com.tjhruska.spring.jesque.JesqueContainer.java Source code

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Here is the source code for com.tjhruska.spring.jesque.JesqueContainer.java

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/*
 * Copyright 2014 Timothy Hruska <https://github.com/tjhruska>
 *
 * 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 com.tjhruska.spring.jesque;

import java.util.concurrent.Callable;

import net.greghaines.jesque.worker.Worker;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.BeanNameAware;

/**
 * JesqueContainer maintains a group of workers that are all created using the
 * same injected workerFactory.
 *
 * @author Timothy Hruska <https://github.com/tjhruska>
 *
 */
public class JesqueContainer implements BeanNameAware {
    private static final Logger log = LoggerFactory.getLogger(JesqueContainer.class);

    private Callable<Worker> workerFactory;

    private Integer maxWorkerCount;
    private Worker[] workers;
    private Thread[] workerThreads;
    private boolean paused;
    private String beanName;

    public Worker[] getWorkers() {
        return workers;
    }

    public Thread[] getWorkerThreads() {
        return workerThreads;
    }

    public Integer getMaxWorkerCount() {
        return maxWorkerCount;
    }

    /**
     * This JesqueContainer that will hold exactly one worker.
     *
     * @param workerFactory
     *          that will create/replenish the workers for this container
     */
    public JesqueContainer(Callable<Worker> workerFactory) {
        this.workerFactory = workerFactory;
        this.maxWorkerCount = 1;
        this.workers = new Worker[maxWorkerCount];
        this.workerThreads = new Thread[maxWorkerCount];
        this.paused = false;
    }

    /**
     * This JesqueContainer that will hold up to maxWorkerCount.
     *
     * @param workerFactory
     *          that will create/replenish the workers for this container
     * @param maxWorkerCount
     *          up to this number of workers will be maintained in this container
     */
    public JesqueContainer(Callable<Worker> workerFactory, Integer maxWorkerCount) {
        this.workerFactory = workerFactory;
        this.maxWorkerCount = maxWorkerCount;
        this.workers = new Worker[maxWorkerCount];
        this.workerThreads = new Thread[maxWorkerCount];
        this.paused = false;
    }

    /**
     * Spin through to attempt to replace any dead/missing workers. WorkerFactory
     * is not required to return a worker. (This is mostly useful when the workers
     * are tied to limited resources.)
     */
    public void checkWorkers() {
        for (int i = 0; i < maxWorkerCount; i++) {
            if (!paused && (workerThreads[i] == null || !workerThreads[i].isAlive())) {
                Worker worker;
                try {
                    worker = workerFactory.call();
                } catch (Exception e) {
                    throw new RuntimeException("Failed to get a worker from the workerFactory", e);
                }
                if (worker != null) {
                    log.info(beanName + " started worker(s) of type '{}' with queues: '{}'", worker.getName(),
                            worker.getQueues());

                    Thread workerThread = new Thread(worker);
                    workerThread.setDaemon(false);
                    workerThread.start();

                    workers[i] = worker;
                    workerThreads[i] = workerThread;
                }
            }
        }
    }

    /**
     * This does not check the state of the contained workers.
     *
     * @return current pause state of the container.
     */
    public boolean isPaused() {
        return paused;
    }

    /**
     * Container will remember the last pause state, and only send changes to
     * workers. Workers will pause after they complete any currently running jobs.
     *
     * @param paused
     *          state to send to the workers if changing
     */
    public void togglePause(boolean paused) {
        if (this.paused == paused) {
            return;
        }
        this.paused = paused;
        for (int i = 0; i < maxWorkerCount; i++) {
            if (workerThreads[i] != null && workerThreads[i].isAlive()) {
                if (paused) {
                    log.info(beanName + " pausing worker(s) '{}' with queues '{}'", workers[i].getName(),
                            workers[i].getQueues());
                } else {
                    log.info(beanName + " unpausing worker(s) '{}' with queues '{}'", workers[i].getName(),
                            workers[i].getQueues());
                }
                workers[i].togglePause(paused);
            }
        }
    }

    /**
     * Sends end() message to all currently live workers. If now is false workers
     * won't die until they complete current jobs.
     *
     * @param now
     *          if true will abort currently running jobs.
     */
    public void stop(boolean now) {
        for (int i = 0; i < maxWorkerCount; i++) {
            if (workerThreads[i] != null && workerThreads[i].isAlive()) {
                log.info(beanName + " stopping worker(s) '{}' with queues '{}'", workers[i].getName(),
                        workers[i].getQueues());
                workers[i].end(now);
            }
        }
    }

    /**
     * Wait on any currently live worker threads until they exit.
     *
     * @param millis
     *          how long to wait for each worker before moving on to join the next
     *          worker
     * @throws InterruptedException
     */
    public void join(long millis) throws InterruptedException {
        for (int i = 0; i < maxWorkerCount; i++) {
            if (workerThreads[i] != null && workerThreads[i].isAlive()) {
                log.info(beanName + " joinging against worker(s) '{}' with queues '{}'", workers[i].getName(),
                        workers[i].getQueues());
                workers[i].join(millis);
            }
        }
    }

    @Override
    public void setBeanName(String name) {
        this.beanName = name;
    }
}