org.apache.hadoop.metrics.spi.NullContext Maven / Gradle / Ivy
/*
* NullContext.java
* 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.hadoop.metrics.spi;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/**
* Null metrics context: a metrics context which does nothing. Used as the
* default context, so that no performance data is emitted if no configuration
* data is found.
*
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public class NullContext extends AbstractMetricsContext {
/** Creates a new instance of NullContext */
@InterfaceAudience.Private
public NullContext() {
}
/**
* Do-nothing version of startMonitoring
*/
@InterfaceAudience.Private
public void startMonitoring() {
}
/**
* Do-nothing version of emitRecord
*/
@InterfaceAudience.Private
protected void emitRecord(String contextName, String recordName,
OutputRecord outRec)
{}
/**
* Do-nothing version of update
*/
@InterfaceAudience.Private
protected void update(MetricsRecordImpl record) {
}
/**
* Do-nothing version of remove
*/
@InterfaceAudience.Private
protected void remove(MetricsRecordImpl record) {
}
}