KisSafeBlockingQueueConnectionProxy.h

Go to the documentation of this file.

/*
 *  SPDX-FileCopyrightText: 2020 Dmitry Kazakov <dimula73@gmail.com>
 *
 *  SPDX-License-Identifier: GPL-2.0-or-later
 */
#ifndef KISSAFEBLOCKINGQUEUECONNECTIONPROXY_H
#define KISSAFEBLOCKINGQUEUECONNECTIONPROXY_H
 
#include <QObject>
#include <QQueue>
#include <functional>
#include "kis_signal_compressor_with_param.h"
#include "kis_assert.h"
#include "kritaimage_export.h"
 
namespace KisSafeBlockingQueueConnectionProxyPrivate {
void KRITAIMAGE_EXPORT passBlockingSignalSafely(FunctionToSignalProxy &source, SignalToFunctionProxy &destination);
void KRITAIMAGE_EXPORT initProxyObject(QObject *object);
}
 
 
template <typename T>
class KisSafeBlockingQueueConnectionProxy
{
    using CallbackFunction = std::function<void (T)>;
public:
    KisSafeBlockingQueueConnectionProxy(CallbackFunction function)
        : m_function(function),
          m_destination(std::bind(&KisSafeBlockingQueueConnectionProxy::fakeSlotTimeout, this))
    {
        KisSafeBlockingQueueConnectionProxyPrivate::initProxyObject(&m_source);
        KisSafeBlockingQueueConnectionProxyPrivate::initProxyObject(&m_destination);
 
        QObject::connect(&m_source, SIGNAL(timeout()), &m_destination, SLOT(start()), Qt::BlockingQueuedConnection);
    }
 
    void start(T value) {
        const int sanityQueueSize = m_value.size();
 
        m_value.enqueue(value);
        KisSafeBlockingQueueConnectionProxyPrivate::passBlockingSignalSafely(m_source, m_destination);
 
        KIS_SAFE_ASSERT_RECOVER_NOOP(m_value.size() == sanityQueueSize);
    }
 
private:
    void fakeSlotTimeout() {
        KIS_SAFE_ASSERT_RECOVER_RETURN(!m_value.isEmpty());
        m_function(m_value.dequeue());
    }
 
private:
    CallbackFunction m_function;
    FunctionToSignalProxy m_source;
    SignalToFunctionProxy m_destination;
    QQueue<T> m_value;
};
 
template <>
class KisSafeBlockingQueueConnectionProxy<void>
{
    using CallbackFunction = std::function<void ()>;
public:
    KisSafeBlockingQueueConnectionProxy(CallbackFunction function)
        : m_function(function),
          m_destination(std::bind(&KisSafeBlockingQueueConnectionProxy::fakeSlotTimeout, this))
    {
        KisSafeBlockingQueueConnectionProxyPrivate::initProxyObject(&m_source);
        KisSafeBlockingQueueConnectionProxyPrivate::initProxyObject(&m_destination);
 
        QObject::connect(&m_source, SIGNAL(timeout()), &m_destination, SLOT(start()), Qt::BlockingQueuedConnection);
    }
 
    void start() {
        KisSafeBlockingQueueConnectionProxyPrivate::passBlockingSignalSafely(m_source, m_destination);
    }
 
private:
    void fakeSlotTimeout() {
        m_function();
    }
 
private:
    CallbackFunction m_function;
    FunctionToSignalProxy m_source;
    SignalToFunctionProxy m_destination;
};
 
#endif // KISSAFEBLOCKINGQUEUECONNECTIONPROXY_H