database.php

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<?php
/**
* @version		$Id: database.php 8575 2007-08-26 20:02:09Z jinx $
* @package		Joomla.Framework
* @subpackage	Database
* @copyright	Copyright (C) 2005 - 2007 Open Source Matters. All rights reserved.
* @license		GNU/GPL, see LICENSE.php
* Joomla! is free software. This version may have been modified pursuant
* to the GNU General Public License, and as distributed it includes or
* is derivative of works licensed under the GNU General Public License or
* other free or open source software licenses.
* See COPYRIGHT.php for copyright notices and details.
*/

// Check to ensure this file is within the rest of the framework
defined('JPATH_BASE') or die();

/**
 * Database connector class
 *
 * @abstract
 * @package		Joomla.Framework
 * @subpackage	Database
 * @since		1.0
 */
class JDatabase extends JObject
{
	/** @var string The database driver name */
	var $name			= '';
	/** @var string Internal variable to hold the query sql */
	var $_sql			= '';
	/** @var int Internal variable to hold the database error number */
	var $_errorNum		= 0;
	/** @var string Internal variable to hold the database error message */
	var $_errorMsg		= '';
	/** @var string Internal variable to hold the prefix used on all database tables */
	var $_table_prefix	= '';
	/** @var Internal variable to hold the connector resource */
	var $_resource		= '';
	/** @var Internal variable to hold the last query cursor */
	var $_cursor		= null;
	/** @var boolean Debug option */
	var $_debug			= 0;
	/** @var int The limit for the query */
	var $_limit			= 0;
	/** @var int The for offset for the limit */
	var $_offset		= 0;
	/** @var int A counter for the number of queries performed by the object instance */
	var $_ticker		= 0;
	/** @var array A log of queries */
	var $_log			= null;
	/** @var string The null/zero date string */
	var $_nullDate		= null;
	/** @var string Quote for named objects */
	var $_nameQuote		= null;
	/**
	 * @var boolean UTF-8 support
	 * @since	1.5
	 */
	var $_utf			= 0;
	/**
	 * @var array The fields that are to be quote
	 * @since	1.5
	 */
	var $_quoted	= null;
	/**
	 * @var bool Legacy compatibility
	 * @since	1.5
	 */
	var $_hasQuoted	= null;

	/**
	* Database object constructor
	*
	* @access	public
	* @param	array	List of options used to configure the connection
	* @since	1.5
	*/
	function __construct( $options )
	{
		$prefix		= array_key_exists('prefix', $options)	? $options['prefix']	: 'jos_';

		// Determine utf-8 support
		$this->_utf = $this->hasUTF();

		//Set charactersets (needed for MySQL 4.1.2+)
		if ($this->_utf){
			$this->setUTF();
		}

		$this->_table_prefix	= $prefix;
		$this->_ticker			= 0;
		$this->_errorNum		= 0;
		$this->_log				= array();
		$this->_quoted			= array();
		$this->_hasQuoted		= false;

		// Register faked "destructor" in PHP4 to close all connections we might have made
		if (version_compare(PHP_VERSION, '5') == -1) {
			register_shutdown_function(array(&$this, '__destruct'));
		}
	}

	/**
	 * Returns a reference to the global Database object, only creating it
	 * if it doesn't already exist.
	 *
	 * @param string  Database driver
	 * @param string Database host
	 * @param string Database user name
	 * @param string Database user password
	 * @param string Database name
	 * @param string Common prefix for all tables
	 * @return JDatabase A database object
	 * @since 1.5
	*/
	function &getInstance( $options	= array() )
	{
		static $instances;

		if (!isset( $instances )) {
			$instances = array();
		}

		$signature = serialize( $options );

		if (empty($instances[$signature]))
		{
			$driver		= array_key_exists('driver', $options) 		? $options['driver']	: 'mysql';
			$select		= array_key_exists('select', $options)		? $options['select']	: true;
			$database	= array_key_exists('database', $options)	? $options['database']	: null;

			$driver = preg_replace('/[^A-Z0-9_\.-]/i', '', $driver);
			$path	= JPATH_LIBRARIES.DS.'joomla'.DS.'database'.DS.'database'.DS.$driver.'.php';

			if (file_exists($path)) {
				$path	= "joomla.database.database.$driver";
				jimport( $path );
			} else {
				$error = new JException( E_ERROR, 500, 'Unable to load Database Driver:' .$driver);
				return $error;
				//die('Unable to load Database Driver:' .$driver);
			}

			$adapter	= 'JDatabase'.$driver;
			$instance	= new $adapter($options);

			if ( $error = $instance->getErrorMsg() )
			{
				$error = new JException( E_ERROR, 500, 'Unable to connect to the database:' .$error);
				return $error;
				//die('Unable to connect to the database: '.$error);
			}

			$instances[$signature] = & $instance;
		}

		return $instances[$signature];
	}

	/**
	 * Database object destructor
	 *
	 * @abstract
	 * @access private
	 * @return boolean
	 * @since 1.5
	 */
	function __destruct()
	{
		return true;
	}

	/**
	 * Get the database connectors
	 *
	 * @access public
	 * @return array An array of available session handlers
	 */
	function getConnectors()
	{
		jimport('joomla.filesystem.folder');
		$handlers = JFolder::files(dirname(__FILE__).DS.'database', '.php$');

		$names = array();
		foreach($handlers as $handler)
		{
			$name = substr($handler, 0, strrpos($handler, '.'));
			jimport('joomla.database.database.'.$name);
			$class = 'JDatabase'.ucfirst($name);
			if(call_user_func_array( array( trim($class), 'test' ), null)) {
				$names[] = $name;
			}
		}

		return $names;
	}

	/**
	 * Test to see if the MySQLi connector is available
	 *
	 * @static
	 * @access public
	 * @return boolean  True on success, false otherwise.
	 */
	function test()
	{
		return false;
	}

	/**
	 * Determines if the connection to the server is active.
	 *
	 * @access      public
	 * @return      boolean
	 * @since       1.5
	 */
	function connected()
	{
		return false;
	}

	/**
	 * Determines UTF support
	 *
	 * @abstract
	 * @access public
	 * @return boolean
	 * @since 1.5
	 */
	function hasUTF() {
		return false;
	}

	/**
	 * Custom settings for UTF support
	 *
	 * @abstract
	 * @access public
	 * @since 1.5
	 */
	function setUTF() {
	}

	/**
	 * Adds a field or array of field names to the list that are to be quoted
	 *
	 * @access public
	 * @param mixed Field name or array of names
	 * @since 1.5
	 */
	function addQuoted( $quoted )
	{
		if (is_string( $quoted )) {
			$this->_quoted[] = $quoted;
		} else {
			$this->_quoted = array_merge( $this->_quoted, (array)$quoted );
		}
		$this->_hasQuoted = true;
	}

	/**
	 * Checks if field name needs to be quoted
	 *
	 * @access public
	 * @param string The field name
	 * @return bool
	 */
	function isQuoted( $fieldName )
	{
		if ($this->_hasQuoted) {
			return in_array( $fieldName, $this->_quoted );
		} else {
			return true;
		}
	}

	/**
	 * Sets the debug level on or off
	 *
	 * @access public
	 * @param int 0 = off, 1 = on
	 */
	function debug( $level ) {
		$this->_debug = intval( $level );
	}

	/**
	 * Get the database UTF-8 support
	 *
	 * @access public
	 * @return boolean
	 * @since 1.5
	 */
	function getUTFSupport() {
		return $this->_utf;
	}

	/**
	 * Get the error number
	 *
	 * @access public
	 * @return int The error number for the most recent query
	 */
	function getErrorNum() {
		return $this->_errorNum;
	}


	/**
	 * Get the error message
	 *
	 * @access public
	 * @return string The error message for the most recent query
	 */
	function getErrorMsg($escaped = false) {
		if($escaped) {
			return addslashes($this->_errorMsg);
		} else {
			return $this->_errorMsg;
		}
	}

	/**
	 * Get a database escaped string
	 *
	 * @abstract
	 * @access public
	 * @return string
	 */
	function getEscaped( $text ) {
		return;
	}

	/**
	 * Quote an identifier name (field, table, etc)
	 *
	 * @access public
	 * @param string The name
	 * @return string The quoted name
	 */
	function nameQuote( $s )
	{
		$q = $this->_nameQuote;
		if (strlen( $q ) == 1) {
			return $q . $s . $q;
		} else {
			return $q{0} . $s . $q{1};
		}
	}
	/**
	 * Get the database table prefix
	 *
	 * @access public
	 * @return string The database prefix
	 */
	function getPrefix() {
		return $this->_table_prefix;
	}

	/**
	 * Get the database null date
	 *
	 * @access public
	 * @return string Quoted null/zero date string
	 */
	function getNullDate() {
		return $this->_nullDate;
	}

	/**
	 * Sets the SQL query string for later execution.
	 *
	 * This function replaces a string identifier <var>$prefix</var> with the
	 * string held is the <var>_table_prefix</var> class variable.
	 *
	 * @access public
	 * @param string The SQL query
	 * @param string The offset to start selection
	 * @param string The number of results to return
	 * @param string The common table prefix
	 */
	function setQuery( $sql, $offset = 0, $limit = 0, $prefix='#__' )
	{
		$this->_sql		= $this->replacePrefix( $sql, $prefix );
		$this->_limit	= (int) $limit;
		$this->_offset	= (int) $offset;
	}

	/**
	 * This function replaces a string identifier <var>$prefix</var> with the
	 * string held is the <var>_table_prefix</var> class variable.
	 *
	 * @access public
	 * @param string The SQL query
	 * @param string The common table prefix
	 */
	function replacePrefix( $sql, $prefix='#__' )
	{
		$sql = trim( $sql );

		$escaped = false;
		$quoteChar = '';

		$n = strlen( $sql );

		$startPos = 0;
		$literal = '';
		while ($startPos < $n) {
			$ip = strpos($sql, $prefix, $startPos);
			if ($ip === false) {
				break;
			}

			$j = strpos( $sql, "'", $startPos );
			$k = strpos( $sql, '"', $startPos );
			if (($k !== FALSE) && (($k < $j) || ($j === FALSE))) {
				$quoteChar	= '"';
				$j			= $k;
			} else {
				$quoteChar	= "'";
			}

			if ($j === false) {
				$j = $n;
			}

			$literal .= str_replace( $prefix, $this->_table_prefix,substr( $sql, $startPos, $j - $startPos ) );
			$startPos = $j;

			$j = $startPos + 1;

			if ($j >= $n) {
				break;
			}

			// quote comes first, find end of quote
			while (TRUE) {
				$k = strpos( $sql, $quoteChar, $j );
				$escaped = false;
				if ($k === false) {
					break;
				}
				$l = $k - 1;
				while ($l >= 0 && $sql{$l} == '\\') {
					$l--;
					$escaped = !$escaped;
				}
				if ($escaped) {
					$j	= $k+1;