View Javadoc

1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.hadoop.hbase.regionserver.compactions;
20  
21  import java.util.ArrayList;
22  import java.util.Iterator;
23  import java.util.List;
24  
25  import org.apache.commons.math.random.GaussianRandomGenerator;
26  import org.apache.commons.math.random.MersenneTwister;
27  import org.apache.hadoop.hbase.regionserver.StoreFile;
28  
29  class GaussianFileListGenerator extends StoreFileListGenerator {
30  
31    GaussianFileListGenerator() {
32      super(GaussianFileListGenerator.class);
33    }
34  
35    @Override
36    public Iterator<List<StoreFile>> iterator() {
37      return new Iterator<List<StoreFile>>() {
38        private GaussianRandomGenerator gen =
39            new GaussianRandomGenerator(new MersenneTwister(random.nextInt()));
40        private int count = 0;
41  
42        @Override
43        public boolean hasNext() {
44          return count < MAX_FILE_GEN_ITERS;
45        }
46  
47        @Override
48        public List<StoreFile> next() {
49          count += 1;
50          ArrayList<StoreFile> files = new ArrayList<StoreFile>(NUM_FILES_GEN);
51          for (int i = 0; i < NUM_FILES_GEN; i++) {
52            files.add(createMockStoreFile(
53                (int) Math.ceil(Math.max(0, gen.nextNormalizedDouble() * 32 + 32)))
54            );
55          }
56  
57          return files;
58        }
59  
60        @Override
61        public void remove() {
62        }
63      };
64    }
65  }