Merge pull request #361 from aol/micro-metrics-instant-gauge

InstantGauge to use with datadog

micro-metrics/src/main/java/com/aol/micro/server/spring/metrics/InstantGauge.java

@@ -0,0 +1,24 @@
+package com.aol.micro.server.spring.metrics;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+import com.codahale.metrics.Gauge;
+
+
+public class InstantGauge implements Gauge<Long> {
+
+	private final AtomicLong counter = new AtomicLong(0l);
+
+	@Override
+	public Long getValue() {
+		return counter.getAndSet(0l);
+		}
+
+	public void increment() {
+		counter.incrementAndGet();
+	}
+
+	public void increase(long value) {
+		counter.addAndGet(value);
+	}
+}

micro-metrics/src/test/java/com/aol/micro/server/spring/metrics/InstantGaugeTest.java

@@ -0,0 +1,19 @@
+package com.aol.micro.server.spring.metrics;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class InstantGaugeTest {
+
+	@Test
+	public void instantGauge() {
+		InstantGauge gauge = new InstantGauge();
+		gauge.increment();
+		gauge.increase(3);
+
+		assertEquals(4l ,gauge.getValue().longValue());
+		assertEquals(0l ,gauge.getValue().longValue());
+
+	}
+
+}