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.regionserver.compactions;
019
020import java.util.ArrayList;
021import java.util.Iterator;
022import java.util.List;
023
024import org.apache.commons.math3.random.GaussianRandomGenerator;
025import org.apache.commons.math3.random.MersenneTwister;
026import org.apache.hadoop.hbase.regionserver.HStoreFile;
027
028class GaussianFileListGenerator extends StoreFileListGenerator {
029
030  GaussianFileListGenerator() {
031    super(GaussianFileListGenerator.class);
032  }
033
034  @Override
035  public Iterator<List<HStoreFile>> iterator() {
036    return new Iterator<List<HStoreFile>>() {
037      private GaussianRandomGenerator gen =
038          new GaussianRandomGenerator(new MersenneTwister(random.nextInt()));
039      private int count = 0;
040
041      @Override
042      public boolean hasNext() {
043        return count < MAX_FILE_GEN_ITERS;
044      }
045
046      @Override
047      public List<HStoreFile> next() {
048        count += 1;
049        ArrayList<HStoreFile> files = new ArrayList<>(NUM_FILES_GEN);
050        for (int i = 0; i < NUM_FILES_GEN; i++) {
051          files.add(createMockStoreFile(
052              (int) Math.ceil(Math.max(0, gen.nextNormalizedDouble() * 32 + 32)))
053          );
054        }
055
056        return files;
057      }
058
059      @Override
060      public void remove() {
061      }
062    };
063  }
064}