| /* |
| * 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.samza.metadatastore; |
| |
| import org.apache.samza.annotation.InterfaceStability; |
| import org.apache.samza.config.Config; |
| import org.apache.samza.metrics.MetricsRegistry; |
| import java.util.Map; |
| |
| /** |
| * Store abstraction responsible for managing the metadata of a Samza job. |
| */ |
| @InterfaceStability.Evolving |
| public interface MetadataStore { |
| |
| /** |
| * Initializes the metadata store, if applicable, setting up the underlying resources |
| * and connections to the store endpoints. |
| * |
| * @param config the configuration for instantiating the MetadataStore. |
| */ |
| void init(Config config, MetricsRegistry metricsRegistry); |
| |
| /** |
| * Gets the value associated with the specified {@code key}. |
| * |
| * @param key the key with which the associated value is to be fetched. |
| * @return if found, the value associated with the specified {@code key}; otherwise, {@code null}. |
| */ |
| byte[] get(byte[] key); |
| |
| /** |
| * Updates the mapping of the specified key-value pair. |
| * |
| * @param key the key with which the specified {@code value} is to be associated. |
| * @param value the value with which the specified {@code key} is to be associated. |
| */ |
| void put(byte[] key, byte[] value); |
| |
| /** |
| * Deletes the mapping for the specified {@code key} from this metadata store (if such mapping exists). |
| * |
| * @param key the key for which the mapping is to be deleted. |
| */ |
| void delete(byte[] key); |
| |
| /** |
| * Returns all the entries in this metadata store. |
| * |
| * @return all entries in this metadata store. |
| */ |
| Map<byte[], byte[]> all(); |
| |
| /** |
| * Flushes the metadata store, if applicable. |
| */ |
| void flush(); |
| |
| /** |
| * Closes the metadata store, if applicable, relinquishing all the underlying resources |
| * and connections. |
| */ |
| void close(); |
| } |