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//
// Copyright 2010-2011 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 <uhd/transport/usb_device_handle.hpp>
#include <uhd/transport/zero_copy.hpp>
#include <uhd/types/device_addr.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 recv_endpoint an integer specifiying an IN endpoint number
* \param send_endpoint an integer specifiying an OUT endpoint number
* \param hints optional parameters to pass to the underlying transport
* \return a new zero copy usb object
*/
static sptr make(
usb_device_handle::sptr handle,
size_t recv_endpoint,
size_t send_endpoint,
const device_addr_t &hints = device_addr_t()
);
/*!
* Make a wrapper around a zero copy implementation.
* The wrapper performs the following functions:
* - Pad commits to the frame boundary
* - Extract multiple packets on recv
*
* When enable multiple receive packets is set to true,
* the implementation inspects the vita length on transfers,
* and may split a single transfer into multiple managed buffers.
*
* \param usb_zc a usb zero copy interface object
* \param usb_frame_boundary bytes per frame
* \return a new zero copy wrapper object
*/
static sptr make_wrapper(
sptr usb_zc, size_t usb_frame_boundary = 512
);
};
}} //namespace
#endif /* INCLUDED_UHD_TRANSPORT_USB_ZERO_COPY_HPP */
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