number
	 * See mysql_errno()
	 */
	function lastErrno() {
		if ( $this->mConn ) {
			return mysql_errno( $this->mConn );
		} else {
			return mysql_errno();
		}
	}

	/**
	 * Get a description of the last error
	 * See mysql_error() for more details
	 */
	function lastError() {
		if ( $this->mConn ) {
			# Even if it's non-zero, it can still be invalid
			wfSuppressWarnings();
			$error = mysql_error( $this->mConn );
			if ( !$error ) {
				$error = mysql_error();
			}
			wfRestoreWarnings();
		} else {
			$error = mysql_error();
		}
		if( $error ) {
			$error .= ' (' . $this->mServer . ')';
		}
		return $error;
	}
	/**
	 * Get the number of rows affected by the last write query
	 * See mysql_affected_rows() for more details
	 */
	function affectedRows() { return mysql_affected_rows( $this->mConn ); }
	/**#@-*/ // end of template : @param $result

	/**
	 * Simple UPDATE wrapper
	 * Usually aborts on failure
	 * If errors are explicitly ignored, returns success
	 *
	 * This function exists for historical reasons, Database::update() has a more standard
	 * calling convention and feature set
	 */
	function set( $table, $var, $value, $cond, $fname = 'Database::set' )
	{
		$table = $this->tableName( $table );
		$sql = "UPDATE $table SET $var = '" .
		  $this->strencode( $value ) . "' WHERE ($cond)";
		return (bool)$this->query( $sql, $fname );
	}

	/**
	 * Simple SELECT wrapper, returns a single field, input must be encoded
	 * Usually aborts on failure
	 * If errors are explicitly ignored, returns FALSE on failure
	 */
	function selectField( $table, $var, $cond='', $fname = 'Database::selectField', $options = array() ) {
		if ( !is_array( $options ) ) {
			$options = array( $options );
		}
		$options['LIMIT'] = 1;

		$res = $this->select( $table, $var, $cond, $fname, $options );
		if ( $res === false || !$this->numRows( $res ) ) {
			return false;
		}
		$row = $this->fetchRow( $res );
		if ( $row !== false ) {
			$this->freeResult( $res );
			return $row[0];
		} else {
			return false;
		}
	}

	/**
	 * Returns an optional USE INDEX clause to go after the table, and a
	 * string to go at the end of the query
	 *
	 * @access private
	 *
	 * @param array $options an associative array of options to be turned into
	 *              an SQL query, valid keys are listed in the function.
	 * @return array
	 */
	function makeSelectOptions( $options ) {
		$tailOpts = '';

		if ( isset( $options['GROUP BY'] ) ) {
			$tailOpts .= " GROUP BY {$options['GROUP BY']}";
		}
		if ( isset( $options['ORDER BY'] ) ) {
			$tailOpts .= " ORDER BY {$options['ORDER BY']}";
		}
		if (isset($options['LIMIT'])) {
			$tailOpts .= $this->limitResult('', $options['LIMIT'],
				isset($options['OFFSET']) ? $options['OFFSET'] : false);
		}
		if ( is_numeric( array_search( 'FOR UPDATE', $options ) ) ) {
			$tailOpts .= ' FOR UPDATE';
		}

		if ( is_numeric( array_search( 'LOCK IN SHARE MODE', $options ) ) ) {
			$tailOpts .= ' LOCK IN SHARE MODE';
		}

		if ( isset( $options['USE INDEX'] ) && ! is_array( $options['USE INDEX'] ) ) {
			$useIndex = $this->useIndexClause( $options['USE INDEX'] );
		} else {
			$useIndex = '';
		}
		return array( $useIndex, $tailOpts );
	}

	/**
	 * SELECT wrapper
	 */
	function select( $table, $vars, $conds='', $fname = 'Database::select', $options = array() )
	{
		if( is_array( $vars ) ) {
			$vars = implode( ',', $vars );
		}
		if( !is_array( $options ) ) {
			$options = array( $options );
		}
		if( is_array( $table ) ) {
			if ( @is_array( $options['USE INDEX'] ) )
				$from = ' FROM ' . $this->tableNamesWithUseIndex( $table, $options['USE INDEX'] );
			else
				$from = ' FROM ' . implode( ',', array_map( array( &$this, 'tableName' ), $table ) );
		} elseif ($table!='') {
			$from = ' FROM ' . $this->tableName( $table );
		} else {
			$from = '';
		}

		list( $useIndex, $tailOpts ) = $this->makeSelectOptions( $options );

		if( !empty( $conds ) ) {
			if ( is_array( $conds ) ) {
				$conds = $this->makeList( $conds, LIST_AND );
			}
			$sql = "SELECT $vars $from $useIndex WHERE $conds $tailOpts";
		} else {
			$sql = "SELECT $vars $from $useIndex $tailOpts";
		}

		return $this->query( $sql, $fname );
	}

	/**
	 * Single row SELECT wrapper
	 * Aborts or returns FALSE on error
	 *
	 * $vars: the selected variables
	 * $conds: a condition map, terms are ANDed together.
	 *   Items with numeric keys are taken to be literal conditions
	 * Takes an array of selected variables, and a condition map, which is ANDed
	 * e.g: selectRow( "page", array( "page_id" ), array( "page_namespace" =>
	 * NS_MAIN, "page_title" => "Astronomy" ) )   would return an object where
	 * $obj- >page_id is the ID of the Astronomy article
	 *
	 * @todo migrate documentation to phpdocumentor format
	 */
	function selectRow( $table, $vars, $conds, $fname = 'Database::selectRow', $options = array() ) {
		$options['LIMIT'] = 1;
		$res = $this->select( $table, $vars, $conds, $fname, $options );
		if ( $res === false )
			return false;
		if ( !$this->numRows($res) ) {
			$this->freeResult($res);
			return false;
		}
		$obj = $this->fetchObject( $res );
		$this->freeResult( $res );
		return $obj;

	}

	/**
	 * Removes most variables from an SQL query and replaces them with X or N for numbers.
	 * It's only slightly flawed. Don't use for anything important.
	 *
	 * @param string $sql A SQL Query
	 * @static
	 */
	function generalizeSQL( $sql ) {
		# This does the same as the regexp below would do, but in such a way
		# as to avoid crashing php on some large strings.
		# $sql = preg_replace ( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql);

		$sql = str_replace ( "\\\\", '', $sql);
		$sql = str_replace ( "\\'", '', $sql);
		$sql = str_replace ( "\\\"", '', $sql);
		$sql = preg_replace ("/'.*'/s", "'X'", $sql);
		$sql = preg_replace ('/".*"/s', "'X'", $sql);

		# All newlines, tabs, etc replaced by single space
		$sql = preg_replace ( "/\s+/", ' ', $sql);

		# All numbers => N
		$sql = preg_replace ('/-?[0-9]+/s', 'N', $sql);

		return $sql;
	}

	/**
	 * Determines whether a field exists in a table
	 * Usually aborts on failure
	 * If errors are explicitly ignored, returns NULL on failure
	 */
	function fieldExists( $table, $field, $fname = 'Database::fieldExists' ) {
		$table = $this->tableName( $table );
		$res = $this->query( 'DESCRIBE '.$table, $fname );
		if ( !$res ) {
			return NULL;
		}

		$found = false;

		while ( $row = $this->fetchObject( $res ) ) {
			if ( $row->Field == $field ) {
				$found = true;
				break;
			}
		}
		return $found;
	}

	/**
	 * Determines whether an index exists
	 * Usually aborts on failure
	 * If errors are explicitly ignored, returns NULL on failure
	 */
	function indexExists( $table, $index, $fname = 'Database::indexExists' ) {
		$info = $this->indexInfo( $table, $index, $fname );
		if ( is_null( $info ) ) {
			return NULL;
		} else {
			return $info !== false;
		}
	}


	/**
	 * Get information about an index into an object
	 * Returns false if the index does not exist
	 */
	function indexInfo( $table, $index, $fname = 'Database::indexInfo' ) {
		# SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
		# SHOW INDEX should work for 3.x and up:
		# http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
		$table = $this->tableName( $table );
		$sql = 'SHOW INDEX FROM '.$table;
		$res = $this->query( $sql, $fname );
		if ( !$res ) {
			return NULL;
		}

		while ( $row = $this->fetchObject( $res ) ) {
			if ( $row->Key_name == $index ) {
				return $row;
			}
		}
		return false;
	}

	/**
	 * Query whether a given table exists
	 */
	function tableExists( $table ) {
		$table = $this->tableName( $table );
		$old = $this->ignoreErrors( true );
		$res = $this->query( "SELECT 1 FROM $table LIMIT 1" );
		$this->ignoreErrors( $old );
		if( $res ) {
			$this->freeResult( $res );
			return true;
		} else {
			return false;
		}
	}

	/**
	 * mysql_fetch_field() wrapper
	 * Returns false if the field doesn't exist
	 *
	 * @param $table
	 * @param $field
	 */
	function fieldInfo( $table, $field ) {
		$table = $this->tableName( $table );