| /* |
| * 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.dataflow.worker; |
| |
| import com.google.api.services.dataflow.model.SideInputInfo; |
| import java.util.HashSet; |
| import java.util.Set; |
| import javax.annotation.Nullable; |
| import org.apache.beam.runners.core.SideInputReader; |
| import org.apache.beam.sdk.transforms.windowing.BoundedWindow; |
| import org.apache.beam.sdk.values.PCollectionView; |
| import org.apache.beam.sdk.values.TupleTag; |
| import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Supplier; |
| import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Suppliers; |
| |
| /** |
| * A {@link SideInputReader} which initializes on first {@link #get(PCollectionView, BoundedWindow)} |
| * call. |
| */ |
| public class LazilyInitializedSideInputReader implements SideInputReader { |
| private final Set<TupleTag<?>> tupleTags; |
| private final Supplier<SideInputReader> lazyInitSideInputReader; |
| |
| public LazilyInitializedSideInputReader( |
| Iterable<? extends SideInputInfo> sideInputInfos, Supplier<SideInputReader> sideInputReader) { |
| tupleTags = new HashSet<>(); |
| for (SideInputInfo sideInputInfo : sideInputInfos) { |
| tupleTags.add(new TupleTag<>(sideInputInfo.getTag())); |
| } |
| lazyInitSideInputReader = Suppliers.memoize(sideInputReader); |
| } |
| |
| @Nullable |
| @Override |
| public <T> T get(PCollectionView<T> view, BoundedWindow window) { |
| return lazyInitSideInputReader.get().get(view, window); |
| } |
| |
| @Override |
| public <T> boolean contains(PCollectionView<T> view) { |
| return tupleTags.contains(view.getTagInternal()); |
| } |
| |
| @Override |
| public boolean isEmpty() { |
| return tupleTags.isEmpty(); |
| } |
| } |