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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2016 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * 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 org.wildfly.discovery.impl;

import java.net.URI;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;

import org.wildfly.common.Assert;
import org.wildfly.discovery.FilterSpec;
import org.wildfly.discovery.ServiceType;
import org.wildfly.discovery.ServiceURL;
import org.wildfly.discovery.spi.DiscoveryProvider;
import org.wildfly.discovery.spi.DiscoveryRequest;
import org.wildfly.discovery.spi.DiscoveryResult;

/**
 * A discovery provider which aggregates multiple other providers together.  The aggregate request is complete when
 * all of the delegate provider requests are complete.
 *
 * @author David M. Lloyd
 */
public final class AggregateDiscoveryProvider implements DiscoveryProvider {
    private final DiscoveryProvider[] delegates;

    /**
     * Construct a new instance.
     *
     * @param delegates the array of delegates (must not be {@code null})
     */
    public AggregateDiscoveryProvider(final DiscoveryProvider[] delegates) {
        Assert.checkNotNullParam("delegates", delegates);
        this.delegates = delegates;
    }

    public DiscoveryRequest discover(final ServiceType serviceType, final FilterSpec filterSpec, final DiscoveryResult result) {
        final AtomicInteger count = new AtomicInteger(delegates.length);
        final DiscoveryRequest[] delegateRequests = new DiscoveryRequest[delegates.length];
        for (int i = 0, delegatesLength = delegates.length; i < delegatesLength; i++) {
            final DiscoveryProvider delegate = delegates[i];
            if (delegate != null) {
                delegateRequests[i] = delegate.discover(serviceType, filterSpec, new AggregatingDiscoveryResult(result, count));
            } else {
                handleComplete(count, result);
            }
        }
        return new AggregatingDiscoveryRequest(delegateRequests);
    }

    void handleComplete(AtomicInteger count, DiscoveryResult delegate) {
        if (count.decrementAndGet() == 0) {
            delegate.complete();
        }
    }

    public void processMissingTarget(URI location, Exception cause) {
        for (DiscoveryProvider delegate : delegates) {
            if (delegate != null) {
                delegate.processMissingTarget(location, cause);
            }
        }
    }

    static class AggregatingDiscoveryRequest implements DiscoveryRequest {
        private final DiscoveryRequest[] delegateRequests;

        AggregatingDiscoveryRequest(final DiscoveryRequest[] delegateRequests) {
            this.delegateRequests = delegateRequests;
        }

        public void cancel() {
            for (DiscoveryRequest request : delegateRequests) {
                if (request != null) request.cancel();
            }
        }
    }

    @SuppressWarnings("serial")
    final class AggregatingDiscoveryResult extends AtomicBoolean implements DiscoveryResult {
        private final DiscoveryResult delegate;
        private final AtomicInteger count;

        AggregatingDiscoveryResult(final DiscoveryResult delegate, final AtomicInteger count) {
            this.delegate = delegate;
            this.count = count;
        }

        public void complete() {
            if (compareAndSet(false, true)) {
                handleComplete(count, delegate);
            }
        }

        public void reportProblem(final Throwable description) {
            if (! get()) delegate.reportProblem(description);
        }

        public void addMatch(final URI uri) {
            if (! get()) delegate.addMatch(uri);
        }

        public void addMatch(final ServiceURL serviceURL) {
            if (! get()) delegate.addMatch(serviceURL);
        }
    }
}