EventsUtils.h#

// Copyright (c) 2019-2025, NVIDIA CORPORATION. All rights reserved.
//
// NVIDIA CORPORATION and its licensors retain all intellectual property
// and proprietary rights in and to this software, related documentation
// and any modifications thereto. Any use, reproduction, disclosure or
// distribution of this software and related documentation without an express
// license agreement from NVIDIA CORPORATION is strictly prohibited.
//

#pragma once

#include "../Defines.h"
#include "../InterfaceUtils.h"
#include "../ObjectUtils.h"
#include "IEvents.h"

#include <functional>
#include <utility>

namespace carb
{
namespace events
{

inline IEvents* getCachedEventsInterface()
{
    return getCachedInterface<IEvents>();
}

class LambdaEventListener : public IEventListener
{
public:
    LambdaEventListener(std::function<void(IEvent*)> fn) : m_fn(std::move(fn))
    {
    }

    void onEvent(IEvent* e) override
    {
        if (m_fn)
            m_fn(e);
    }

private:
    std::function<void(IEvent*)> m_fn;

    CARB_IOBJECT_IMPL
};

[[nodiscard]] inline ObjectPtr<ISubscription> createSubscriptionToPop(IEventStream* stream,
                                                                      std::function<void(IEvent*)> onEventFn,
                                                                      Order order = kDefaultOrder,
                                                                      const char* subscriptionName = nullptr)
{
    return stream->createSubscriptionToPop(
        carb::stealObject(new LambdaEventListener(std::move(onEventFn))).get(), order, subscriptionName);
}

[[nodiscard]] inline ObjectPtr<ISubscription> createSubscriptionToPopByType(IEventStream* stream,
                                                                            EventType eventType,
                                                                            std::function<void(IEvent*)> onEventFn,
                                                                            Order order = kDefaultOrder,
                                                                            const char* subscriptionName = nullptr)
{
    return stream->createSubscriptionToPopByType(
        eventType, carb::stealObject(new LambdaEventListener(std::move(onEventFn))).get(), order, subscriptionName);
}

[[nodiscard]] inline ObjectPtr<ISubscription> createSubscriptionToPush(IEventStream* stream,
                                                                       std::function<void(IEvent*)> onEventFn,
                                                                       Order order = kDefaultOrder,
                                                                       const char* subscriptionName = nullptr)
{
    return stream->createSubscriptionToPush(
        carb::stealObject(new LambdaEventListener(std::move(onEventFn))).get(), order, subscriptionName);
}

[[nodiscard]] inline ObjectPtr<ISubscription> createSubscriptionToPushByType(IEventStream* stream,
                                                                             EventType eventType,
                                                                             std::function<void(IEvent*)> onEventFn,
                                                                             Order order = kDefaultOrder,
                                                                             const char* subscriptionName = nullptr)
{
    return stream->createSubscriptionToPushByType(
        eventType, carb::stealObject(new LambdaEventListener(std::move(onEventFn))).get(), order, subscriptionName);
}

[[nodiscard]] inline std::vector<ObjectPtr<ISubscription>> getSubscriptionsToPop(IEventStream* stream)
{
    std::vector<ObjectPtr<ISubscription>> subscriptions;
    subscriptions.reserve(stream->getSubscriptionToPopCount());
    stream->walkSubscriptionsToPop(
        [](ISubscription* s, void* userData) {
            auto& subs = *static_cast<decltype(subscriptions)*>(userData);
            subs.emplace_back(carb::borrowObject(s));
            return true;
        },
        &subscriptions);
    return subscriptions;
}

[[nodiscard]] inline std::vector<ObjectPtr<ISubscription>> getSubscriptionsToPush(IEventStream* stream)
{
    std::vector<ObjectPtr<ISubscription>> subscriptions;
    subscriptions.reserve(stream->getSubscriptionToPushCount());
    stream->walkSubscriptionsToPush(
        [](ISubscription* s, void* userData) {
            auto& subs = *static_cast<decltype(subscriptions)*>(userData);
            subs.emplace_back(carb::borrowObject(s));
            return true;
        },
        &subscriptions);
    return subscriptions;
}

} // namespace events
} // namespace carb