CryptLib/Core/BigMath.php

   1 <?php
   2 /**
   3  * A class for arbitrary precision math functions
   4  *
   5  * PHP version 5.3
   6  *
   7  * @category   PHPCryptLib
   8  * @package    Core
   9  * @author     Anthony Ferrara <ircmaxell@ircmaxell.com>
  10  * @copyright  2011 The Authors
  11  * @license    http://www.opensource.org/licenses/mit-license.html  MIT License
  12  * @version    Build @@version@@
  13  */
  14 namespace CryptLib\Core;
  15
  16 /**
  17  * A class for arbitrary precision math functions
  18  *
  19  * @category   PHPCryptLib
  20  * @package    Core
  21  * @author     Anthony Ferrara <ircmaxell@ircmaxell.com>
  22  */
  23 abstract class BigMath {
  24
  25     /**
  26      * Get an instance of the big math class
  27      *
  28      * This is NOT a singleton.  It simply loads the proper strategy
  29      * given the current server configuration
  30      *
  31      * @return \CryptLib\Core\BigMath A big math instance
  32      */
  33     public static function createFromServerConfiguration() {
  34         //@codeCoverageIgnoreStart
  35         if (extension_loaded('bcmath')) {
  36             return new \CryptLib\Core\BigMath\BCMath();
  37         } elseif (extension_loaded('gmp')) {
  38             return new \CryptLib\Core\BigMath\GMP();
  39         } else {
  40             return new \CryptLib\Core\BigMath\PHPMath();
  41         }
  42         //@codeCoverageIgnoreEnd
  43     }
  44
  45     /**
  46      * Add two numbers together
  47      *
  48      * @param string $left  The left argument
  49      * @param string $right The right argument
  50      *
  51      * @return A base-10 string of the sum of the two arguments
  52      */
  53     abstract public function add($left, $right);
  54
  55     /**
  56      * Subtract two numbers
  57      *
  58      * @param string $left  The left argument
  59      * @param string $right The right argument
  60      *
  61      * @return A base-10 string of the difference of the two arguments
  62      */
  63     abstract public function subtract($left, $right);
  64
  65 }