Merge pull request #111 from brharrington/servo-guage-gaps

fix sporadic gaps on gauges reported to servo

Author: brharrington

spectator-reg-servo/src/main/java/com/netflix/spectator/servo/ServoGauge.java

@@ -0,0 +1,40 @@
+/**
+ * Copyright 2015 Netflix, Inc.
+ *
+ * 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 com.netflix.spectator.servo;
+
+import com.netflix.servo.monitor.AbstractMonitor;
+import com.netflix.servo.monitor.MonitorConfig;
+import com.netflix.servo.monitor.NumericMonitor;
+
+/**
+ * Reports a constant value passed into the constructor.
+ */
+final class ServoGauge<T extends Number> extends AbstractMonitor<Double>
+    implements NumericMonitor<Double> {
+  private final double value;
+
+  /**
+   * Create a new monitor that returns {@code value}.
+   */
+  ServoGauge(MonitorConfig config, double value) {
+    super(config);
+    this.value = value;
+  }
+
+  @Override public Double getValue(int pollerIndex) {
+    return value;
+  }
+}

spectator-reg-servo/src/main/java/com/netflix/spectator/servo/ServoRegistry.java

@@ -121,7 +121,7 @@ MonitorConfig toMonitorConfig(Id id) {
         }
       } else {
         for (Measurement m : meter.measure()) {
-          monitors.add(new NumberGauge(toMonitorConfig(m.id()), m.value()));
+          monitors.add(new ServoGauge(toMonitorConfig(m.id()), m.value()));
         }
       }
     }