content: /**
   * Copyright The Apache Software Foundation
   *
   * 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.bookkeeper.bookie;
  
  import java.io.Serializable;
  import java.util.Comparator;
  
  /**
   * An {@code EntryKey} represents an entry in a ledger, identified by {@code ledgerId} and {@code entryId}.
   *
   * <p>This class is mainly used in {@code SortedLedgerStorage} for managing and sorting the entries in the memtable.
   */
  public class EntryKey {
      long ledgerId;
      long entryId;
  
      public EntryKey() {
          this(0, 0);
      }
  
      public EntryKey(long ledgerId, long entryId) {
          this.ledgerId = ledgerId;
          this.entryId = entryId;
      }
  
      public long getLedgerId() {
          return ledgerId;
      }
  
      public long getEntryId() {
          return entryId;
      }
  
      /**
      * Comparator for the key portion.
      */
      public static final KeyComparator COMPARATOR = new KeyComparator();
  
      // Only compares the key portion
      @Override
      public boolean equals(Object other) {
          if (!(other instanceof EntryKey)) {
            return false;
          }
          EntryKey key = (EntryKey) other;
          return ledgerId == key.ledgerId && entryId == key.entryId;
      }
  
      @Override
      public int hashCode() {
          return (int) (ledgerId * 13 ^ entryId * 17);
      }
  }
  
  /**
  * Compare EntryKey.
  */
  class KeyComparator implements Comparator<EntryKey>, Serializable {
  
      private static final long serialVersionUID = 0L;
  
      @Override
      public int compare(EntryKey left, EntryKey right) {
          long ret = left.ledgerId - right.ledgerId;
          if (ret == 0) {
              ret = left.entryId - right.entryId;
          }
          return (ret < 0) ? -1 : ((ret > 0) ? 1 : 0);
      }
  }
  