| /** |
| * 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.storm.state; |
| |
| import java.util.Map; |
| |
| /** |
| * A state that supports key-value mappings. |
| */ |
| public interface KeyValueState<K, V> extends State, Iterable<Map.Entry<K, V>> { |
| /** |
| * 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); |
| |
| /** |
| * Deletes the value mapped to the key, if there is any. |
| * |
| * @param key the key |
| */ |
| V delete(K key); |
| } |