Added NullGauge in metrics.simple to avoid having to re-create null implementation in wrappers

2 files changed, 22 insertions, 3 deletions

diff --git a/simplemetrics/src/main/java/com/yahoo/metrics/simple/Gauge.java b/simplemetrics/src/main/java/com/yahoo/metrics/simple/Gauge.java
index 87ea7ffdaf0..edfa198416e 100644
--- a/simplemetrics/src/main/java/com/yahoo/metrics/simple/Gauge.java
+++ b/simplemetrics/src/main/java/com/yahoo/metrics/simple/Gauge.java
@@ -14,7 +14,7 @@ import edu.umd.cs.findbugs.annotations.Nullable;
  * @author steinar
  */
 @Beta
-public final class Gauge {
+public class Gauge {
     @Nullable
     private final Point defaultPosition;
     private final String name;
diff --git a/simplemetrics/src/main/java/com/yahoo/metrics/simple/MetricReceiver.java b/simplemetrics/src/main/java/com/yahoo/metrics/simple/MetricReceiver.java
index a0b94f1e571..c45d50db065 100644
--- a/simplemetrics/src/main/java/com/yahoo/metrics/simple/MetricReceiver.java
+++ b/simplemetrics/src/main/java/com/yahoo/metrics/simple/MetricReceiver.java
@@ -55,6 +55,25 @@ public class MetricReceiver {
         }
     }
 
+    private static final class NullGauge extends Gauge {
+        NullGauge() {
+            super(null, null, null);
+        }
+
+        @Override
+        public void sample(double x) {
+        }
+
+        @Override
+        public void sample(double x, Point p) {
+        }
+
+        @Override
+        public PointBuilder builder() {
+            return super.builder();
+        }
+    }
+
     private static final class NullReceiver extends MetricReceiver {
         NullReceiver() {
             super(null, null);
@@ -76,12 +95,12 @@ public class MetricReceiver {
 
         @Override
         public Gauge declareGauge(String name) {
-            return null;
+            return new NullGauge();
         }
 
         @Override
         public Gauge declareGauge(String name, Point boundDimensions) {
-            return null;
+            return new NullGauge();
         }
 
         @Override