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.jupiter.api.Assertions.assertEquals;
021
022import org.apache.hadoop.hbase.testclassification.MasterTests;
023import org.apache.hadoop.hbase.testclassification.SmallTests;
024import org.junit.jupiter.api.Tag;
025import org.junit.jupiter.api.Test;
026
027@Tag(MasterTests.TAG)
028@Tag(SmallTests.TAG)
029public class TestDoubleArrayCost {
030
031  @Test
032  public void testComputeCost() {
033    DoubleArrayCost cost = new DoubleArrayCost();
034
035    cost.prepare(100);
036    cost.applyCostsChange(costs -> {
037      for (int i = 0; i < 100; i++) {
038        costs[i] = 10;
039      }
040    });
041    assertEquals(0, cost.cost(), 0.01);
042
043    cost.prepare(101);
044    cost.applyCostsChange(costs -> {
045      for (int i = 0; i < 100; i++) {
046        costs[i] = 0;
047      }
048      costs[100] = 100;
049    });
050    assertEquals(1, cost.cost(), 0.01);
051
052    cost.prepare(200);
053    cost.applyCostsChange(costs -> {
054      for (int i = 0; i < 100; i++) {
055        costs[i] = 0;
056        costs[i + 100] = 100;
057      }
058      costs[100] = 100;
059    });
060    assertEquals(0.0708, cost.cost(), 0.01);
061  }
062}