org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators
Class POLoad

java.lang.Object
  extended by org.apache.pig.impl.plan.Operator<PhyPlanVisitor>
      extended by org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator
          extended by org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POLoad
All Implemented Interfaces:
Serializable, Cloneable, Comparable<Operator>, Illustrable

public class POLoad
extends PhysicalOperator

The load operator which is used in two ways: 1) As a local operator it can be used to load files 2) In the Map Reduce setting, it is used to create jobs from MapReduce operators which keep the loads and stores in the Map and Reduce Plans till the job is created

See Also:
Serialized Form

Field Summary
 
Fields inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator
alias, dummyBag, dummyBool, dummyDBA, dummyDouble, dummyFloat, dummyInt, dummyLong, dummyMap, dummyString, dummyTuple, illustrator, input, inputAttached, inputs, lineageTracer, outputs, parentPlan, pigLogger, reporter, requestedParallelism, res, resultType
 
Fields inherited from class org.apache.pig.impl.plan.Operator
mKey
 
Constructor Summary
POLoad(OperatorKey k)
           
POLoad(OperatorKey k, FileSpec lFile)
           
POLoad(OperatorKey k, int rp, FileSpec lFile)
           
POLoad(OperatorKey k, LoadFunc lf)
           
 
Method Summary
 FileSpec getLFile()
           
 long getLimit()
           
 LoadFunc getLoadFunc()
           
 Result getNext(Tuple t)
          The main method used by this operator's successor to read tuples from the specified file using the specified load function.
 PigContext getPc()
           
 String getSignature()
           
 Tuple illustratorMarkup(Object in, Object out, int eqClassIndex)
          input tuple mark up to be illustrate-able
 String name()
           
 void setLFile(FileSpec file)
           
 void setLimit(long limit)
           
 void setPc(PigContext pc)
           
 void setSignature(String signature)
           
 void setUp()
          Set up the loader by 1) Instantiating the load func 2) Opening an input stream to the specified file and 3) Binding to the input stream at the specified offset.
 boolean supportsMultipleInputs()
          Indicates whether this operator supports multiple inputs.
 boolean supportsMultipleOutputs()
          Indicates whether this operator supports multiple outputs.
 void tearDown()
          At the end of processing, the inputstream is closed using this method
 void visit(PhyPlanVisitor v)
          Visit this node with the provided visitor.
 
Methods inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator
attachInput, clone, cloneHelper, detachInput, getAlias, getAliasString, getDummy, getIllustrator, getInputs, getLogger, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getPigLogger, getRequestedParallelism, getResultType, isAccumStarted, isAccumulative, isBlocking, isInputAttached, processInput, reset, setAccumEnd, setAccumStart, setAccumulative, setAlias, setIllustrator, setInputs, setParentPlan, setPigLogger, setReporter, setRequestedParallelism, setResultType
 
Methods inherited from class org.apache.pig.impl.plan.Operator
compareTo, equals, getOperatorKey, getProjectionMap, hashCode, regenerateProjectionMap, rewire, toString, unsetProjectionMap
 
Methods inherited from class java.lang.Object
finalize, getClass, notify, notifyAll, wait, wait, wait
 

Constructor Detail

POLoad

public POLoad(OperatorKey k)

POLoad

public POLoad(OperatorKey k,
              FileSpec lFile)

POLoad

public POLoad(OperatorKey k,
              int rp,
              FileSpec lFile)

POLoad

public POLoad(OperatorKey k,
              LoadFunc lf)
Method Detail

setUp

public void setUp()
           throws IOException
Set up the loader by 1) Instantiating the load func 2) Opening an input stream to the specified file and 3) Binding to the input stream at the specified offset.

Throws:
IOException

tearDown

public void tearDown()
              throws IOException
At the end of processing, the inputstream is closed using this method

Throws:
IOException

getNext

public Result getNext(Tuple t)
               throws ExecException
The main method used by this operator's successor to read tuples from the specified file using the specified load function.

Overrides:
getNext in class PhysicalOperator
Returns:
Whatever the loader returns A null from the loader is indicative of EOP and hence the tearDown of connection
Throws:
ExecException

name

public String name()
Specified by:
name in class Operator<PhyPlanVisitor>

supportsMultipleInputs

public boolean supportsMultipleInputs()
Description copied from class: Operator
Indicates whether this operator supports multiple inputs.

Specified by:
supportsMultipleInputs in class Operator<PhyPlanVisitor>
Returns:
true if it does, otherwise false.

supportsMultipleOutputs

public boolean supportsMultipleOutputs()
Description copied from class: Operator
Indicates whether this operator supports multiple outputs.

Specified by:
supportsMultipleOutputs in class Operator<PhyPlanVisitor>
Returns:
true if it does, otherwise false.

visit

public void visit(PhyPlanVisitor v)
           throws VisitorException
Description copied from class: Operator
Visit this node with the provided visitor. This should only be called by the visitor class itself, never directly.

Specified by:
visit in class PhysicalOperator
Parameters:
v - Visitor to visit with.
Throws:
VisitorException - if the visitor has a problem.

getLFile

public FileSpec getLFile()

setLFile

public void setLFile(FileSpec file)

getPc

public PigContext getPc()

setPc

public void setPc(PigContext pc)

getSignature

public String getSignature()

setSignature

public void setSignature(String signature)

getLoadFunc

public LoadFunc getLoadFunc()

illustratorMarkup

public Tuple illustratorMarkup(Object in,
                               Object out,
                               int eqClassIndex)
Description copied from interface: Illustrable
input tuple mark up to be illustrate-able

Parameters:
in - input tuple
out - output tuple before wrapped in ExampleTuple
eqClassIndex - index into equivalence classes in illustrator
Returns:
tuple

getLimit

public long getLimit()

setLimit

public void setLimit(long limit)


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