org.apache.pig.backend.hadoop.executionengine.mapReduceLayer

Class PigGenericMapBase

java.lang.Object

org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.Text,Tuple,PigNullableWritable,org.apache.hadoop.io.Writable>

org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase

Direct Known Subclasses:

PigMapBase

public abstract class PigGenericMapBase
extends org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.Text,Tuple,PigNullableWritable,org.apache.hadoop.io.Writable>

This class is the base class for PigMapBase, which has slightly difference among different versions of hadoop. PigMapBase implementation is located in $PIG_HOME/shims.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Mapper

org.apache.hadoop.mapreduce.Mapper.Context

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	errorInMap
protected byte	keyType
protected PhysicalPlan	mp
protected List<POStore>	stores
protected TupleFactory	tf

Constructor Summary

Constructors

Constructor and Description
PigGenericMapBase()

Method Summary

Modifier and Type	Method and Description
void	cleanup(org.apache.hadoop.mapreduce.Mapper.Context context) Will be called when all the tuples in the input are done.
abstract void	collect(org.apache.hadoop.mapreduce.Mapper.Context oc, Tuple tuple)
abstract org.apache.hadoop.mapreduce.Mapper.Context	getIllustratorContext(org.apache.hadoop.conf.Configuration conf, DataBag input, List<Pair<PigNullableWritable,org.apache.hadoop.io.Writable>> output, org.apache.hadoop.mapreduce.InputSplit split)
byte	getKeyType()
abstract boolean	inIllustrator(org.apache.hadoop.mapreduce.Mapper.Context context)
protected void	map(org.apache.hadoop.io.Text key, Tuple inpTuple, org.apache.hadoop.mapreduce.Mapper.Context context) The map function that attaches the inpTuple appropriately and executes the map plan if its not empty.
protected void	runPipeline(PhysicalOperator leaf)
void	setKeyType(byte keyType)
void	setMapPlan(PhysicalPlan plan) for local map/reduce simulation
void	setup(org.apache.hadoop.mapreduce.Mapper.Context context) Configures the mapper with the map plan and the reproter thread

Methods inherited from class org.apache.hadoop.mapreduce.Mapper

run

Methods inherited from class java.lang.Object

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

Field Detail

keyType

protected byte keyType

mp

protected PhysicalPlan mp

stores

protected List<POStore> stores

tf

protected TupleFactory tf

errorInMap

protected boolean errorInMap

Constructor Detail

PigGenericMapBase

public PigGenericMapBase()

Method Detail

setMapPlan

public void setMapPlan(PhysicalPlan plan)

for local map/reduce simulation

Parameters:

plan - the map plan

cleanup

public void cleanup(org.apache.hadoop.mapreduce.Mapper.Context context)
             throws IOException,
                    InterruptedException

Will be called when all the tuples in the input are done. So reporter thread should be closed.

Overrides:

cleanup in class org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.Text,Tuple,PigNullableWritable,org.apache.hadoop.io.Writable>

Throws:

IOException

InterruptedException

setup

public void setup(org.apache.hadoop.mapreduce.Mapper.Context context)
           throws IOException,
                  InterruptedException

Configures the mapper with the map plan and the reproter thread

Overrides:

setup in class org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.Text,Tuple,PigNullableWritable,org.apache.hadoop.io.Writable>

Throws:

IOException

InterruptedException

map

protected void map(org.apache.hadoop.io.Text key,
                   Tuple inpTuple,
                   org.apache.hadoop.mapreduce.Mapper.Context context)
            throws IOException,
                   InterruptedException

The map function that attaches the inpTuple appropriately and executes the map plan if its not empty. Collects the result of execution into oc or the input directly to oc if map plan empty. The collection is left abstract for the map-only or map-reduce job to implement. Map-only collects the tuple as-is whereas map-reduce collects it after extracting the key and indexed tuple.

Overrides:

map in class org.apache.hadoop.mapreduce.Mapper<org.apache.hadoop.io.Text,Tuple,PigNullableWritable,org.apache.hadoop.io.Writable>

Throws:

IOException

InterruptedException

runPipeline

protected void runPipeline(PhysicalOperator leaf)
                    throws IOException,
                           InterruptedException

Throws:

IOException

InterruptedException

collect

public abstract void collect(org.apache.hadoop.mapreduce.Mapper.Context oc,
                             Tuple tuple)
                      throws InterruptedException,
                             IOException

Throws:

InterruptedException

IOException

inIllustrator

public abstract boolean inIllustrator(org.apache.hadoop.mapreduce.Mapper.Context context)

getKeyType

public byte getKeyType()

Returns:

the keyType

setKeyType

public void setKeyType(byte keyType)

Parameters:

keyType - the keyType to set

getIllustratorContext

public abstract org.apache.hadoop.mapreduce.Mapper.Context getIllustratorContext(org.apache.hadoop.conf.Configuration conf,
                                                                                 DataBag input,
                                                                                 List<Pair<PigNullableWritable,org.apache.hadoop.io.Writable>> output,
                                                                                 org.apache.hadoop.mapreduce.InputSplit split)
                                                                          throws IOException,
                                                                                 InterruptedException

Throws:

IOException

InterruptedException