activeobjectmgr.h

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/*
Minetest
Copyright (C) 2010-2018 nerzhul, Loic BLOT <loic.blot@unix-experience.fr>
 
This program 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 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 Lesser General Public License for more details.
 
You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
 
#pragma once
 
#include <memory>
#include "debug.h"
#include "util/container.h"
#include "irrlichttypes.h"
#include "util/basic_macros.h"
 
class TestClientActiveObjectMgr;
class TestServerActiveObjectMgr;
 
template <typename T>
class ActiveObjectMgr
{
    friend class ::TestClientActiveObjectMgr;
    friend class ::TestServerActiveObjectMgr;
 
public:
    ActiveObjectMgr() = default;
    DISABLE_CLASS_COPY(ActiveObjectMgr);
 
    virtual ~ActiveObjectMgr()
    {
        SANITY_CHECK(m_active_objects.empty());
        // Note: Do not call clear() here. The derived class is already half
        // destructed.
    }
 
    virtual void step(float dtime, const std::function<void(T *)> &f) = 0;
    virtual bool registerObject(std::unique_ptr<T> obj) = 0;
    virtual void removeObject(u16 id) = 0;
 
    void clear()
    {
        // on_destruct could add new objects so this has to be a loop
        do {
            for (auto &it : m_active_objects.iter()) {
                if (!it.second)
                    continue;
                m_active_objects.remove(it.first);
            }
        } while (!m_active_objects.empty());
    }
 
    T *getActiveObject(u16 id)
    {
        return m_active_objects.get(id).get();
    }
 
protected:
    u16 getFreeId() const
    {
        // try to reuse id's as late as possible
        static thread_local u16 last_used_id = 0;
        u16 startid = last_used_id;
        while (!isFreeId(++last_used_id)) {
            if (last_used_id == startid)
                return 0;
        }
 
        return last_used_id;
    }
 
    bool isFreeId(u16 id) const
    {
        return id != 0 && !m_active_objects.get(id);
    }
 
    // Note that this is ordered to fix #10985
    ModifySafeMap<u16, std::unique_ptr<T>> m_active_objects;
};