| /* |
| * 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.core; |
| |
| /** |
| * An empty {@link TraceScope}. |
| */ |
| class NullScope extends TraceScope { |
| NullScope(Tracer tracer) { |
| super(tracer, null, null); |
| } |
| |
| @Override |
| public SpanId getSpanId() { |
| return SpanId.INVALID; |
| } |
| |
| @Override |
| public void detach() { |
| if (detached) { |
| Tracer.throwClientError("Can't detach this TraceScope because " + |
| "it is already detached."); |
| } |
| detached = true; |
| } |
| |
| @Override |
| public void reattach() { |
| if (!detached) { |
| Tracer.throwClientError("Can't reattach this TraceScope because " + |
| "it is not detached."); |
| } |
| detached = false; |
| } |
| |
| @Override |
| public void close() { |
| tracer.popNullScope(); |
| } |
| |
| @Override |
| public String toString() { |
| return "NullScope"; |
| } |
| |
| @Override |
| public void addKVAnnotation(String key, String value) { |
| // do nothing |
| } |
| |
| @Override |
| public void addTimelineAnnotation(String msg) { |
| // do nothing |
| } |
| } |