org.apache.cassandra.hadoop
Class ColumnFamilyRecordReader

java.lang.Object
  org.apache.hadoop.mapreduce.RecordReader<java.nio.ByteBuffer,java.util.SortedMap<java.nio.ByteBuffer,IColumn>>
      org.apache.cassandra.hadoop.ColumnFamilyRecordReader

All Implemented Interfaces:

java.io.Closeable

public class ColumnFamilyRecordReader
extends org.apache.hadoop.mapreduce.RecordReader<java.nio.ByteBuffer,java.util.SortedMap<java.nio.ByteBuffer,IColumn>>

Constructor Summary

ColumnFamilyRecordReader()

Method Summary

void	close() Close the record reader.
java.nio.ByteBuffer	getCurrentKey() Get the current key
java.util.SortedMap<java.nio.ByteBuffer,IColumn>	getCurrentValue() Get the current value.
float	getProgress() The current progress of the record reader through its data.
void	initialize(org.apache.hadoop.mapreduce.InputSplit split, org.apache.hadoop.mapreduce.TaskAttemptContext context) Called once at initialization.
boolean	nextKeyValue() Read the next key, value pair.

Methods inherited from class java.lang.Object

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

Constructor Detail

ColumnFamilyRecordReader

public ColumnFamilyRecordReader()

Method Detail

close

public void close()

Description copied from class: org.apache.hadoop.mapreduce.RecordReader

Close the record reader.

Specified by:

close in interface java.io.Closeable

Specified by:

close in class org.apache.hadoop.mapreduce.RecordReader<java.nio.ByteBuffer,java.util.SortedMap<java.nio.ByteBuffer,IColumn>>

getCurrentKey

public java.nio.ByteBuffer getCurrentKey()

Description copied from class: org.apache.hadoop.mapreduce.RecordReader

Get the current key

Specified by:

getCurrentKey in class org.apache.hadoop.mapreduce.RecordReader<java.nio.ByteBuffer,java.util.SortedMap<java.nio.ByteBuffer,IColumn>>

Returns:

the current key or null if there is no current key

getCurrentValue

public java.util.SortedMap<java.nio.ByteBuffer,IColumn> getCurrentValue()

Description copied from class: org.apache.hadoop.mapreduce.RecordReader

Get the current value.

Specified by:

getCurrentValue in class org.apache.hadoop.mapreduce.RecordReader<java.nio.ByteBuffer,java.util.SortedMap<java.nio.ByteBuffer,IColumn>>

Returns:

the object that was read

getProgress

public float getProgress()

Description copied from class: org.apache.hadoop.mapreduce.RecordReader

The current progress of the record reader through its data.

Specified by:

getProgress in class org.apache.hadoop.mapreduce.RecordReader<java.nio.ByteBuffer,java.util.SortedMap<java.nio.ByteBuffer,IColumn>>

Returns:

a number between 0.0 and 1.0 that is the fraction of the data read

initialize

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

Description copied from class: org.apache.hadoop.mapreduce.RecordReader

Called once at initialization.

Specified by:

initialize in class org.apache.hadoop.mapreduce.RecordReader<java.nio.ByteBuffer,java.util.SortedMap<java.nio.ByteBuffer,IColumn>>

Parameters:

split - the split that defines the range of records to read

context - the information about the task

Throws:

java.io.IOException

nextKeyValue

public boolean nextKeyValue()
                     throws java.io.IOException

Description copied from class: org.apache.hadoop.mapreduce.RecordReader

Read the next key, value pair.

Specified by:

nextKeyValue in class org.apache.hadoop.mapreduce.RecordReader<java.nio.ByteBuffer,java.util.SortedMap<java.nio.ByteBuffer,IColumn>>

Returns:

true if a key/value pair was read

Throws:

java.io.IOException