| /** |
| * 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.crunch; |
| |
| import static org.junit.Assert.assertEquals; |
| |
| import java.io.IOException; |
| |
| import org.apache.crunch.fn.IdentityFn; |
| import org.apache.crunch.impl.mr.MRPipeline; |
| import org.apache.crunch.test.TemporaryPath; |
| import org.apache.crunch.test.TemporaryPaths; |
| import org.apache.crunch.types.PTableType; |
| import org.apache.crunch.types.PType; |
| import org.apache.crunch.types.writable.Writables; |
| import org.junit.Before; |
| import org.junit.Rule; |
| import org.junit.Test; |
| |
| /** |
| * Collection of tests re-using the same PCollection in various unions. |
| */ |
| public class UnionFromSameSourceIT { |
| |
| private static final int NUM_ELEMENTS = 4; |
| |
| @Rule |
| public transient TemporaryPath tmpDir = TemporaryPaths.create(); |
| |
| private Pipeline pipeline; |
| private PType<String> elementType = Writables.strings(); |
| private PTableType<String, String> tableType = Writables.tableOf(Writables.strings(), |
| Writables.strings()); |
| |
| @Before |
| public void setUp() { |
| pipeline = new MRPipeline(UnionFromSameSourceIT.class, tmpDir.getDefaultConfiguration()); |
| } |
| |
| @Test |
| public void testUnion_SingleRead() throws IOException { |
| PCollection<String> strings = pipeline.readTextFile(tmpDir.copyResourceFileName("set1.txt")); |
| PCollection<String> union = strings.union(strings.parallelDo(IdentityFn.<String> getInstance(), |
| strings.getPType())); |
| |
| assertEquals(NUM_ELEMENTS * 2, getCount(union)); |
| } |
| |
| @Test |
| public void testUnion_TwoReads() throws IOException { |
| PCollection<String> stringsA = pipeline.readTextFile(tmpDir.copyResourceFileName("set1.txt")); |
| PCollection<String> stringsB = pipeline.readTextFile(tmpDir.copyResourceFileName("set1.txt")); |
| |
| PCollection<String> union = stringsA.union(stringsB); |
| |
| assertEquals(NUM_ELEMENTS * 2, getCount(union)); |
| } |
| |
| @Test |
| public void testDoubleUnion_EndingWithGBK() throws IOException { |
| runDoubleUnionPipeline(true); |
| } |
| |
| @Test |
| public void testDoubleUnion_EndingWithoutGBK() throws IOException { |
| runDoubleUnionPipeline(false); |
| } |
| |
| private void runDoubleUnionPipeline(boolean endWithGBK) throws IOException { |
| PCollection<String> strings = pipeline.readTextFile(tmpDir.copyResourceFileName("set1.txt")); |
| PTable<String, String> tableA = strings.parallelDo("to table A", new ToTableFn(), tableType); |
| PTable<String, String> tableB = strings.parallelDo("to table B", new ToTableFn(), tableType); |
| |
| PGroupedTable<String, String> groupedTable = tableA.union(tableB).groupByKey(); |
| PCollection<String> ungrouped = groupedTable.parallelDo("ungroup before union", |
| new FromGroupedTableFn(), elementType).union( |
| strings.parallelDo("fake id", IdentityFn.<String> getInstance(), elementType)); |
| |
| PTable<String, String> table = ungrouped.parallelDo("union back to table", new ToTableFn(), |
| tableType); |
| |
| if (endWithGBK) { |
| table = table.groupByKey().ungroup(); |
| } |
| |
| assertEquals(3 * NUM_ELEMENTS, getCount(table)); |
| } |
| |
| private int getCount(PCollection<?> pcollection) { |
| int cnt = 0; |
| for (Object v : pcollection.materialize()) { |
| cnt++; |
| } |
| return cnt; |
| } |
| |
| private static class ToTableFn extends MapFn<String, Pair<String, String>> { |
| |
| @Override |
| public Pair<String, String> map(String input) { |
| return Pair.of(input, input); |
| } |
| |
| } |
| |
| private static class FromGroupedTableFn extends DoFn<Pair<String, Iterable<String>>, String> { |
| |
| @Override |
| public void process(Pair<String, Iterable<String>> input, Emitter<String> emitter) { |
| for (String value : input.second()) { |
| emitter.emit(value); |
| } |
| } |
| |
| } |
| |
| } |