content: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   * <p>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p>
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.atlas.utils;
  
  import org.apache.commons.lang.RandomStringUtils;
  import org.testng.annotations.Test;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import static org.testng.Assert.assertEquals;
  import static org.testng.Assert.assertFalse;
  import static org.testng.Assert.assertNull;
  import static org.testng.Assert.assertTrue;
  
  /**
   * Tests the LruCache.
   */
  @Test
  public class LruCacheTest {
      /**
       * Tests the basic operations on the cache.
       */
      @Test
      public void testBasicOps() {
          LruCache<String, String> cache = new LruCache<>(1000, 0);
          // Get the static cache and populate it. Its size and other
          // characteristics depend on the bootstrap properties that are hard to
          // control in a test. So it is hard to see that if we add more entries
          // than the size of the cache one is evicted, or that it gets reaped at
          // the right time. However, a lot of this type of functionality is
          // tested by the underlying LruCache's test.
  
          // Note that query handle IDs are of the form sessionID::queryID
          String h1 = createHandle("s1::", "1::");
          String q1 = createQuery();
  
          String h2 = createHandle("s1::", "2::");
          String q2 = createQuery();
  
          String h3 = createHandle("s2::", "1::");
          String q3 = createQuery();
  
          String h4 = createHandle("s1::", "3::");
          String q4 = createQuery();
  
          String h5 = createHandle("s3::", null);
          String q5 = createQuery();
  
          String h5b = createHandle("s3::", null);
          String q5b = createQuery();
  
          String h6 = createHandle(null, "3::");
          String q6 = createQuery();
  
          String h6b = createHandle(null, "3::");
          String q6b = createQuery();
  
          // Test put and get.
          cache.put(h1, q1);
          cache.put(h2, q2);
          cache.put(h3, q3);
          cache.put(h4, q4);
          cache.put(h5, q5);
          cache.put(h6, q6);
  
          assertEquals(cache.get(h1), q1);
          assertEquals(cache.get(h2), q2);
          assertEquals(cache.get(h3), q3);
          assertEquals(cache.get(h4), q4);
          assertEquals(cache.get(h5), q5);
  
          assertEquals(cache.remove(h1), q1);
          assertEquals(cache.remove(h2), q2);
          assertEquals(cache.remove(h3), q3);
          assertEquals(cache.remove(h4), q4);
          assertEquals(cache.remove(h5), q5);
          assertNull(cache.remove(h5b));
          assertEquals(q6, cache.remove(h6));
          assertNull(cache.remove(h6b));
  
          cache.put(h5b, q5b);
          cache.put(h6b, q6b);
  
          assertEquals(q5b, cache.remove(h5));
          assertNull(cache.remove(h5b));
          assertEquals(q6b, cache.remove(h6));
          assertNull(cache.remove(h6b));
      }
  
      @Test
      public void testMapOperations() {
          Map<String, String> reference = new HashMap<>();
  
          reference.put("name", "Fred");
          reference.put("occupation", "student");
          reference.put("height", "5'11");
          reference.put("City", "Littleton");
          reference.put("State", "MA");
  
          LruCache<String, String> map = new LruCache<>(10, 10);
  
          map.putAll(reference);
  
          assertEquals(map.size(), reference.size());
          assertEquals(map.size(), reference.size());
          assertTrue(map.keySet().containsAll(reference.keySet()));
          assertTrue(reference.keySet().containsAll(map.keySet()));
  
          assertEquals(reference.size(), map.size());
  
          for (Map.Entry<String, String> entry : map.entrySet()) {
              assertTrue(reference.containsKey(entry.getKey()));
              assertEquals(entry.getValue(), reference.get(entry.getKey()));
              assertTrue(map.containsKey(entry.getKey()));
              assertTrue(map.containsValue(entry.getValue()));
              assertTrue(map.containsValue(entry.getValue()));
          }
  
          assertEquals(map, reference);
          assertEquals(reference, map);
      }
  
      @Test
      public void testReplaceValueInMap() {
          LruCache<String, String> map = new LruCache<>(10, 10);
  
          map.put("name", "Fred");
          map.put("name", "George");
  
          assertEquals(map.get("name"), "George");
          assertEquals(map.size(), 1);
      }
  
      @Test
      public void testOrderUpdatedWhenAddExisting() {
          LruCache<String, String> map = new LruCache<>(2, 10);
  
          map.put("name", "Fred");
          map.put("age", "15");
          map.put("name", "George");
  
          //age should be evicted
          map.put("height", "5'3\"");
  
          //age is now least recently used
          assertFalse(map.containsKey("age"));
      }
  
      @Test
      public void testMapRemove() {
          LruCache<String, String> map = new LruCache<>(10, 10);
  
          map.put("name", "Fred");
          map.put("occupation", "student");
          map.put("height", "5'11");
          map.put("City", "Littleton");
          map.put("State", "MA");
  
          assertMapHasSize(map, 5);
          assertTrue(map.containsKey("State"));
  
          map.remove("State");
  
          assertMapHasSize(map, 4);
          assertFalse(map.containsKey("State"));
      }
  
      @Test
      public void testEvict() {
          LruCache<String, String> map = new LruCache<>(5, 10);
  
          map.put("name", "Fred");
          map.put("occupation", "student");
          map.put("height", "5'11");
          map.put("City", "Littleton");
          map.put("State", "MA");
  
          assertMapHasSize(map, 5);
  
          //name should be evicted next
          assertTrue(map.containsKey("name"));
          map.put("zip", "01460");
          assertFalse(map.containsKey("name"));
          assertMapHasSize(map, 5);
  
          map.get("occupation");
          //height should be evicted next
          assertTrue(map.containsKey("height"));
          map.put("country", "USA");
          assertFalse(map.containsKey("height"));
          assertMapHasSize(map, 5);
      }
  
      private void assertMapHasSize(LruCache<String, String> map, int size) {
          assertEquals(map.size(), size);
          assertEquals(map.size(), size);
          assertEquals(map.size(), size);
          assertEquals(map.size(), size);
      }
  
      /**
       * Create a fake query handle for testing.
       *
       * @param s1
       * @param s2
       * @return a new query handle.
       */
      private String createHandle(String s1, String s2) {
          return s1 + ": " + s2 + ":select x from x in y";
      }
  
      /**
       * Create a mock IInternalQuery.
       *
       * @return a mock IInternalQuery.
       */
      private String createQuery() {
          return RandomStringUtils.randomAlphabetic(10);
      }
  }
  