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rxjava2-extensions developed by David Karnok

There is a newer version: 0.20.10

/*
 * Copyright 2016-2017 David Karnok
 *
 * 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 hu.akarnokd.rxjava2.joins;

import java.util.*;
import java.util.concurrent.atomic.AtomicReference;

import io.reactivex.Observer;
import io.reactivex.functions.*;

/**
 * Represents an execution plan for join patterns.
 * @param  the result type
 */
final class PlanN extends Plan {
    protected final PatternN expression;
    protected final Function selector;

    PlanN(PatternN expression, Function selector) {
        this.expression = expression;
        this.selector = selector;
    }

    @Override
    public ActivePlan0 activate(Map externalSubscriptions,
            final Observer observer, final Consumer deactivate) {
        Consumer onError = onErrorFrom(observer);

        final List> observers = new ArrayList>();
        for (int i = 0; i < expression.size(); i++) {
            observers.add(createObserver(externalSubscriptions, expression.get(i), onError));
        }
        final AtomicReference self = new AtomicReference();

        ActivePlanN activePlan = new ActivePlanN(observers, new Consumer() {
                    @Override
                    public void accept(Object[]args) {
                        R result;
                        try {
                            result = selector.apply(args);
                        } catch (Throwable t) {
                            observer.onError(t);
                            return;
                        }
                        observer.onNext(result);
                    }
                },
                new Action() {
                    @Override
                    public void run() throws Exception {
                        for (JoinObserver1 jo : observers) {
                            jo.removeActivePlan(self.get());
                        }
                        deactivate.accept(self.get());
                    }
                });

        self.set(activePlan);

        for (JoinObserver1 jo : observers) {
            jo.addActivePlan(activePlan);
        }

        return activePlan;
    }

}