load_balancer.h

/*
 * Copyright (c) 2008-2025, Hazelcast, Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#pragma once
 
#include "hazelcast/util/export.h"
#include "hazelcast/client/member.h"
 
namespace hazelcast {
namespace client {
 
class cluster;
 
namespace connection {
class ClientConnectionManagerImpl;
}

class HAZELCAST_API load_balancer final
{
public:
    template<typename Handler,
             typename = util::enable_if_rvalue_ref_trait<Handler&&>>
    load_balancer& init(Handler&& h) &
    {
        init_ = std::forward<Handler>(h);
        return *this;
    }
 
    template<typename Handler,
             typename = util::enable_if_rvalue_ref_trait<Handler&&>>
    load_balancer&& init(Handler&& h) &&
    {
        init_ = std::forward<Handler>(h);
        return std::move(*this);
    }

    template<typename Handler,
             typename = util::enable_if_rvalue_ref_trait<Handler&&>>
    load_balancer& next(Handler&& h) &
    {
        next_ = std::forward<Handler>(h);
        return *this;
    }
 
    template<typename Handler,
             typename = util::enable_if_rvalue_ref_trait<Handler&&>>
    load_balancer&& next(Handler&& h) &&
    {
        next_ = std::forward<Handler>(h);
        return std::move(*this);
    }
 
private:
    std::function<void(cluster&)> init_ = util::noop<cluster&>;
    std::function<boost::optional<member>(cluster&)> next_ = [](cluster&) {
        return boost::none;
    };
 
    friend class connection::ClientConnectionManagerImpl;
};
} // namespace client
} // namespace hazelcast