/// <exception cref="System.IO.IOException"/> public override void Initialize(InputSplit genericSplit, TaskAttemptContext context ) { FileSplit split = (FileSplit)genericSplit; Configuration job = context.GetConfiguration(); this.maxLineLength = job.GetInt(MaxLineLength, int.MaxValue); start = split.GetStart(); end = start + split.GetLength(); Path file = split.GetPath(); // open the file and seek to the start of the split FileSystem fs = file.GetFileSystem(job); fileIn = fs.Open(file); CompressionCodec codec = new CompressionCodecFactory(job).GetCodec(file); if (null != codec) { isCompressedInput = true; decompressor = CodecPool.GetDecompressor(codec); if (codec is SplittableCompressionCodec) { SplitCompressionInputStream cIn = ((SplittableCompressionCodec)codec).CreateInputStream (fileIn, decompressor, start, end, SplittableCompressionCodec.READ_MODE.Byblock); @in = new CompressedSplitLineReader(cIn, job, this.recordDelimiterBytes); start = cIn.GetAdjustedStart(); end = cIn.GetAdjustedEnd(); filePosition = cIn; } else { @in = new SplitLineReader(codec.CreateInputStream(fileIn, decompressor), job, this .recordDelimiterBytes); filePosition = fileIn; } } else { fileIn.Seek(start); @in = new UncompressedSplitLineReader(fileIn, job, this.recordDelimiterBytes, split .GetLength()); filePosition = fileIn; } // If this is not the first split, we always throw away first record // because we always (except the last split) read one extra line in // next() method. if (start != 0) { start += @in.ReadLine(new Text(), 0, MaxBytesToConsume(start)); } this.pos = start; }
/// <exception cref="System.IO.IOException"/> public LineRecordReader(Configuration job, FileSplit split, byte[] recordDelimiter ) { this.maxLineLength = job.GetInt(LineRecordReader.MaxLineLength, int.MaxValue); start = split.GetStart(); end = start + split.GetLength(); Path file = split.GetPath(); compressionCodecs = new CompressionCodecFactory(job); codec = compressionCodecs.GetCodec(file); // open the file and seek to the start of the split FileSystem fs = file.GetFileSystem(job); fileIn = fs.Open(file); if (IsCompressedInput()) { decompressor = CodecPool.GetDecompressor(codec); if (codec is SplittableCompressionCodec) { SplitCompressionInputStream cIn = ((SplittableCompressionCodec)codec).CreateInputStream (fileIn, decompressor, start, end, SplittableCompressionCodec.READ_MODE.Byblock); @in = new CompressedSplitLineReader(cIn, job, recordDelimiter); start = cIn.GetAdjustedStart(); end = cIn.GetAdjustedEnd(); filePosition = cIn; } else { // take pos from compressed stream @in = new SplitLineReader(codec.CreateInputStream(fileIn, decompressor), job, recordDelimiter ); filePosition = fileIn; } } else { fileIn.Seek(start); @in = new UncompressedSplitLineReader(fileIn, job, recordDelimiter, split.GetLength ()); filePosition = fileIn; } // If this is not the first split, we always throw away first record // because we always (except the last split) read one extra line in // next() method. if (start != 0) { start += @in.ReadLine(new Text(), 0, MaxBytesToConsume(start)); } this.pos = start; }