/home/travis/build/lis-epfl/MAVRIC_Library/util/buffer.hxx

/*******************************************************************************
 * Copyright (c) 2009-2016, MAV'RIC Development Team
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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 ******************************************************************************/

/*******************************************************************************
 * \file buffer.cpp
 *
 * \author MAV'RIC Team
 * \author Felix Schill
 * \author Julien Lecoeur
 *
 * \brief Buffer
 *
 ******************************************************************************/

#ifndef BUFFER_HXX_
#define BUFFER_HXX_


template<uint32_t S, typename T>
Buffer_T<S, T>::Buffer_T(void):
    head_(0),
    tail_(0)
{}


template<uint32_t S, typename T>
bool Buffer_T<S, T>::put_lossy(const T& data)
{
    uint32_t tmp;

    tmp = (head_ + 1) % (S + 1);

    if (tmp == tail_)
    {
        // error: receive buffer overflow!!
        // lose old incoming data at the end of the buffer
        tail_ = (tail_ + 1) % (S + 1);
    }

    // store incoming data in buffer
    buffer_[head_] = data;
    head_ = tmp;

    return true;
}


template<uint32_t S, typename T>
bool Buffer_T<S, T>::put(const T& data)
{
    uint32_t tmp;
    tmp = (head_ + 1) % (S + 1);

    if (tmp == tail_)
    {
        // error: buffer full!
        return false;
    }
    else
    {
        // store incoming data in buffer
        buffer_[head_] = data;
        head_ = tmp;

        return true;
    }
}


template<uint32_t S, typename T>
bool Buffer_T<S, T>::get(T& data)
{
    bool ret = false;

    if (head_ != tail_)
    {
        data  = buffer_[tail_];
        tail_ = (tail_ + 1) % (S + 1);
        ret = true;
    }

    return ret;
}


template<uint32_t S, typename T>
void Buffer_T<S, T>::clear(void)
{
    head_ = 0;
    tail_ = 0;
}


template<uint32_t S, typename T>
uint32_t Buffer_T<S, T>::readable(void) const
{
    return (S + 1 + head_ - tail_) % (S + 1);
}


template<uint32_t S, typename T>
uint32_t Buffer_T<S, T>::writeable(void) const
{
    return S - readable();
}


template<uint32_t S, typename T>
bool Buffer_T<S, T>::full(void) const
{
    return (((head_ + 1) % (S + 1)) == tail_);
}


template<uint32_t S, typename T>
bool Buffer_T<S, T>::empty(void) const
{
    return (head_ == tail_);
}

template<uint32_t S, typename T>
bool Buffer_T<S, T>::get_element(uint32_t index, T& elem) const
{
    if (index > S)
    {
        return false;
    }
    else if (readable() < index)
    {
        return false;
    }
    else
    {
        elem = buffer_[(tail_ + index)%(S+1)];
        return true;
    }
}


#endif /* BUFFER_HXX_ */