co.cask.cdap.internal.app.runtime.workflow.WorkflowProgramController.java Source code

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Here is the source code for co.cask.cdap.internal.app.runtime.workflow.WorkflowProgramController.java

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/*
 * Copyright  2014-2015 Cask Data, Inc.
 *
 * 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 co.cask.cdap.internal.app.runtime.workflow;

import co.cask.cdap.app.program.Program;
import co.cask.cdap.internal.app.runtime.AbstractProgramController;
import com.google.common.util.concurrent.Service;
import org.apache.twill.api.RunId;
import org.apache.twill.api.ServiceAnnouncer;
import org.apache.twill.common.Cancellable;
import org.apache.twill.common.Threads;
import org.apache.twill.internal.ServiceListenerAdapter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.net.InetSocketAddress;

/**
 *
 */
final class WorkflowProgramController extends AbstractProgramController {

    private static final Logger LOG = LoggerFactory.getLogger(WorkflowProgramController.class);

    private final WorkflowDriver driver;
    private final String serviceName;
    private final ServiceAnnouncer serviceAnnouncer;
    private Cancellable cancelAnnounce;

    WorkflowProgramController(Program program, WorkflowDriver driver, ServiceAnnouncer serviceAnnouncer,
            RunId runId) {
        super(program.getName(), runId);
        this.driver = driver;
        this.serviceName = getServiceName(program, runId);
        this.serviceAnnouncer = serviceAnnouncer;
        startListen(driver);
    }

    @Override
    protected void doSuspend() throws Exception {
        driver.suspend();
    }

    @Override
    protected void doResume() throws Exception {
        driver.resume();
    }

    @Override
    protected void doStop() throws Exception {
        driver.stopAndWait();
    }

    @Override
    protected void doCommand(String name, Object value) throws Exception {
        LOG.info("Command ignored {}, {}", name, value);
    }

    private void startListen(Service service) {
        // Forward state changes from the given service to this controller.
        service.addListener(new ServiceListenerAdapter() {
            @Override
            public void running() {
                InetSocketAddress endpoint = driver.getServiceEndpoint();
                cancelAnnounce = serviceAnnouncer.announce(serviceName, endpoint.getPort());
                LOG.info("Workflow service {} announced at {}", serviceName, endpoint);
                started();
            }

            @Override
            public void terminated(Service.State from) {
                LOG.info("Workflow service terminated from {}. Un-registering service {}.", from, serviceName);
                cancelAnnounce.cancel();
                LOG.info("Service {} unregistered.", serviceName);
                if (getState() != State.STOPPING) {
                    // service completed itself.
                    complete();
                } else {
                    // service was terminated
                    stop();
                }
            }

            @Override
            public void failed(Service.State from, Throwable failure) {
                LOG.info("Workflow service failed from {}. Un-registering service {}.", from, serviceName, failure);
                cancelAnnounce.cancel();
                LOG.info("Service {} unregistered.", serviceName);
                error(failure);
            }
        }, Threads.SAME_THREAD_EXECUTOR);
    }

    private String getServiceName(Program program, RunId runId) {
        return String.format("workflow.%s.%s.%s.%s", program.getNamespaceId(), program.getApplicationId(),
                program.getName(), runId.getId());
    }
}