/*
 * 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.tsfile.external.commons.collections4;

import java.util.Collection;
import java.util.Set;

/**
 * The "read" subset of the {@link java.util.Map} interface.
 *
 * @param <K> the type of the keys in this map
 * @param <V> the type of the values in this map
 * @since 4.0
 * @see Put
 */
public interface Get<K, V> {

  /**
   * @param key key whose presence in this map is to be tested
   * @return <code>true</code> if this map contains a mapping for the specified key
   * @see java.util.Map#containsKey(Object)
   */
  boolean containsKey(Object key);

  /**
   * @param value value whose presence in this map is to be tested
   * @return <code>true</code> if this map maps one or more keys to the specified value
   * @see java.util.Map#containsValue(Object)
   */
  boolean containsValue(Object value);

  /**
   * @return a set view of the mappings contained in this map
   * @see java.util.Map#entrySet()
   */
  Set<java.util.Map.Entry<K, V>> entrySet();

  /**
   * @param key the key whose associated value is to be returned
   * @return the value to which the specified key is mapped, or {@code null} if this map contains no
   *     mapping for the key
   * @see java.util.Map#get(Object)
   */
  V get(Object key);

  /**
   * @param key key whose mapping is to be removed from the map
   * @return the previous value associated with <code>key</code>, or <code>null</code> if there was
   *     no mapping for <code>key</code>.
   * @see java.util.Map#remove(Object)
   */
  V remove(Object key);

  /**
   * @return <code>true</code> if this map contains no key-value mappings
   * @see java.util.Map#isEmpty()
   */
  boolean isEmpty();

  /**
   * @return a set view of the keys contained in this map
   * @see java.util.Map#keySet()
   */
  Set<K> keySet();

  /**
   * @return the number of key-value mappings in this map
   * @see java.util.Map#size()
   */
  int size();

  /**
   * @return a collection view of the values contained in this map
   * @see java.util.Map#values()
   */
  Collection<V> values();
}
