Chronicle-Ticker

A time ticker as a light weight clock

Simple Tickers

Tickers which use System.currentTimeMillis() or nanoTime()

Ticker ticker = Ticker.millis();
// or
Ticker ticker = Ticker.nanos();

double timeInSec = ticker.count() / (double) ticker.countPerSecond();

Ticker for testing purposes

Ticker ticker = Ticker.forTesting()
                      .count(System.currentTimeMillis());
// or
Ticker ticker = Ticker.forTesting()
                      .count(System.currentTimeMillis() * 1000)
                      .countPerSecond(1_000_000)
                      .countFromEpoch(0);

double timeInSecs = ticker.count() / (double) ticker.countPerSecond();

High resolution ticker

Ticker which uses a high resolution time

Ticker ticker = Ticker.highResolution();

long start = ticker.count();
// do some work
long end = ticker.count();

double timeInSecs = (double) (end - start) / ticker.countPerSecond();
// or
long timeInMicros = (end - start) * 1_000 / ticker.countPerSecond();
// or
long timeInMillis = (end - start) * 1_000_000 / ticker.countPerSecond();

Performance

Table 1. Measured on a i7 - 7820X (3.6 GHz)

Ticker	Latency
Ticker.nanos().count()	14.8 ns
Ticker.highResolution().count()	6.8 ns

Epoch time

Example from tests

        Ticker instance = ...
        long epochOffset = instance.countFromEpoch();
        long epochTicks = instance.count() + epochOffset;
        long epochMillis = epochTicks / (instance.countPerSecond() / 1000);
        long diffMillis = epochMillis - System.currentTimeMillis();
        Assert.assertTrue(Math.abs(diffMillis) < 1000);