| /* |
| * 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 static org.apache.beam.vendor.guava.v20_0.com.google.common.base.Preconditions.checkState; |
| |
| import org.apache.beam.sdk.extensions.euphoria.core.client.operator.CompositeOperator; |
| import org.apache.beam.sdk.extensions.euphoria.core.client.operator.base.Operator; |
| import org.apache.beam.sdk.values.PCollection; |
| import org.apache.beam.sdk.values.PCollectionList; |
| |
| /** |
| * A translator that expands {@link CompositeOperator composite operators}. |
| * |
| * @param <InputT> input type |
| * @param <OutputT> output type |
| * @param <OperatorT> operator type |
| */ |
| public class CompositeOperatorTranslator<InputT, OutputT, OperatorT extends Operator> |
| implements OperatorTranslator<InputT, OutputT, OperatorT> { |
| |
| @SuppressWarnings("unchecked") |
| @Override |
| public PCollection<OutputT> translate(OperatorT operator, PCollectionList<InputT> inputs) { |
| checkState(operator instanceof CompositeOperator, "Operator is not composite."); |
| return ((CompositeOperator<InputT, OutputT>) operator).expand(inputs); |
| } |
| |
| @Override |
| public boolean canTranslate(OperatorT operator) { |
| return operator instanceof CompositeOperator; |
| } |
| } |