| /** |
| * 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.mrql; |
| |
| import java.io.*; |
| import java.util.Iterator; |
| import org.apache.hadoop.fs.*; |
| import org.apache.hadoop.io.*; |
| import org.apache.hadoop.mapred.*; |
| |
| |
| /** A superclass for all MRQL FileInputFormats */ |
| abstract public class SparkMRQLFileInputFormat extends FileInputFormat<MRContainer,MRContainer> implements MRQLFileInputFormat { |
| public SparkMRQLFileInputFormat () {} |
| |
| /** record reader for spark */ |
| abstract public RecordReader<MRContainer,MRContainer> |
| getRecordReader ( InputSplit split, JobConf job, Reporter reporter ) throws IOException; |
| |
| /** materialize the input file into a memory Bag */ |
| public Bag materialize ( final Path file ) throws IOException { |
| final JobConf job = new JobConf(Plan.conf,MRQLFileInputFormat.class); |
| setInputPaths(job,file); |
| final InputSplit[] splits = getSplits(job,1); |
| final Reporter reporter = null; |
| final RecordReader<MRContainer,MRContainer> rd = getRecordReader(splits[0],job,reporter); |
| return new Bag(new BagIterator () { |
| RecordReader<MRContainer,MRContainer> reader = rd; |
| MRContainer key = reader.createKey(); |
| MRContainer value = reader.createKey(); |
| int i = 0; |
| public boolean hasNext () { |
| try { |
| if (reader.next(key,value)) |
| return true; |
| do { |
| if (++i >= splits.length) |
| return false; |
| reader.close(); |
| reader = getRecordReader(splits[i],job,reporter); |
| } while (!reader.next(key,value)); |
| return true; |
| } catch (IOException e) { |
| throw new Error("Cannot collect values from an intermediate result"); |
| } |
| } |
| public MRData next () { |
| return value.data(); |
| } |
| }); |
| } |
| |
| /** materialize the entire dataset into a Bag |
| * @param x the DataSet in HDFS to collect values from |
| * @param strip is not used in MapReduce mode |
| * @return the Bag that contains the collected values |
| */ |
| public final Bag collect ( final DataSet x, boolean strip ) throws Exception { |
| Bag res = new Bag(); |
| for ( DataSource s: x.source ) |
| if (s instanceof RDDDataSource) |
| res = res.union(SparkEvaluator.bag(((RDDDataSource)s).rdd)); |
| else if (s.to_be_merged) |
| res = res.union(Plan.merge(s)); |
| else res = res.union(s.inputFormat.newInstance().materialize(new Path(s.path))); |
| return res; |
| } |
| } |