org.apache.hadoop.hive.ql.lib

Class CostLessRuleDispatcher

java.lang.Object

org.apache.hadoop.hive.ql.lib.CostLessRuleDispatcher

All Implemented Interfaces:

Dispatcher, SemanticDispatcher

public class CostLessRuleDispatcher
extends Object
implements SemanticDispatcher

Dispatches calls to relevant method in processor. The user registers various rules with the dispatcher, and the processor corresponding to the type of node

Constructor Summary

Constructors

Constructor and Description
CostLessRuleDispatcher(SemanticNodeProcessor defaultProc, com.google.common.collect.SetMultimap<Integer,SemanticNodeProcessor> rules, NodeProcessorCtx procCtx) Constructor.

Method Summary

Modifier and Type	Method and Description
Object	dispatch(Node nd, Stack<Node> ndStack, Object... nodeOutputs) Dispatcher function.

Methods inherited from class java.lang.Object

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

Constructor Detail

CostLessRuleDispatcher

public CostLessRuleDispatcher(SemanticNodeProcessor defaultProc,
                              com.google.common.collect.SetMultimap<Integer,SemanticNodeProcessor> rules,
                              NodeProcessorCtx procCtx)

Constructor.

Parameters:

defaultProc - default processor to be fired if no rule matches

rules - Map mapping the node's type to processor

procCtx - operator processor context, which is opaque to the dispatcher

Method Detail

dispatch

public Object dispatch(Node nd,
                       Stack<Node> ndStack,
                       Object... nodeOutputs)
                throws SemanticException

Dispatcher function.

Specified by:

dispatch in interface Dispatcher

Specified by:

dispatch in interface SemanticDispatcher

Parameters:

nd - operator to process

ndStack - the operators encountered so far

nodeOutputs - The argument list of outputs from processing other nodes that are passed to this dispatcher from the walker.

Returns:

Object The return object from the processing call.

Throws:

SemanticException