CInterfaceFTDI_common.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

#include "comms-precomp.h"  // Precompiled headers

#include <mrpt/comms/CInterfaceFTDI.h>
#include <algorithm>  // min()

using namespace mrpt;
using namespace mrpt::comms;

/*-------------------------------------------------------------
                                        Read
-------------------------------------------------------------*/
size_t CInterfaceFTDI::Read(void* Buffer, size_t Count)
{
        if (!Count) return 0;

        // Employ a circular_buffer to speed-up lots of small readings:
        if (m_readBuffer.size() >= Count)
        {
                // It's enough with the data in the buffer:
                m_readBuffer.pop_many(reinterpret_cast<uint8_t*>(Buffer), Count);
                return Count;
        }
        else
        {
                // More data must be read:
                uint8_t buf[4000];

                unsigned long nActualRead = 0;
                unsigned long to_read = std::min(m_readBuffer.available(), sizeof(buf));

                ftdi_read(
                        buf, to_read,
                        &nActualRead);  // ftdi_read(Buffer,(unsigned long)Count, &ret );

                // Save data into the circular buffer:
                m_readBuffer.push_many(buf, nActualRead);

                // Read the required amount of bytes:
                size_t nActualReturn = std::min(m_readBuffer.size(), Count);

                m_readBuffer.pop_many(
                        reinterpret_cast<uint8_t*>(Buffer), nActualReturn);

                return nActualReturn;
        }
}

/*-------------------------------------------------------------
                                        Write
-------------------------------------------------------------*/
size_t CInterfaceFTDI::Write(const void* Buffer, size_t Count)
{
        unsigned long ret = 0;
        ftdi_write(Buffer, (unsigned long)Count, &ret);
        return (size_t)ret;
}

/*-------------------------------------------------------------
                                        Seek
-------------------------------------------------------------*/
uint64_t CInterfaceFTDI::Seek(uint64_t Offset, CStream::TSeekOrigin Origin)
{
        MRPT_UNUSED_PARAM(Offset);
        MRPT_UNUSED_PARAM(Origin);
        return 0;
}

/*-------------------------------------------------------------
                                        getTotalBytesCount
-------------------------------------------------------------*/
uint64_t CInterfaceFTDI::getTotalBytesCount() { return 0; }
/*-------------------------------------------------------------
                                        getPosition
-------------------------------------------------------------*/
uint64_t CInterfaceFTDI::getPosition() { return 0; }
/*-------------------------------------------------------------
                                        ReadBufferImmediate
-------------------------------------------------------------*/
size_t CInterfaceFTDI::ReadBufferImmediate(void* Buffer, size_t Count)
{
        unsigned long nRead;
        ftdi_read(Buffer, Count, &nRead);
        return nRead;
}