org.apache.cassandra.hadoop.cql3

Class CqlPagingRecordReader

java.lang.Object

org.apache.hadoop.mapreduce.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

org.apache.cassandra.hadoop.cql3.CqlPagingRecordReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, org.apache.hadoop.mapred.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

public class CqlPagingRecordReader
extends org.apache.hadoop.mapreduce.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>
implements org.apache.hadoop.mapred.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

Hadoop RecordReader read the values return from the CQL query It use CQL key range query to page through the wide rows.

Return List as keys columns

Map as column name to columns mappings

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_CQL_PAGE_LIMIT

Constructor Summary

Constructors

Constructor and Description
CqlPagingRecordReader()

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
java.util.Map<java.lang.String,java.nio.ByteBuffer>	createKey()
java.util.Map<java.lang.String,java.nio.ByteBuffer>	createValue()
java.util.Map<java.lang.String,java.nio.ByteBuffer>	getCurrentKey()
java.util.Map<java.lang.String,java.nio.ByteBuffer>	getCurrentValue()
long	getPos()
float	getProgress()
void	initialize(org.apache.hadoop.mapreduce.InputSplit split, org.apache.hadoop.mapreduce.TaskAttemptContext context)
boolean	next(java.util.Map<java.lang.String,java.nio.ByteBuffer> keys, java.util.Map<java.lang.String,java.nio.ByteBuffer> value)
boolean	nextKeyValue()

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_CQL_PAGE_LIMIT

public static final int DEFAULT_CQL_PAGE_LIMIT

See Also:

Constant Field Values

Constructor Detail

CqlPagingRecordReader

public CqlPagingRecordReader()

Method Detail

initialize

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

Specified by:

initialize in class org.apache.hadoop.mapreduce.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

Throws:

java.io.IOException

close

public void close()

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface org.apache.hadoop.mapred.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

Specified by:

close in class org.apache.hadoop.mapreduce.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

getCurrentKey

public java.util.Map<java.lang.String,java.nio.ByteBuffer> getCurrentKey()

Specified by:

getCurrentKey in class org.apache.hadoop.mapreduce.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

getCurrentValue

public java.util.Map<java.lang.String,java.nio.ByteBuffer> getCurrentValue()

Specified by:

getCurrentValue in class org.apache.hadoop.mapreduce.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

getProgress

public float getProgress()

Specified by:

getProgress in interface org.apache.hadoop.mapred.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

Specified by:

getProgress in class org.apache.hadoop.mapreduce.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

nextKeyValue

public boolean nextKeyValue()
                     throws java.io.IOException

Specified by:

nextKeyValue in class org.apache.hadoop.mapreduce.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

Throws:

java.io.IOException

next

public boolean next(java.util.Map<java.lang.String,java.nio.ByteBuffer> keys,
           java.util.Map<java.lang.String,java.nio.ByteBuffer> value)
             throws java.io.IOException

Specified by:

next in interface org.apache.hadoop.mapred.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

Throws:

java.io.IOException

getPos

public long getPos()
            throws java.io.IOException

Specified by:

getPos in interface org.apache.hadoop.mapred.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

Throws:

java.io.IOException

createKey

public java.util.Map<java.lang.String,java.nio.ByteBuffer> createKey()

Specified by:

createKey in interface org.apache.hadoop.mapred.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>

createValue

public java.util.Map<java.lang.String,java.nio.ByteBuffer> createValue()

Specified by:

createValue in interface org.apache.hadoop.mapred.RecordReader<java.util.Map<java.lang.String,java.nio.ByteBuffer>,java.util.Map<java.lang.String,java.nio.ByteBuffer>>