/*
 * 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.geode.internal.cache.persistence.query;

import org.apache.geode.internal.cache.CachedDeserializable;

/**
 * The contract for a sorted set of temporary results for a query. This set may be persisted on
 * disk.
 * 
 * This class is threadsafe. Iterators will reflect all entries added to the set up until the time
 * that the iterator was obtained. After that they may or may not reflect modifications to the set
 * while the iteration is in progress. They will guarantee that entries will be returned in the
 * correct order.
 * 
 * The key and value are both allowed to be an object, or a CachedDeserializable.
 * 
 * @since GemFire cedar
 */
public interface ResultMap {

  /**
   * Add an entry to the map. If the same key exists in the map it is replaced with the new value
   * 
   * @param key the key for the entry. The key may be NULL.
   * @param value a value for the entry, or NULL for no value
   */
  void put(Object key, Object value);

  /**
   * Remove an entry from the map.
   * 
   * @param key the key to remove
   * 
   *        This method has no effect if the key does not exist in the map.
   */
  void remove(Object key);

  /**
   * Return the Entry for a given key
   */
  Entry getEntry(Object key);

  /**
   * Return the value for a given key
   */
  CachedDeserializable get(Object key);

  /**
   * return true if this map contains the given key
   */
  public boolean containsKey(Object e);

  /**
   * Return all of the IndexEntries in the range between start and end. If end < start, this will
   * return a descending iterator going from end to start.
   */
  CloseableIterator<Entry> iterator(Object start, boolean startInclusive, Object end,
      boolean endInclusive);

  /**
   * Return all of the IndexEntries that from start to the tail of the map.
   */
  CloseableIterator<Entry> iterator(Object start, boolean startInclusive);

  /**
   * Return all of the IndexEntries in the map.
   */
  CloseableIterator<Entry> iterator();

  /**
   * Return all of the region keys from start to end.
   */
  CloseableIterator<CachedDeserializable> keyIterator(Object start, boolean startInclusive,
      Object end, boolean endInclusive);

  /**
   * Return all of the region keys from start to the tail of the map
   */
  CloseableIterator<CachedDeserializable> keyIterator(Object start, boolean startInclusive);

  /**
   * Return all of the region keys in the map
   */
  CloseableIterator<CachedDeserializable> keyIterator();

  /**
   * Close the map to free up resources.
   */
  void close();

  /**
   * A single entry in an index
   * 
   * @since GemFire cedar
   */
  interface Entry {
    /**
     * Return the index key of the entry. May be NULL.
     */
    CachedDeserializable getKey();

    /**
     * Return the value of the entry. May be NULL.
     */
    CachedDeserializable getValue();
  }
}
