CodeIgniter static website generator

MY_Output.php

<?php

/**
 * Creates static version of CodeIgniter site
 *
 * @author aquilax
 */
class MY_Output extends CI_Output {

  function __construct() {
    parent::__construct();
  }

  /**
   * Write a Cache File
   *
   * @access	public
   * @param 	string
   * @return	void
   */
  function _write_cache($output) {
    $CI = & get_instance();
    $path = $CI->config->item('cache_path');

    $cache_path = ($path == '') ? FCPATH : $path;

    if (!is_dir($cache_path) OR !is_really_writable($cache_path)) {
      log_message('error', "Unable to write cache file: " . $cache_path);
      return;
    }

    if (pathinfo($CI->uri->uri_string(), PATHINFO_EXTENSION) == '') {
      $extra = rtrim($CI->uri->uri_string(), '/') . '/index.html';
    } else {
      $extra = $CI->uri->uri_string();
    }

    if (pathinfo($extra, PATHINFO_EXTENSION) !== 'html') {
      return;
    }

    $cache_path .= $extra;

    $path = dirname($cache_path);

    if (!file_exists($path)) {
      if (!mkdir($path, 0755, TRUE)) {
        log_message('error', "Unable to create directory: " . $path);
        return;
      }
    }

    if (!$fp = @fopen($cache_path, FOPEN_WRITE_CREATE_DESTRUCTIVE)) {
      log_message('error', "Unable to write cache file: " . $cache_path);
      return;
    }


    if (flock($fp, LOCK_EX)) {
      fwrite($fp, $output);
      flock($fp, LOCK_UN);
    } else {
      log_message('error', "Unable to secure a file lock for file at: " . $cache_path);
      return;
    }
    fclose($fp);
    @chmod($cache_path, FILE_WRITE_MODE);

    log_message('debug', "Cache file written: " . $cache_path);
  }

}

?>