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.master.balancer;
019
020import static org.junit.Assert.assertEquals;
021
022import org.apache.hadoop.hbase.HBaseClassTestRule;
023import org.apache.hadoop.hbase.testclassification.MasterTests;
024import org.apache.hadoop.hbase.testclassification.SmallTests;
025import org.junit.ClassRule;
026import org.junit.Test;
027import org.junit.experimental.categories.Category;
028
029@Category({ MasterTests.class, SmallTests.class })
030public class TestDoubleArrayCost {
031
032  @ClassRule
033  public static final HBaseClassTestRule CLASS_RULE =
034    HBaseClassTestRule.forClass(TestDoubleArrayCost.class);
035
036  @Test
037  public void testComputeCost() {
038    DoubleArrayCost cost = new DoubleArrayCost();
039
040    cost.prepare(100);
041    cost.applyCostsChange(costs -> {
042      for (int i = 0; i < 100; i++) {
043        costs[i] = 10;
044      }
045    });
046    assertEquals(0, cost.cost(), 0.01);
047
048    cost.prepare(101);
049    cost.applyCostsChange(costs -> {
050      for (int i = 0; i < 100; i++) {
051        costs[i] = 0;
052      }
053      costs[100] = 100;
054    });
055    assertEquals(1, cost.cost(), 0.01);
056
057    cost.prepare(200);
058    cost.applyCostsChange(costs -> {
059      for (int i = 0; i < 100; i++) {
060        costs[i] = 0;
061        costs[i + 100] = 100;
062      }
063      costs[100] = 100;
064    });
065    assertEquals(0.0708, cost.cost(), 0.01);
066  }
067}