/zf/library/Zend/Crypt/Math/BigInteger.php

  1<?php
  2/**
  3 * Zend Framework
  4 *
  5 * LICENSE
  6 *
  7 * This source file is subject to the new BSD license that is bundled
  8 * with this package in the file LICENSE.txt.
  9 * It is also available through the world-wide-web at this URL:
 10 * http://framework.zend.com/license/new-bsd
 11 * If you did not receive a copy of the license and are unable to
 12 * obtain it through the world-wide-web, please send an email
 13 * to license@zend.com so we can send you a copy immediately.
 14 *
 15 * @category   Zend
 16 * @package    Zend_Crypt
 17 * @subpackage Math
 18 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 19 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 20 * @version    $Id: BigInteger.php 23775 2011-03-01 17:25:24Z ralph $
 21 */
 22
 23/**
 24 * Support for arbitrary precision mathematics in PHP.
 25 *
 26 * Zend_Crypt_Math_BigInteger is a wrapper across three PHP extensions: bcmath, gmp
 27 * and big_int. Since each offer similar functionality, but availability of
 28 * each differs across installations of PHP, this wrapper attempts to select
 29 * the fastest option available and encapsulate a subset of its functionality
 30 * which all extensions share in common.
 31 *
 32 * This class requires one of the three extensions to be available. BCMATH
 33 * while the slowest, is available by default under Windows, and under Unix
 34 * if PHP is compiled with the flag "--enable-bcmath". GMP requires the gmp
 35 * library from http://www.swox.com/gmp/ and PHP compiled with the "--with-gmp"
 36 * flag. BIG_INT support is available from a big_int PHP library available from
 37 * only from PECL (a Windows port is not available).
 38 *
 39 * @category   Zend
 40 * @package    Zend_Crypt
 41 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 42 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 43 */
 44class Zend_Crypt_Math_BigInteger
 45{
 46
 47    /**
 48     * Holds an instance of one of the three arbitrary precision wrappers.
 49     *
 50     * @var Zend_Crypt_Math_BigInteger_Interface
 51     */
 52    protected $_math = null;
 53
 54    /**
 55     * Constructor; a Factory which detects a suitable PHP extension for
 56     * arbitrary precision math and instantiates the suitable wrapper
 57     * object.
 58     *
 59     * @param string $extension
 60     * @throws  Zend_Crypt_Math_BigInteger_Exception
 61     */
 62    public function __construct($extension = null)
 63    {
 64        if ($extension !== null && !in_array($extension, array('bcmath', 'gmp', 'bigint'))) {
 65            require_once('Zend/Crypt/Math/BigInteger/Exception.php');
 66            throw new Zend_Crypt_Math_BigInteger_Exception('Invalid extension type; please use one of bcmath, gmp or bigint');
 67        }
 68        $this->_loadAdapter($extension);
 69    }
 70
 71    /**
 72     * Redirect all public method calls to the wrapped extension object.
 73     *
 74     * @param   string $methodName
 75     * @param   array $args
 76     * @throws  Zend_Crypt_Math_BigInteger_Exception
 77     */
 78    public function __call($methodName, $args)
 79    {
 80        if(!method_exists($this->_math, $methodName)) {
 81            require_once 'Zend/Crypt/Math/BigInteger/Exception.php';
 82            throw new Zend_Crypt_Math_BigInteger_Exception('invalid method call: ' . get_class($this->_math) . '::' . $methodName . '() does not exist');
 83        }
 84        return call_user_func_array(array($this->_math, $methodName), $args);
 85    }
 86
 87    /**
 88     * @param string $extension
 89     * @throws  Zend_Crypt_Math_BigInteger_Exception
 90     */
 91    protected function _loadAdapter($extension = null)
 92    {
 93        if ($extension === null) {
 94            if (extension_loaded('gmp')) {
 95                $extension = 'gmp';
 96            //} elseif (extension_loaded('big_int')) {
 97            //    $extension = 'big_int';
 98            } else {
 99                $extension = 'bcmath';
100            }
101        }
102        if($extension == 'gmp' && extension_loaded('gmp')) {
103            require_once 'Zend/Crypt/Math/BigInteger/Gmp.php';
104            $this->_math = new Zend_Crypt_Math_BigInteger_Gmp();
105        //} elseif($extension == 'bigint' && extension_loaded('big_int')) {
106        //    require_once 'Zend/Crypt_Math/BigInteger/Bigint.php';
107        //    $this->_math = new Zend_Crypt_Math_BigInteger_Bigint();
108        } elseif ($extension == 'bcmath' && extension_loaded('bcmath')) {
109            require_once 'Zend/Crypt/Math/BigInteger/Bcmath.php';
110            $this->_math = new Zend_Crypt_Math_BigInteger_Bcmath();
111        } else {
112            require_once 'Zend/Crypt/Math/BigInteger/Exception.php';
113            throw new Zend_Crypt_Math_BigInteger_Exception($extension . ' big integer precision math support not detected');
114        }
115    }
116
117}