<?php
/**
 * PHP Opcode-Cache detection
 *
 * @author Alexander Over <hide@address.com>
 * @example DetectOpCodeCache::checkAll();
 * @example DetectOpCodeCache::hasApc();
 */
class DetectOpCodeCache
{

  /**
   * @var $extensions
   */
  private $extensions = array();

  /**
   * @var $instance
   */
  private static $instance;

  public function __construct()
  {
    $this->extensions = get_loaded_extensions();
  }

  public static function getInstance()
  {
    if( empty( self::$instance ) )
    {
      self::$instance = new DetectOpCodeCache();
    }
    return self::$instance;
  }

  final public static function checkAll()
  {
    $object = self::getInstance();

    return ( $object->hasXcache() or
             $object->hasWincache() or
             $object->hasApc() or
             $object->hasEaccelerator() or
             $object->hasIoncube() or
             $object->hasZend() or
             $object->hasNusphere()
           );
  }

  /**
   * check if we have Xcache
   *
   * @link http://xcache.lighttpd.net
   * @return bool
   */
  public static function hasXcache()
  {
    return function_exists( 'xcache_isset' );
  }

  /**
   * check if we have Wincache
   *
   * @link http://www.iis.net/expand/WinCacheForPHP
   * @return bool
   */
  public static function hasWincache()
  {
    return function_exists( 'wincache_fcache_fileinfo' );
  }

  /**
   * check if we have Alternative PHP Cache
   *
   * @link http://pecl.php.net/package/apc
   * @return bool
   */
  public static function hasApc()
  {
    return function_exists( 'apc_add' );
  }

  /**
   * check if we have eAccelerator
   *
   * @link http://eaccelerator.net
   * @return bool
   */
  public static function hasEaccelerator()
  {
    // !empty doesn't work, because no variable
    return (bool)strlen( ini_get( 'eaccelerator.enable' ) );
  }

  /**
   * check if we have ionCube Loader
   *
   * @link http://www.php-accelerator.co.uk
   * @return bool
   */
  public static function hasIoncube()
  {
    return (bool)strlen( ini_get( 'phpa' ) );
  }

  /**
   * check if we have Zend Optimizer+
   *
   * @link http://www.zend.com/products/server
   * @return bool
   */
  public static function hasZend()
  {
    return (bool)strlen( ini_get( 'zend_optimizer.enable_loader' ) );
  }

  /**
   * check if we have nuSphere phpExpress
   *
   * @link http://www.nusphere.com/products/phpexpress.htm
   * @return bool
   */
  public static function hasNusphere()
  {
    // in_array() check is slower then function_exists(), so don't use in production environment
    $object = self::getInstance();
    return in_array( 'phpexpress', $object->extensions );
  }
}