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.util;
019
020import static org.junit.Assert.assertEquals;
021
022import java.util.ArrayList;
023import java.util.List;
024import java.util.Random;
025import java.util.concurrent.ExecutionException;
026import java.util.concurrent.ThreadLocalRandom;
027import org.apache.hadoop.hbase.HBaseClassTestRule;
028import org.apache.hadoop.hbase.testclassification.MiscTests;
029import org.apache.hadoop.hbase.testclassification.SmallTests;
030import org.apache.hadoop.hbase.util.PoolMap.PoolType;
031import org.junit.ClassRule;
032import org.junit.Test;
033import org.junit.experimental.categories.Category;
034
035@Category({ MiscTests.class, SmallTests.class })
036public class TestRoundRobinPoolMap extends PoolMapTestBase {
037
038  @ClassRule
039  public static final HBaseClassTestRule CLASS_RULE =
040      HBaseClassTestRule.forClass(TestRoundRobinPoolMap.class);
041
042  @Override
043  protected PoolType getPoolType() {
044    return PoolType.RoundRobin;
045  }
046
047  @Test
048  public void testSingleThreadedClient() throws InterruptedException, ExecutionException {
049    Random rand = ThreadLocalRandom.current();
050    String randomKey = String.valueOf(rand.nextInt());
051    String randomValue = String.valueOf(rand.nextInt());
052    // As long as the pool is not full, we'll get null back.
053    // This forces the user to create new values that can be used to populate
054    // the pool.
055    runThread(randomKey, randomValue, null);
056    assertEquals(1, poolMap.size(randomKey));
057  }
058
059  @Test
060  public void testMultiThreadedClients() throws InterruptedException, ExecutionException {
061    Random rand = ThreadLocalRandom.current();
062    for (int i = 0; i < POOL_SIZE; i++) {
063      String randomKey = String.valueOf(rand.nextInt());
064      String randomValue = String.valueOf(rand.nextInt());
065      // As long as the pool is not full, we'll get null back
066      runThread(randomKey, randomValue, null);
067      // As long as we use distinct keys, each pool will have one value
068      assertEquals(1, poolMap.size(randomKey));
069    }
070    poolMap.clear();
071    String randomKey = String.valueOf(rand.nextInt());
072    for (int i = 0; i < POOL_SIZE - 1; i++) {
073      String randomValue = String.valueOf(rand.nextInt());
074      // As long as the pool is not full, we'll get null back
075      runThread(randomKey, randomValue, null);
076      // since we use the same key, the pool size should grow
077      assertEquals(i + 1, poolMap.size(randomKey));
078    }
079    // at the end of the day, there should be as many values as we put
080    assertEquals(POOL_SIZE - 1, poolMap.size(randomKey));
081  }
082
083  @Test
084  public void testPoolCap() throws InterruptedException, ExecutionException {
085    Random rand = ThreadLocalRandom.current();
086    String randomKey = String.valueOf(rand.nextInt());
087    List<String> randomValues = new ArrayList<>();
088    for (int i = 0; i < POOL_SIZE * 2; i++) {
089      String randomValue = String.valueOf(rand.nextInt());
090      randomValues.add(randomValue);
091      if (i < POOL_SIZE - 1) {
092        // As long as the pool is not full, we'll get null back
093        runThread(randomKey, randomValue, null);
094      } else {
095        // when the pool becomes full, we expect the value we get back to be
096        // what we put earlier, in round-robin order
097        runThread(randomKey, randomValue, randomValues.get((i - POOL_SIZE + 1) % POOL_SIZE));
098      }
099    }
100    assertEquals(POOL_SIZE, poolMap.size(randomKey));
101  }
102}