steveloughran commented on a change in pull request #1982: URL: https://github.com/apache/hadoop/pull/1982#discussion_r422987566
########## File path: hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/DynamicIOStatisticsBuilder.java ########## @@ -0,0 +1,115 @@ +/* + * 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.impl; + +import java.util.concurrent.atomic.AtomicInteger; +import java.util.concurrent.atomic.AtomicLong; +import java.util.function.ToLongFunction; + +import org.apache.hadoop.fs.statistics.IOStatistics; +import org.apache.hadoop.metrics2.lib.MutableCounterLong; + +import static com.google.common.base.Preconditions.checkState; + +/** + * Builder of Dynamic IO Statistics. + * Instantiate through + * {@link IOStatisticsBinding#dynamicIOStatistics()}. + */ +public class DynamicIOStatisticsBuilder { + + /** + * the instance being built up. Will be null after the (single) + * call to {@link #build()}. + */ + private DynamicIOStatistics instance = new DynamicIOStatistics(); + + /** + * Add a new evaluator to the statistics being built up. + * @param key key of this statistic + * @param eval evaluator for the statistic + * @return the builder. + */ + public DynamicIOStatisticsBuilder add(String key, Review comment: via a lambda expression ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org
