es.upv.grycap.relevantdata.core.instance.RdInstance.java Source code

Introduction

Here is the source code for es.upv.grycap.relevantdata.core.instance.RdInstance.java

Source

/*
 * Relevant Data - Core Components.
 * Copyright 2015-2016 GRyCAP (Universitat Politecnica de Valencia)
 * 
 * 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.
 * 
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * 
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 */

package es.upv.grycap.relevantdata.core.instance;

import static com.google.common.base.Preconditions.checkState;
import static com.typesafe.config.ConfigRenderOptions.concise;
import static org.slf4j.LoggerFactory.getLogger;

import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.stream.Collectors;

import javax.annotation.Nullable;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;

import com.google.common.util.concurrent.MoreExecutors;
import com.google.common.util.concurrent.ServiceManager;
import com.google.common.util.concurrent.ServiceManager.Listener;
import com.typesafe.config.Config;

import es.upv.grycap.coreutils.common.config.Configurer;
import es.upv.grycap.relevantdata.core.events.RdEventbus;
import es.upv.grycap.relevantdata.core.ingestion.RdDataIngestor;

/**
 * Entry point to RelevantData.
 * @author Erik Torres <etserrano@gmail.com>
 * @since 0.0.1
 */
public class RdInstance {

    private static final Logger LOGGER = getLogger(RdInstance.class);

    private Config config;
    private ServiceManager serviceManager;

    /**
     * Convenient constructor which is available inside the package, allowing factory methods to create new instances of this class,
     * optionally passing a path to an external file with the configuration properties.
     * @param confname - configuration filename
     */
    RdInstance(final @Nullable String confname) {
        // load configuration properties
        config = new Configurer().loadConfig(confname, "relevantdata");
        if (LOGGER.isTraceEnabled()) {
            LOGGER.trace(config.root().render());
        } else {
            LOGGER.info("Configuration: " + config.getObject("relevantdata").render(concise()));
        }
        // create services
        final List<RdService> services = config.getStringList("relevantdata.services").stream()
                .map(StringUtils::trimToNull).filter(Objects::nonNull).collect(Collectors.toSet()).stream()
                .map(this::newService).collect(Collectors.toList());
        checkState(services != null && !services.isEmpty(), "At least one service expected");
        serviceManager = new ServiceManager(services);
        serviceManager.addListener(new Listener() {
            @Override
            public void healthy() {
                final double startupTime = serviceManager.startupTimes().entrySet().stream()
                        .mapToDouble(Map.Entry::getValue).sum();
                LOGGER.info("Services started in: " + ((long) startupTime / 1000l) + " seconds.");
            }
        }, MoreExecutors.directExecutor());
        // add termination logic
        Runtime.getRuntime().addShutdownHook(new Thread() {
            public void run() {
                try {
                    serviceManager.stopAsync().awaitStopped(5, TimeUnit.SECONDS);
                    LOGGER.info("Service manager was stopped.");
                } catch (TimeoutException timeout) {
                    LOGGER.info("Stopping timed out.");
                }
            }
        });
        // start services
        serviceManager.startAsync();
    }

    /**
     * Description copied from the method {@link ServiceManager#awaitHealthy(long, TimeUnit)}: Waits for this instance to become 
     * {@link ServiceManager#isHealthy() healthy} for no more than the given time.
     * @param timeout - the maximum time to wait
     * @param unit - the time unit of the timeout argument
     * @throws TimeoutException if not all of the services have finished starting within the deadline
     */
    public void awaitHealthy(final long timeout, final TimeUnit unit) throws TimeoutException {
        serviceManager.awaitHealthy(timeout, unit);
    }

    /**
     * Description copied from the method {@link ServiceManager#awaitStopped(long, TimeUnit)}: Waits for the all the services to 
     * reach a terminal state for no more than the given time.
     * @param timeout - the maximum time to wait
     * @param unit - the time unit of the timeout argument
     * @throws TimeoutException if not all of the services have stopped within the deadline
     */
    public void awaitStopped(final long timeout, final TimeUnit unit) throws TimeoutException {
        serviceManager.stopAsync().awaitStopped(timeout, unit);
    }

    private RdService newService(final String name) {
        RdService service = null;
        switch (name) {
        case "eventbus":
            service = new RdEventbus(config);
            break;
        case "ingestion":
            service = new RdDataIngestor(config);
            break;
        default:
            throw new IllegalArgumentException("Unknown service: " + name);
        }
        return service;
    }

}