| /** |
| * 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 org.apache.mrql.gen.Trees; |
| import java.io.*; |
| import java.util.Iterator; |
| import org.apache.hadoop.fs.*; |
| import org.apache.hadoop.io.*; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.mapreduce.InputSplit; |
| import org.apache.hadoop.mapreduce.TaskAttemptContext; |
| import org.apache.hadoop.mapreduce.RecordReader; |
| import org.apache.hadoop.mapreduce.lib.input.FileSplit; |
| |
| |
| /** A FileInputFormat for text files (CVS, XML, JSON, ...) */ |
| final public class MapReduceParsedInputFormat extends MapReduceMRQLFileInputFormat { |
| |
| public static class ParsedRecordReader extends RecordReader<MRContainer,MRContainer> { |
| final FSDataInputStream fsin; |
| final long start; |
| final long end; |
| Iterator<MRData> result; |
| MRData data; |
| Parser parser; |
| |
| public ParsedRecordReader ( FileSplit split, |
| TaskAttemptContext context, |
| Class<? extends Parser> parser_class, |
| Trees args ) throws IOException { |
| Configuration conf = context.getConfiguration(); |
| start = split.getStart(); |
| end = start + split.getLength(); |
| Path file = split.getPath(); |
| FileSystem fs = file.getFileSystem(conf); |
| fsin = fs.open(split.getPath()); |
| try { |
| parser = parser_class.newInstance(); |
| } catch (Exception ex) { |
| throw new Error("Unrecognized parser:"+parser_class); |
| }; |
| parser.initialize(args); |
| parser.open(fsin,start,end); |
| result = null; |
| } |
| |
| public boolean nextKeyValue () throws IOException { |
| while (result == null || !result.hasNext()) { |
| String s = parser.slice(); |
| if (s == null) |
| return false; |
| result = parser.parse(s).iterator(); |
| }; |
| data = (MRData)result.next(); |
| return true; |
| } |
| |
| public MRContainer getCurrentKey () throws IOException { |
| return new MRContainer(new MR_long(fsin.getPos())); |
| } |
| |
| public MRContainer getCurrentValue () throws IOException { |
| return new MRContainer(data); |
| } |
| |
| public long getPos () throws IOException { return fsin.getPos(); } |
| |
| public void close () throws IOException { fsin.close(); } |
| |
| public float getProgress () throws IOException { |
| if (end == start) |
| return 0.0f; |
| else return Math.min(1.0f, (getPos() - start) / (float)(end - start)); |
| } |
| |
| public void initialize ( InputSplit split, TaskAttemptContext context ) throws IOException { } |
| } |
| |
| public RecordReader<MRContainer,MRContainer> |
| createRecordReader ( InputSplit split, |
| TaskAttemptContext context ) throws IOException, InterruptedException { |
| Configuration conf = context.getConfiguration(); |
| String path = ((FileSplit)split).getPath().toString(); |
| ParsedDataSource ds = (ParsedDataSource)DataSource.get(path,conf); |
| return new ParsedRecordReader((FileSplit)split,context,ds.parser,(Trees)ds.args); |
| } |
| |
| /** Find the parser associated with each file in the path and parse the file, |
| * inserting all results into a Bag. The Bag is lazily constructed. |
| * @param path the path directory with the files |
| * @return a Bag that contains all data |
| */ |
| public Bag materialize ( final Path path ) throws IOException { |
| Configuration conf = Plan.conf; |
| ParsedDataSource ds = (ParsedDataSource)DataSource.get(path.toString(),conf); |
| final FileSystem fs = path.getFileSystem(conf); |
| FileStatus[] fds = fs.listStatus(path); |
| final int dl = fds.length; |
| final Path[] paths = new Path[dl]; |
| for ( int i = 0; i < dl; i++ ) |
| paths[i] = fds[i].getPath(); |
| Parser p; |
| try { |
| p = ds.parser.newInstance(); |
| } catch (Exception ex) { |
| throw new Error("Unrecognized parser:"+ds.parser); |
| }; |
| final Parser parser = p; |
| parser.initialize(ds.args); |
| parser.open(fs.open(paths[0]),0,Long.MAX_VALUE); |
| return new Bag(new BagIterator () { |
| Iterator<MRData> iter; |
| int i = 0; |
| String line; |
| public boolean hasNext () { |
| while (iter == null || !iter.hasNext()) { |
| line = parser.slice(); |
| while (line == null) |
| if (++i < dl) |
| try { |
| parser.open(fs.open(paths[i]),0,Long.MAX_VALUE); |
| } catch (IOException ex) { |
| throw new Error("Cannot open the file: "+paths[i]); |
| } |
| else return false; |
| iter = parser.parse(line).iterator(); |
| }; |
| return true; |
| } |
| public MRData next () { |
| return iter.next(); |
| } |
| }); |
| } |
| } |