simple_socket.cpp

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#ifndef FLATHEADERS
#include "simple_message/socket/simple_socket.h"
#include "simple_message/log_wrapper.h"
#else
#include "simple_socket.h"
#include "log_wrapper.h"
#endif

using namespace industrial::byte_array;
using namespace industrial::shared_types;

namespace industrial
{
  namespace simple_socket
  {

    bool SimpleSocket::sendBytes(ByteArray & buffer)
    {
      int rc = this->SOCKET_FAIL;
      bool rtn = false;

      if (this->isConnected())
      {
        // Nothing restricts the ByteArray from being larger than the what the socket
        // can handle.
        if (this->MAX_BUFFER_SIZE > (int)buffer.getBufferSize())
        {

          rc = rawSendBytes(buffer.getRawDataPtr(), buffer.getBufferSize());
          if (this->SOCKET_FAIL != rc)
          {
            rtn = true;
          }
          else
          {
            rtn = false;
            logSocketError("Socket sendBytes failed", rc);
          }

        }
        else
        {
          LOG_ERROR("Buffer size: %u, is greater than max socket size: %u", buffer.getBufferSize(), this->MAX_BUFFER_SIZE);
          rtn = false;
        }

      }
      else
      {
        rtn = false;
        LOG_WARN("Not connected, bytes not sent");
      }

      if (!rtn)
      {
        this->setConnected(false);
      }

      return rtn;

    }

    bool SimpleSocket::receiveBytes(ByteArray & buffer, shared_int num_bytes)
    {
      int rc = this->SOCKET_FAIL;
      bool rtn = false;
      shared_int remainBytes = num_bytes;
      bool ready, error;

      // Reset the buffer (this is not required since the buffer length should
      // ensure that we don't read any of the garbage that may be left over from
      // a previous read), but it is good practice.

      memset(&this->buffer_, 0, sizeof(this->buffer_));

      // Doing a sanity check to determine if the byte array buffer is larger than
      // what can be sent in the socket.  This should not happen and might be indicative
      // of some code synchronization issues between the client and server base.
      if (this->MAX_BUFFER_SIZE < (int)buffer.getMaxBufferSize())
      {
        LOG_WARN("Socket buffer max size: %u, is larger than byte array buffer: %u",
            this->MAX_BUFFER_SIZE, buffer.getMaxBufferSize());
      }
      if (this->isConnected())
      {
        buffer.init();
        while (remainBytes > 0)
        {
          // Polling the socket results in an "interruptable" socket read.  This
          // allows Control-C to break out of a socket read.  Without polling,
          // a sig-term is required to kill a program in a socket read function.
          if (this->poll(this->SOCKET_POLL_TO, ready, error))
          {
            if(ready)
            {
              rc = rawReceiveBytes(this->buffer_, remainBytes);
              if (this->SOCKET_FAIL == rc)
              {
                this->logSocketError("Socket received failed", rc);
                        remainBytes = 0;
                rtn = false;
                break;
              }
              else if (0 == rc)
              {
                LOG_WARN("Recieved zero bytes: %u", rc);
                        remainBytes = 0;
                rtn = false;
                break;
              }
              else
              {
                remainBytes = remainBytes - rc;
                LOG_COMM("Byte array receive, bytes read: %u, bytes reqd: %u, bytes left: %u",
                    rc, num_bytes, remainBytes);
                buffer.load(&this->buffer_, rc);
                rtn = true;
              }
            }
            else if(error)
            {
              LOG_ERROR("Socket poll returned an error");
              rtn = false;
              break;
            }
            else
            {
              LOG_ERROR("Uknown error from socket poll");
              rtn = false;
              break;
            }
          }
          else
          {
            LOG_COMM("Socket poll timeout, trying again");
          }
        }
      }
      else
      {
        LOG_WARN("Not connected, bytes not sent");
        rtn = false;
      }

      if (!rtn)
      {
        this->setConnected(false);
      }
      return rtn;
    }

    bool SimpleSocket::poll(int timeout, bool & ready, bool & error)
    {
      timeval time;
      fd_set read, write, except;
      int rc = this->SOCKET_FAIL;
      bool rtn = false;
      ready = false;
      error = false;

      // The select function uses the timeval data structure
      time.tv_sec = timeout / 1000;
      time.tv_usec = (timeout % 1000) * 1000;

      FD_ZERO(&read);
      FD_ZERO(&write);
      FD_ZERO(&except);

      FD_SET(this->getSockHandle(), &read);
      FD_SET(this->getSockHandle(), &except);

      rc = SELECT(this->getSockHandle() + 1, &read, &write, &except, &time);

      if (this->SOCKET_FAIL != rc)
      {
        if (0 == rc)
        {
          rtn = false;
        }
        else
        {
          if (FD_ISSET(this->getSockHandle(), &read))
          {
            ready = true;
            rtn = true;
          }
          else if(FD_ISSET(this->getSockHandle(), &except))
          {
            error = true;
            rtn = true;
          }
          else
          {
            LOG_WARN("Select returned, but no flags are set");
            rtn = false;
          }
        }
      }
      else
      {
        this->logSocketError("Socket select function failed", rc);
        rtn = false;
      }

      return rtn;
    }

  }  //simple_socket
}  //industrial