org.apache.pig.newplan.logical.rules
Class LogicalExpressionSimplifier.LogicalExpressionSimplifierTransformer

java.lang.Object
  extended by org.apache.pig.newplan.optimizer.Transformer
      extended by org.apache.pig.newplan.logical.rules.LogicalExpressionSimplifier.LogicalExpressionSimplifierTransformer
Enclosing class:
LogicalExpressionSimplifier

public static class LogicalExpressionSimplifier.LogicalExpressionSimplifierTransformer
extends Transformer


Constructor Summary
LogicalExpressionSimplifier.LogicalExpressionSimplifierTransformer()
           
 
Method Summary
 boolean check(OperatorPlan matched)
          check if the transform should be done.
 OperatorPlan reportChanges()
          Report what parts of the tree were transformed.
 void transform(OperatorPlan plan)
          Transform the tree
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

LogicalExpressionSimplifier.LogicalExpressionSimplifierTransformer

public LogicalExpressionSimplifier.LogicalExpressionSimplifierTransformer()
Method Detail

check

public boolean check(OperatorPlan matched)
              throws FrontendException
Description copied from class: Transformer
check if the transform should be done. If this is being called then the pattern matches, but there may be other criteria that must be met as well.

Specified by:
check in class Transformer
Parameters:
matched - the sub-set of the plan that matches the pattern. This subset has the same graph as the pattern, but the operators point to the same objects as the plan to be matched.
Returns:
true if the transform should be done.
Throws:
FrontendException

transform

public void transform(OperatorPlan plan)
               throws FrontendException
Description copied from class: Transformer
Transform the tree

Specified by:
transform in class Transformer
Parameters:
plan - the sub-set of the plan that matches the pattern. This subset has the same graph as the pattern, but the operators point to the same objects as the plan to be matched.
Throws:
FrontendException

reportChanges

public OperatorPlan reportChanges()
Description copied from class: Transformer
Report what parts of the tree were transformed. This is so that listeners can know which part of the tree to visit and modify schemas, annotations, etc. So any nodes that were removed need will not be in this plan, only nodes that were added or moved.

Specified by:
reportChanges in class Transformer
Returns:
OperatorPlan that describes just the changed nodes.


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