colab.cpp

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//
// colab.cpp
//
// (c) 2010 SICK AG, Hamburg, Germany

#include "colab.hpp"
#include <cstring>
#include <cassert>
#include <stdexcept>
#include <stdlib.h>
#include <limits>

namespace colab
{

void addStringToBuffer(UINT8* buffer, UINT16& pos, const std::string& stringValue)
{
        UINT16 length = stringValue.length();
        strcpy((char*) &buffer[pos], stringValue.c_str());
        pos += length;
}



void addStringToBuffer(BYTE* buffer, const std::string& stringValue)
{
//      UINT16 length = stringValue.length();
        strcpy((char*) buffer, stringValue.c_str());
//      buffer += length;
}



std::string getStringFromBuffer(UINT8* buffer, UINT16& pos, UINT16 length)
{
        UINT16 start = pos;
        pos += length;
        return std::string((char *) &buffer[start], length);
}



std::string getStringFromBuffer(BYTE*& buffer, UINT16 length)
{
        std::string str((char *) &buffer[0], length);
        buffer += length;
        return str;
}



std::string getCommandStringFromBuffer(UINT8* buffer)
{
        return std::string((char*) &buffer[9], 2);
}



std::string getIdentifierFromBuffer(UINT8* buffer, UINT16& nextData, UINT16 bufferLength)
{
        UINT16 start;
        UINT16 length;

        if (buffer[11] == 0x20)
        {
                start = 12;
        }
        else
        {
                start = 11;
        }

        int i = start;
        do
        {
                if (i == bufferLength - 2)
                {
                        // found checksum field -> end of buffer reached.
                        nextData = 0; // indicates that there is no more data
                        break;
                }
                if (buffer[i] == 0x20)
                {
                        // found identifier delimiter
                        nextData = i + 1; // points to next data field
                        break;
                }
                i++;
        }
        while (true);

        length = i - start; // last byte of identifier

        return std::string((char*) &buffer[start], length);
}



void addFrameToBuffer(UINT8* sendBuffer, UINT8* cmdBuffer, UINT16* len)
{
        UINT16 pos = 0;
        UINT32 length = *len;

        // write header
        sendBuffer[pos++] = 0x02;
        sendBuffer[pos++] = 0x02;
        sendBuffer[pos++] = 0x02;
        sendBuffer[pos++] = 0x02;
        // Write payload length to buffer
        colab::addIntegerToBuffer<UINT32>(sendBuffer, pos, length + 1); // s counts to the payload length
        sendBuffer[pos++] = 's';

        // write telegram
        memcpy(&(sendBuffer[pos]), cmdBuffer, length);
        pos += length;

        // write checksum (of payload)
        UINT8 checksum = sendBuffer[8];
        for (int i = 9; i < pos; i++)
        {
                checksum = checksum ^ sendBuffer[i]; // XOR
        }
        colab::addIntegerToBuffer<UINT8>(sendBuffer, pos, checksum);

        *len = pos;
}

//
//  Returns the requested value. pos points then to the first byte of the next data field.
//
double getDoubleFromBuffer(UINT8* buffer, UINT16& pos)
{
        UINT16 width = sizeof(double);  // 8
//      UINT8* buffer2 = buffer;
//      T floatValue = memread<T>(buffer2);
        double* valuePtr = (double*)buffer;
        double value = *valuePtr;
        
        pos += width;
        return value;
}


UINT16 decodeUINT16(BYTE* buffer)
{
        UINT16 value = (((UINT16)buffer[0]) << 8) +
                                        ((UINT16)buffer[1]);
        return value;
}


} // END namespace colab