org.teiid.query.function.aggregate

Class AggregateFunction

java.lang.Object

org.teiid.query.function.aggregate.AggregateFunction

Direct Known Subclasses:

Count, CountBig, LeadLagValue, NthValue, RankingFunction, RankingFunctionBig, SingleArgumentAggregateFunction, SortingFilter, StringAgg, UserDefined

public abstract class AggregateFunction
extends Object

This represents the interface for an aggregate function. The basic lifecycle is that the AggregateFunction is initialize()'d with the type of the element being aggregated, then addInput() is called for every row in the group, then getResult() is called to retrieve the result.

Field Summary

Fields

Modifier and Type	Field and Description
protected int[]	argIndexes

Constructor Summary

Constructors

Constructor and Description
AggregateFunction()

Method Summary

Modifier and Type	Method and Description
void	addInput(List<?> tuple, CommandContext commandContext)
abstract void	addInputDirect(List<?> tuple, CommandContext commandContext) Called for the element value in every row of a group.
boolean	filter(List<?> tuple)
int[]	getArgIndexes()
Class<?>	getOutputType(AggregateSymbol function)
abstract Object	getResult(CommandContext commandContext) Called after all values have been processed to get the result.
void	getState(List<Object> state)
List<? extends Class<?>>	getStateTypes()
void	initialize(Class<?> dataType, Class<?>[] inputTypes) Called to initialize the function.
abstract void	reset() Called to reset the state of the function.
boolean	respectsNull()
void	setArgIndexes(int[] argIndexes)
void	setConditionIndex(int conditionIndex)
int	setState(List<?> state, int index)

Methods inherited from class java.lang.Object

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

Field Detail

argIndexes

protected int[] argIndexes

Constructor Detail

AggregateFunction

public AggregateFunction()

Method Detail

setArgIndexes

public void setArgIndexes(int[] argIndexes)

setConditionIndex

public void setConditionIndex(int conditionIndex)

initialize

public void initialize(Class<?> dataType,
                       Class<?>[] inputTypes)

Called to initialize the function. In the future this may expand with additional information.

Parameters:

dataType - Data type of element begin aggregated

inputTypes -

getArgIndexes

public int[] getArgIndexes()

reset

public abstract void reset()

Called to reset the state of the function.

addInput

public void addInput(List<?> tuple,
                     CommandContext commandContext)
              throws TeiidComponentException,
                     TeiidProcessingException

Throws:

TeiidComponentException

TeiidProcessingException

filter

public boolean filter(List<?> tuple)

respectsNull

public boolean respectsNull()

addInputDirect

public abstract void addInputDirect(List<?> tuple,
                                    CommandContext commandContext)
                             throws TeiidComponentException,
                                    TeiidProcessingException

Called for the element value in every row of a group.

Parameters:

tuple -

commandContext -

Throws:

TeiidProcessingException

TeiidComponentException

getResult

public abstract Object getResult(CommandContext commandContext)
                          throws FunctionExecutionException,
                                 ExpressionEvaluationException,
                                 TeiidComponentException,
                                 TeiidProcessingException

Called after all values have been processed to get the result.

Parameters:

commandContext -

Returns:

Result value

Throws:

TeiidProcessingException

FunctionExecutionException

ExpressionEvaluationException

TeiidComponentException

getStateTypes

public List<? extends Class<?>> getStateTypes()

getState

public void getState(List<Object> state)

setState

public int setState(List<?> state,
                    int index)

getOutputType

public Class<?> getOutputType(AggregateSymbol function)