From 75af71584c5abf2ddca9139d52083f862bc2b1d9 Mon Sep 17 00:00:00 2001
From: Brian Devins-Suresh <brian.devinssuresh@datadoghq.com>
Date: Mon, 24 Feb 2020 13:11:10 -0500
Subject: [PATCH] Refactor an agent usage, and fix logic issue

---
 .../java/datadog/trace/agent/tooling/Instrumenter.java   | 9 +++++----
 .../trace/agent/tooling/muzzle/ReferenceMatcher.java     | 2 +-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/Instrumenter.java b/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/Instrumenter.java
index f532086ae4..294724a1e3 100644
--- a/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/Instrumenter.java
+++ b/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/Instrumenter.java
@@ -133,9 +133,10 @@ public interface Instrumenter {
          */
         final ReferenceMatcher muzzle = getInstrumentationMuzzle();
         if (null != muzzle) {
-          final List<Reference.Mismatch> mismatches =
-              muzzle.getMismatchedReferenceSources(classLoader);
-          if (mismatches.size() > 0) {
+          final boolean isMatch = muzzle.matches(classLoader);
+          if (!isMatch) {
+            final List<Reference.Mismatch> mismatches =
+                muzzle.getMismatchedReferenceSources(classLoader);
             if (log.isDebugEnabled()) {
               log.debug(
                   "Instrumentation muzzled: {} -- {} on {}",
@@ -153,7 +154,7 @@ public interface Instrumenter {
                 Instrumenter.Default.this.getClass().getName(),
                 classLoader);
           }
-          return mismatches.size() == 0;
+          return isMatch;
         }
         return true;
       }
diff --git a/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/muzzle/ReferenceMatcher.java b/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/muzzle/ReferenceMatcher.java
index bfc9bed9d6..4997dc98d4 100644
--- a/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/muzzle/ReferenceMatcher.java
+++ b/dd-java-agent/agent-tooling/src/main/java/datadog/trace/agent/tooling/muzzle/ReferenceMatcher.java
@@ -66,7 +66,7 @@ public class ReferenceMatcher
     }
 
     mismatchCache.put(loader, mismatches);
-    return true;
+    return mismatches.size() == 0;
   }
 
   /**