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, ExprNodeDynamicValueEvaluator, ExprNodeEvaluatorHead, ExprNodeEvaluatorRef, ExprNodeFieldEvaluator, ExprNodeGenericFuncEvaluator

public abstract class ExprNodeEvaluator<T extends ExprNodeDesc>
extends Object

ExprNodeEvaluator.

Field Summary

Fields

Modifier and Type	Field and Description
protected org.apache.hadoop.conf.Configuration	conf
protected T	expr
protected ObjectInspector	outputOI

Constructor Summary

Constructors

Constructor and Description
ExprNodeEvaluator(T expr, org.apache.hadoop.conf.Configuration conf)

Method Summary

Modifier and Type	Method and Description
protected abstract Object	_evaluate(Object row, int version) Evaluate value
Object	evaluate(Object row)
protected Object	evaluate(Object row, int version) Evaluate the expression given the row.
ExprNodeEvaluator[]	getChildren() Return child evaluators if exist
org.apache.hadoop.conf.Configuration	getConf()
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	isConsistentWithinQuery() Returns whether the expression, for a single query, returns the same result given the same arguments.
boolean	isDeterministic() Return whether this node (and all children nodes) are deterministic.
boolean	isRuntimeConstant() Return whether this node (or any children nodes) are runtime constants.
boolean	isStateful() Return whether this node (or any children nodes) are stateful.
void	setConf(org.apache.hadoop.conf.Configuration conf)
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

expr

protected final T extends ExprNodeDesc expr

outputOI

protected ObjectInspector outputOI

conf

protected org.apache.hadoop.conf.Configuration conf

Constructor Detail

ExprNodeEvaluator

public ExprNodeEvaluator(T expr,
                         org.apache.hadoop.conf.Configuration conf)

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 initialized, throws runtime exception

evaluate

public Object evaluate(Object row)
                throws HiveException

Throws:

HiveException

evaluate

protected Object evaluate(Object row,
                          int version)
                   throws HiveException

Evaluate the expression given the row. This method should use the rowInspector passed in from initialize to inspect the row object. The return value will be inspected by the return value of initialize. If this evaluator is referenced by others, store it for them

Throws:

HiveException

_evaluate

protected abstract Object _evaluate(Object row,
                                    int version)
                             throws HiveException

Evaluate value

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.

isRuntimeConstant

public boolean isRuntimeConstant()

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

isConsistentWithinQuery

public boolean isConsistentWithinQuery()

Returns whether the expression, for a single query, returns the same result given the same arguments. This includes deterministic functions as well as runtime constants (which may not be deterministic across queries).

getChildren

public ExprNodeEvaluator[] getChildren()

Return child evaluators if exist

toString

public String toString()

Overrides:

toString in class Object

getConf

public org.apache.hadoop.conf.Configuration getConf()

setConf

public void setConf(org.apache.hadoop.conf.Configuration conf)