fix unused import, apply to PercentileDistributionSummary

build.gradle

@@ -113,7 +113,7 @@ subprojects {
     profilers = ['stack', 'gc']
     includeTests = false
     duplicateClassesStrategy = DuplicatesStrategy.WARN
-    includes = ['.*Caching.*']
+    includes = ['.*PercentileTimers.*']
   }
 
   checkstyle {

spectator-api/src/main/java/com/netflix/spectator/api/histogram/PercentileDistributionSummary.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2019 Netflix, Inc.
+ * Copyright 2014-2024 Netflix, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,7 +22,6 @@
 import com.netflix.spectator.api.Measurement;
 import com.netflix.spectator.api.Registry;
 import com.netflix.spectator.api.Statistic;
-import com.netflix.spectator.api.Utils;
 import com.netflix.spectator.api.patterns.IdBuilder;
 import com.netflix.spectator.api.patterns.TagsBuilder;
 
@@ -66,8 +65,20 @@ public final class PercentileDistributionSummary implements DistributionSummary
    */
   private static PercentileDistributionSummary computeIfAbsent(
       Registry registry, Id id, long min, long max) {
-    Object summary = Utils.computeIfAbsent(
-        registry.state(), id, i -> new PercentileDistributionSummary(registry, id, min, max));
+    // Inlined:
+    // Object summary = Utils.computeIfAbsent(
+    //        registry.state(), id, i -> new PercentileDistributionSummary(registry, id, min, max));
+    //
+    // The lambda needs to capture the parameters for registry, min, and max which can lead to
+    // a high allocation rate for the lambda instance.
+    Object summary = registry.state().get(id);
+    if (summary == null) {
+      PercentileDistributionSummary newSummary = new PercentileDistributionSummary(registry, id, min, max);
+      summary = registry.state().putIfAbsent(id, newSummary);
+      if (summary == null) {
+        return newSummary;
+      }
+    }
     return (summary instanceof PercentileDistributionSummary)
         ? ((PercentileDistributionSummary) summary).withRange(min, max)
         : new PercentileDistributionSummary(registry, id, min, max);

spectator-api/src/main/java/com/netflix/spectator/api/histogram/PercentileTimer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2023 Netflix, Inc.
+ * Copyright 2014-2024 Netflix, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,7 +23,6 @@
 import com.netflix.spectator.api.Registry;
 import com.netflix.spectator.api.Statistic;
 import com.netflix.spectator.api.Timer;
-import com.netflix.spectator.api.Utils;
 import com.netflix.spectator.api.patterns.IdBuilder;
 import com.netflix.spectator.api.patterns.TagsBuilder;
 
@@ -72,6 +71,12 @@ public final class PercentileTimer implements Timer {
    * site.
    */
   private static PercentileTimer computeIfAbsent(Registry registry, Id id, long min, long max) {
+    // Inlined:
+    // Object timer = Utils.computeIfAbsent(
+    //        registry.state(), id, i -> new PercentileTimer(registry, id, min, max));
+    //
+    // The lambda needs to capture the parameters for registry, min, and max which can lead to
+    // a high allocation rate for the lambda instance.
     Object timer = registry.state().get(id);
     if (timer == null) {
       PercentileTimer newTimer = new PercentileTimer(registry, id, min, max);