org.apache.hadoop.zebra.mapreduce

Class TableRecordReader

java.lang.Object

org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.BytesWritable,Tuple>

org.apache.hadoop.zebra.mapreduce.TableRecordReader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class TableRecordReader
extends org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.BytesWritable,Tuple>

Adaptor class to implement RecordReader on top of Scanner.

Constructor Summary

Constructors

Constructor and Description
TableRecordReader(org.apache.hadoop.zebra.mapreduce.TableExpr expr, java.lang.String projection, org.apache.hadoop.mapreduce.InputSplit split, org.apache.hadoop.mapreduce.JobContext jobContext)

Method Summary

Methods

Modifier and Type	Method and Description
boolean	atEnd() Check if the end of the input has been reached
void	close()
org.apache.hadoop.io.BytesWritable	getCurrentKey()
Tuple	getCurrentValue()
long	getPos()
float	getProgress()
void	initialize(org.apache.hadoop.mapreduce.InputSplit arg0, org.apache.hadoop.mapreduce.TaskAttemptContext arg1)
boolean	nextKeyValue()
boolean	seekTo(org.apache.hadoop.io.BytesWritable key) Seek to the position at the first row which has the key or just after the key; only applicable for sorted Zebra table

Methods inherited from class java.lang.Object

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

Constructor Detail

TableRecordReader

public TableRecordReader(org.apache.hadoop.zebra.mapreduce.TableExpr expr,
                 java.lang.String projection,
                 org.apache.hadoop.mapreduce.InputSplit split,
                 org.apache.hadoop.mapreduce.JobContext jobContext)
                  throws java.io.IOException,
                         ParseException

Parameters:

expr - Table expression

projection - projection schema. Should never be null.

split - the split to work on

jobContext - JobContext object

Throws:

java.io.IOException

ParseException

Method Detail

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.BytesWritable,Tuple>

Throws:

java.io.IOException

getPos

public long getPos()
            throws java.io.IOException

Throws:

java.io.IOException

getProgress

public float getProgress()
                  throws java.io.IOException

Specified by:

getProgress in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.BytesWritable,Tuple>

Throws:

java.io.IOException

seekTo

public boolean seekTo(org.apache.hadoop.io.BytesWritable key)
               throws java.io.IOException

Seek to the position at the first row which has the key or just after the key; only applicable for sorted Zebra table

Parameters:

key - the key to seek on

Throws:

java.io.IOException

atEnd

public boolean atEnd()
              throws java.io.IOException

Check if the end of the input has been reached

Returns:

true if the end of the input is reached

Throws:

java.io.IOException

getCurrentKey

public org.apache.hadoop.io.BytesWritable getCurrentKey()
                                                 throws java.io.IOException,
                                                        java.lang.InterruptedException

Specified by:

getCurrentKey in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.BytesWritable,Tuple>

Throws:

java.io.IOException

java.lang.InterruptedException

getCurrentValue

public Tuple getCurrentValue()
                      throws java.io.IOException,
                             java.lang.InterruptedException

Specified by:

getCurrentValue in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.BytesWritable,Tuple>

Throws:

java.io.IOException

java.lang.InterruptedException

initialize

public void initialize(org.apache.hadoop.mapreduce.InputSplit arg0,
              org.apache.hadoop.mapreduce.TaskAttemptContext arg1)
                throws java.io.IOException,
                       java.lang.InterruptedException

Specified by:

initialize in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.BytesWritable,Tuple>

Throws:

java.io.IOException

java.lang.InterruptedException

nextKeyValue

public boolean nextKeyValue()
                     throws java.io.IOException,
                            java.lang.InterruptedException

Specified by:

nextKeyValue in class org.apache.hadoop.mapreduce.RecordReader<org.apache.hadoop.io.BytesWritable,Tuple>

Throws:

java.io.IOException

java.lang.InterruptedException