/*

* Copyright (c) 2016-present, RxJava Contributors.

*

* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in

* compliance with the License. You may obtain a copy of the License at

*

* http://www.apache.org/licenses/LICENSE-2.0

*

* Unless required by applicable law or agreed to in writing, software distributed under the License is

* distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See

* the License for the specific language governing permissions and limitations under the License.

*/

package io.reactivex.rxjava3.core;

import static org.junit.Assert.assertEquals;

import static org.junit.Assert.assertFalse;

import static org.junit.Assert.assertTrue;

import org.junit.After;

import org.junit.Test;

import java.util.concurrent.TimeUnit;

public class SchedulerTest {

private static final String DRIFT_USE_NANOTIME = "rx3.scheduler.use-nanotime";

@After

public void cleanup() {

// reset value to default in order to not influence other tests

Scheduler.IS_DRIFT_USE_NANOTIME = false;

}

@Test

public void driftUseNanoTimeNotSetByDefault() {

assertFalse(Scheduler.IS_DRIFT_USE_NANOTIME);

assertFalse(Boolean.getBoolean(DRIFT_USE_NANOTIME));

}

@Test

public void computeNow_currentTimeMillis() {

TimeUnit unit = TimeUnit.MILLISECONDS;

assertTrue(isInRange(System.currentTimeMillis(), Scheduler.computeNow(unit), unit, 250, TimeUnit.MILLISECONDS));

}

@Test

public void computeNow_nanoTime() {

TimeUnit unit = TimeUnit.NANOSECONDS;

Scheduler.IS_DRIFT_USE_NANOTIME = true;

assertFalse(isInRange(System.currentTimeMillis(), Scheduler.computeNow(unit), unit, 250, TimeUnit.MILLISECONDS));

assertTrue(isInRange(System.nanoTime(), Scheduler.computeNow(unit), TimeUnit.NANOSECONDS, 250, TimeUnit.MILLISECONDS));

}

private boolean isInRange(long start, long stop, TimeUnit source, long maxDiff, TimeUnit diffUnit) {

long diff = Math.abs(stop - start);

return diffUnit.convert(diff, source) <= maxDiff;

}

@Test

public void clockDriftCalculation() {

assertEquals(100_000_000L, Scheduler.computeClockDrift(100, "milliseconds"));

assertEquals(2_000_000_000L, Scheduler.computeClockDrift(2, "seconds"));

assertEquals(180_000_000_000L, Scheduler.computeClockDrift(3, "minutes"));

assertEquals(240_000_000_000L, Scheduler.computeClockDrift(4, "random"));

assertEquals(300_000_000_000L, Scheduler.computeClockDrift(5, null));

}

}