Avoid allocation in TimeWindowMax#record (#3206)

The capturing lambda that was used resulted in allocation on each invocation of the record method, which is on the hot path for metrics recording. To reduce the overhead of metrics, avoid the capturing lambda that results in allocation.

Resolves gh-3193

Author: shakuzen

micrometer-core/src/main/java/io/micrometer/core/instrument/distribution/TimeWindowMax.java

@@ -22,7 +22,6 @@
 import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.function.DoubleSupplier;
-import java.util.function.LongSupplier;
 
 /**
  * An implementation of a decaying maximum for a distribution based on a configurable ring
@@ -71,12 +70,11 @@ public TimeWindowMax(Clock clock, long rotateFrequencyMillis, int bufferLength)
      * @param timeUnit The unit of time of the incoming sample.
      */
     public void record(double sample, TimeUnit timeUnit) {
-        record(() -> (long) TimeUtils.convert(sample, timeUnit, TimeUnit.NANOSECONDS));
+        record((long) TimeUtils.convert(sample, timeUnit, TimeUnit.NANOSECONDS));
     }
 
-    private void record(LongSupplier sampleSupplier) {
+    private void record(long sample) {
         rotate();
-        long sample = sampleSupplier.getAsLong();
         for (AtomicLong max : ringBuffer) {
             updateMax(max, sample);
         }
@@ -109,7 +107,7 @@ public double poll() {
      * @param sample The value to record.
      */
     public void record(double sample) {
-        record(() -> Double.doubleToLongBits(sample));
+        record(Double.doubleToLongBits(sample));
     }
 
     private void updateMax(AtomicLong max, long sample) {