uhd

//

// Copyright 2010 Ettus Research LLC

//

// This program is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// This program is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

//

#ifndef INCLUDED_UHD_TRANSPORT_USB_ZERO_COPY_HPP

#define INCLUDED_UHD_TRANSPORT_USB_ZERO_COPY_HPP

#include "usb_device_handle.hpp"

#include <uhd/transport/zero_copy.hpp>

namespace uhd { namespace transport {

/*!

 * A zero copy usb transport provides an efficient way to handle data.

 * by avoiding the extra copy when recv() or send() is called on the handle.

 * Rather, the zero copy transport gives the caller memory references.

 * The caller informs the transport when it is finished with the reference.

 *

 * On linux systems, the zero copy transport can use a kernel packet ring.

 * If no platform specific solution is available, make returns a boost asio

 * implementation that wraps functionality around standard send/recv calls.

 */

class UHD_API usb_zero_copy : public virtual zero_copy_if {

public:

    typedef boost::shared_ptr<usb_zero_copy> sptr;

    /*!

     * Make a new zero copy usb transport:

     * This transport is for sending and receiving between the host

     * and a pair of USB bulk transfer endpoints.

     * The primary usage for this transport is data transactions.

     * The underlying implementation may be platform specific.

     *

     * \param handle a device handle that uniquely identifying the device

     * \param rx_endpoint an integer specifiying an IN endpoint number 

     * \param tx_endpoint an integer specifiying an OUT endpoint number

     * \param buff_size total number of bytes of buffer space to allocate 

     * \param block_size number of bytes allocated for each I/O transaction 

     */

    static sptr make(usb_device_handle::sptr handle,

                     unsigned int rx_endpoint,

                     unsigned int tx_endpoint,

                     size_t buff_size = 0, 

                     size_t block_size = 0);

};

}} //namespace

#endif /* INCLUDED_UHD_TRANSPORT_USB_ZERO_COPY_HPP */