程序包 ai.nextbillion.maps.internal.ratelimiter

类 Stopwatch

java.lang.Object
ai.nextbillion.maps.internal.ratelimiter.Stopwatch
public final class Stopwatch
extends java.lang.Object
An object that measures elapsed time in nanoseconds. It is useful to measure elapsed time using this class instead of direct calls to System.nanoTime() for a few reasons:
  • An alternate time source can be substituted, for testing or performance reasons.
  • As documented by nanoTime, the value returned has no absolute meaning, and can only be interpreted as relative to another timestamp returned by nanoTime at a different time. Stopwatch is a more effective abstraction because it exposes only these relative values, not the absolute ones.

Basic usage: 


 Stopwatch stopwatch = Stopwatch.createStarted();
 doSomething();
 stopwatch.stop(); // optional

 long millis = stopwatch.elapsed(MILLISECONDS);

 log.info("time: " + stopwatch); // formatted string like "12.3 ms"

Stopwatch methods are not idempotent; it is an error to start or stop a stopwatch that is already in the desired state.

When testing code that uses this class, use createUnstarted(Ticker) or createStarted(Ticker) to supply a fake or mock ticker. This allows you to simulate any valid behavior of the stopwatch.

Note: This class is not thread-safe.

Warning for Android users: a stopwatch with default behavior may not continue to keep time while the device is asleep. Instead, create one like this: 


 Stopwatch.createStarted(
      new Ticker() {
        public long read() {
          return android.os.SystemClock.elapsedRealtimeNanos();
        }
      });
作者:
Kevin Bourrillion