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rxjava2-extensions developed by David Karnok

There is a newer version: 0.20.10

/*
 * Copyright 2016 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.parallel;

import io.reactivex.functions.Function;

import org.reactivestreams.*;

import io.reactivex.internal.operators.flowable.FlowableFlatMap;

/**
 * Flattens the generated Publishers on each rail.
 *
 * @param  the input value type
 * @param  the output value type
 */
final class ParallelFlatMap extends ParallelFlowable {

    final ParallelFlowable source;

    final Function> mapper;

    final boolean delayError;

    final int maxConcurrency;

    final int prefetch;

    ParallelFlatMap(
            ParallelFlowable source,
            Function> mapper,
            boolean delayError,
            int maxConcurrency,
            int prefetch) {
        this.source = source;
        this.mapper = mapper;
        this.delayError = delayError;
        this.maxConcurrency = maxConcurrency;
        this.prefetch = prefetch;
    }

    @Override
    public int parallelism() {
        return source.parallelism();
    }

    @Override
    public void subscribe(Subscriber[] subscribers) {
        if (!validate(subscribers)) {
            return;
        }

        int n = subscribers.length;

        @SuppressWarnings("unchecked")
        final Subscriber[] parents = new Subscriber[n];

        // FIXME cheat until we have support from RxJava2 internals
        Publisher p = new Publisher() {
            int i;

            @SuppressWarnings("unchecked")
            @Override
            public void subscribe(Subscriber s) {
                parents[i++] = (Subscriber)s;
            }
        };

        FlowableFlatMap op = new FlowableFlatMap(p, mapper, delayError, maxConcurrency, prefetch);

        for (int i = 0; i < n; i++) {

            op.subscribe(subscribers[i]);
// FIXME needs a FlatMap subscriber
//            parents[i] = FlowableFlatMap.createSubscriber(s, mapper, delayError, maxConcurrency, prefetch);
        }

        source.subscribe(parents);
    }
}