me.ferrybig.javacoding.teamspeakconnector.internal.SubscriptionHandler.java Source code

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Here is the source code for me.ferrybig.javacoding.teamspeakconnector.internal.SubscriptionHandler.java

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/*
 * The MIT License
 *
 * Copyright 2017 Fernando van Loenhout.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package me.ferrybig.javacoding.teamspeakconnector.internal;

import io.netty.util.concurrent.Future;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.function.BiConsumer;
import me.ferrybig.javacoding.teamspeakconnector.TeamspeakConnection;
import me.ferrybig.javacoding.teamspeakconnector.event.Handler;
import me.ferrybig.javacoding.teamspeakconnector.internal.packets.ComplexRequest;

public class SubscriptionHandler<L> implements Handler<L> {

    private final ComplexRequest subscribe;
    private final ComplexRequest unsubscribe;
    private final List<L> listeners = new CopyOnWriteArrayList<>();
    private final TeamspeakConnection con;
    private Future<?> lastFuture;

    public SubscriptionHandler(TeamspeakConnection con, ComplexRequest subscribe, ComplexRequest unsubscribe) {
        this.subscribe = subscribe;
        this.unsubscribe = unsubscribe;
        this.con = con;
    }

    public <T> void callAll(BiConsumer<? super L, T> consumer, T type) {
        listeners.forEach(r -> consumer.accept(r, type));
    }

    public Future<?> clear() {
        synchronized (this) {
            boolean isEmpty = listeners.isEmpty();
            if (isEmpty) {
                return lastFuture;
            }
            listeners.clear();
            return lastFuture = con.io().sendPacket(unsubscribe);
        }
    }

    @Override
    public Future<?> addHandler(L handler) {
        Future<?> f;
        synchronized (this) {
            boolean wasEmpty = listeners.isEmpty();
            listeners.add(handler);
            if (wasEmpty) {
                f = con.io().sendPacket(subscribe);
                lastFuture = f;
            } else {
                f = lastFuture;
            }
        }
        f.addListener(future -> {
            assert future == f;
            if (!future.isSuccess()) {
                removeHandler(handler);
            }
        });
        return f;

    }

    @Override
    public Future<?> removeHandler(L handler) {
        synchronized (this) {
            if (!listeners.remove(handler)) {
                return lastFuture;
            }
            if (listeners.isEmpty()) {
                lastFuture = con.io().sendPacket(unsubscribe);
            }
            return lastFuture;
        }
    }

}