/// <exception cref="System.IO.IOException"/>
public SequenceFileRecordReader(Configuration conf, FileSplit split)
{
Path path = split.GetPath();
FileSystem fs = path.GetFileSystem(conf);
this.@in = new SequenceFile.Reader(fs, path, conf);
this.end = split.GetStart() + split.GetLength();
this.conf = conf;
if (split.GetStart() > @in.GetPosition())
{
@in.Sync(split.GetStart());
}
// sync to start
this.start = @in.GetPosition();
more = start < end;
}
/// <exception cref="System.IO.IOException"/>
public SequenceFileAsBinaryRecordReader(Configuration conf, FileSplit split)
{
Path path = split.GetPath();
FileSystem fs = path.GetFileSystem(conf);
this.@in = new SequenceFile.Reader(fs, path, conf);
this.end = split.GetStart() + split.GetLength();
if (split.GetStart() > @in.GetPosition())
{
@in.Sync(split.GetStart());
}
// sync to start
this.start = @in.GetPosition();
vbytes = @in.CreateValueBytes();
done = start >= end;
}
/// <exception cref="System.IO.IOException"/>
public FixedLengthRecordReader(Configuration job, FileSplit split, int recordLength
)
{
// Make use of the new API implementation to avoid code duplication.
this.recordLength = recordLength;
reader = new Org.Apache.Hadoop.Mapreduce.Lib.Input.FixedLengthRecordReader(recordLength
);
reader.Initialize(job, split.GetStart(), split.GetLength(), split.GetPath());
}
/// <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;
}
/// <exception cref="System.Exception"/>
public virtual void TestLocality()
{
JobConf job = new JobConf(conf);
dfs = NewDFSCluster(job);
FileSystem fs = dfs.GetFileSystem();
System.Console.Out.WriteLine("FileSystem " + fs.GetUri());
Path inputDir = new Path("/foo/");
string fileName = "part-0000";
CreateInputs(fs, inputDir, fileName);
// split it using a file input format
TextInputFormat.AddInputPath(job, inputDir);
TextInputFormat inFormat = new TextInputFormat();
inFormat.Configure(job);
InputSplit[] splits = inFormat.GetSplits(job, 1);
FileStatus fileStatus = fs.GetFileStatus(new Path(inputDir, fileName));
BlockLocation[] locations = fs.GetFileBlockLocations(fileStatus, 0, fileStatus.GetLen
());
System.Console.Out.WriteLine("Made splits");
// make sure that each split is a block and the locations match
for (int i = 0; i < splits.Length; ++i)
{
FileSplit fileSplit = (FileSplit)splits[i];
System.Console.Out.WriteLine("File split: " + fileSplit);
foreach (string h in fileSplit.GetLocations())
{
System.Console.Out.WriteLine("Location: " + h);
}
System.Console.Out.WriteLine("Block: " + locations[i]);
NUnit.Framework.Assert.AreEqual(locations[i].GetOffset(), fileSplit.GetStart());
NUnit.Framework.Assert.AreEqual(locations[i].GetLength(), fileSplit.GetLength());
string[] blockLocs = locations[i].GetHosts();
string[] splitLocs = fileSplit.GetLocations();
NUnit.Framework.Assert.AreEqual(2, blockLocs.Length);
NUnit.Framework.Assert.AreEqual(2, splitLocs.Length);
NUnit.Framework.Assert.IsTrue((blockLocs[0].Equals(splitLocs[0]) && blockLocs[1].
Equals(splitLocs[1])) || (blockLocs[1].Equals(splitLocs[0]) && blockLocs[0].Equals
(splitLocs[1])));
}
NUnit.Framework.Assert.AreEqual("Expected value of " + FileInputFormat.NumInputFiles
, 1, job.GetLong(FileInputFormat.NumInputFiles, 0));
}
