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    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
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   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
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  package org.apache.hadoop.hbase.util;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertTrue;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.HBaseConfiguration;
  import org.apache.hadoop.hbase.testclassification.MiscTests;
  import org.apache.hadoop.hbase.testclassification.SmallTests;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  @Category({MiscTests.class, SmallTests.class})
  public class TestLossyCounting {
  
    private final Configuration conf = HBaseConfiguration.create();
  
    @Test
    public void testBucketSize() {
      LossyCounting<?> lossyCounting = new LossyCounting<>("testBucketSize", 0.01);
      assertEquals(100L, lossyCounting.getBucketSize());
      LossyCounting<?> lossyCounting2 = new LossyCounting<>("testBucketSize2", conf);
      assertEquals(50L, lossyCounting2.getBucketSize());
    }
  
    @Test
    public void testAddByOne() {
      LossyCounting<String> lossyCounting = new LossyCounting<>("testAddByOne", 0.01);
      for (int i = 0; i < 100; i++) {
        String key = "" + i;
        lossyCounting.add(key);
      }
      assertEquals(100L, lossyCounting.getDataSize());
      for (int i = 0; i < 100; i++) {
        String key = "" + i;
        assertTrue(lossyCounting.contains(key));
      }
    }
  
    @Test
    public void testSweep1() throws Exception {
      LossyCounting<String> lossyCounting = new LossyCounting<>("testSweep1", 0.01);
      for(int i = 0; i < 400; i++){
        String key = "" + i;
        lossyCounting.add(key);
      }
      assertEquals(4L, lossyCounting.getCurrentTerm());
      waitForSweep(lossyCounting);
  
      //Do last one sweep as some sweep will be skipped when first one was running
      lossyCounting.sweep();
      assertEquals(lossyCounting.getBucketSize() - 1, lossyCounting.getDataSize());
    }
  
    private void waitForSweep(LossyCounting<?> lossyCounting) throws InterruptedException {
      //wait for sweep thread to complete
      int retry = 0;
      while (!lossyCounting.getSweepFuture().isDone() && retry < 10) {
        Thread.sleep(100);
        retry++;
      }
    }
  
    @Test
    public void testSweep2() throws Exception {
      LossyCounting<String> lossyCounting = new LossyCounting<>("testSweep2", 0.1);
      for (int i = 0; i < 10; i++) {
        String key = "" + i;
        lossyCounting.add(key);
      }
      waitForSweep(lossyCounting);
      assertEquals(10L, lossyCounting.getDataSize());
      for(int i = 0; i < 10; i++){
        String key = "1";
        lossyCounting.add(key);
      }
      waitForSweep(lossyCounting);
      assertEquals(1L, lossyCounting.getDataSize());
    }
  }