001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.hbtop.mode;
019
020import java.util.List;
021import java.util.stream.Collectors;
022import java.util.stream.Stream;
023
024import org.apache.hadoop.hbase.hbtop.Record;
025import org.apache.hadoop.hbase.hbtop.RecordFilter;
026import org.apache.hadoop.hbase.hbtop.field.Field;
027
028public final class ModeStrategyUtils {
029  private ModeStrategyUtils() {
030
031  }
032
033  /**
034   * Filter records as per the supplied filters,
035   * @param records records to be processed
036   * @param filters List of filters
037   * @return filtered records
038   */
039  public static List<Record> applyFilterAndGet(List<Record> records,
040      List<RecordFilter> filters) {
041    if (filters != null && !filters.isEmpty()) {
042      return records.stream().filter(r -> filters.stream().allMatch(f -> f.execute(r)))
043          .collect(Collectors.toList());
044    }
045    return records;
046  }
047
048
049  /**
050   * Group by records on the basis of supplied groupBy field and
051   * Aggregate records using {@link Record#combine(Record)}
052   *
053   * @param records records needs to be processed
054   * @param groupBy Field to be used for group by
055   * @return aggregated records
056   */
057  public static List<Record> aggregateRecords(List<Record> records, Field groupBy) {
058    return records.stream().collect(Collectors.groupingBy(r -> r.get(groupBy))).entrySet().stream()
059        .flatMap(e -> e.getValue().stream().reduce(Record::combine).map(Stream::of)
060            .orElse(Stream.empty())).collect(Collectors.toList());
061  }
062
063}