<?php
//
// +----------------------------------------------------------------------+
// |zen-cart Open Source E-commerce                                       |
// +----------------------------------------------------------------------+
// | Copyright (c) 2003 The zen-cart developers                           |
// |                                                                      |
// | http://www.zen-cart.com/index.php                                    |
// |                                                                      |
// | Portions Copyright (c) 2003 osCommerce                               |
// +----------------------------------------------------------------------+
// | This source file is subject to version 2.0 of the GPL license,       |
// | that is bundled with this package in the file LICENSE, and is        |
// | available through the world-wide-web at the following url:           |
// | http://www.zen-cart.com/license/2_0.txt.                             |
// | If you did not receive a copy of the zen-cart license and are unable |
// | to obtain it through the world-wide-web, please send a note to       |
// | license@zen-cart.com so we can mail you a copy immediately.          |
// +----------------------------------------------------------------------+
// $Id: gzip_compression.php 1969 2005-09-13 06:57:21Z drbyte $
//

  function zen_check_gzip() {

    if (headers_sent() || connection_aborted()) {
      return false;
    }

    if (strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'x-gzip') !== false) return 'x-gzip';

    if (strpos($_SERVER['HTTP_ACCEPT_ENCODING'],'gzip') !== false) return 'gzip';

    return false;
  }

/* $level = compression level 0-9, 0=none, 9=max */
  function zen_gzip_output($level = GZIP_LEVEL) {
    if ($encoding = zen_check_gzip()) {
      $contents = ob_get_contents();
      ob_end_clean();

      header('Content-Encoding: ' . $encoding);

      $size = strlen($contents);
      $crc = crc32($contents);

      $contents = gzcompress($contents, $level);
      $contents = substr($contents, 0, strlen($contents) - 4);

      echo "\x1f\x8b\x08\x00\x00\x00\x00\x00";
      echo $contents;
      echo pack('V', $crc);
      echo pack('V', $size);
    } else {
      ob_end_flush();
    }
  }
?>