/**
 * Get the remaining upload space for this site.
 *
 * @since MU
 *
 * @param int $size Current max size in bytes
 * @return int Max size in bytes
 */
function fix_import_form_size($size)
{
    if (upload_is_user_over_quota(false)) {
        return 0;
    }
    $available = get_upload_space_available();
    return min($size, $available);
}

/**
 * @since 3.0.0
 *
 * @return int of upload size limit in bytes
 */
function upload_size_limit_filter( $size ) {
	$fileupload_maxk = 1024 * get_site_option( 'fileupload_maxk', 1500 );
	if ( get_site_option( 'upload_space_check_disabled' ) )
		return min( $size, $fileupload_maxk );

	return min( $size, $fileupload_maxk, get_upload_space_available() );
}

 /**
  * Attach a new secondary image to the current CataBlogItem object. You
  * should validate the image you wish to attach using validateImage before
  * running this function with an uploaded file.
  *
  * @param string $tmp_path A file path to an uploaded image.
  * @return boolean|string Wether or not the image was successfully attached to the catalog item.
  */
 public function addSubImage($tmp_path)
 {
     if (function_exists('get_upload_space_available')) {
         $space_available = get_upload_space_available();
         $image_size = filesize($tmp_path);
         if ($image_size > $space_available) {
             $space_available = round($space_available / 1024 / 1024, 2);
             $image_size = round($image_size / 1024 / 1024, 2);
             $error = __('Can not write uploaded image to server, your storage space is exhausted.', 'catablog') . '<br />';
             $error .= __('Please delete some media files to free up space and try again.', 'catablog') . '<br />';
             $error .= sprintf(__('You have %sMB of available space on your server and your image is %sMB.', 'catablog'), $space_available, $image_size);
             return $error;
         }
     }
     // check if any image is of a bad format
     list($width, $height, $format) = getimagesize($tmp_path);
     switch ($format) {
         case IMAGETYPE_GIF:
             break;
         case IMAGETYPE_JPEG:
             break;
         case IMAGETYPE_PNG:
             break;
         default:
             return __("The image could not be used because it is an unsupported format. JPEG, GIF and PNG formats only, please.", 'catablog');
     }
     $filename = $_FILES['new_sub_image']['name'];
     $image_name = $this->unique_filename($filename);
     $move_path = $this->_wp_upload_dir . "/catablog/originals/{$image_name}";
     // move file to originals folder and set the filename into sub images array in the object
     $moved = move_uploaded_file($tmp_path, $move_path);
     $this->sub_images[] = $image_name;
     $this->updatePostMeta();
     // generate a thumbnail for the new image
     $this->makeThumbnail($image_name);
     if ($this->_options['lightbox-render']) {
         $this->makeFullsize($image_name);
     }
     delete_transient('dirsize_cache');
     // WARNING!!! transient label hard coded.
     return true;
 }