[jira] [Commented] (CARBONDATA-296) 1.Add CSVInputFormat to read csv files.

[Akash R Nilugal (Jira)]

    [ https://issues.apache.org/jira/browse/CARBONDATA-296?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15574276#comment-15574276 ]

ASF GitHub Bot commented on CARBONDATA-296:
-------------------------------------------

Github user jackylk commented on a diff in the pull request:

    https://github.com/apache/incubator-carbondata/pull/233#discussion_r83360131
 
    --- Diff: hadoop/src/main/java/org/apache/carbondata/hadoop/mapreduce/CSVInputFormat.java ---
    @@ -0,0 +1,180 @@
    +/*
    + * 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,
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    + * "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.carbondata.hadoop.mapreduce;
    +
    +import java.io.IOException;
    +import java.io.InputStream;
    +import java.io.InputStreamReader;
    +import java.io.Reader;
    +
    +import org.apache.carbondata.hadoop.io.BoundedInputStream;
    +import org.apache.carbondata.hadoop.io.StringArrayWritable;
    +import org.apache.carbondata.hadoop.util.CSVInputFormatUtil;
    +
    +import com.univocity.parsers.csv.CsvParser;
    +import org.apache.hadoop.conf.Configuration;
    +import org.apache.hadoop.fs.FSDataInputStream;
    +import org.apache.hadoop.fs.FileSystem;
    +import org.apache.hadoop.fs.Path;
    +import org.apache.hadoop.fs.Seekable;
    +import org.apache.hadoop.io.NullWritable;
    +import org.apache.hadoop.io.Text;
    +import org.apache.hadoop.io.compress.CodecPool;
    +import org.apache.hadoop.io.compress.CompressionCodec;
    +import org.apache.hadoop.io.compress.CompressionCodecFactory;
    +import org.apache.hadoop.io.compress.CompressionInputStream;
    +import org.apache.hadoop.io.compress.Decompressor;
    +import org.apache.hadoop.io.compress.SplitCompressionInputStream;
    +import org.apache.hadoop.io.compress.SplittableCompressionCodec;
    +import org.apache.hadoop.mapreduce.InputSplit;
    +import org.apache.hadoop.mapreduce.RecordReader;
    +import org.apache.hadoop.mapreduce.TaskAttemptContext;
    +import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
    +import org.apache.hadoop.mapreduce.lib.input.FileSplit;
    +import org.apache.hadoop.util.LineReader;
    +
    +/**
    + * An {@link org.apache.hadoop.mapreduce.InputFormat} for csv files.  Files are broken into lines.
    + * Values are the line of csv files.
    + */
    +public class CSVInputFormat extends FileInputFormat<NullWritable, StringArrayWritable> {
    +
    +  @Override
    +  public RecordReader<NullWritable, StringArrayWritable> createRecordReader(InputSplit inputSplit,
    +      TaskAttemptContext context) throws IOException, InterruptedException {
    +    return new NewCSVRecordReader();
    +  }
    +
    +  /**
    +   * Treats value as line in file. Key is null.
    +   */
    +  public static class NewCSVRecordReader extends RecordReader<NullWritable, StringArrayWritable> {
    +
    +    private long start;
    +    private long end;
    +    private BoundedInputStream boundedInputStream;
    +    private Reader reader;
    +    private CsvParser csvParser;
    +    private StringArrayWritable value;
    +    private String[] columns;
    +    private Seekable filePosition;
    +    private boolean isCompressedInput;
    +    private Decompressor decompressor;
    +
    +    @Override
    +    public void initialize(InputSplit inputSplit, TaskAttemptContext context)
    +        throws IOException, InterruptedException {
    +      FileSplit split = (FileSplit) inputSplit;
    +      this.start = split.getStart();
    +      this.end = this.start + split.getLength();
    +      Path file = split.getPath();
    +      Configuration job = context.getConfiguration();
    +      CompressionCodec codec = (new CompressionCodecFactory(job)).getCodec(file);
    +      FileSystem fs = file.getFileSystem(job);
    +      FSDataInputStream fileIn = fs.open(file);
    +      InputStream inputStream = null;
    +      if (codec != null) {
    +        this.isCompressedInput = true;
    +        this.decompressor = CodecPool.getDecompressor(codec);
    +        if (codec instanceof SplittableCompressionCodec) {
    +          SplitCompressionInputStream scIn = ((SplittableCompressionCodec) codec)
    +              .createInputStream(fileIn, this.decompressor, this.start, this.end,
    +                  SplittableCompressionCodec.READ_MODE.BYBLOCK);
    +          this.start = scIn.getAdjustedStart();
    +          this.end = scIn.getAdjustedEnd();
    +          if (this.start != 0) {
    +            LineReader lineReader = new LineReader(scIn, 1);
    +            this.start += lineReader.readLine(new Text(), 0);
    +          }
    +          this.filePosition = scIn;
    +          inputStream = scIn;
    +        } else {
    +          CompressionInputStream cIn = codec.createInputStream(fileIn, decompressor);
    +          this.filePosition = cIn;
    +          inputStream = cIn;
    +        }
    +      } else {
    +        fileIn.seek(this.start);
    +        if (this.start != 0) {
    +          LineReader lineReader = new LineReader(fileIn, 1);
    +          this.start += lineReader.readLine(new Text(), 0);
    +        }
    +        boundedInputStream = new BoundedInputStream(fileIn, this.end - this.start);
    +        this.filePosition = fileIn;
    +        inputStream = boundedInputStream;
    +      }
    +      reader = new InputStreamReader(inputStream);
    +      csvParser = new CsvParser(CSVInputFormatUtil.extractCsvParserSettings(job, this.start));
    +      csvParser.beginParsing(reader);
    +    }
    +
    +    @Override
    +    public boolean nextKeyValue() throws IOException, InterruptedException {
    +      this.columns = csvParser.parseNext();
    +      if (this.columns == null) {
    +        this.value = null;
    +        return false;
    +      }
    +      if (this.value == null) {
    +        this.value = new StringArrayWritable();
    +      }
    +      this.value.set(this.columns);
    +      return true;
    +    }
    +
    +    @Override
    +    public NullWritable getCurrentKey() throws IOException, InterruptedException {
    +      return NullWritable.get();
    +    }
    +
    +    @Override
    +    public StringArrayWritable getCurrentValue() throws IOException, InterruptedException {
    +      return this.value;
    +    }
    +
    +    private long getPos() throws IOException {
    +      long retVal = this.start;
    +      if (null != this.boundedInputStream) {
    +        retVal = this.end - this.boundedInputStream.getRemaining();
    +      } else if (this.isCompressedInput && null != this.filePosition) {
    +        retVal = this.filePosition.getPos();
    +      }
    +      return retVal;
    +    }
    +
    +    @Override
    +    public float getProgress() throws IOException, InterruptedException {
    +      return this.start == this.end?0.0F:Math.min(1.0F, (float)(this.getPos() -
    --- End diff --
   
    code style issue

> 1.Add CSVInputFormat to read csv files.
> ---------------------------------------
>
>                 Key: CARBONDATA-296
>                 URL: https://issues.apache.org/jira/browse/CARBONDATA-296
>             Project: CarbonData
>          Issue Type: Sub-task
>            Reporter: Ravindra Pesala
>            Assignee: QiangCai
>             Fix For: 0.2.0-incubating
>
>
> Add CSVInputFormat to read csv files, it should use Univocity parser to read csv files to get optimal performance.

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