For example: * *
- * protected Throttle _throttle = new Throttle(5, 60);
+ * protected Throttle _throttle = new Throttle(5, 60000L);
*
* public void performOp ()
* throws UnavailableException
@@ -101,23 +101,49 @@ public class Throttle
*/
public boolean throttleOp (long timeStamp)
{
- // if the oldest operation was performed less than _period ago, we
- // need to throttle
- if ((timeStamp - _ops[_lastOp]) < _period) {
+ if (wouldThrottle(timeStamp)) {
return true;
}
- // otherwise overwrite the oldest operation with the current time
+ noteOp(timeStamp);
+ return false;
+ }
+
+ /**
+ * Check to see if we would throttle an operation occuring at the specified
+ * timestamp. Typically used in conjunction with {@link #noteOp}.
+ */
+ public boolean wouldThrottle (long timeStamp)
+ {
+ // if the oldest operation was performed less than _period ago, we
+ // need to throttle
+ return (timeStamp - _ops[_lastOp]) < _period;
+ }
+
+ /**
+ * Note that an operation occurred at the specified timestamp. This
+ * method should be used with {@link #wouldThrottle} to note an operation
+ * that has already been cleared to occur. Typically this is used if
+ * there is another limiting factor besides the throttle that determines
+ * whether the operation can occur. You are responsible for calling this
+ * method in a safe and timely manner after using wouldThrottle.
+ */
+ public void noteOp (long timeStamp)
+ {
+ // overwrite the oldest operation with the current time
// and move the oldest operation pointer to the second oldest
// operation (which is now the oldest as we overwrote the oldest)
_ops[_lastOp] = timeStamp;
_lastOp = (_lastOp + 1) % _ops.length;
- return false;
}
+ /**
+ * Used for testing.
+ */
public static void main (String[] args)
{
- Throttle throttle = new Throttle(5, 10);
+ // set up a throttle for 5 ops per 10 seconds
+ Throttle throttle = new Throttle(5, 10000);
// try doing one operation per second and we should hit the
// throttle on the sixth operation and then kick in again on the