RingBuffer.cpp

/*
  Copyright (c) 2011 Arduino.  All right reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library 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 Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include "RingBuffer.h"
#include <string.h>

RingBuffer::RingBuffer(void)
{
  memset((void *)_aucBuffer, 0, SERIAL_BUFFER_SIZE) ;
  _iHead = 0 ;
  _iTail = 0 ;
}

void RingBuffer::store_char(uint8_t c)
{
  int i = (uint32_t)(_iHead + 1) % SERIAL_BUFFER_SIZE ;

  // if we should be storing the received character into the location
  // just before the tail (meaning that the head would advance to the
  // current location of the tail), we're about to overflow the buffer
  // and so we don't write the character or advance the head.
  if (i != _iTail) {
    _aucBuffer[_iHead] = c ;
    _iHead = i ;
  }
}