fixed_queue.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef TITANIC_FIXED_QUEUE_H
#define TITANIC_FIXED_QUEUE_H

#include "common/scummsys.h"
#include "common/array.h"

namespace Titanic {

template<class T, uint MAX_SIZE = 10>
class FixedQueue {
    typedef uint size_type;
protected:
    Common::Array<T> _data;
    size_type _topIndex;
public:
    FixedQueue() : _topIndex(0) {
        _data.reserve(MAX_SIZE);
    }

    size_type size() const { return _data.size() - _topIndex; }

    size_type freeSize() const { return MAX_SIZE - size(); }

    bool empty() const {
        return size() == 0;
    }

    bool full() const {
        return freeSize() == 0;
    }

    void clear() {
        _data.clear();
        _topIndex = 0;
    }

    void compact() {
        if (_data.size() == MAX_SIZE && _topIndex > 0) {
            if (_topIndex < MAX_SIZE)
                Common::copy(&_data[_topIndex], &_data[0] + MAX_SIZE, &_data[0]);
            _data.resize(size());
            _topIndex = 0;
        }
    }

    void push(const T &v) {
        assert(size() < MAX_SIZE);
        compact();
        _data.push_back(v);
    }

    const T &top() const {
        assert(size() > 0);
        return _data[_topIndex];
    }

    T &top() {
        assert(size() > 0);
        return _data[_topIndex];
    }

    T pop() {
        T tmp = top();
        ++_topIndex;
        return tmp;
    }

    T &operator[](size_type i) {
        assert(i < size());
        return _data[_topIndex + i];
    }

    const T &operator[](size_type i) const {
        assert(i < size());
        return _data[_topIndex + i];
    }
};

} // End of namespace Titanic

#endif