org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators
Class ConstantExpression

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.expressionOperators.ExpressionOperator
              extended by org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.ConstantExpression
All Implemented Interfaces:
Serializable, Cloneable, Comparable<Operator>

public class ConstantExpression
extends ExpressionOperator

This class implements a Constant of any type. Its value can be set using the setValue method.

See Also:
Serialized Form

Field Summary
 
Fields inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.ExpressionOperator
log
 
Fields inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator
alias, dummyBag, dummyBool, dummyDBA, dummyDouble, dummyFloat, dummyInt, dummyLong, dummyMap, dummyString, dummyTuple, input, inputAttached, inputs, lineageTracer, outputs, parentPlan, pigLogger, reporter, requestedParallelism, resultType
 
Fields inherited from class org.apache.pig.impl.plan.Operator
mKey
 
Constructor Summary
ConstantExpression(OperatorKey k)
           
ConstantExpression(OperatorKey k, int rp)
           
 
Method Summary
 ConstantExpression clone()
          Make a deep copy of this operator.
 List<ExpressionOperator> getChildExpressions()
          Get the child expressions of this expression
 Result getNext(Boolean b)
           
 Result getNext(DataBag db)
           
 Result getNext(DataByteArray ba)
           
 Result getNext(Double d)
           
 Result getNext(Float f)
           
 Result getNext(Integer i)
           
 Result getNext(Long l)
           
 Result getNext(Map m)
           
 Result getNext(String s)
           
 Result getNext(Tuple t)
           
 Object getValue()
           
 String name()
           
 void setValue(Object value)
           
 boolean supportsMultipleInputs()
          Indicates whether this operator supports multiple inputs.
 boolean supportsMultipleOutputs()
          Indicates whether this operator supports multiple outputs.
 void visit(PhyPlanVisitor v)
          Visit this node with the provided visitor.
 
Methods inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.ExpressionOperator
accumChild, accumChild, accumChild, accumChild, accumChild, accumChild, accumChild, accumChild, accumChild, accumChild, containUDF
 
Methods inherited from class org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator
attachInput, cloneHelper, detachInput, getAlias, getAliasString, getInputs, getLogger, getPigLogger, getRequestedParallelism, getResultType, isAccumStarted, isAccumulative, isBlocking, isInputAttached, processInput, reset, setAccumEnd, setAccumStart, setAccumulative, setAlias, setInputs, setLineageTracer, 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

ConstantExpression

public ConstantExpression(OperatorKey k)

ConstantExpression

public ConstantExpression(OperatorKey k,
                          int rp)
Method Detail

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.

Overrides:
supportsMultipleOutputs in class ExpressionOperator
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 ExpressionOperator
Parameters:
v - Visitor to visit with.
Throws:
VisitorException - if the visitor has a problem.

getValue

public Object getValue()

setValue

public void setValue(Object value)

getNext

public Result getNext(DataBag db)
               throws ExecException
Overrides:
getNext in class ExpressionOperator
Throws:
ExecException

getNext

public Result getNext(DataByteArray ba)
               throws ExecException
Overrides:
getNext in class PhysicalOperator
Throws:
ExecException

getNext

public Result getNext(Double d)
               throws ExecException
Overrides:
getNext in class PhysicalOperator
Throws:
ExecException

getNext

public Result getNext(Float f)
               throws ExecException
Overrides:
getNext in class PhysicalOperator
Throws:
ExecException

getNext

public Result getNext(Integer i)
               throws ExecException
Overrides:
getNext in class PhysicalOperator
Throws:
ExecException

getNext

public Result getNext(Long l)
               throws ExecException
Overrides:
getNext in class PhysicalOperator
Throws:
ExecException

getNext

public Result getNext(String s)
               throws ExecException
Overrides:
getNext in class PhysicalOperator
Throws:
ExecException

getNext

public Result getNext(Tuple t)
               throws ExecException
Overrides:
getNext in class PhysicalOperator
Throws:
ExecException

getNext

public Result getNext(Boolean b)
               throws ExecException
Overrides:
getNext in class PhysicalOperator
Throws:
ExecException

getNext

public Result getNext(Map m)
               throws ExecException
Overrides:
getNext in class PhysicalOperator
Throws:
ExecException

clone

public ConstantExpression clone()
                         throws CloneNotSupportedException
Description copied from class: ExpressionOperator
Make a deep copy of this operator. This is declared here to make it possible to call clone on ExpressionOperators.

Overrides:
clone in class ExpressionOperator
Throws:
CloneNotSupportedException
See Also:
Do not use the clone method directly. Operators are cloned when logical plans are cloned using {@link LogicalPlanCloner}

getChildExpressions

public List<ExpressionOperator> getChildExpressions()
Get the child expressions of this expression

Specified by:
getChildExpressions in class ExpressionOperator


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