Add functions to stopwatch

hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/util/StopWatch.java

@@ -2,7 +2,9 @@ package ca.uhn.fhir.jpa.util;
 
 import org.apache.commons.lang3.time.DateUtils;
 
+import java.text.DecimalFormat;
 import java.util.Date;
+import java.util.concurrent.TimeUnit;
 
 /*
  * #%L
@@ -37,9 +39,20 @@ public class StopWatch {
 
 	/**
 	 * Constructor
+	 *
+	 * @param theStart The time to record as the start for this timer
 	 */
-	public StopWatch(Date theNow) {
+	public StopWatch(Date theStart) {
-		myStarted = theNow.getTime();
+		myStarted = theStart.getTime();
+	}
+
+	public long getMillis() {
+		long now = System.currentTimeMillis();
+		return now - myStarted;
+	}
+
+	public long getMillis(Date theNow) {
+		return theNow.getTime() - myStarted;
 	}
 
 	public long getMillisAndRestart() {
@@ -49,21 +62,40 @@ public class StopWatch {
 		return retVal;
 	}
 
-	public long getMillis() {
+	/**
-		long now = System.currentTimeMillis();
+	 * @param theNumOperations Ok for this to be 0, it will be treated as 1
-		long retVal = now - myStarted;
+	 */
-		return retVal;
+	public int getMillisPerOperation(int theNumOperations) {
-	}
+		return (int) (((double) getMillis()) / Math.max(1.0, theNumOperations));
-
-	public long getMillis(Date theNow) {
-		long retVal = theNow.getTime() - myStarted;
-		return retVal;
 	}
 
 	public Date getStartedDate() {
 		return new Date(myStarted);
 	}
 
+	public double getThroughput(int theNumOperations, TimeUnit theUnit) {
+		if (theNumOperations <= 0) {
+			return 0.0f;
+		}
+
+		long millisElapsed = Math.max(1, getMillis());
+		long periodMillis = theUnit.toMillis(1);
+
+		double numerator = theNumOperations;
+		double denominator = ((double)millisElapsed)/((double)periodMillis);
+
+		return numerator / denominator;
+	}
+
+	public String formatThroughput(int theNumOperations, TimeUnit theUnit) {
+		double throughput = getThroughput(theNumOperations, theUnit);
+		return new DecimalFormat("0.0").format(throughput);
+	}
+
+	public void restart() {
+		myStarted = System.currentTimeMillis();
+	}
+
 	/**
 	 * Formats value in the format [DD d ]HH:mm:ss.SSSS
 	 */
@@ -72,6 +104,23 @@ public class StopWatch {
 		return formatMillis(getMillis());
 	}
 
+	/**
+	 * Append a right-aligned and zero-padded numeric value to a `StringBuilder`.
+	 */
+	static private void append(StringBuilder tgt, String pfx, int dgt, long val) {
+		tgt.append(pfx);
+		if (dgt > 1) {
+			int pad = (dgt - 1);
+			for (long xa = val; xa > 9 && pad > 0; xa /= 10) {
+				pad--;
+			}
+			for (int xa = 0; xa < pad; xa++) {
+				tgt.append('0');
+			}
+		}
+		tgt.append(val);
+	}
+
 	static public String formatMillis(long val) {
 		StringBuilder buf = new StringBuilder(20);
 		if (val >= DateUtils.MILLIS_PER_DAY) {
@@ -92,27 +141,4 @@ public class StopWatch {
 		return buf.toString();
 	}
 
-	/** Append a right-aligned and zero-padded numeric value to a `StringBuilder`. */
-	static private void append(StringBuilder tgt, String pfx, int dgt, long val) {
-		tgt.append(pfx);
-		if (dgt > 1) {
-			int pad = (dgt - 1);
-			for (long xa = val; xa > 9 && pad > 0; xa /= 10) {
-				pad--;
-			}
-			for (int xa = 0; xa < pad; xa++) {
-				tgt.append('0');
-			}
-		}
-		tgt.append(val);
-	}
-
-	/**
-	 * @param theNumOperations Ok for this to be 0, it will be treated as 1
-	 */
-	public int getMillisPerOperation(int theNumOperations) {
-		int numOperations = Math.min(1, theNumOperations);
-		return (int)(((double) getMillis()) / Math.max(1.0, numOperations));
-	}
-
 }

hapi-fhir-jpaserver-base/src/test/java/ca/uhn/fhir/jpa/util/StopWatchTest.java

@@ -1,14 +1,14 @@
 package ca.uhn.fhir.jpa.util;
 
-import static org.hamcrest.Matchers.greaterThan;
+import static org.hamcrest.Matchers.*;
-import static org.hamcrest.Matchers.lessThan;
-import static org.hamcrest.Matchers.startsWith;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThat;
 
 import java.util.Date;
+import java.util.concurrent.TimeUnit;
 
 import org.apache.commons.lang3.time.DateUtils;
+import org.hamcrest.Matchers;
 import org.junit.Test;
 
 public class StopWatchTest {
@@ -37,6 +37,62 @@ public class StopWatchTest {
 		assertThat(sw.getStartedDate().getTime(), lessThan(System.currentTimeMillis()));
 	}
 
+	@Test
+	public void testRestart() throws InterruptedException {
+		StopWatch sw = new StopWatch();
+		Thread.sleep(500);
+		sw.restart();
+		assertThat(sw.getMillis(), lessThan(100L));
+	}
+
+	@Test
+	public void testMillisPerOperation() {
+		int minutes = 60;
+		StopWatch sw = new StopWatch(DateUtils.addMinutes(new Date(), -minutes));
+		int numOperations = 60;
+		int millis = sw.getMillisPerOperation(numOperations);
+		ourLog.info("{} operations in {}ms = {}ms / operation", numOperations, minutes*DateUtils.MILLIS_PER_MINUTE, millis);
+
+		assertThat(millis, Matchers.lessThan(62000));
+		assertThat(millis, Matchers.greaterThan(58000));
+	}
+
+	@Test
+	public void testOperationThroughput60Ops1Min() {
+		double throughput = calculateThroughput(1, 60);
+		assertThat(throughput, greaterThan(59.0));
+		assertThat(throughput, lessThan(61.0));
+	}
+
+	@Test
+	public void testOperationThroughput30Ops1Min() {
+		double throughput = calculateThroughput(1, 30);
+		assertThat(throughput, greaterThan(29.0));
+		assertThat(throughput, lessThan(31.0));
+	}
+
+	@Test
+	public void testOperationThroughput60Ops4Min() {
+		double throughput = calculateThroughput(4, 60);
+		assertThat(throughput, greaterThan(14.0));
+		assertThat(throughput, lessThan(16.0));
+	}
+
+	@Test
+	public void testFormatThroughput60Ops4Min() {
+		StopWatch sw = new StopWatch(DateUtils.addMinutes(new Date(), -4));
+		String throughput = sw.formatThroughput(60, TimeUnit.MINUTES);
+		ourLog.info("{} operations in {}ms = {} ops / second", 60, sw.getMillis(), throughput);
+		assertThat(throughput, oneOf("14.9", "15.0", "15.1"));
+	}
+
+	private double calculateThroughput(int theMinutesElapsed, int theNumOperations) {
+		StopWatch sw = new StopWatch(DateUtils.addMinutes(new Date(), -theMinutesElapsed));
+		double throughput = sw.getThroughput(theNumOperations, TimeUnit.MINUTES);
+		ourLog.info("{} operations in {}ms = {} ops / second", theNumOperations, sw.getMillis(), throughput);
+		return throughput;
+	}
+
 	@Test
 	public void testToString() throws Exception {
 		StopWatch sw = new StopWatch();