org.eclipse.scada.protocol.iec60870.server.data.AbstractBaseDataModel.java Source code

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Here is the source code for org.eclipse.scada.protocol.iec60870.server.data.AbstractBaseDataModel.java

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/*******************************************************************************
 * Copyright (c) 2014 IBH SYSTEMS GmbH and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBH SYSTEMS GmbH - initial API and implementation
 *******************************************************************************/
package org.eclipse.scada.protocol.iec60870.server.data;

import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.Callable;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import org.eclipse.scada.protocol.iec60870.asdu.types.ASDUAddress;
import org.eclipse.scada.protocol.iec60870.asdu.types.InformationObjectAddress;
import org.eclipse.scada.protocol.iec60870.asdu.types.Value;
import org.eclipse.scada.utils.concurrent.NamedThreadFactory;

import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningScheduledExecutorService;
import com.google.common.util.concurrent.MoreExecutors;

public abstract class AbstractBaseDataModel implements DataModel {
    private final Set<DefaultSubscription> subscriptions = new HashSet<>();

    private volatile int numberOfSubscriptions;

    protected final ListeningScheduledExecutorService executor;

    public AbstractBaseDataModel(final String threadName) {
        this.executor = MoreExecutors.listeningDecorator(
                Executors.newSingleThreadScheduledExecutor(new NamedThreadFactory(threadName, false, true)));
    }

    @Override
    public synchronized Subscription subscribe(final DataListener listener) {
        final DefaultSubscription subscription = new DefaultSubscription(this, listener);
        this.subscriptions.add(subscription);
        this.numberOfSubscriptions = this.subscriptions.size();
        return subscription;
    }

    protected int getNumberOfSubscriptions() {
        return this.numberOfSubscriptions;
    }

    protected synchronized ListenableFuture<Void> disposeSubscription(final DefaultSubscription subscription) {
        this.subscriptions.remove(subscription);
        this.numberOfSubscriptions = this.subscriptions.size();

        if (this.executor.isShutdown()) {
            // if we are already disposed
            return Futures.immediateFuture(null);
        }

        // the completion will come from the executor, so the completion has to wait in line
        // with possible remaining updated
        return this.executor.submit(new Callable<Void>() {
            @Override
            public Void call() throws Exception {
                // this is only a marker
                return null;
            }
        });
    }

    protected synchronized void notifyChangeBoolean(final ASDUAddress asduAddress,
            final InformationObjectAddress startAddress, final List<Value<Boolean>> values) {
        for (final DefaultSubscription sub : this.subscriptions) {
            this.executor.execute(new Runnable() {

                @Override
                public void run() {
                    sub.notifyChangeBoolean(asduAddress, startAddress, values);
                }
            });
        }
    }

    protected synchronized void notifyChangeFloat(final ASDUAddress asduAddress,
            final InformationObjectAddress startAddress, final List<Value<Float>> values) {
        for (final DefaultSubscription sub : this.subscriptions) {
            this.executor.execute(new Runnable() {

                @Override
                public void run() {
                    sub.notifyChangeFloat(asduAddress, startAddress, values);
                }
            });
        }
    }

    @Override
    public synchronized void dispose() {
        this.executor.shutdown();
        this.subscriptions.clear();
        this.numberOfSubscriptions = 0;
    }

    public void disposeAndWait() throws InterruptedException {
        dispose();
        this.executor.awaitTermination(Long.MAX_VALUE, TimeUnit.MILLISECONDS);
    }

}