CooldownUtil.java

package co.ryred.rybot;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.TimeUnit;

/**
 * Created by rissa on 01/07/2015.
 */
public class CooldownUtil {

    private static CooldownUtil __INSTANCE__ = null;

    private static long cooldownTime = TimeUnit.SECONDS.toMillis(500);

    private final ConcurrentHashMap<String, Long> cooldownMap;
    private long lastPurged = 0;

    public static CooldownUtil getCooldown(){
        return __INSTANCE__ == null ? (__INSTANCE__ = new CooldownUtil()) : __INSTANCE__;
    };

    public static void setCooldownTime(TimeUnit timeUnit, long cooldownTime){
        CooldownUtil.cooldownTime = timeUnit.toMillis(cooldownTime);
    };

    public static String userStringPlease(String sender, String login, String hostname) {
        return new StringBuilder(sender).append(login).append(hostname).toString();
    }

    private CooldownUtil(){
        this.cooldownMap = new ConcurrentHashMap<String, Long>();
    }

    public void chillBabes( String sender, String login, String hostname ) {

        String user = userStringPlease(sender, login, hostname);
        long time = System.currentTimeMillis() + cooldownTime;

        cooldownMap.put(user, time);

    }

    public boolean isChilling( String sender, String login, String hostname ) {

        String user = userStringPlease(sender, login, hostname);
        long time = System.currentTimeMillis();
        long userTime = cooldownMap.getOrDefault(user, time - 300);

        return (time - userTime) < 0;

    }

    public synchronized void purge() {

        long time = System.currentTimeMillis();
        lastPurged = System.currentTimeMillis();
        if( time - lastPurged  )

        Iterator<Map.Entry<String, Long>> iterator = cooldownMap.entrySet().iterator();

        while( iterator.hasNext() )
            if( (time - iterator.next().getValue()) < 0 ) iterator.remove();

    }

}