<?php
    /**
     *	base include file for SimpleTest
     *	@package	SimpleTest
     *	@version	$Id: compatibility.php 1532 2006-12-01 12:28:55Z xue $
     */

    /**
     *  Static methods for compatibility between different
     *  PHP versions.
     *  @package	SimpleTest
     */
    class SimpleTestCompatibility {

    	/**
    	 *	  Creates a copy whether in PHP5 or PHP4.
    	 *	  @param object $object		Thing to copy.
    	 *	  @return object			A copy.
    	 *	  @access public
    	 *	  @static
    	 */
    	static function copy($object) {
            if (version_compare(phpversion(), '5') >= 0) {
            	eval('$copy = clone $object;');
            	return $copy;
            }
            return $object;
    	}

        /**
         *    Identity test. Drops back to equality + types for PHP5
         *    objects as the === operator counts as the
         *    stronger reference constraint.
         *    @param mixed $first    Test subject.
         *    @param mixed $second   Comparison object.
         *	  @return boolean		 True if identical.
         *    @access public
         *    @static
         */
        static function isIdentical($first, $second) {
            if ($first != $second) {
                return false;
            }
            if (version_compare(phpversion(), '5') >= 0) {
                return SimpleTestCompatibility::_isIdenticalType($first, $second);
            }
            return ($first === $second);
        }

        /**
         *    Recursive type test.
         *    @param mixed $first    Test subject.
         *    @param mixed $second   Comparison object.
         *	  @return boolean		 True if same type.
         *    @access private
         *    @static
         */
        static function _isIdenticalType($first, $second) {
            if (gettype($first) != gettype($second)) {
                return false;
            }
            if (is_object($first) && is_object($second)) {
                if (get_class($first) != get_class($second)) {
                    return false;
                }
                return SimpleTestCompatibility::_isArrayOfIdenticalTypes(
                        get_object_vars($first),
                        get_object_vars($second));
            }
            if (is_array($first) && is_array($second)) {
                return SimpleTestCompatibility::_isArrayOfIdenticalTypes($first, $second);
            }
            return true;
        }

        /**
         *    Recursive type test for each element of an array.
         *    @param mixed $first    Test subject.
         *    @param mixed $second   Comparison object.
         *	  @return boolean		 True if identical.
         *    @access private
         *    @static
         */
        static function _isArrayOfIdenticalTypes($first, $second) {
            if (array_keys($first) != array_keys($second)) {
                return false;
            }
            foreach (array_keys($first) as $key) {
                $is_identical = SimpleTestCompatibility::_isIdenticalType(
                        $first[$key],
                        $second[$key]);
                if (! $is_identical) {
                    return false;
                }
            }
            return true;
        }

        /**
         *    Test for two variables being aliases.
         *    @param mixed $first    Test subject.
         *    @param mixed $second   Comparison object.
         *	  @return boolean		 True if same.
         *    @access public
         *    @static
         */
        static function isReference($first, $second) {
            if (version_compare(phpversion(), '5', '>=')
	    	    && is_object($first)) {
	    	    return ($first === $second);
	        }
	        if (is_object($first) && is_object($second)) {
                $id = uniqid("test");
                $first->$id = true;
                $is_ref = isset($second->$id);
                unset($first->$id);
                return $is_ref;
	        }
	        $temp = $first;
            $first = uniqid("test");
            $is_ref = ($first === $second);
            $first = $temp;
            return $is_ref;
        }

        /**
         *    Test to see if an object is a member of a
         *    class hiearchy.
         *    @param object $object    Object to test.
         *    @param string $class     Root name of hiearchy.
         *    @return boolean		  True if class in hiearchy.
         *    @access public
         *    @static
         */
        static function isA($object, $class) {
            if (version_compare(phpversion(), '5') >= 0) {
                if (! class_exists($class, false)) {
                    if (function_exists('interface_exists')) {
                        if (! interface_exists($class, false))  {
                            return false;
                        }
                    }
                }
                eval("\$is_a = \$object instanceof $class;");
                return $is_a;
            }
            if (function_exists('is_a')) {
                return is_a($object, $class);
            }
            return ((strtolower($class) == get_class($object))
                    or (is_subclass_of($object, $class)));
        }

        /**
         *    Sets a socket timeout for each chunk.
         *    @param resource $handle    Socket handle.
         *    @param integer $timeout    Limit in seconds.
         *    @access public
         *    @static
         */
        static function setTimeout($handle, $timeout) {
            if (function_exists('stream_set_timeout')) {
                stream_set_timeout($handle, $timeout, 0);
            } elseif (function_exists('socket_set_timeout')) {
                socket_set_timeout($handle, $timeout, 0);
            } elseif (function_exists('set_socket_timeout')) {
                set_socket_timeout($handle, $timeout, 0);
            }
        }

        /**
         *    Gets the current stack trace topmost first.
         *    @return array        List of stack frames.
         *    @access public
         *    @static
         */
        static function getStackTrace() {
            if (function_exists('debug_backtrace')) {
                return array_reverse(debug_backtrace());
            }
            return array();
        }
    }
?>
