From 436aeaf99adb3eb14ea63036c9c75837202165cb Mon Sep 17 00:00:00 2001
From: Trask Stalnaker <trask.stalnaker@gmail.com>
Date: Mon, 30 Aug 2021 09:02:59 -0700
Subject: [PATCH] Another ClassValue optimization (#4013)

* Another ClassValue optimization

* Spotless
---
 .../HandlerAdapterInstrumentation.java        |  3 ++-
 .../springwebmvc/IsGrailsHandler.java         | 23 +++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 instrumentation/spring/spring-webmvc-3.1/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/springwebmvc/IsGrailsHandler.java

diff --git a/instrumentation/spring/spring-webmvc-3.1/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/springwebmvc/HandlerAdapterInstrumentation.java b/instrumentation/spring/spring-webmvc-3.1/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/springwebmvc/HandlerAdapterInstrumentation.java
index 2438db45c5..23d89a7770 100644
--- a/instrumentation/spring/spring-webmvc-3.1/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/springwebmvc/HandlerAdapterInstrumentation.java
+++ b/instrumentation/spring/spring-webmvc-3.1/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/springwebmvc/HandlerAdapterInstrumentation.java
@@ -8,6 +8,7 @@ package io.opentelemetry.javaagent.instrumentation.springwebmvc;
 import static io.opentelemetry.instrumentation.api.servlet.ServerSpanNaming.Source.CONTROLLER;
 import static io.opentelemetry.javaagent.extension.matcher.AgentElementMatchers.hasClassesNamed;
 import static io.opentelemetry.javaagent.extension.matcher.AgentElementMatchers.implementsInterface;
+import static io.opentelemetry.javaagent.instrumentation.springwebmvc.IsGrailsHandler.isGrailsHandler;
 import static io.opentelemetry.javaagent.instrumentation.springwebmvc.SpringWebMvcSingletons.handlerInstrumenter;
 import static net.bytebuddy.matcher.ElementMatchers.isMethod;
 import static net.bytebuddy.matcher.ElementMatchers.isPublic;
@@ -60,7 +61,7 @@ public class HandlerAdapterInstrumentation implements TypeInstrumentation {
         @Advice.Local("otelContext") Context context,
         @Advice.Local("otelScope") Scope scope) {
       // TODO (trask) should there be a way to customize Instrumenter.shouldStart()?
-      if (handler.getClass().getName().startsWith("org.grails.")) {
+      if (isGrailsHandler(handler)) {
         // skip creating handler span for grails, grails instrumentation will take care of it
         return;
       }
diff --git a/instrumentation/spring/spring-webmvc-3.1/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/springwebmvc/IsGrailsHandler.java b/instrumentation/spring/spring-webmvc-3.1/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/springwebmvc/IsGrailsHandler.java
new file mode 100644
index 0000000000..f3a35cfd6b
--- /dev/null
+++ b/instrumentation/spring/spring-webmvc-3.1/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/springwebmvc/IsGrailsHandler.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.javaagent.instrumentation.springwebmvc;
+
+public final class IsGrailsHandler {
+
+  private static final ClassValue<Boolean> cache =
+      new ClassValue<Boolean>() {
+        @Override
+        protected Boolean computeValue(Class<?> type) {
+          return type.getName().startsWith("org.grails.");
+        }
+      };
+
+  public static boolean isGrailsHandler(Object handler) {
+    return cache.get(handler.getClass());
+  }
+
+  private IsGrailsHandler() {}
+}