[#noissue] Reduce memory usage of DisableTrace

profiler/src/main/java/com/navercorp/pinpoint/profiler/context/DisableTrace.java

@@ -34,7 +34,7 @@ public class DisableTrace implements Trace {
 
     private final long id;
     private final long startTime;
-    private final DefaultTraceScopePool scopePool = new DefaultTraceScopePool();
+    private DefaultTraceScopePool scopePool;
     private final ActiveTraceHandle handle;
     private boolean closed = false;
 
@@ -135,11 +135,17 @@ public SpanEventRecorder currentSpanEventRecorder() {
 
     @Override
     public TraceScope getScope(String name) {
+        if (scopePool == null) {
+            return null;
+        }
         return scopePool.get(name);
     }
 
     @Override
     public TraceScope addScope(String name) {
+        if (scopePool == null) {
+            scopePool = new DefaultTraceScopePool();
+        }
         return scopePool.add(name);
     }
 }

profiler/src/test/java/com/navercorp/pinpoint/profiler/context/DisableTraceTest.java

@@ -0,0 +1,29 @@
+package com.navercorp.pinpoint.profiler.context;
+
+import com.navercorp.pinpoint.bootstrap.context.Trace;
+import com.navercorp.pinpoint.profiler.context.active.ActiveTraceHandle;
+import org.junit.Assert;
+import org.junit.Test;
+
+import static org.mockito.Mockito.mock;
+
+public class DisableTraceTest {
+    @Test
+    public void testGetScope() {
+        Trace trace = newTrace();
+        Assert.assertNull(trace.addScope("empty"));
+    }
+
+    @Test
+    public void testAddScope() {
+        Trace trace = newTrace();
+
+        trace.addScope("aaa");
+        Assert.assertNotNull(trace.getScope("aaa"));
+    }
+
+    private Trace newTrace() {
+        ActiveTraceHandle activeTraceHandle = mock(ActiveTraceHandle.class);
+        return new DisableTrace(1, 2, activeTraceHandle);
+    }
+}