providers/direct/src/main/java/org/apache/edgent/providers/direct/DirectTopology.java

/*
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or more contributor license agreements.  See the NOTICE file
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regarding copyright ownership.  The ASF licenses this file
to you 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

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specific language governing permissions and limitations
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*/
package org.apache.edgent.providers.direct;

import java.util.concurrent.Callable;
import java.util.concurrent.Future;

import org.apache.edgent.execution.Configs;
import org.apache.edgent.execution.Job;
import org.apache.edgent.execution.services.RuntimeServices;
import org.apache.edgent.execution.services.ServiceContainer;
import org.apache.edgent.function.Supplier;
import org.apache.edgent.graph.Graph;
import org.apache.edgent.runtime.etiao.Executable;
import org.apache.edgent.runtime.etiao.graph.DirectGraph;
import org.apache.edgent.topology.spi.graph.GraphTopology;

import com.google.gson.JsonElement;
import com.google.gson.JsonNull;
import com.google.gson.JsonObject;

/**
 * {@code DirectTopology} is a {@link GraphTopology} that
 * is executed in threads in the current virtual machine.
 * <P> 
 * The org.apache.edgent.org.apache.edgent.topology is backed by a {@code DirectGraph} and its
 * execution is controlled and monitored by a {@code EtiaoJob}.
 * </P>
 */
public class DirectTopology extends GraphTopology<DirectTester> {

    private final DirectGraph eg;
    private final Executable executable;
    private Job job; // created at submit time

    /**
     * Creates a {@code DirectTopology} instance.
     * 
     * @param name org.apache.edgent.org.apache.edgent.topology name
     * @param container container which provides runtime services
     */
    DirectTopology(String name, ServiceContainer container) {
        super(name);

        this.eg = new DirectGraph(name, container);
        this.executable = eg.executable();
    }

    @Override
    public Graph graph() {
        return eg;
    }

    Executable getExecutable() {
        return executable;
    }

    @Override
    public Supplier<RuntimeServices> getRuntimeServiceSupplier() {
        return () -> getExecutable();
    }

    @Override
    protected DirectTester newTester() {
        return new DirectTester(this);
    }

    private Callable<Job> getCallable() {
        return new Callable<Job>() {

            @Override
            public Job call() throws Exception {
                execute();
                return job;
            }
        };
    }

    Future<Job> executeCallable(JsonObject config) {
        JsonElement value = null;
        if (config != null) 
            value = config.get(Configs.JOB_NAME);

        String jobName = null;
        if (value != null && !(value instanceof JsonNull))
            jobName = value.getAsString();

        this.job = getExecutable().createJob(graph(), getName(), jobName);
        return getExecutable().getScheduler().submit(getCallable());
    }

    private void execute() {
        job.stateChange(Job.Action.INITIALIZE);
        job.stateChange(Job.Action.START);
    }
}