com.almende.eve.scheduler.clock.RunnableClock.java Source code

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Here is the source code for com.almende.eve.scheduler.clock.RunnableClock.java

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/*
 * Copyright: Almende B.V. (2014), Rotterdam, The Netherlands
 * License: The Apache Software License, Version 2.0
 */
package com.almende.eve.scheduler.clock;

import java.util.NavigableMap;
import java.util.TreeMap;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;

import org.joda.time.DateTime;
import org.joda.time.Interval;

import com.almende.eve.config.Config;

/**
 * The Class RunnableClock.
 */
public class RunnableClock implements Runnable, Clock {
    private static final NavigableMap<ClockEntry, ClockEntry> TIMELINE = new TreeMap<ClockEntry, ClockEntry>();
    private static final ScheduledExecutorService POOL = Executors.newScheduledThreadPool(4,
            Config.getThreadFactory());
    private static ScheduledFuture<?> future = null;

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Runnable#run()
     */
    @Override
    public void run() {
        synchronized (TIMELINE) {
            while (!TIMELINE.isEmpty()) {
                final ClockEntry ce = TIMELINE.firstEntry().getValue();
                if (future != null) {
                    future.cancel(false);
                    future = null;
                }
                final DateTime now = DateTime.now();
                if (ce.getDue().isBefore(now)) {
                    TIMELINE.remove(ce);
                    POOL.execute(ce.getCallback());
                    continue;
                }
                final long interval = new Interval(now, ce.getDue()).toDurationMillis();
                future = POOL.schedule(this, interval, TimeUnit.MILLISECONDS);
                break;
            }
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * com.almende.eve.scheduler.clock.Clock#requestTrigger(java.lang.String,
     * org.joda.time.DateTime, java.lang.Runnable)
     */
    @Override
    public void requestTrigger(final String triggerId, final DateTime due, final Runnable callback) {
        synchronized (TIMELINE) {
            final ClockEntry ce = new ClockEntry(triggerId, due, callback);
            final ClockEntry oldVal = TIMELINE.get(ce);
            if (oldVal == null || oldVal.getDue().isAfter(due)) {
                TIMELINE.put(ce, ce);
                run();
            }
        }
    }

    @Override
    public void cancel(final String triggerId) {
        synchronized (TIMELINE) {
            final ClockEntry ce = new ClockEntry(triggerId, null, null);
            TIMELINE.remove(ce);
        }
    }

    @Override
    public void clear() {
        synchronized (TIMELINE) {
            TIMELINE.clear();
            if (future != null) {
                future.cancel(false);
                future = null;
            }
        }
    }
}

/**
 * @author Almende
 * 
 */
class ClockEntry implements Comparable<ClockEntry> {
    private String triggerId;
    private DateTime due;
    private Runnable callback;

    /**
     * @param triggerId
     * @param due
     * @param callback
     */
    public ClockEntry(final String triggerId, final DateTime due, final Runnable callback) {
        this.triggerId = triggerId;
        this.due = due;
        this.callback = callback;
    }

    /**
     * @return AgentId
     */
    public String getAgentId() {
        return triggerId;
    }

    /**
     * @param agentId
     */
    public void setAgentId(final String agentId) {
        this.triggerId = agentId;
    }

    /**
     * @return Due date
     */
    public DateTime getDue() {
        return due;
    }

    /**
     * @param due
     */
    public void setDue(final DateTime due) {
        this.due = due;
    }

    /**
     * @return This tasks callback.
     */
    public Runnable getCallback() {
        return callback;
    }

    /**
     * @param callback
     */
    public void setCallback(final Runnable callback) {
        this.callback = callback;
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(final Object o) {
        if (this == o) {
            return true;
        }
        if (!(o instanceof ClockEntry)) {
            return false;
        }
        final ClockEntry other = (ClockEntry) o;
        return triggerId.equals(other.triggerId);
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        return triggerId.hashCode();
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Comparable#compareTo(java.lang.Object)
     */
    @Override
    public int compareTo(final ClockEntry o) {
        if (due == null || o.due == null) {
            if (this.equals(o)) {
                return 0;
            } else {
                return -1;
            }
        }
        if (due.equals(o.due)) {
            return 0;
        }
        return due.compareTo(o.due);
    }
}