org.apache.hadoop.hive.ql.lib

Class PreOrderWalker

java.lang.Object

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

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

All Implemented Interfaces:

GraphWalker

Direct Known Subclasses:

PreOrderOnceWalker

public class PreOrderWalker
extends DefaultGraphWalker

base class for operator graph walker this class takes list of starting ops and walks them one by one.

Field Summary

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

dispatcher, opQueue, opStack, retMap, toWalk

Constructor Summary

Constructors

Constructor and Description
PreOrderWalker(Dispatcher disp) Constructor.

Method Summary

Modifier and Type	Method and Description
protected 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

PreOrderWalker

public PreOrderWalker(Dispatcher disp)

Constructor.

Parameters:

disp - dispatcher to call for each op encountered

Method Detail

walk

protected void walk(Node nd)
             throws SemanticException

Walk the current operator and its descendants.

Overrides:

walk in class DefaultGraphWalker

Parameters:

nd - current operator in the graph

Throws:

SemanticException