INT-3956: peekLast for timeSinceLastSend

JIRA: https://jira.spring.io/browse/INT-3956

Use reflection in tests to access private members

fix assertion imports

Polishing author rights.
Make tests `Threas.sleep()` free.

spring-integration-core/src/main/java/org/springframework/integration/support/management/ExponentialMovingAverageRate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2015 the original author or authors.
+ * Copyright 2009-2016 the original author or authors.
  *
  * 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
@@ -37,6 +37,7 @@ import java.util.List;
  * sum.
  * @author Dave Syer
  * @author Gary Russell
+ * @author Steven Swor
  *
  */
 public class ExponentialMovingAverageRate {
@@ -205,7 +206,7 @@ public class ExponentialMovingAverageRate {
 
 	private synchronized double lastTime() {
 		if (this.times.size() > 0) {
-			return this.times.peekFirst() / this.factor;
+			return this.times.peekLast() / this.factor;
 		}
 		else {
 			 return this.t0;

spring-integration-core/src/main/java/org/springframework/integration/support/management/ExponentialMovingAverageRatio.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2009-2015 the original author or authors.
+ * Copyright 2009-2016 the original author or authors.
  *
  * 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
@@ -37,6 +37,7 @@ import java.util.List;
  * sum.
  * @author Dave Syer
  * @author Gary Russell
+ * @author Steven Swor
  * @since 2.0
  */
 public class ExponentialMovingAverageRatio {
@@ -224,7 +225,7 @@ public class ExponentialMovingAverageRatio {
 
 	private synchronized double lastTime() {
 		if (this.times.size() > 0) {
-			return this.times.peekFirst();
+			return this.times.peekLast();
 		}
 		else {
 			return this.t0 * this.factor;

spring-integration-core/src/test/java/org/springframework/integration/support/management/ExponentialMovingAverageRateTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * 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
@@ -10,25 +10,30 @@
  * 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 org.springframework.integration.support.management;
 
 import static org.hamcrest.Matchers.lessThan;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
+import java.util.Deque;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.junit.Ignore;
 import org.junit.Test;
 
+import org.springframework.integration.test.util.TestUtils;
 import org.springframework.util.StopWatch;
 
 /**
  * @author Dave Syer
  * @author Gary Russell
- *
+ * @author Steven Swor
  */
 public class ExponentialMovingAverageRateTests {
 
@@ -44,10 +49,33 @@ public class ExponentialMovingAverageRateTests {
 	}
 
 	@Test
+	@SuppressWarnings("unchecked")
 	public void testGetTimeSinceLastMeasurement() throws Exception {
-		history.increment();
+		long sleepTime = 20L;
-		Thread.sleep(20L);
+
-		assertTrue(history.getTimeSinceLastMeasurement() > 0);
+		// fill history with the same value.
+		long now = System.nanoTime() - 2 * sleepTime * 1000000;
+		for (int i = 0; i < TestUtils.getPropertyValue(history, "retention", Integer.class); i++) {
+			history.increment(now);
+		}
+		final Deque<Long> times = TestUtils.getPropertyValue(history, "times", Deque.class);
+		assertEquals(Long.valueOf(now), times.peekFirst());
+		assertEquals(Long.valueOf(now), times.peekLast());
+
+		//increment just so we'll have a different value between first and last
+		history.increment(System.nanoTime()  - sleepTime * 1000000);
+		assertNotEquals(times.peekFirst(), times.peekLast());
+
+		/*
+		 * We've called Thread.sleep twice with the same value in quick
+		 * succession. If timeSinceLastSend is pulling off the correct end of
+		 * the queue, then we should be closer to the sleep time than we are to
+		 * 2 x sleepTime, but we should definitely be greater than the sleep
+		 * time.
+		*/
+		double timeSinceLastMeasurement = history.getTimeSinceLastMeasurement();
+		assertTrue(timeSinceLastMeasurement > sleepTime);
+		assertTrue(timeSinceLastMeasurement <= (1.5 * sleepTime));
 	}
 
 	@Test
@@ -111,7 +139,7 @@ public class ExponentialMovingAverageRateTests {
 		history.increment();
 		Thread.sleep(30L);
 		history.increment();
-		assertFalse(0==history.getStandardDeviation());
+		assertFalse(0 == history.getStandardDeviation());
 		history.reset();
 		assertEquals(0, history.getStandardDeviation(), 0.01);
 		assertEquals(0, history.getCount());
@@ -121,7 +149,8 @@ public class ExponentialMovingAverageRateTests {
 		assertEquals(0, history.getMax(), 0.01);
 	}
 
-	@Test @Ignore // tolerance needed is too dependent on hardware
+	@Test
+	@Ignore // tolerance needed is too dependent on hardware
 	public void testRate() {
 		ExponentialMovingAverageRate rate = new ExponentialMovingAverageRate(1, 60, 10);
 		int count = 1000000;
@@ -135,7 +164,8 @@ public class ExponentialMovingAverageRateTests {
 		assertEquals(calculatedRate, rate.getMean(), 4000000);
 	}
 
-	@Test @Ignore
+	@Test
+	@Ignore
 	public void testPerf() {
 		ExponentialMovingAverageRate rate = new ExponentialMovingAverageRate(1, 60, 10);
 		for (int i = 0; i < 1000000; i++) {

spring-integration-core/src/test/java/org/springframework/integration/support/management/ExponentialMovingAverageRatioTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,17 +18,22 @@ package org.springframework.integration.support.management;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.not;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertThat;
 
+import java.util.Deque;
+
 import org.hamcrest.Matchers;
 import org.junit.Ignore;
 import org.junit.Test;
 
+import org.springframework.integration.test.util.TestUtils;
+
 /**
  * @author Dave Syer
  * @author Gary Russell
  * @author Artem Bilan
- *
+ * @author Steven Swor
  */
 public class ExponentialMovingAverageRatioTests {
 
@@ -43,9 +48,32 @@ public class ExponentialMovingAverageRatioTests {
 	}
 
 	@Test
+	@SuppressWarnings("unchecked")
 	public void testGetTimeSinceLastMeasurement() throws Exception {
-		history.success(System.nanoTime() - 20000000);
+		long sleepTime = 20L;
-		assertThat(history.getTimeSinceLastMeasurement(), Matchers.greaterThan(0.));
+		// fill history with the same value.
+		long now = System.nanoTime() - 2 * sleepTime * 1000000;
+		for (int i = 0; i < TestUtils.getPropertyValue(history, "retention", Integer.class); i++) {
+			history.success(now);
+		}
+		final Deque<Long> times = TestUtils.getPropertyValue(history, "times", Deque.class);
+		assertEquals(Long.valueOf(now), times.peekFirst());
+		assertEquals(Long.valueOf(now), times.peekLast());
+
+		//increment just so we'll have a different value between first and last
+		history.success(System.nanoTime() - sleepTime * 1000000);
+		assertNotEquals(times.peekFirst(), times.peekLast());
+
+		/*
+		 * We've called Thread.sleep twice with the same value in quick
+		 * succession. If timeSinceLastSend is pulling off the correct end of
+		 * the queue, then we should be closer to the sleep time than we are to
+		 * 2 x sleepTime, but we should definitely be greater than the sleep
+		 * time.
+		 */
+		double timeSinceLastMeasurement = history.getTimeSinceLastMeasurement();
+		assertThat(timeSinceLastMeasurement, Matchers.greaterThan((double) (sleepTime / 100)));
+		assertThat(timeSinceLastMeasurement, Matchers.lessThanOrEqualTo(1.5 * sleepTime / 100));
 	}
 
 	@Test
@@ -152,7 +180,8 @@ public class ExponentialMovingAverageRatioTests {
 		assertEquals(0.9, ratio.getMean(), 0.03);
 	}
 
-	@Test @Ignore
+	@Test
+	@Ignore
 	public void testPerf() {
 		ExponentialMovingAverageRatio ratio = new ExponentialMovingAverageRatio(60, 10);
 		for (int i = 0; i < 100000; i++) {