org.apache.kafka.streams.state.KeyValueStore Maven / Gradle / Ivy

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/*
 * 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.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  The key type
 * @param  The value type
 */
public interface KeyValueStore extends StateStore, ReadOnlyKeyValueStore {

    /**
     * Update the value associated with this key.
     *
     * @param key   The key to associate the value to
     * @param value The value to update, it can be {@code null};
     *              if the serialized bytes are also {@code null} it is interpreted as deletes
     * @throws NullPointerException If {@code null} is used for key.
     */
    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 to update, it can be {@code null};
     *              if the serialized bytes are also {@code null} it is interpreted as deletes
     * @return The old value or {@code null} if there is no such key.
     * @throws NullPointerException If {@code null} is used for key.
     */
    V putIfAbsent(K key, V value);

    /**
     * Update all the given key/value pairs.
     *
     * @param entries A list of entries to put into the store;
     *                if the serialized bytes are also {@code null} it is interpreted as deletes
     * @throws NullPointerException If {@code null} is used for key.
     */
    void putAll(List> entries);

    /**
     * Delete the value from the store (if there is one).
     *
     * @param key The key
     * @return The old value or {@code null} if there is no such key.
     * @throws NullPointerException If {@code null} is used for key.
     */
    V delete(K key);
}