internal_queue.h

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// -*- mode: c++; tab-width: 4; indent-tabs-mode: t; c-file-style: "stroustrup"; -*-
// vi:set ts=4 sts=4 sw=4 noet cino+=(0 :
// Copyright 2010, 2011, The TPIE development team
// 
// This file is part of TPIE.
// 
// TPIE 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 3 of the License, or (at your
// option) any later version.
// 
// TPIE 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 TPIE.  If not, see <http://www.gnu.org/licenses/>
#ifndef __TPIE_INTERNAL_QUEUE_H__
#define __TPIE_INTERNAL_QUEUE_H__

#include <tpie/array.h>
#include <tpie/util.h>
#include <tpie/tpie_assert.h>

namespace tpie {

template <typename T>
class internal_queue: public linear_memory_base<internal_queue<T> > {
    array<T> m_elements;
    size_t m_first, m_last;
public:
    static double memory_coefficient() {return array<T>::memory_coefficient();}

    static double memory_overhead() {return array<T>::memory_overhead() - sizeof(array<T>) + sizeof(internal_queue);}

    internal_queue(size_t size=0): m_first(0), m_last(0) {m_elements.resize(size);}

    void resize(size_t size=0) {m_elements.resize(size); m_first = m_last = 0;}
    
    const T & front() const {tp_assert(!empty(), "front() on empty queue"); return m_elements[m_first % m_elements.size()];}

    const T & back() const {return m_elements[(m_last-1) % m_elements.size()];}

    inline void push(T val){m_elements[m_last++ % m_elements.size()] = val;}

    inline void pop(){++m_first;}

    inline bool empty() const {return m_first == m_last;}

    inline bool full() const {return m_last - m_first == m_elements.size();}

    inline size_t size() const { return m_last - m_first;}
    
    inline void clear(){m_first = m_last =0;}
}; // class internal_queue

} // namespace tpie
#endif //__TPIE_INTERNAL_QUEUE_H__