| /* |
| * 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.parquet.cascading; |
| |
| import java.io.IOException; |
| import java.util.List; |
| import java.util.Objects; |
| |
| import org.apache.hadoop.mapred.JobConf; |
| import org.apache.hadoop.mapred.OutputCollector; |
| import org.apache.hadoop.mapred.RecordReader; |
| |
| import cascading.flow.FlowProcess; |
| import cascading.scheme.Scheme; |
| import cascading.scheme.SinkCall; |
| import cascading.scheme.SourceCall; |
| import cascading.tap.CompositeTap; |
| import cascading.tap.Tap; |
| import cascading.tap.TapException; |
| import cascading.tap.hadoop.Hfs; |
| import cascading.tuple.Fields; |
| import cascading.tuple.Tuple; |
| import cascading.tuple.TupleEntry; |
| import org.apache.parquet.filter2.predicate.FilterPredicate; |
| import org.apache.parquet.hadoop.Footer; |
| import org.apache.parquet.hadoop.ParquetInputFormat; |
| import org.apache.parquet.hadoop.ParquetOutputFormat; |
| import org.apache.parquet.hadoop.mapred.Container; |
| import org.apache.parquet.hadoop.mapred.DeprecatedParquetInputFormat; |
| import org.apache.parquet.hadoop.mapred.DeprecatedParquetOutputFormat; |
| import org.apache.parquet.schema.MessageType; |
| |
| /** |
| * A Cascading Scheme that converts Parquet groups into Cascading tuples. |
| * If you provide it with sourceFields, it will selectively materialize only the columns for those fields. |
| * The names must match the names in the Parquet schema. |
| * If you do not provide sourceFields, or use Fields.ALL or Fields.UNKNOWN, it will create one from the |
| * Parquet schema. |
| * Currently, only primitive types are supported. TODO: allow nested fields in the Parquet schema to be |
| * flattened to a top-level field in the Cascading tuple. |
| */ |
| |
| @Deprecated // The parquet-cascading module depends on Cascading 2.x, and is being superseded with parquet-cascading3 for Cascading 3.x |
| public class ParquetTupleScheme extends Scheme<JobConf, RecordReader, OutputCollector, Object[], Object[]>{ |
| |
| private static final long serialVersionUID = 0L; |
| private String parquetSchema; |
| private final FilterPredicate filterPredicate; |
| |
| public ParquetTupleScheme() { |
| super(); |
| this.filterPredicate = null; |
| } |
| |
| public ParquetTupleScheme(Fields sourceFields) { |
| super(sourceFields); |
| this.filterPredicate = null; |
| } |
| |
| public ParquetTupleScheme(FilterPredicate filterPredicate) { |
| this.filterPredicate = Objects.requireNonNull(filterPredicate, "filterPredicate cannot be null"); |
| } |
| |
| public ParquetTupleScheme(FilterPredicate filterPredicate, Fields sourceFields) { |
| super(sourceFields); |
| this.filterPredicate = Objects.requireNonNull(filterPredicate, "filterPredicate cannot be null"); |
| } |
| |
| /** |
| * ParquetTupleScheme constructor used a sink need to be implemented |
| * |
| * @param sourceFields used for the reading step |
| * @param sinkFields used for the writing step |
| * @param schema is mandatory if you add sinkFields and needs to be the |
| * toString() from a MessageType. This value is going to be parsed when the |
| * parquet file will be created. |
| */ |
| public ParquetTupleScheme(Fields sourceFields, Fields sinkFields, final String schema) { |
| super(sourceFields, sinkFields); |
| parquetSchema = schema; |
| this.filterPredicate = null; |
| } |
| |
| @SuppressWarnings("rawtypes") |
| @Override |
| public void sourceConfInit(FlowProcess<JobConf> fp, |
| Tap<JobConf, RecordReader, OutputCollector> tap, JobConf jobConf) { |
| |
| if (filterPredicate != null) { |
| ParquetInputFormat.setFilterPredicate(jobConf, filterPredicate); |
| } |
| |
| jobConf.setInputFormat(DeprecatedParquetInputFormat.class); |
| ParquetInputFormat.setReadSupportClass(jobConf, TupleReadSupport.class); |
| TupleReadSupport.setRequestedFields(jobConf, getSourceFields()); |
| } |
| |
| @Override |
| public Fields retrieveSourceFields(FlowProcess<JobConf> flowProcess, Tap tap) { |
| MessageType schema = readSchema(flowProcess, tap); |
| SchemaIntersection intersection = new SchemaIntersection(schema, getSourceFields()); |
| |
| setSourceFields(intersection.getSourceFields()); |
| |
| return getSourceFields(); |
| } |
| |
| private MessageType readSchema(FlowProcess<JobConf> flowProcess, Tap tap) { |
| try { |
| Hfs hfs; |
| |
| if( tap instanceof CompositeTap ) |
| hfs = (Hfs) ( (CompositeTap) tap ).getChildTaps().next(); |
| else |
| hfs = (Hfs) tap; |
| |
| List<Footer> footers = getFooters(flowProcess, hfs); |
| |
| if(footers.isEmpty()) { |
| throw new TapException("Could not read Parquet metadata at " + hfs.getPath()); |
| } else { |
| return footers.get(0).getParquetMetadata().getFileMetaData().getSchema(); |
| } |
| } catch (IOException e) { |
| throw new TapException(e); |
| } |
| } |
| |
| private List<Footer> getFooters(FlowProcess<JobConf> flowProcess, Hfs hfs) throws IOException { |
| JobConf jobConf = flowProcess.getConfigCopy(); |
| DeprecatedParquetInputFormat format = new DeprecatedParquetInputFormat(); |
| format.addInputPath(jobConf, hfs.getPath()); |
| return format.getFooters(jobConf); |
| } |
| |
| @SuppressWarnings("unchecked") |
| @Override |
| public boolean source(FlowProcess<JobConf> fp, SourceCall<Object[], RecordReader> sc) |
| throws IOException { |
| Container<Tuple> value = (Container<Tuple>) sc.getInput().createValue(); |
| boolean hasNext = sc.getInput().next(null, value); |
| if (!hasNext) { return false; } |
| |
| // Skip nulls |
| if (value == null) { return true; } |
| |
| sc.getIncomingEntry().setTuple(value.get()); |
| return true; |
| } |
| |
| |
| @SuppressWarnings("rawtypes") |
| @Override |
| public void sinkConfInit(FlowProcess<JobConf> fp, |
| Tap<JobConf, RecordReader, OutputCollector> tap, JobConf jobConf) { |
| DeprecatedParquetOutputFormat.setAsOutputFormat(jobConf); |
| jobConf.set(TupleWriteSupport.PARQUET_CASCADING_SCHEMA, parquetSchema); |
| ParquetOutputFormat.setWriteSupportClass(jobConf, TupleWriteSupport.class); |
| } |
| |
| @Override |
| public boolean isSink() { |
| return parquetSchema != null; |
| } |
| |
| @Override |
| public void sink(FlowProcess<JobConf> fp, SinkCall<Object[], OutputCollector> sink) |
| throws IOException { |
| TupleEntry tuple = sink.getOutgoingEntry(); |
| OutputCollector outputCollector = sink.getOutput(); |
| outputCollector.collect(null, tuple); |
| } |
| } |