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())
        {

          // copy to local array, since ByteArray no longer supports
          // direct pointer-access to data values
          std::vector<char> localBuffer;
          buffer.copyTo(localBuffer);
          rc = rawSendBytes(&localBuffer[0], localBuffer.size());
          if (this->SOCKET_FAIL != rc)
          {
            rtn = true;
          }
          else
          {
            rtn = false;
            logSocketError("Socket sendBytes failed", rc, errno);
          }

        }
        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, shared_int timeout_ms)
    {
      int rc = this->SOCKET_FAIL;
      bool rtn = false;
      shared_int remainBytes = num_bytes;
      shared_int remainTimeMs = timeout_ms;
      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 smaller than
      // what can be received by the socket.
      if (this->MAX_BUFFER_SIZE > 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 && (timeout_ms < 0 || remainTimeMs > 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->rawPoll(this->SOCKET_POLL_TO, ready, error))
          {
            if(ready)
            {
              rc = rawReceiveBytes(this->buffer_, remainBytes);
              if (this->SOCKET_FAIL == rc)
              {
                this->logSocketError("Socket received failed", rc, errno);
                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;
                remainTimeMs = timeout_ms;  // Reset the timeout on successful read
                LOG_COMM("Byte array receive, bytes read: %u, bytes reqd: %u, bytes left: %u",
                    rc, num_bytes, remainBytes);
                buffer.load(&this->buffer_, rc);
                if (remainBytes <= 0) {
                  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
          {
            remainTimeMs = remainTimeMs - this->SOCKET_POLL_TO;
            LOG_COMM("Socket poll timeout, trying again");
          }
        }
      }
      else
      {
        LOG_WARN("Not connected, bytes not received");
        rtn = false;
      }

      // Close the socket on all failures except timeouts
      if (!rtn && (timeout_ms < 0 || remainTimeMs > 0))
      {
        this->setConnected(false);
      }
      return rtn;
    }

  }  //simple_socket
}  //industrial