includes/math.php
author Dan Fuhry <dan@enanocms.org>
Thu, 28 Oct 2010 03:05:31 -0400
changeset 1308 f9bee9b125ee
parent 1227 bdac73ed481e
child 1380 0e400f946644
permissions -rw-r--r--
Parser updates. Added the "styled" keyword to wikitables to allow them to be styled using the current theme's standard table skinning, and changes to how the image tag parser decides how to display an image (framed, inline or raw).

<?php

/*
 * Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between
 * Copyright (C) 2006-2009 Dan Fuhry
 * diffiehellman.php - Diffie Hellman key exchange and supporting functions
 *
 * This program is Free Software; you can redistribute and/or modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.
 */

/**
 * EnanoMath GMP backend
 */

class EnanoMath_GMP
{
	var $api = 'GMP';
	
	/**
 	* Initializes a number to a GMP integer.
 	* @param string String representation of the number
 	* @param int Base the number is currently in, defaults to 10
 	* @return resource
 	*/
	
	function init($int, $base = 10)
	{
		return ( is_resource($int) ) ? $int : gmp_init($int, $base);
	}
	
	/**
 	* Converts a number from a GMP integer to a string
 	* @param resource
 	* @param int Base, default is 10
 	* @return string
 	*/
	
	function str($int, $base = 10)
	{
		return ( is_string($int) ) ? $int : gmp_strval($int, $base);
	}
	
	/**
 	* Converts a number between bases.
 	* @param resource BigInt to convert
 	* @param int Base to convert from
 	* @param int Base to convert to
 	*/
 	
	function basecon($int, $from, $to)
	{
		return $this->init(gmp_strval(gmp_init($this->str($int), $from), $to));
	}
	
	/**
 	* Generates a random integer.
 	* @param int Length
 	* @return resource
 	*/
	
	function random($len)
	{
		return gmp_random($len / 8);
	}
	
	/**
 	* Powmod operation (calculates (a ^ b) mod m)
 	* @param resource a
 	* @param resource b
 	* @param resource m
 	* @return resource
 	*/
	
	function powmod($a, $b, $m)
	{
		$a = $this->init($a);
		$b = $this->init($b);
		$m = $this->init($m);
		return ( function_exists('gmp_powm') ) ? gmp_powm($a, $b, $m) : gmp_mod(gmp_pow($a, $b), $m);
	}
}

/**
 * EnanoMath big_int backend
 */

class EnanoMath_BigInt
{
	var $api = 'big_int';
	
	/**
 	* Initializes a number to a BigInt integer.
 	* @param string String representation of the number
 	* @param int Base the number is in, defaults to 10
 	* @return resource
 	*/
	
	function init($int, $base = 10)
	{
		return (is_resource($int)) ? $int : bi_from_str($int, $base);
	}
	
	/**
 	* Converts a number from a BigInt integer to a string
 	* @param resource
 	* @param int Base, default is 10
 	* @return string
 	*/
	
	function str($int, $base = 10)
	{
		return ( is_string($int) ) ? $int : bi_to_str($int, $base);
	}
	
	/**
 	* Generates a random integer
 	* @param int Length (bits)
 	* @return resource
 	*/
	
	function random($len)
	{
		return bi_rand($len);
	}
	
	/**
 	* Converts a number between bases.
 	* @param resource BigInt to convert
 	* @param int Base to convert from
 	* @param int Base to convert to
 	*/
	
	function basecon($int, $from, $to)
	{
		return bi_base_convert($this->str($int, $from), $from, $to);
	}
	
	/**
 	* Powmod operation (calculates (a ^ b) mod m)
 	* @param resource a
 	* @param resource b
 	* @param resource m
 	* @return resource
 	*/
	
	function powmod($a, $b, $m)
	{
		$a = $this->init($a);
		$b = $this->init($b);
		$m = $this->init($m);
		return bi_powmod($a, $b, $m);
	}
}

/**
 * EnanoMath BCMath backend
 */

class EnanoMath_BCMath
{
	var $api = 'BCMath';
	
	/**
 	* Initializes a number to a BCMath integer.
 	* @param string String representation of the number
 	* @param int Base the number is in, defaults to 10
 	* @return resource
 	*/
	
	function init($int, $base = 10)
	{
		return $this->basecon($int, $base, 10);
	}
	
	/**
 	* Converts a number from a BCMath integer to a string
 	* @param resource
 	* @param int Base, default is 10
 	* @return string
 	*/
 	
	function str($res)
	{
		return ( is_string($res) ) ? $res : strval($this->basecon($res, 10, $base));
	}
	
	/**
 	* Generates a random integer
 	* @param int Length in bits
 	* @return resource
 	*/
	
	function random($len)
	{
		$len = 4 * $len;
		$chars = '0123456789abcdef';
		$ret = '';
		for ( $i = 0; $i < $len; $i++ )
		{
			$chid = mt_rand ( 0, strlen($chars) - 1 );
			$chr = $chars{$chid};
			$ret .= $chr;
		}
		return $this->basecon($this->init($ret), 16, 10);
	}
	
	/**
 	* Converts a number between bases.
 	* @param resource BigInt to convert
 	* @param int Base to convert from
 	* @param int Base to convert to
 	*/
	
	function basecon($int, $from, $to)
	{
		if ( $from != 10 )
			$int = $this->_bcmath_base2dec($int, $from);
		if ( $to != 10 )
			$int = $this->_bcmath_dec2base($int, $to);
		return $int;
	}
	
	/**
 	* Powmod operation (calculates (a ^ b) mod m)
 	* @param resource a
 	* @param resource b
 	* @param resource m
 	* @return resource
 	*/
	
	function powmod($a, $b, $m)
	{
		$a = $this->init($a);
		$b = $this->init($b);
		$m = $this->init($m);
		return ( function_exists('bcpowmod') ) ? bcpowmod($a, $b, $m) : bcmod( bcpow($a, $b), $m );
	}
	
	// from us.php.net/bc:
	// convert a decimal value to any other base value
	function _bcmath_dec2base($dec,$base,$digits=FALSE) {
			if($base<2 or $base>256) die("Invalid Base: ".$base);
			bcscale(0);
			$value="";
			if(!$digits) $digits=$this->_bcmath_digits($base);
			while($dec>$base-1) {
					$rest=bcmod($dec,$base);
					$dec=bcdiv($dec,$base);
					$value=$digits[$rest].$value;
			}
			$value=$digits[intval($dec)].$value;
			return (string) $value;
	}
	
	// convert another base value to its decimal value
	function _bcmath_base2dec($value,$base,$digits=FALSE) {
			if($base<2 or $base>256) die("Invalid Base: ".$base);
			bcscale(0);
			if($base<37) $value=strtolower($value);
			if(!$digits) $digits=$this->_bcmath_digits($base);
			$size=strlen($value);
			$dec="0";
			for($loop=0;$loop<$size;$loop++) {
					$element=strpos($digits,$value[$loop]);
					$power=bcpow($base,$size-$loop-1);
					$dec=bcadd($dec,bcmul($element,$power));
			}
			return (string) $dec;
	}
	
	function _bcmath_digits($base) {
			if($base>64) {
					$digits="";
					for($loop=0;$loop<256;$loop++) {
							$digits.=chr($loop);
					}
			} else {
					$digits ="0123456789abcdefghijklmnopqrstuvwxyz";
					$digits.="ABCDEFGHIJKLMNOPQRSTUVWXYZ-_";
			}
			$digits=substr($digits,0,$base);
			return (string) $digits;
	}
}

/**
 * Creates a new math object based on what libraries are available.
 * @return object
 */

function enanomath_create()
{
	if ( function_exists('gmp_init') )
		return new EnanoMath_GMP();
	else if ( function_exists('bi_from_str') )
		return new EnanoMath_BigInt();
	else if ( function_exists('bcadd') )
		return new EnanoMath_BCMath();
	else
		throw new Exception('dh_err_not_supported');
}

?>