<?php

// -*- coding: utf-8 -*-

/**
 * Interface BackWPup_Destination_Downloader_Service_Interface.
 */
interface BackWPup_Destination_Downloader_Interface
{
    /**
     * Download part of the backup file.
     *
     * @param int $start_byte
     * @param int $end_byte
     *
     * @throws Exception in case something went wrong
     */
    public function download_chunk($start_byte, $end_byte);

    /**
     * Calculated the size of the source file.
     *
     * @return int
     */
    public function calculate_size();
}