eu.lucaventuri.common.TimeProvider Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of fibry Show documentation

The first Java Actor System supporting fibers from Project Loom

There is a newer version: 3.0.1

package eu.lucaventuri.common;

import java.util.concurrent.atomic.AtomicLong;

@FunctionalInterface
public interface TimeProvider {
    long get();

    class FlexibleTime implements TimeProvider {
        private final AtomicLong time;

        public FlexibleTime(long timeMs) {
            this.time = new AtomicLong(timeMs);
        }

        public FlexibleTime() {
            this.time = new AtomicLong(0);
        }

        @Override
        public long get() {
            return time.get();
        }

        public void inc() {
            time.incrementAndGet();
        }

        public void inc(long delta) {
            time.addAndGet(delta);
        }

        public void dec() {
            time.decrementAndGet();
        }

        public void dec(long delta) {
            time.addAndGet(-delta);
        }
    }

    default void sleepMs(long timeout) {
        assert timeout >= 0;

        long now = get();
        long wakeupTime = now + timeout;

        while (wakeupTime > get()) {
            SystemUtils.sleep(0);
        }
    }

    default void sleepUntil(long wakeupTime) {
        long now = get();

        while (wakeupTime > get()) {
            SystemUtils.sleep(0);
        }
    }

    default TimeProvider freeze() {
        return fixedTime(get());
    }

    default FlexibleTime toFlexible() {
        return TimeProvider.flexible(get());
    }

    static TimeProvider fixedTime(long timeMs) {
        return () -> timeMs;
    }

    static TimeProvider fromSystemTime() {
        return new TimeProvider() {
            @Override
            public long get() {
                return System.currentTimeMillis();
            }

            @Override
            public void sleepMs(long timeout) {
                SystemUtils.sleepEnsure(timeout);
            }
        };
    }

    static TimeProvider fromSystemTimeRelative() {
        long start = System.currentTimeMillis();

        return new TimeProvider() {
            @Override
            public long get() {
                return System.currentTimeMillis() - start;
            }

            @Override
            public void sleepMs(long timeout) {
                SystemUtils.sleepEnsure(timeout);
            }
        };
    }

    static FlexibleTime flexible(long start) {
        return new FlexibleTime(start);
    }

    static FlexibleTime flexible() {
        return new FlexibleTime();
    }
}