| /** |
| * 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.contrib.text; |
| |
| import java.util.List; |
| |
| import org.apache.crunch.Emitter; |
| import org.apache.crunch.MapFn; |
| import org.apache.crunch.PCollection; |
| import org.apache.crunch.PTable; |
| import org.apache.crunch.Pair; |
| import org.apache.crunch.types.PTableType; |
| import org.apache.crunch.types.PType; |
| import org.apache.crunch.types.PTypeFamily; |
| |
| /** |
| * Methods for parsing instances of {@code PCollection<String>} into {@code PCollection}'s of strongly-typed |
| * tuples. |
| */ |
| public final class Parse { |
| |
| /** |
| * Parses the lines of the input {@code PCollection<String>} and returns a {@code PCollection<T>} using |
| * the given {@code Extractor<T>}. |
| * |
| * @param groupName A label to use for tracking errors related to the parsing process |
| * @param input The input {@code PCollection<String>} to convert |
| * @param extractor The {@code Extractor<T>} that converts each line |
| * @return A {@code PCollection<T>} |
| */ |
| public static <T> PCollection<T> parse(String groupName, PCollection<String> input, |
| Extractor<T> extractor) { |
| return parse(groupName, input, input.getTypeFamily(), extractor); |
| } |
| |
| /** |
| * Parses the lines of the input {@code PCollection<String>} and returns a {@code PCollection<T>} using |
| * the given {@code Extractor<T>} that uses the given {@code PTypeFamily}. |
| * |
| * @param groupName A label to use for tracking errors related to the parsing process |
| * @param input The input {@code PCollection<String>} to convert |
| * @param ptf The {@code PTypeFamily} of the returned {@code PCollection<T>} |
| * @param extractor The {@code Extractor<T>} that converts each line |
| * @return A {@code PCollection<T>} |
| */ |
| public static <T> PCollection<T> parse(String groupName, PCollection<String> input, PTypeFamily ptf, |
| Extractor<T> extractor) { |
| return input.parallelDo(groupName, new ExtractorFn<T>(groupName, extractor), extractor.getPType(ptf)); |
| } |
| |
| /** |
| * Parses the lines of the input {@code PCollection<String>} and returns a {@code PTable<K, V>} using |
| * the given {@code Extractor<Pair<K, V>>}. |
| * |
| * @param groupName A label to use for tracking errors related to the parsing process |
| * @param input The input {@code PCollection<String>} to convert |
| * @param extractor The {@code Extractor<Pair<K, V>>} that converts each line |
| * @return A {@code PTable<K, V>} |
| */ |
| public static <K, V> PTable<K, V> parseTable(String groupName, PCollection<String> input, |
| Extractor<Pair<K, V>> extractor) { |
| return parseTable(groupName, input, input.getTypeFamily(), extractor); |
| } |
| |
| /** |
| * Parses the lines of the input {@code PCollection<String>} and returns a {@code PTable<K, V>} using |
| * the given {@code Extractor<Pair<K, V>>} that uses the given {@code PTypeFamily}. |
| * |
| * @param groupName A label to use for tracking errors related to the parsing process |
| * @param input The input {@code PCollection<String>} to convert |
| * @param ptf The {@code PTypeFamily} of the returned {@code PTable<K, V>} |
| * @param extractor The {@code Extractor<Pair<K, V>>} that converts each line |
| * @return A {@code PTable<K, V>} |
| */ |
| public static <K, V> PTable<K, V> parseTable(String groupName, PCollection<String> input, |
| PTypeFamily ptf, Extractor<Pair<K, V>> extractor) { |
| List<PType> st = extractor.getPType(ptf).getSubTypes(); |
| PTableType<K, V> ptt = ptf.tableOf((PType<K>) st.get(0), (PType<V>) st.get(1)); |
| return input.parallelDo(groupName, new ExtractorFn<Pair<K, V>>(groupName, extractor), ptt); |
| } |
| |
| private static class ExtractorFn<T> extends MapFn<String, T> { |
| |
| private final String groupName; |
| private final Extractor<T> extractor; |
| |
| public ExtractorFn(String groupName, Extractor<T> extractor) { |
| this.groupName = groupName; |
| this.extractor = extractor; |
| } |
| |
| @Override |
| public void initialize() { |
| extractor.initialize(); |
| } |
| |
| @Override |
| public T map(String input) { |
| return extractor.extract(input); |
| } |
| |
| @Override |
| public void cleanup(Emitter<T> emitter) { |
| if (getContext() != null) { |
| ExtractorStats stats = extractor.getStats(); |
| increment(groupName, "OVERALL_ERRORS", stats.getErrorCount()); |
| List<Integer> fieldErrors = stats.getFieldErrors(); |
| for (int i = 0; i < fieldErrors.size(); i++) { |
| increment(groupName, "ERRORS_FOR_FIELD_" + i, fieldErrors.get(i)); |
| } |
| } |
| } |
| } |
| |
| // Non-instantiable. |
| private Parse() { } |
| } |