com.google.instrumentation.trace.BlankSpan Maven / Gradle / Ivy
/*
* Copyright 2016, Google Inc.
* Licensed 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 com.google.instrumentation.trace;
import java.util.Map;
import javax.annotation.concurrent.Immutable;
/**
* The {@code BlankSpan} is a singleton class, which is the default {@link Span} that is used when
* no {@code Span} implementation is available. All operations are no-op.
*
* Used also to stop tracing, see {@link Tracer#withSpan}.
*/
@Immutable
public final class BlankSpan extends Span {
/** Singleton instance of this class. */
public static final BlankSpan INSTANCE = new BlankSpan();
private BlankSpan() {
super(SpanContext.INVALID, null);
}
/** No-op implementation of the {@link Span#addAttributes(Map)} method. */
@Override
public void addAttributes(Map attributes) {}
/** No-op implementation of the {@link Span#addAnnotation(String, Map)} method. */
@Override
public void addAnnotation(String description, Map attributes) {}
/** No-op implementation of the {@link Span#addAnnotation(Annotation)} method. */
@Override
public void addAnnotation(Annotation annotation) {}
/** No-op implementation of the {@link Span#addNetworkEvent(NetworkEvent)} method. */
@Override
public void addNetworkEvent(NetworkEvent networkEvent) {}
/** No-op implementation of the {@link Span#addLink(Link)} method. */
@Override
public void addLink(Link link) {}
/** No-op implementation of the {@link Span#end(EndSpanOptions)} method. */
@Override
public void end(EndSpanOptions options) {}
@Override
public String toString() {
return "BlankSpan";
}
}