org.apache.hadoop.hive.ql.io
Class FlatFileInputFormat.FlatFileRecordReader<R>

java.lang.Object
  org.apache.hadoop.hive.ql.io.FlatFileInputFormat.FlatFileRecordReader<R>

All Implemented Interfaces:

org.apache.hadoop.mapred.RecordReader<Void,FlatFileInputFormat.RowContainer<R>>

Enclosing class:

FlatFileInputFormat<T>

public class FlatFileInputFormat.FlatFileRecordReader<R>
extends Object
implements org.apache.hadoop.mapred.RecordReader<Void,FlatFileInputFormat.RowContainer<R>>

An RecordReader for plain files with Deserializer records Reads one row at a time of type R. R is intended to be a base class of something such as: Record, Writable, Text, ...

Field Summary

static String

SerializationContextImplKey The JobConf key of the SerializationContext to use.

Constructor Summary

FlatFileInputFormat.FlatFileRecordReader(org.apache.hadoop.conf.Configuration conf, org.apache.hadoop.mapred.FileSplit split)
FlatFileRecordReader constructor constructs the underlying stream (potentially decompressed) and creates the deserializer.

Method Summary

void	close()
Void	createKey()
FlatFileInputFormat.RowContainer<R>	createValue()
long	getPos()
float	getProgress()
boolean	next(Void key, FlatFileInputFormat.RowContainer<R> value) Returns the next row # and value.

Methods inherited from class java.lang.Object

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

Field Detail

SerializationContextImplKey

public static final String SerializationContextImplKey

The JobConf key of the SerializationContext to use.

See Also:

Constant Field Values

Constructor Detail

FlatFileInputFormat.FlatFileRecordReader

public FlatFileInputFormat.FlatFileRecordReader(org.apache.hadoop.conf.Configuration conf,
                                                org.apache.hadoop.mapred.FileSplit split)
                                         throws IOException

FlatFileRecordReader constructor constructs the underlying stream (potentially decompressed) and creates the deserializer.

Parameters:

conf - the jobconf

split - the split for this file

Throws:

IOException

Method Detail

createKey

public Void createKey()

Specified by:

createKey in interface org.apache.hadoop.mapred.RecordReader<Void,FlatFileInputFormat.RowContainer<R>>

Returns:

null

createValue

public FlatFileInputFormat.RowContainer<R> createValue()

Specified by:

createValue in interface org.apache.hadoop.mapred.RecordReader<Void,FlatFileInputFormat.RowContainer<R>>

Returns:

a new R instance.

next

public boolean next(Void key,
                    FlatFileInputFormat.RowContainer<R> value)
             throws IOException

Returns the next row # and value.

Specified by:

next in interface org.apache.hadoop.mapred.RecordReader<Void,FlatFileInputFormat.RowContainer<R>>

Parameters:

key - - void as these files have a value only

value - - the row container which is always re-used, but the internal value may be set to a new Object

Returns:

whether the key and value were read. True if they were and false if EOF

Throws:

IOException - from the deserializer

getProgress

public float getProgress()
                  throws IOException

Specified by:

getProgress in interface org.apache.hadoop.mapred.RecordReader<Void,FlatFileInputFormat.RowContainer<R>>

Throws:

IOException

getPos

public long getPos()
            throws IOException

Specified by:

getPos in interface org.apache.hadoop.mapred.RecordReader<Void,FlatFileInputFormat.RowContainer<R>>

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface org.apache.hadoop.mapred.RecordReader<Void,FlatFileInputFormat.RowContainer<R>>

Throws:

IOException