| /* |
| * 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.beam.runners.core; |
| |
| import org.apache.beam.sdk.annotations.Experimental; |
| import org.apache.beam.sdk.annotations.Experimental.Kind; |
| import org.apache.beam.sdk.state.State; |
| import org.apache.beam.sdk.state.StateContext; |
| import org.apache.beam.sdk.state.StateContexts; |
| import org.apache.beam.sdk.transforms.GroupByKey; |
| |
| /** |
| * {@code StateInternals} describes the functionality a runner needs to provide for the State API to |
| * be supported. |
| * |
| * <p>The SDK will only use this after elements have been partitioned by key. For instance, after a |
| * {@link GroupByKey} operation. The runner implementation must ensure that any writes using {@link |
| * StateInternals} are implicitly scoped to the key being processed and the specific step accessing |
| * state. |
| * |
| * <p>The runner implementation must also ensure that any writes to the associated state objects are |
| * persisted together with the completion status of the processing that produced these writes. |
| * |
| * <p>This is a low-level API intended for use by the Beam SDK. It should not be used directly, and |
| * is highly likely to change. |
| */ |
| @Experimental(Kind.STATE) |
| public interface StateInternals { |
| |
| /** The key for this {@link StateInternals}. */ |
| Object getKey(); |
| |
| /** Return the state associated with {@code address} in the specified {@code namespace}. */ |
| default <T extends State> T state(StateNamespace namespace, StateTag<T> address) { |
| return state(namespace, address, StateContexts.nullContext()); |
| } |
| |
| /** |
| * Return the state associated with {@code address} in the specified {@code namespace} with the |
| * {@link StateContext}. |
| */ |
| <T extends State> T state(StateNamespace namespace, StateTag<T> address, StateContext<?> c); |
| } |