org.apache.pig.experimental.logical.optimizer
Class PlanPrinter.DepthFirstMemoryWalker

java.lang.Object
  extended by org.apache.pig.experimental.plan.PlanWalker
      extended by org.apache.pig.experimental.plan.DepthFirstWalker
          extended by org.apache.pig.experimental.logical.optimizer.PlanPrinter.DepthFirstMemoryWalker
Enclosing class:
PlanPrinter

public class PlanPrinter.DepthFirstMemoryWalker
extends DepthFirstWalker


Field Summary
 
Fields inherited from class org.apache.pig.experimental.plan.PlanWalker
plan
 
Constructor Summary
PlanPrinter.DepthFirstMemoryWalker(OperatorPlan plan, int startingLevel)
           
 
Method Summary
 String getPrefix()
           
 PlanWalker spawnChildWalker(OperatorPlan plan)
          Return a new instance of this same type of walker for a subplan.
 void walk(PlanVisitor visitor)
          Begin traversing the graph.
 
Methods inherited from class org.apache.pig.experimental.plan.PlanWalker
getPlan, setPlan
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

PlanPrinter.DepthFirstMemoryWalker

public PlanPrinter.DepthFirstMemoryWalker(OperatorPlan plan,
                                          int startingLevel)
Method Detail

spawnChildWalker

public PlanWalker spawnChildWalker(OperatorPlan plan)
Description copied from class: PlanWalker
Return a new instance of this same type of walker for a subplan. When this method is called the same type of walker with the provided plan set as the plan, must be returned. This can then be used to walk subplans. This allows abstract visitors to clone walkers without knowning the type of walker their subclasses used.

Overrides:
spawnChildWalker in class DepthFirstWalker
Parameters:
plan - Plan for the new walker.
Returns:
Instance of the same type of walker with plan set to plan.

walk

public void walk(PlanVisitor visitor)
          throws IOException
Begin traversing the graph.

Overrides:
walk in class DepthFirstWalker
Parameters:
visitor - Visitor this walker is being used by.
Throws:
IOException - if an error is encountered while walking.

getPrefix

public String getPrefix()


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