From 1ff3b2e901eedd3eb0dae7eb06d87c95909c7a3e Mon Sep 17 00:00:00 2001
From: Mateusz Rzeszutek <mrzeszutek@splunk.com>
Date: Mon, 10 Jan 2022 11:33:18 +0100
Subject: [PATCH] code review suggestions

---
 .../micrometer/v1_5/OpenTelemetryCounter.java |  2 +-
 .../v1_5/OpenTelemetryFunctionCounter.java    |  2 +-
 .../v1_5/OpenTelemetryFunctionTimer.java      | 31 +++++++------------
 3 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryCounter.java b/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryCounter.java
index 88d3103e2607..18299258fda2 100644
--- a/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryCounter.java
+++ b/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryCounter.java
@@ -50,7 +50,7 @@ public void increment(double v) {
   @Override
   public double count() {
     UnsupportedReadLogger.logWarning();
-    return 0;
+    return Double.NaN;
   }
 
   @Override
diff --git a/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryFunctionCounter.java b/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryFunctionCounter.java
index ba58dcca81fb..55965c424fd6 100644
--- a/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryFunctionCounter.java
+++ b/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryFunctionCounter.java
@@ -36,7 +36,7 @@ final class OpenTelemetryFunctionCounter<T> implements FunctionCounter, Removabl
   @Override
   public double count() {
     UnsupportedReadLogger.logWarning();
-    return 0;
+    return Double.NaN;
   }
 
   @Override
diff --git a/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryFunctionTimer.java b/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryFunctionTimer.java
index 077ad37cd8a7..a157f057a95e 100644
--- a/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryFunctionTimer.java
+++ b/instrumentation/micrometer/micrometer-1.5/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/micrometer/v1_5/OpenTelemetryFunctionTimer.java
@@ -51,13 +51,17 @@ final class OpenTelemetryFunctionTimer<T> implements FunctionTimer, RemovableMet
         /* baseUnit = */ "ms",
         attributes,
         obj,
-        new ConvertToMillisDecorator<>(totalTimeFunction, totalTimeFunctionUnit));
+        val ->
+            TimeUtils.convert(
+                totalTimeFunction.applyAsDouble(val),
+                totalTimeFunctionUnit,
+                TimeUnit.MILLISECONDS));
   }
 
   @Override
   public double count() {
     UnsupportedReadLogger.logWarning();
-    return 0;
+    return Double.NaN;
   }
 
   @Override
@@ -66,6 +70,12 @@ public double totalTime(TimeUnit unit) {
     return Double.NaN;
   }
 
+  @Override
+  public double mean(TimeUnit unit) {
+    UnsupportedReadLogger.logWarning();
+    return Double.NaN;
+  }
+
   @Override
   public TimeUnit baseTimeUnit() {
     return TimeUnit.MILLISECONDS;
@@ -98,21 +108,4 @@ public boolean equals(Object o) {
   public int hashCode() {
     return MeterEquivalence.hashCode(this);
   }
-
-  private static final class ConvertToMillisDecorator<T> implements ToDoubleFunction<T> {
-
-    private final ToDoubleFunction<T> original;
-    private final TimeUnit originalUnit;
-
-    private ConvertToMillisDecorator(ToDoubleFunction<T> original, TimeUnit originalUnit) {
-      this.original = original;
-      this.originalUnit = originalUnit;
-    }
-
-    @Override
-    public double applyAsDouble(T value) {
-      double time = original.applyAsDouble(value);
-      return TimeUtils.convert(time, originalUnit, TimeUnit.MILLISECONDS);
-    }
-  }
 }