Copyright (c) 2016-present, RxJava Contributors.
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.
/**
 * Copyright (c) 2016-present, RxJava Contributors.
 *
 * 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.
 */

package io.reactivex.internal.operators.observable;

import java.util.concurrent.atomic.AtomicInteger;

import io.reactivex.*;
import io.reactivex.disposables.Disposable;
import io.reactivex.functions.Consumer;
import io.reactivex.observables.ConnectableObservable;

Wraps a ConnectableObservable and calls its connect() method once
the specified number of Observers have subscribed.
Type parameters:
<T> – the value type of the chain/**
 * Wraps a ConnectableObservable and calls its connect() method once
 * the specified number of Observers have subscribed.
 *
 * @param <T> the value type of the chain
 */
public final class ObservableAutoConnect<T> extends Observable<T> {
    final ConnectableObservable<? extends T> source;
    final int numberOfObservers;
    final Consumer<? super Disposable> connection;
    final AtomicInteger clients;

    public ObservableAutoConnect(ConnectableObservable<? extends T> source,
            int numberOfObservers,
            Consumer<? super Disposable> connection) {
        this.source = source;
        this.numberOfObservers = numberOfObservers;
        this.connection = connection;
        this.clients = new AtomicInteger();
    }

    @Override
    public void subscribeActual(Observer<? super T> child) {
        source.subscribe(child);
        if (clients.incrementAndGet() == numberOfObservers) {
            source.connect(connection);
        }
    }
}