org.apache.calcite.adapter.enumerable

Class StrictAggImplementor

java.lang.Object

org.apache.calcite.adapter.enumerable.StrictAggImplementor

All Implemented Interfaces:

AggImplementor

Direct Known Subclasses:

RexImpTable.UserDefinedAggReflectiveImplementor, StrictWinAggImplementor

public abstract class StrictAggImplementor
extends Object
implements AggImplementor

The base implementation of strict aggregate function.

See Also:

RexImpTable.CountImplementor, RexImpTable.SumImplementor

Constructor Summary

Constructors

Constructor and Description
StrictAggImplementor()

Method Summary

Methods

Modifier and Type	Method and Description
protected void	accAdvance(AggAddContext add, Expression acc, Expression next)
List<Type>	getNotNullState(AggContext info)
protected int	getStateSize()
List<Type>	getStateType(AggContext info) Returns the types of the intermediate variables used by the aggregate implementation.
void	implementAdd(AggContext info, AggAddContext add) Updates intermediate values to account for the newly added value.
protected abstract void	implementNotNullAdd(AggContext info, AggAddContext add)
protected void	implementNotNullReset(AggContext info, AggResetContext reset)
protected Expression	implementNotNullResult(AggContext info, AggResultContext result)
void	implementReset(AggContext info, AggResetContext reset) Implements reset of the intermediate variables to the initial state.
Expression	implementResult(AggContext info, AggResultContext result) Calculates the resulting value based on the intermediate variables.
protected boolean	nonDefaultOnEmptySet(AggContext info)

Methods inherited from class java.lang.Object

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

Constructor Detail

StrictAggImplementor

public StrictAggImplementor()

Method Detail

nonDefaultOnEmptySet

protected boolean nonDefaultOnEmptySet(AggContext info)

getStateSize

protected final int getStateSize()

accAdvance

protected final void accAdvance(AggAddContext add,
              Expression acc,
              Expression next)

getStateType

public final List<Type> getStateType(AggContext info)

Description copied from interface: AggImplementor

Returns the types of the intermediate variables used by the aggregate implementation.

For instance, for "concatenate to string" this can be StringBuilder. Calcite calls this method before all other implement* methods.

Specified by:

getStateType in interface AggImplementor

Parameters:

info - Aggregate context

Returns:

Types of the intermediate variables used by the aggregate implementation

getNotNullState

public List<Type> getNotNullState(AggContext info)

implementReset

public final void implementReset(AggContext info,
                  AggResetContext reset)

Description copied from interface: AggImplementor

Implements reset of the intermediate variables to the initial state. AggResetContext.accumulator() should be used to reference the state variables. For instance, to zero the count, use the following code:

reset.currentBlock().add(
Expressions.statement(
Expressions.assign(reset.accumulator().get(0),
Expressions.constant(0)));

Specified by:

implementReset in interface AggImplementor

Parameters:

info - Aggregate context

reset - Reset context

implementNotNullReset

protected void implementNotNullReset(AggContext info,
                         AggResetContext reset)

implementAdd

public final void implementAdd(AggContext info,
                AggAddContext add)

Description copied from interface: AggImplementor

Updates intermediate values to account for the newly added value. AggResetContext.accumulator() should be used to reference the state variables.

Specified by:

implementAdd in interface AggImplementor

Parameters:

info - Aggregate context

add - Add context

implementNotNullAdd

protected abstract void implementNotNullAdd(AggContext info,
                       AggAddContext add)

implementResult

public final Expression implementResult(AggContext info,
                         AggResultContext result)

Description copied from interface: AggImplementor

Calculates the resulting value based on the intermediate variables. Note: this method must NOT destroy the intermediate variables as calcite might reuse the state when calculating sliding aggregates. AggResetContext.accumulator() should be used to reference the state variables.

Specified by:

implementResult in interface AggImplementor

Parameters:

info - Aggregate context

result - Result context

Returns:

Expression that is a result of calculating final value of the aggregate being implemented

implementNotNullResult

protected Expression implementNotNullResult(AggContext info,
                                AggResultContext result)