org.apache.hadoop.streaming

Class StreamBaseRecordReader

java.lang.Object

org.apache.hadoop.streaming.StreamBaseRecordReader

All Implemented Interfaces:

RecordReader<Text,Text>

Direct Known Subclasses:

StreamXmlRecordReader

public abstract class StreamBaseRecordReader
extends Object
implements RecordReader<Text,Text>

Shared functionality for hadoopStreaming formats. A custom reader can be defined to be a RecordReader with the constructor below and is selected with the option bin/hadoopStreaming -inputreader ...

See Also:

StreamXmlRecordReader

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.apache.commons.logging.Log	LOG

Constructor Summary

Constructors

Constructor and Description
StreamBaseRecordReader(FSDataInputStream in, FileSplit split, Reporter reporter, JobConf job, FileSystem fs)

Method Summary

Modifier and Type	Method and Description
void	close() Close this to future operations.
Text	createKey()
Text	createValue()
long	getPos() Returns the current position in the input.
float	getProgress()
abstract boolean	next(Text key, Text value) Read a record.
abstract void	seekNextRecordBoundary() Implementation should seek forward in_ to the first byte of the next record.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOG

protected static final org.apache.commons.logging.Log LOG

Constructor Detail

StreamBaseRecordReader

public StreamBaseRecordReader(FSDataInputStream in,
                              FileSplit split,
                              Reporter reporter,
                              JobConf job,
                              FileSystem fs)
                       throws IOException

Throws:

IOException

Method Detail

next

public abstract boolean next(Text key,
                             Text value)
                      throws IOException

Read a record. Implementation should call numRecStats at the end

Specified by:

next in interface RecordReader<Text,Text>

Throws:

IOException

getPos

public long getPos()
            throws IOException

Returns the current position in the input.

Specified by:

getPos in interface RecordReader<Text,Text>

Throws:

IOException

close

public void close()
           throws IOException

Close this to future operations.

Specified by:

close in interface RecordReader<Text,Text>

Throws:

IOException

getProgress

public float getProgress()
                  throws IOException

Specified by:

getProgress in interface RecordReader<Text,Text>

Throws:

IOException

createKey

public Text createKey()

Specified by:

createKey in interface RecordReader<Text,Text>

createValue

public Text createValue()

Specified by:

createValue in interface RecordReader<Text,Text>

seekNextRecordBoundary

public abstract void seekNextRecordBoundary()
                                     throws IOException

Implementation should seek forward in_ to the first byte of the next record. The initial byte offset in the stream is arbitrary.

Throws:

IOException