org.apache.hadoop.fs.statistics.IOStatisticsAggregator Maven / Gradle / Ivy
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* 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.fs.statistics;
import javax.annotation.Nullable;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/**
* Interface exported by classes which support
* aggregation of {@link IOStatistics}.
* Implementations MAY aggregate all statistics
* exported by the IOStatistics reference passed in to
* {@link #aggregate(IOStatistics)}, or they
* may selectively aggregate specific values/classes
* of statistics.
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public interface IOStatisticsAggregator {
/**
* Aggregate the supplied statistics into the current
* set.
*
* @param statistics statistics; may be null
* @return true if the statistics reference was not null and
* so aggregated.
*/
boolean aggregate(@Nullable IOStatistics statistics);
}