com.github.davidmoten.rx.operators.SortedOutputQueue.java Source code

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Here is the source code for com.github.davidmoten.rx.operators.SortedOutputQueue.java

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package com.github.davidmoten.rx.operators;

// copied from https://github.com/davidmoten/rtree/blob/master/src/main/java/com/github/davidmoten/rx/operators/OperatorBoundedPriorityQueue.java
// Apache License

import java.util.Comparator;

import rx.Observable.Operator;
import rx.Subscriber;

import com.google.common.collect.MinMaxPriorityQueue;

public final class SortedOutputQueue<T> implements Operator<T, T> {

    private final int maximumSize;
    private final Comparator<? super T> comparator;

    public SortedOutputQueue(int maximumSize, Comparator<? super T> comparator) {
        this.maximumSize = maximumSize;
        this.comparator = comparator;
    }

    @Override
    public Subscriber<? super T> call(final Subscriber<? super T> child) {
        final MinMaxPriorityQueue<T> q = MinMaxPriorityQueue.orderedBy(comparator).maximumSize(maximumSize)
                .create();
        return new Subscriber<T>(child) {

            @Override
            public void onCompleted() {
                T t;
                while ((t = q.removeFirst()) != null) {
                    if (isUnsubscribed())
                        return;
                    child.onNext(t);
                }
                if (isUnsubscribed())
                    return;
                child.onCompleted();
            }

            @Override
            public void onError(Throwable t) {
                if (!isUnsubscribed())
                    child.onError(t);
            }

            @Override
            public void onNext(T t) {
                if (!isUnsubscribed())
                    q.add(t);
            }
        };
    }

}