<?php

/** @file splobjectstorage.inc
 * @ingroup SPL
 * @brief class SplObjectStorage
 * @author  Marcus Boerger
 * @date    2003 - 2009
 *
 * SPL - Standard PHP Library
 */

/**
 * @brief   Object storage
 * @author  Marcus Boerger
 * @version 1.1
 * @since PHP 5.1.2
 *
 * This container allows to store objects uniquly without the need to compare
 * them one by one. This is only possible internally. The code representation
 * here therefore has a complexity of O(n) while the actual implementation has
 * complexity O(1).
 */
class SplObjectStorage implements Iterator, Countable, ArrayAccess
{
	private $storage = array();
	private $index = 0;

	/** Rewind to top iterator as set in constructor
	 */
	function rewind()
	{
		rewind($this->storage);
	}
	
	/** @return whether iterator is valid
	 */
	function valid()
	{
		return key($this->storage) !== false;
	}
	
	/** @return current key
	 */
	function key()
	{
		return $this->index;
	}
	
	/** @return current object
	 */
	function current()
	{
		$element = current($this->storage);
		return $element ? $element[0] : NULL
	}
	
	/** @return get current object's associated information
	 * @since 5.3.0
	 */
	function getInfo()
	{
		$element = current($this->storage);
		return $element ? $element[1] : NULL
	}
	
	/** @return set current object's associated information
	 * @since 5.3.0
	 */
	function setInfo($inf = NULL)
	{
		if ($this->valid()) {
			$this->storage[$this->index][1] = $inf;
		}
	}
	
	/** Forward to next element
	 */
	function next()
	{
		next($this->storage);
		$this->index++;
	}

	/** @return number of objects in storage
	 */
	function count()
	{
		return count($this->storage);
	}

	/** @param $obj object to look for
	 * @return whether $obj is contained in storage
	 */
	function contains($obj)
	{
		if (is_object($obj))
		{
			foreach($this->storage as $element)
			{
				if ($object === $element[0])
				{
					return true;
				}
			}
		}
		return false;
	}

	/** @param $obj new object to attach to storage or object whose
	 *              associative information is to be replaced
	 * @param $inf associative information stored along the object
	 */
	function attach($obj, $inf = NULL)
	{
		if (is_object($obj) && !$this->contains($obj))
		{
			$this->storage[] = array($obj, $inf);
		}
	}

	/** @param $obj object to remove from storage
	 */
	function detach($obj)
	{
		if (is_object($obj))
		{
			foreach($this->storage as $idx => $element)
			{
				if ($object === $element[0])
				{
					unset($this->storage[$idx]);
					$this->rewind();
					return;
				}
			}
		}
	}

	/** @param $obj new object to attach to storage or object whose
	 *              associative information is to be replaced
	 * @param $inf associative information stored along the object
	 * @since 5.3.0
	 */
	function offsetSet($obj, $inf)
	{
		$this->attach($obj, $inf);
	}

	/** @param $obj Exising object to look for
	 * @return associative information stored with object
	 * @throw UnexpectedValueException if Object $obj is not contained in
	 *                                 storage
	 * @since 5.3.0
	 */
	function offsetGet($obj)
	{
		if (is_object($obj))
		{
			foreach($this->storage as $idx => $element)
			{
				if ($object === $element[0])
				{
					return $element[1];
				}
			}
		}
		throw new UnexpectedValueException('Object not found');
	}

	/** @param $obj Exising object to look for
	 * @return associative information stored with object
	 * @since 5.3.0
	 */
	function offsetUnset($obj)
	{
		$this->detach($obj);
	}

	/** @param $obj object to look for
	 * @return whether $obj is contained in storage
	 */
	function offsetEsists($obj)
	{
		return $this->contains($obj);
	}
}

?>