org.apache.hadoop.hive.ql.lib

Class PreOrderOnceWalker

java.lang.Object

org.apache.hadoop.hive.ql.lib.DefaultGraphWalker

org.apache.hadoop.hive.ql.lib.PreOrderWalker

org.apache.hadoop.hive.ql.lib.PreOrderOnceWalker

All Implemented Interfaces:

GraphWalker

public class PreOrderOnceWalker
extends PreOrderWalker

Graph walker this class takes list of starting nodes and walks them in pre-order. If a rule fires up against a given node, we do not try to apply the rule on its children.

Field Summary

Fields inherited from class org.apache.hadoop.hive.ql.lib.DefaultGraphWalker

dispatcher, opQueue, opStack, retMap, toWalk

Constructor Summary

Constructors

Constructor and Description
PreOrderOnceWalker(Dispatcher disp)

Method Summary

Modifier and Type	Method and Description
void	walk(Node nd) Walk the current operator and its descendants.

Methods inherited from class org.apache.hadoop.hive.ql.lib.DefaultGraphWalker

dispatch, dispatchAndReturn, getDispatchedList, startWalking

Methods inherited from class java.lang.Object

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

Constructor Detail

PreOrderOnceWalker

public PreOrderOnceWalker(Dispatcher disp)

Method Detail

walk

public void walk(Node nd)
          throws SemanticException

Walk the current operator and its descendants.

Overrides:

walk in class PreOrderWalker

Parameters:

nd - current operator in the graph

Throws:

SemanticException