| /** |
| * 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 org.apache.hadoop.fs.*; |
| import org.apache.hadoop.io.*; |
| import org.apache.hadoop.mapreduce.RecordReader; |
| import org.apache.hadoop.mapreduce.InputSplit; |
| import org.apache.hadoop.mapreduce.TaskAttemptContext; |
| import org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat; |
| |
| |
| /** Input format for Apache Hadoop sequence files */ |
| final public class MapReduceBinaryInputFormat extends MapReduceMRQLFileInputFormat { |
| final static SequenceFileInputFormat<MRContainer,MRContainer> inputFormat |
| = new SequenceFileInputFormat<MRContainer,MRContainer>(); |
| |
| public RecordReader<MRContainer,MRContainer> |
| createRecordReader ( InputSplit split, |
| TaskAttemptContext context ) throws IOException, InterruptedException { |
| return inputFormat.createRecordReader(split,context); |
| } |
| |
| /** collect the data from multiple sequence files at the path directory into a Bag |
| * @param path the path directory |
| * @return a Bag that contains all data |
| */ |
| public Bag materialize ( final Path path ) throws IOException { |
| final FileSystem fs = path.getFileSystem(Plan.conf); |
| final FileStatus[] ds |
| = fs.listStatus(path, |
| new PathFilter () { |
| public boolean accept ( Path path ) { |
| return !path.getName().startsWith("_"); |
| } |
| }); |
| if (ds.length > 0) |
| return new Bag(new BagIterator () { |
| SequenceFile.Reader reader = new SequenceFile.Reader(fs,ds[0].getPath(),Plan.conf); |
| MRContainer key = new MRContainer(new MR_int(0)); |
| MRContainer value = new MRContainer(new MR_int(0)); |
| int i = 1; |
| public boolean hasNext () { |
| try { |
| if (reader.next(key,value)) |
| return true; |
| do { |
| if (i >= ds.length) |
| return false; |
| reader.close(); |
| reader = new SequenceFile.Reader(fs,ds[i++].getPath(),Plan.conf); |
| } 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(); |
| } |
| }); |
| return new Bag(); |
| } |
| } |