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// serial_base.cc
// nono - programme du robot 2004. {{{
//
// Copyright (C) 2004 Nicolas Schodet
//
// Robot APB Team/Efrei 2004.
//        Web: http://assos.efrei.fr/robot/
//      Email: robot AT efrei DOT fr
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// }}}
#include "serial_base.h"
#include "utils/errno_exception.h"

#include <sys/types.h>
#include <sys/time.h>

/// Constructeur.
SerialBase::SerialBase (void)
    : fdIn_ (-1), fdOut_ (-1)
{
}

/// Destructeur.
SerialBase::~SerialBase (void)
{
}

/// Lit un bloc, retourne le nombre d'octets lus ou <= 0 en cas d'erreur
/// ou si aucun caract�re n'est disponible. Pour le robot, pr�ferer en
/// g�n�ral getchar() pour du non-bloquant.
ssize_t
SerialBase::read (void *buf, size_t size)
{
    return ::read (fdIn_, buf, size);
}

/// Lit un caract�re, ou -1 en cas d'erreur ou si aucun caract�re n'est
/// disponible.
int
SerialBase::getchar (void)
{
    char c;
    if (read (&c, 1) == 1)
	return c;
    else
	return -1;
}

/// Ecrit un bloc.
void
SerialBase::write (const void *buf, size_t size)
{
    ::write (fdOut_, buf, size);
}

/// Ecrit un caract�re.
void
SerialBase::putchar (int c)
{
    write (&c, 1);
}

/// Attend que des caract�res soient disponibles pendant un delay en
/// millisecondes.
bool
SerialBase::wait (int timeout/*-1*/)
{
    fd_set fds;
    int r;
    // Setup fd_set.
    FD_ZERO (&fds);
    FD_SET (fdIn_, &fds);
    if (timeout == -1)
      { 
        // Without timeout.
        r = select (FD_SETSIZE, &fds, 0, 0, 0);
      }
    else
      { 
        // With timeout.
        struct timeval tv;
        tv.tv_sec = timeout / 1000;
        tv.tv_usec = (timeout % 1000) * 1000;
        r = select (FD_SETSIZE, &fds, 0, 0, &tv);
      }
    switch (r)
      {
      case -1:
        // Error.
        throw errno_exception (errno);
      case 0:
        // Timeout.
        return false;
      default:
        // Data availlable.
        return true;
      }
}