| /* |
| * 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.wayang.java.operators; |
| |
| import java.util.Collection; |
| import java.util.stream.Stream; |
| import org.apache.wayang.core.api.exception.WayangException; |
| import org.apache.wayang.core.optimizer.OptimizationContext; |
| import org.apache.wayang.core.plan.wayangplan.ExecutionOperator; |
| import org.apache.wayang.core.platform.ChannelInstance; |
| import org.apache.wayang.core.platform.lineage.ExecutionLineageNode; |
| import org.apache.wayang.core.util.Tuple; |
| import org.apache.wayang.java.channels.CollectionChannel; |
| import org.apache.wayang.java.channels.JavaChannelInstance; |
| import org.apache.wayang.java.channels.StreamChannel; |
| import org.apache.wayang.java.execution.JavaExecutor; |
| import org.apache.wayang.java.platform.JavaPlatform; |
| |
| /** |
| * Execution operator for the Java platform. |
| */ |
| public interface JavaExecutionOperator extends ExecutionOperator { |
| |
| @Override |
| default JavaPlatform getPlatform() { |
| return JavaPlatform.getInstance(); |
| } |
| |
| /** |
| * Evaluates this operator. Takes a set of Java {@link Stream}s according to the operator inputs and produces |
| * a set of {@link Stream}s according to the operator outputs -- unless the operator is a sink, then it triggers |
| * execution. |
| * <p>In addition, this method should give feedback of what this instance was doing by wiring the |
| * {@link org.apache.wayang.core.platform.lineage.LazyExecutionLineageNode}s of input and ouput {@link ChannelInstance}s and |
| * providing a {@link Collection} of executed {@link OptimizationContext.OperatorContext}s.</p> |
| * |
| * @param inputs {@link ChannelInstance}s that satisfy the inputs of this operator |
| * @param outputs {@link ChannelInstance}s that collect the outputs of this operator |
| * @param javaExecutor that executes this instance |
| * @param operatorContext optimization information for this instance |
| * @return {@link Collection}s of what has been executed and produced |
| */ |
| Tuple<Collection<ExecutionLineageNode>, Collection<ChannelInstance>> evaluate( |
| ChannelInstance[] inputs, |
| ChannelInstance[] outputs, |
| JavaExecutor javaExecutor, |
| OptimizationContext.OperatorContext operatorContext); |
| |
| /** |
| * Utility method to forward a {@link JavaChannelInstance} to another. |
| * |
| * @param input that should be forwarded |
| * @param output to that should be forwarded |
| */ |
| static void forward(ChannelInstance input, ChannelInstance output) { |
| // Do the forward. |
| if (output instanceof CollectionChannel.Instance) { |
| ((CollectionChannel.Instance) output).accept(((CollectionChannel.Instance) input).provideCollection()); |
| } else if (output instanceof StreamChannel.Instance) { |
| ((StreamChannel.Instance) output).accept(((JavaChannelInstance) input).provideStream()); |
| } else { |
| throw new WayangException(String.format("Cannot forward %s to %s.", input, output)); |
| } |
| |
| // Manipulate the lineage. |
| output.getLineage().addPredecessor(input.getLineage()); |
| } |
| |
| } |