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
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * 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.kafka.common.cache;
  
  import org.junit.jupiter.api.Test;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertNull;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  public class LRUCacheTest {
  
      @Test
      public void testPutGet() {
          Cache<String, String> cache = new LRUCache<>(4);
  
          cache.put("a", "b");
          cache.put("c", "d");
          cache.put("e", "f");
          cache.put("g", "h");
  
          assertEquals(4, cache.size());
  
          assertEquals("b", cache.get("a"));
          assertEquals("d", cache.get("c"));
          assertEquals("f", cache.get("e"));
          assertEquals("h", cache.get("g"));
      }
  
      @Test
      public void testRemove() {
          Cache<String, String> cache = new LRUCache<>(4);
  
          cache.put("a", "b");
          cache.put("c", "d");
          cache.put("e", "f");
          assertEquals(3, cache.size());
  
          assertTrue(cache.remove("a"));
          assertEquals(2, cache.size());
          assertNull(cache.get("a"));
          assertEquals("d", cache.get("c"));
          assertEquals("f", cache.get("e"));
  
          assertFalse(cache.remove("key-does-not-exist"));
  
          assertTrue(cache.remove("c"));
          assertEquals(1, cache.size());
          assertNull(cache.get("c"));
          assertEquals("f", cache.get("e"));
  
          assertTrue(cache.remove("e"));
          assertEquals(0, cache.size());
          assertNull(cache.get("e"));
      }
  
      @Test
      public void testEviction() {
          Cache<String, String> cache = new LRUCache<>(2);
  
          cache.put("a", "b");
          cache.put("c", "d");
          assertEquals(2, cache.size());
  
          cache.put("e", "f");
          assertEquals(2, cache.size());
          assertNull(cache.get("a"));
          assertEquals("d", cache.get("c"));
          assertEquals("f", cache.get("e"));
  
          // Validate correct access order eviction
          cache.get("c");
          cache.put("g", "h");
          assertEquals(2, cache.size());
          assertNull(cache.get("e"));
          assertEquals("d", cache.get("c"));
          assertEquals("h", cache.get("g"));
      }
  }
  