/* * 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.kafka.streams.state; import org.apache.kafka.common.annotation.InterfaceStability; import org.apache.kafka.streams.KeyValue; import org.apache.kafka.streams.processor.StateStore; import java.util.List; /** * A key-value store that supports put/get/delete and range queries. * * @param <K> The key type * @param <V> The value type */ @InterfaceStability.Unstable public interface KeyValueStore<K, V> extends StateStore, ReadOnlyKeyValueStore<K, V> { /** * Update the value associated with this key * * @param key The key to associate the value to * @param value The value * @throws NullPointerException If null is used for key or value. */ void put(K key, V value); /** * Update the value associated with this key, unless a value * is already associated with the key * * @param key The key to associate the value to * @param value The value * @return The old value or null if there is no such key. * @throws NullPointerException If null is used for key or value. */ V putIfAbsent(K key, V value); /** * Update all the given key/value pairs * * @param entries A list of entries to put into the store. * @throws NullPointerException If null is used for any key or value. */ void putAll(List<KeyValue<K, V>> entries); /** * Delete the value from the store (if there is one) * * @param key The key * @return The old value or null if there is no such key. * @throws NullPointerException If null is used for key. */ V delete(K key); }