diff --git a/htrace-core/src/main/java/org/apache/htrace/NullScope.java b/htrace-core/src/main/java/org/apache/htrace/NullScope.java index 32963a8..ff9a42c 100644 --- a/htrace-core/src/main/java/org/apache/htrace/NullScope.java +++ b/htrace-core/src/main/java/org/apache/htrace/NullScope.java @@ -28,6 +28,16 @@ public final class NullScope extends TraceScope { } @Override + public Span detach() { + return null; + } + + @Override + public void close() { + return; + } + + @Override public String toString() { return "NullScope"; } diff --git a/htrace-core/src/main/java/org/apache/htrace/TraceScope.java b/htrace-core/src/main/java/org/apache/htrace/TraceScope.java index 3546e69..ab36feb 100644 --- a/htrace-core/src/main/java/org/apache/htrace/TraceScope.java +++ b/htrace-core/src/main/java/org/apache/htrace/TraceScope.java @@ -81,7 +81,7 @@ public class TraceScope implements Closeable { @Override public void close() { - if ((span == null) || detached) { + if (detached) { return; } detached = true; diff --git a/htrace-core/src/test/java/org/apache/htrace/TestNullScope.java b/htrace-core/src/test/java/org/apache/htrace/TestNullScope.java new file mode 100644 index 0000000..26b1cba --- /dev/null +++ b/htrace-core/src/test/java/org/apache/htrace/TestNullScope.java @@ -0,0 +1,37 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.htrace; + +import org.apache.htrace.Trace; +import org.apache.htrace.TraceScope; +import org.apache.htrace.NullScope; +import org.junit.Assert; +import org.junit.Test; + +public class TestNullScope { + @Test + public void testNullScope() { + Assert.assertTrue(!Trace.isTracing()); + TraceScope tc = Trace.startSpan("NullScopeSingleton"); + Assert.assertTrue(tc == NullScope.INSTANCE); + tc.detach(); + tc.detach(); // should not fail even if called multiple times. + Assert.assertFalse(tc.isDetached()); + tc.close(); + tc.close(); // should not fail even if called multiple times. + } +}