SystemTimeStamp.java

package vooga.rts.networking.communications;

/**
 * Represents a timeStamp that will be sent across the network. Uses the built in system time to
 * calculate time.
 * 
 * @author Henrique Moraes
 * @author David Winegar
 * 
 */
public class SystemTimeStamp extends TimeStamp {
    private static final long serialVersionUID = -7292452477020372150L;

    /**
     * Creates a timestamp object with the current time as the initial time
     */
    public SystemTimeStamp () {
        resetStamp();
    }

    /**
     * sets the received message time for this stamp
     * 
     * @return difference in elapsed time since this stamp was created
     */
    @Override
    public long stamp () {
        setFinalTime(System.currentTimeMillis());
        return getDifference();
    }

    /**
     * Stamps as initial time plus time passed in.
     * 
     * @param time to add to stamp
     */
    @Override
    public long stamp (long time) {
        setFinalTime(getInitialTime() + time);
        return getDifference();
    }

    /**
     * @return difference in elapsed time since this stamp was created
     *         in milliseconds
     */
    @Override
    public long getDifference () {
        if (getFinalTime() == DEFAULT_VALUE) {
            setFinalTime(System.currentTimeMillis());
        }
        return getFinalTime() - getInitialTime();
    }

    /**
     * Resets this stamp setting the initial time as the current one
     */
    @Override
    public void resetStamp () {
        setInitialTime(System.currentTimeMillis());
        setFinalTime(DEFAULT_VALUE);
    }

}