| /* |
| * 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.io.BufferedReader; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.InputStreamReader; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.stream.Stream; |
| import org.apache.wayang.basic.operators.TextFileSource; |
| import org.apache.wayang.core.api.exception.WayangException; |
| import org.apache.wayang.core.optimizer.OptimizationContext; |
| import org.apache.wayang.core.optimizer.costs.LoadProfileEstimators; |
| import org.apache.wayang.core.platform.ChannelDescriptor; |
| 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.core.util.fs.FileSystem; |
| import org.apache.wayang.core.util.fs.FileSystems; |
| import org.apache.wayang.java.channels.StreamChannel; |
| import org.apache.wayang.java.execution.JavaExecutor; |
| |
| /** |
| * This is execution operator implements the {@link TextFileSource}. |
| */ |
| public class JavaTextFileSource extends TextFileSource implements JavaExecutionOperator { |
| |
| public JavaTextFileSource(String inputUrl) { |
| super(inputUrl); |
| } |
| |
| /** |
| * Copies an instance (exclusive of broadcasts). |
| * |
| * @param that that should be copied |
| */ |
| public JavaTextFileSource(TextFileSource that) { |
| super(that); |
| } |
| |
| @Override |
| public Tuple<Collection<ExecutionLineageNode>, Collection<ChannelInstance>> evaluate( |
| ChannelInstance[] inputs, |
| ChannelInstance[] outputs, |
| JavaExecutor javaExecutor, |
| OptimizationContext.OperatorContext operatorContext) { |
| assert inputs.length == this.getNumInputs(); |
| assert outputs.length == this.getNumOutputs(); |
| |
| String url = this.getInputUrl().trim(); |
| FileSystem fs = FileSystems.getFileSystem(url).orElseThrow( |
| () -> new WayangException(String.format("Cannot access file system of %s.", url)) |
| ); |
| |
| try { |
| final InputStream inputStream = fs.open(url); |
| Stream<String> lines = new BufferedReader(new InputStreamReader(inputStream)).lines(); |
| ((StreamChannel.Instance) outputs[0]).accept(lines); |
| } catch (IOException e) { |
| throw new WayangException(String.format("Reading %s failed.", url), e); |
| } |
| |
| ExecutionLineageNode prepareLineageNode = new ExecutionLineageNode(operatorContext); |
| prepareLineageNode.add(LoadProfileEstimators.createFromSpecification( |
| "wayang.java.textfilesource.load.prepare", javaExecutor.getConfiguration() |
| )); |
| ExecutionLineageNode mainLineageNode = new ExecutionLineageNode(operatorContext); |
| mainLineageNode.add(LoadProfileEstimators.createFromSpecification( |
| "wayang.java.textfilesource.load.main", javaExecutor.getConfiguration() |
| )); |
| |
| outputs[0].getLineage().addPredecessor(mainLineageNode); |
| |
| return prepareLineageNode.collectAndMark(); |
| } |
| |
| @Override |
| public Collection<String> getLoadProfileEstimatorConfigurationKeys() { |
| return Arrays.asList("wayang.java.textfilesource.load.prepare", "wayang.java.textfilesource.load.main"); |
| } |
| |
| @Override |
| public JavaTextFileSource copy() { |
| return new JavaTextFileSource(this.getInputUrl()); |
| } |
| |
| @Override |
| public List<ChannelDescriptor> getSupportedInputChannels(int index) { |
| throw new UnsupportedOperationException(String.format("%s does not have input channels.", this)); |
| } |
| |
| @Override |
| public List<ChannelDescriptor> getSupportedOutputChannels(int index) { |
| assert index <= this.getNumOutputs() || (index == 0 && this.getNumOutputs() == 0); |
| return Collections.singletonList(StreamChannel.DESCRIPTOR); |
| } |
| |
| } |