TCPPacket.cc

#include "otsdaq/NetworkUtilities/TCPPacket.h"
#include <arpa/inet.h>
#include <iostream>
 
using namespace ots;
 
//==============================================================================
TCPPacket::TCPPacket() : fBuffer("") {}
 
//==============================================================================
TCPPacket::~TCPPacket(void) {}
 
//==============================================================================
std::string TCPPacket::encode(char const* message, std::size_t length)
{
    return encode(std::string(message, length));
}
 
//==============================================================================
std::string TCPPacket::encode(const std::string& message)
{
    uint32_t    size   = htonl(TCPPacket::headerLength + message.length());
    std::string buffer = std::string(TCPPacket::headerLength, ' ') +
                         message;  // THE HEADER LENGTH IS SET TO 4 = sizeof(uint32_t)
    buffer[0] = (size) & 0xff;
    buffer[1] = (size >> 8) & 0xff;
    buffer[2] = (size >> 16) & 0xff;
    buffer[3] = (size >> 24) & 0xff;
 
    // std::cout << __PRETTY_FUNCTION__
    //           << std::hex
    //           << "Message length: "  << message.length()
    //           << ", Buffer length: " << buffer.length()
    //           << ", htonl length: "  << size
    //           << std::dec
 
    //           << std::endl;
    // std::cout << __PRETTY_FUNCTION__ << "Sending-";
    // for (auto l = 0; l < buffer.length(); l++)
    //     std::cout << buffer[l] << "-";
    // std::cout << std::endl;
    return buffer;
}
 
//==============================================================================
void TCPPacket::reset(void) { fBuffer.clear(); }
 
//==============================================================================
bool TCPPacket::isEmpty(void) { return !fBuffer.size(); }
 
//==============================================================================
bool TCPPacket::decode(std::string& message)
{
    if(fBuffer.length() < headerLength)
        return false;
    uint32_t length = ntohl(reinterpret_cast<uint32_t&>(
        fBuffer.at(0)));  // THE HEADER IS FIXED TO SIZE 4 = SIZEOF(uint32_t)
    // std::cout << __PRETTY_FUNCTION__ << "Receiving-";
    // or (auto l = 0; l < fBuffer.length(); l++)
    // for (auto l = 0; l < 4; l++)
    //  std::cout << std::hex << (unsigned int)fBuffer[l] << std::dec << "-";
    // std::cout << std::endl;
    // std::cout << __PRETTY_FUNCTION__
    //           //<< std::hex
    //           << "Buffer length: "
    //           << fBuffer.length()
    //           //              << ", htonl length: " << length
    //           << ", ntohl length: "
    //           << length
    //           //<< std::dec
    //           << std::endl;
    if(fBuffer.length() == length)
    {
        message = fBuffer.substr(headerLength);
        fBuffer.clear();
        return true;
    }
    else if(fBuffer.length() > length)
    {
        message = fBuffer.substr(headerLength, length - headerLength);
        // std::cout << __PRETTY_FUNCTION__ << "Erasing: " << length
        //           << " characters!"
        //           //<< " Msg:-" << message << "-"
        //           << std::endl;
        fBuffer.erase(0, length);
        return true;
    }
    else
    {
        // std::cout << __PRETTY_FUNCTION__ << "Can't decode an incomplete message! Length is only: " << fBuffer.length() << std::endl;
        return false;
    }
}