PluginMemory.h

/* ***** BEGIN LICENSE BLOCK *****
 * This file is part of Natron <https://natrongithub.github.io/>,
 * (C) 2018-2021 The Natron developers
 * (C) 2013-2018 INRIA and Alexandre Gauthier-Foichat
 *
 * Natron 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 2 of the License, or
 * (at your option) any later version.
 *
 * Natron 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 Natron.  If not, see <http://www.gnu.org/licenses/gpl-2.0.html>
 * ***** END LICENSE BLOCK ***** */

#ifndef PLUGINMEMORY_H
#define PLUGINMEMORY_H

// ***** BEGIN PYTHON BLOCK *****
// from <https://docs.python.org/3/c-api/intro.html#include-files>:
// "Since Python may define some pre-processor definitions which affect the standard headers on some systems, you must include Python.h before any standard headers are included."
#include <Python.h>
// ***** END PYTHON BLOCK *****

#include "Global/Macros.h"

#include <cstddef>
#if !defined(Q_MOC_RUN) && !defined(SBK_RUN)
#include <boost/scoped_ptr.hpp>
#endif

#include "Engine/EngineFwd.h"

NATRON_NAMESPACE_ENTER

class PluginMemory
{
public:

    /**
     * @brief Constructs a new memory chunk that can be used freely and that will be registered and known
     * about by Natron.
     * @param effect If not NULL, it will register the size allocated to the associated node so that Natron
     * can clear this memory when in situation of low memory or when the node is no longer used.
     * On the other hand if the parameter is set to NULL, the memory will not be registered and will live
     * until the plug-in decides to free the memory.
     **/
    PluginMemory(const EffectInstancePtr& effect);

    ~PluginMemory();

    // If unregister is true, the destructor will attempt to remove this memory instance from the effect
    void setUnregisterOnDestructor(bool unregister);

    ///throws std::bad_alloc if the allocation failed. Returns false if the memory is already locked.
    ///Returns true on success.
    bool alloc(size_t nBytes);

    ///Frees the memory, it doesn't have to be unlocked.
    void freeMem();

    void* getPtr();

    void lock();

    void unlock();

private:
    struct Implementation;
    boost::scoped_ptr<Implementation> _imp; //!< PImpl
};

NATRON_NAMESPACE_EXIT

#endif // PLUGINMEMORY_H