content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.client.file.cache;
  
  import alluxio.client.file.cache.evictor.CacheEvictorOptions;
  import alluxio.client.file.cache.evictor.LFUCacheEvictor;
  
  import org.junit.Assert;
  import org.junit.Before;
  import org.junit.Test;
  
  /**
   * Tests for the {@link LFUCacheEvictor} class.
   */
  public final class LFUCacheEvictorTest {
    private LFUCacheEvictor mEvictor;
    private final PageId mOne = new PageId("1L", 2L);
    private final PageId mTwo = new PageId("3L", 4L);
    private final PageId mThree = new PageId("5L", 6L);
    private final PageId mFour = new PageId("7L", 8L);
  
    /**
     * Sets up the instances.
     */
    @Before
    public void before() {
      mEvictor = new LFUCacheEvictor(new CacheEvictorOptions());
    }
  
    @Test
    public void evictGetOrder() {
      mEvictor.updateOnGet(mOne);
      mEvictor.updateOnGet(mTwo);
      mEvictor.updateOnGet(mTwo);
      mEvictor.updateOnGet(mFour);
      mEvictor.updateOnGet(mFour);
      mEvictor.updateOnGet(mFour);
      mEvictor.updateOnGet(mFour);
      Assert.assertEquals(mOne, mEvictor.evict());
      mEvictor.updateOnDelete(mOne);
      Assert.assertEquals(mTwo, mEvictor.evict());
      mEvictor.updateOnDelete(mTwo);
      Assert.assertEquals(mFour, mEvictor.evict());
      mEvictor.updateOnDelete(mFour);
    }
  
    @Test
    public void evictGetMixedOrder() {
      mEvictor.updateOnGet(mFour);
      mEvictor.updateOnGet(mTwo);
      mEvictor.updateOnGet(mFour);
      mEvictor.updateOnGet(mTwo);
      mEvictor.updateOnGet(mFour);
      mEvictor.updateOnGet(mOne);
      mEvictor.updateOnGet(mFour);
      Assert.assertEquals(mOne, mEvictor.evict());
      mEvictor.updateOnDelete(mOne);
      Assert.assertEquals(mTwo, mEvictor.evict());
      mEvictor.updateOnDelete(mTwo);
      Assert.assertEquals(mFour, mEvictor.evict());
      mEvictor.updateOnDelete(mFour);
    }
  
    @Test
    public void evictGetRecentOrder() {
      mEvictor.updateOnGet(mOne);
      mEvictor.updateOnGet(mTwo);
      Assert.assertEquals(mOne, mEvictor.evict());
      mEvictor.updateOnDelete(mOne);
      Assert.assertEquals(mTwo, mEvictor.evict());
    }
  
    @Test
    public void evictUpdatedGetRecentOrder() {
      mEvictor.updateOnGet(mOne);
      mEvictor.updateOnGet(mOne);
      mEvictor.updateOnGet(mTwo);
      mEvictor.updateOnGet(mTwo);
      mEvictor.updateOnGet(mThree);
      mEvictor.updateOnGet(mThree);
      mEvictor.updateOnGet(mTwo);
      mEvictor.updateOnGet(mThree);
      mEvictor.updateOnGet(mOne);
      Assert.assertEquals(mTwo, mEvictor.evict());
      mEvictor.updateOnDelete(mTwo);
      Assert.assertEquals(mThree, mEvictor.evict());
      mEvictor.updateOnDelete(mThree);
      Assert.assertEquals(mOne, mEvictor.evict());
    }
  
    @Test
    public void evictDeleteSkippedBucket() {
      mEvictor.updateOnGet(mOne);
      mEvictor.updateOnGet(mFour);
      mEvictor.updateOnGet(mFour);
      mEvictor.updateOnGet(mFour);
      mEvictor.updateOnGet(mFour);
      Assert.assertEquals(mOne, mEvictor.evict());
      mEvictor.updateOnDelete(mOne);
      Assert.assertEquals(mFour, mEvictor.evict());
      mEvictor.updateOnDelete(mFour);
    }
  
    @Test
    public void evictDeleteTwice() {
      mEvictor.updateOnGet(mOne);
      mEvictor.updateOnGet(mOne);
      Assert.assertEquals(mOne, mEvictor.evict());
      mEvictor.updateOnDelete(mOne);
      mEvictor.updateOnGet(mOne);
      Assert.assertEquals(mOne, mEvictor.evict());
    }
  
    @Test
    public void evictAfterDelete() {
      mEvictor.updateOnPut(mOne);
      mEvictor.updateOnPut(mTwo);
      mEvictor.updateOnPut(mTwo);
      mEvictor.updateOnPut(mThree);
      mEvictor.updateOnPut(mThree);
      mEvictor.updateOnPut(mThree);
      mEvictor.updateOnDelete(mTwo);
      Assert.assertEquals(mOne, mEvictor.evict());
      mEvictor.updateOnDelete(mOne);
      Assert.assertEquals(mThree, mEvictor.evict());
    }
  
    @Test
    public void evictEmpty() {
      Assert.assertNull(mEvictor.evict());
    }
  
    @Test
    public void evictAllGone() {
      mEvictor.updateOnPut(mOne);
      mEvictor.updateOnPut(mTwo);
      mEvictor.updateOnPut(mTwo);
      mEvictor.updateOnPut(mThree);
      mEvictor.updateOnPut(mThree);
      mEvictor.updateOnPut(mThree);
      mEvictor.updateOnDelete(mOne);
      mEvictor.updateOnDelete(mTwo);
      mEvictor.updateOnDelete(mThree);
      Assert.assertNull(mEvictor.evict());
    }
  }
  