org.apache.hadoop.hive.ql.io

Class TeradataBinaryRecordReader

java.lang.Object

org.apache.hadoop.hive.ql.io.TeradataBinaryRecordReader

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.BytesWritable>

public class TeradataBinaryRecordReader
extends Object
implements org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.BytesWritable>

The TeradataBinaryRecordReader reads the record from Teradata binary files. In the Teradata Binary File, each record constructs as below: The first 2 bytes represents the length of the bytes next for this record. Then the null bitmap whose length is depended on the number of fields is followed. Then each field of the record is serialized into bytes - the serialization strategy is decided by the type of field. At last, there is one byte (0x0a) in the end of the record. This InputFormat currently doesn't support the split of the file. Teradata binary files are using little endian.

Constructor Summary

Constructors

Constructor and Description
TeradataBinaryRecordReader(org.apache.hadoop.mapred.JobConf job, org.apache.hadoop.mapred.FileSplit fileSplit)

Method Summary

Modifier and Type	Method and Description
void	close()
org.apache.hadoop.io.NullWritable	createKey() Create an object of the appropriate type to be used as a key.
org.apache.hadoop.io.BytesWritable	createValue() Create an object of the appropriate type to be used as a value.
long	getPos() Returns the current position in the input.
float	getProgress() How much of the input has the RecordReader consumed i.e.
boolean	next(org.apache.hadoop.io.NullWritable key, org.apache.hadoop.io.BytesWritable value) Reads the next key/value pair from the input for processing.

Methods inherited from class java.lang.Object

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

Constructor Detail

TeradataBinaryRecordReader

public TeradataBinaryRecordReader(org.apache.hadoop.mapred.JobConf job,
                                  org.apache.hadoop.mapred.FileSplit fileSplit)
                           throws IOException

Throws:

IOException

Method Detail

next

public boolean next(org.apache.hadoop.io.NullWritable key,
                    org.apache.hadoop.io.BytesWritable value)
             throws IOException

Reads the next key/value pair from the input for processing.

Specified by:

next in interface org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.BytesWritable>

Parameters:

key - the key to read data into

value - the value to read data into

Returns:

true iff a key/value was read, false if at EOF

Throws:

IOException

createKey

public org.apache.hadoop.io.NullWritable createKey()

Create an object of the appropriate type to be used as a key.

Specified by:

createKey in interface org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.BytesWritable>

Returns:

a new key object.

createValue

public org.apache.hadoop.io.BytesWritable createValue()

Create an object of the appropriate type to be used as a value.

Specified by:

createValue in interface org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.BytesWritable>

Returns:

a new value object.

getPos

public long getPos()
            throws IOException

Returns the current position in the input.

Specified by:

getPos in interface org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.BytesWritable>

Returns:

the current position in the input.

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.BytesWritable>

Throws:

IOException

getProgress

public float getProgress()
                  throws IOException

How much of the input has the RecordReader consumed i.e. has been processed by?

Specified by:

getProgress in interface org.apache.hadoop.mapred.RecordReader<org.apache.hadoop.io.NullWritable,org.apache.hadoop.io.BytesWritable>

Returns:

progress from 0.0 to 1.0.

Throws:

IOException