org.apache.cassandra.hadoop.cql3

Class CqlRecordReader

java.lang.Object

org.apache.hadoop.mapreduce.RecordReader<Long,com.datastax.driver.core.Row>

org.apache.cassandra.hadoop.cql3.CqlRecordReader

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.hadoop.mapred.RecordReader<Long,com.datastax.driver.core.Row>

public class CqlRecordReader
extends org.apache.hadoop.mapreduce.RecordReader<Long,com.datastax.driver.core.Row>
implements org.apache.hadoop.mapred.RecordReader<Long,com.datastax.driver.core.Row>, AutoCloseable

CqlRecordReader reads the rows return from the CQL query It uses CQL auto-paging.

Return a Long as a local CQL row key starts from 0;

Row as C* java driver CQL result set row 1) select clause must include partition key columns (to calculate the progress based on the actual CF row processed) 2) where clause must include token(partition_key1, ... , partition_keyn) > ? and token(partition_key1, ... , partition_keyn) <= ? (in the right order)

Field Summary

Fields

Modifier and Type	Field and Description
protected int	nativeProtocolVersion

Constructor Summary

Constructors

Constructor and Description
CqlRecordReader()

Method Summary

Modifier and Type	Method and Description
void	close()
Long	createKey()
com.datastax.driver.core.Row	createValue()
Long	getCurrentKey()
com.datastax.driver.core.Row	getCurrentValue()
long	getPos()
float	getProgress()
void	initialize(org.apache.hadoop.mapreduce.InputSplit split, org.apache.hadoop.mapreduce.TaskAttemptContext context)
boolean	next(Long key, com.datastax.driver.core.Row value)
boolean	nextKeyValue()

Methods inherited from class java.lang.Object

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

Field Detail

nativeProtocolVersion

protected int nativeProtocolVersion

Constructor Detail

CqlRecordReader

public CqlRecordReader()

Method Detail

initialize

public void initialize(org.apache.hadoop.mapreduce.InputSplit split,
                       org.apache.hadoop.mapreduce.TaskAttemptContext context)
                throws IOException

Specified by:

initialize in class org.apache.hadoop.mapreduce.RecordReader<Long,com.datastax.driver.core.Row>

Throws:

IOException

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface org.apache.hadoop.mapred.RecordReader<Long,com.datastax.driver.core.Row>

Specified by:

close in class org.apache.hadoop.mapreduce.RecordReader<Long,com.datastax.driver.core.Row>

getCurrentKey

public Long getCurrentKey()

Specified by:

getCurrentKey in class org.apache.hadoop.mapreduce.RecordReader<Long,com.datastax.driver.core.Row>

getCurrentValue

public com.datastax.driver.core.Row getCurrentValue()

Specified by:

getCurrentValue in class org.apache.hadoop.mapreduce.RecordReader<Long,com.datastax.driver.core.Row>

getProgress

public float getProgress()

Specified by:

getProgress in interface org.apache.hadoop.mapred.RecordReader<Long,com.datastax.driver.core.Row>

Specified by:

getProgress in class org.apache.hadoop.mapreduce.RecordReader<Long,com.datastax.driver.core.Row>

nextKeyValue

public boolean nextKeyValue()
                     throws IOException

Specified by:

nextKeyValue in class org.apache.hadoop.mapreduce.RecordReader<Long,com.datastax.driver.core.Row>

Throws:

IOException

next

public boolean next(Long key,
                    com.datastax.driver.core.Row value)
             throws IOException

Specified by:

next in interface org.apache.hadoop.mapred.RecordReader<Long,com.datastax.driver.core.Row>

Throws:

IOException

getPos

public long getPos()

Specified by:

getPos in interface org.apache.hadoop.mapred.RecordReader<Long,com.datastax.driver.core.Row>

createKey

public Long createKey()

Specified by:

createKey in interface org.apache.hadoop.mapred.RecordReader<Long,com.datastax.driver.core.Row>

createValue

public com.datastax.driver.core.Row createValue()

Specified by:

createValue in interface org.apache.hadoop.mapred.RecordReader<Long,com.datastax.driver.core.Row>