ringbuffer.h

/*
  This file is part of the KDAB State Machine Editor Library.

  SPDX-FileCopyrightText: 2014-2021 Klarälvdalens Datakonsult AB, a KDAB Group company <info@kdab.com>
  Author: Kevin Funk <kevin.funk@kdab.com>

  SPDX-License-Identifier: LGPL-2.1-only OR LicenseRef-KDAB-KDStateMachineEditor

  Licensees holding valid commercial KDAB State Machine Editor Library
  licenses may use this file in accordance with the KDAB State Machine Editor
  Library License Agreement provided with the Software.

  Contact info@kdab.com if any conditions of this licensing are not clear to you.
*/

//krazy:excludeall=inline as this is a template
#ifndef KDSME_UTIL_RINGBUFFER_H
#define KDSME_UTIL_RINGBUFFER_H

#include <QQueue>
#include <QList>

namespace KDSME {

template<class T>
class RingBuffer
{
public:
    RingBuffer(int capacity = 10)
        : m_capacity(capacity)
    {}

    void setCapacity(int capacity)
    {
        Q_ASSERT(capacity > 0);
        m_capacity = capacity;
        cleanup();
    }

    void enqueue(T t)
    {
        m_entries.enqueue(t);
        cleanup();
    }

    void clear()
    {
        m_entries.clear();
    }

    inline const T& at(int i) const { return m_entries.at(i); }
    inline int size() const { return m_entries.size(); }
    inline T head() const { return m_entries.head(); }
    inline T last() const { return m_entries.last(); }
    inline QList<T> entries() const { return m_entries; }

  private:
    void cleanup()
    {
        while (m_entries.size() > m_capacity) {
            m_entries.dequeue();
        }
    }

    QQueue<T> m_entries;
    int m_capacity;
};

}

#endif