org.apache.hawq.pxf.plugins.hdfs

Class SequenceFileAccessor

java.lang.Object

org.apache.hawq.pxf.api.utilities.Plugin

org.apache.hawq.pxf.plugins.hdfs.HdfsSplittableDataAccessor

org.apache.hawq.pxf.plugins.hdfs.SequenceFileAccessor

All Implemented Interfaces:

ReadAccessor, WriteAccessor

public class SequenceFileAccessor
extends HdfsSplittableDataAccessor
implements WriteAccessor

A PXF Accessor for reading and writing Sequence File records

Field Summary

Fields inherited from class org.apache.hawq.pxf.plugins.hdfs.HdfsSplittableDataAccessor

data, inputFormat, iter, jobConf, key, reader

Fields inherited from class org.apache.hawq.pxf.api.utilities.Plugin

inputData

Constructor Summary

Constructors

Constructor and Description
SequenceFileAccessor(InputData input) Constructs a SequenceFileAccessor.

Method Summary

Modifier and Type	Method and Description
void	closeForWrite() Closes the resource for write.
org.apache.hadoop.io.compress.CompressionCodec	getCodec()
org.apache.hadoop.io.SequenceFile.CompressionType	getCompressionType()
protected java.lang.Object	getReader(org.apache.hadoop.mapred.JobConf jobConf, org.apache.hadoop.mapred.InputSplit split) Overrides virtual method to create specialized record reader
boolean	openForWrite() Opens the resource for write.
boolean	writeNextObject(OneRow onerow) Writes the next object.

Methods inherited from class org.apache.hawq.pxf.plugins.hdfs.HdfsSplittableDataAccessor

closeForRead, getNextSplit, isThreadSafe, openForRead, readNextObject

Methods inherited from class java.lang.Object

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

Constructor Detail

SequenceFileAccessor

public SequenceFileAccessor(InputData input)

Constructs a SequenceFileAccessor.

Parameters:

input - all input parameters coming from the client request

Method Detail

getReader

protected java.lang.Object getReader(org.apache.hadoop.mapred.JobConf jobConf,
                                     org.apache.hadoop.mapred.InputSplit split)
                              throws java.io.IOException

Overrides virtual method to create specialized record reader

Specified by:

getReader in class HdfsSplittableDataAccessor

Parameters:

jobConf - the hadoop jobconf to use for the selected InputFormat

split - the input split to be read by the accessor

Returns:

a recordreader to be used for reading the data records of the split

Throws:

java.io.IOException - if recordreader could not be created

openForWrite

public boolean openForWrite()
                     throws java.lang.Exception

Description copied from interface: WriteAccessor

Opens the resource for write.

Specified by:

openForWrite in interface WriteAccessor

Returns:

true if the resource is successfully opened

Throws:

java.lang.Exception - if opening the resource failed

writeNextObject

public boolean writeNextObject(OneRow onerow)
                        throws java.io.IOException

Description copied from interface: WriteAccessor

Writes the next object.

Specified by:

writeNextObject in interface WriteAccessor

Parameters:

onerow - the object to be written

Returns:

true if the write succeeded

Throws:

java.io.IOException

closeForWrite

public void closeForWrite()
                   throws java.lang.Exception

Description copied from interface: WriteAccessor

Closes the resource for write.

Specified by:

closeForWrite in interface WriteAccessor

Throws:

java.lang.Exception - if closing the resource failed

getCompressionType

public org.apache.hadoop.io.SequenceFile.CompressionType getCompressionType()

getCodec

public org.apache.hadoop.io.compress.CompressionCodec getCodec()