taegeonum commented on a change in pull request #159: [NEMO-216,251,259] Support side inputs and windowing URL: https://github.com/apache/incubator-nemo/pull/159#discussion_r234430490
########## File path: compiler/frontend/beam/src/main/java/org/apache/nemo/compiler/frontend/beam/transform/SideInputTransform.java ########## @@ -0,0 +1,71 @@ +/* + * 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.nemo.compiler.frontend.beam.transform; + +import org.apache.beam.sdk.util.WindowedValue; +import org.apache.nemo.common.ir.OutputCollector; +import org.apache.nemo.common.ir.vertex.transform.Transform; +import org.apache.nemo.common.punctuation.Watermark; +import org.apache.nemo.compiler.frontend.beam.SideInputElement; + +/** + * Side input transform implementation. + * @param <T> input/output type. + */ +public final class SideInputTransform<T> implements Transform<WindowedValue<T>, SideInputElement> { Review comment: @johnyangk I agree with your concern but I think the cost is negligible and not expensive because creating view is not frequent operation. This is an optimization for special case not common case (main input), so I prefer to use `PCollectionView` and keep the code more explicitly and concisely. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
