/**
* 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 backtype.storm.state;
/**
* A state that supports key-value mappings.
*/
public interface KeyValueState<K, V> extends State {
/**
* Maps the value with the key
*
* @param key the key
* @param value the value
*/
void put(K key, V value);
/**
* Returns the value mapped to the key
*
* @param key the key
* @return the value or null if no mapping is found
*/
V get(K key);
/**
* Returns the value mapped to the key or defaultValue if no mapping is found.
*
* @param key the key
* @param defaultValue the value to return if no mapping is found
* @return the value or defaultValue if no mapping is found
*/
V get(K key, V defaultValue);
}