| /* |
| * 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.sdk.extensions.euphoria.core.translate; |
| |
| import java.util.Optional; |
| import org.apache.beam.sdk.extensions.euphoria.core.client.operator.base.Operator; |
| import org.apache.beam.sdk.transforms.PTransform; |
| import org.apache.beam.sdk.values.PCollection; |
| import org.apache.beam.sdk.values.PCollectionList; |
| import org.apache.beam.vendor.guava.v20_0.com.google.common.base.Preconditions; |
| |
| /** |
| * Expand operator to a beam {@link PTransform}. |
| * |
| * @param <InputT> type of input elements |
| * @param <OutputT> type of output elements |
| * @param <OperatorT> type of operator to expand |
| */ |
| public class OperatorTransform<InputT, OutputT, OperatorT extends Operator<OutputT>> |
| extends PTransform<PCollectionList<InputT>, PCollection<OutputT>> { |
| |
| public static <InputT, OutputT, OperatorT extends Operator<OutputT>> PCollection<OutputT> apply( |
| OperatorT operator, PCollectionList<InputT> inputs) { |
| |
| final Optional<OperatorTranslator<InputT, OutputT, OperatorT>> maybeTranslator = |
| TranslatorProvider.of(inputs.getPipeline()).findTranslator(operator); |
| |
| if (maybeTranslator.isPresent()) { |
| final PCollection<OutputT> output = |
| inputs.apply( |
| operator.getName().orElseGet(() -> operator.getClass().getName()), |
| new OperatorTransform<>(operator, maybeTranslator.orElse(null))); |
| Preconditions.checkState( |
| output.getTypeDescriptor() != null, |
| "Translator should always return a typed PCollection."); |
| return output; |
| } |
| |
| throw new IllegalStateException( |
| "Unable to find translator for basic operator [" |
| + operator.getClass() |
| + "] with name [" |
| + operator.getName().orElse(null) |
| + "]"); |
| } |
| |
| private final OperatorT operator; |
| private final OperatorTranslator<InputT, OutputT, OperatorT> translator; |
| |
| private OperatorTransform( |
| OperatorT operator, OperatorTranslator<InputT, OutputT, OperatorT> translator) { |
| this.operator = operator; |
| this.translator = translator; |
| } |
| |
| @Override |
| public PCollection<OutputT> expand(PCollectionList<InputT> inputs) { |
| return translator.translate(operator, inputs); |
| } |
| |
| public OperatorT getOperator() { |
| return operator; |
| } |
| } |