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/*
 * Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
 *
 * Licensed 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. See accompanying
 * LICENSE file.
 */
package com.gemstone.gemfire.internal.cache.persistence.soplog;

import java.nio.ByteBuffer;

import com.gemstone.gemfire.internal.cache.persistence.soplog.SortedReader.SerializedComparator;

/**
 * Creates and compares composite keys.
 * 
 * @author bakera
 */
public interface CompositeSerializedComparator extends SerializedComparator  {
  /**
   * Constructs a composite key consisting of a primary key and a secondary key.
   * 
   * @param key1 the primary key
   * @param key2 the secondary key
   * @return the composite key
   */
  public byte[] createCompositeKey(byte[] key1, byte[] key2);
  
  /**
   * Constructs a composite key by combining the supplied keys.  The number of
   * keys and their order must match the comparator set.
   * 
   * The WILDCARD_KEY token may be used to match all subkeys in the
   * given ordinal position.  This is useful when constructing a search key to
   * retrieve all keys for a given primary key, ignoring the remaining subkeys.
   * 
   * @param keys the keys, ordered by sort priority
   * @return the composite key
   */
  public byte[] createCompositeKey(byte[]... keys);
  
  /**
   * Returns subkey for the given ordinal position.
   * @param key the composite key
   * @return the subkey
   */
  public ByteBuffer getKey(ByteBuffer key, int ordinal);
}