hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/utils/db/cache/CacheKey.java

/**
 * 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.hadoop.hdds.utils.db.cache;

import java.util.Objects;

/**
 * CacheKey for the RocksDB table.
 * @param <KEY>
 */
public class CacheKey<KEY> implements Comparable<KEY> {

  private final KEY key;

  public CacheKey(KEY key) {
    Objects.requireNonNull(key, "Key Should not be null in CacheKey");
    this.key = key;
  }

  public KEY getCacheKey() {
    return key;
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }
    CacheKey<?> cacheKey = (CacheKey<?>) o;
    return Objects.equals(key, cacheKey.key);
  }

  @Override
  public int hashCode() {
    return Objects.hash(key);
  }

  @Override
  public int compareTo(Object o) {
    if(Objects.equals(key, ((CacheKey<?>)o).key)) {
      return 0;
    } else {
      return key.toString().compareTo((((CacheKey<?>) o).key).toString());
    }
  }
}