org.apache.hadoop.hive.ql.exec
Class ExprNodeEvaluator<T extends ExprNodeDesc>

java.lang.Object
  org.apache.hadoop.hive.ql.exec.ExprNodeEvaluator<T>

Direct Known Subclasses:

ExprNodeColumnEvaluator, ExprNodeConstantEvaluator, ExprNodeEvaluatorHead, ExprNodeEvaluatorRef, ExprNodeFieldEvaluator, ExprNodeGenericFuncEvaluator, ExprNodeNullEvaluator

public abstract class ExprNodeEvaluator<T extends ExprNodeDesc>
extends Object

ExprNodeEvaluator.

Constructor Summary

ExprNodeEvaluator(T expr)

Method Summary

Object	evaluate(Object row)
ExprNodeEvaluator[]	getChildren() Return child evaluators if exist
T	getExpr() Return child evaluators if exist
ObjectInspector	getOutputOI() Return initialized ObjectInspector.
abstract ObjectInspector	initialize(ObjectInspector rowInspector) Initialize should be called once and only once.
boolean	isDeterministic() Return whether this node (and all children nodes) are deterministic.
boolean	isStateful() Return whether this node (or any children nodes) are stateful.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExprNodeEvaluator

public ExprNodeEvaluator(T expr)

Method Detail

getExpr

public T getExpr()

Return child evaluators if exist

initialize

public abstract ObjectInspector initialize(ObjectInspector rowInspector)
                                    throws HiveException

Initialize should be called once and only once. Return the ObjectInspector for the return value, given the rowInspector.

Throws:

HiveException

getOutputOI

public ObjectInspector getOutputOI()

Return initialized ObjectInspector. If it's not initilized, throws runtime exception

evaluate

public Object evaluate(Object row)
                throws HiveException

Throws:

HiveException

isDeterministic

public boolean isDeterministic()

Return whether this node (and all children nodes) are deterministic.

isStateful

public boolean isStateful()

Return whether this node (or any children nodes) are stateful.

getChildren

public ExprNodeEvaluator[] getChildren()

Return child evaluators if exist