Package org.apache.calcite.schema.impl

Class AggregateFunctionImpl

java.lang.Object

org.apache.calcite.schema.impl.AggregateFunctionImpl

All Implemented Interfaces:

AggregateFunction, Function, ImplementableAggFunction

public class AggregateFunctionImpl
extends java.lang.Object
implements AggregateFunction, ImplementableAggFunction

Implementation of AggregateFunction via user-defined class. The class should implement A init(), A add(A, V), and R result(A) methods. All the methods should be either static or instance. Bonus point: when using non-static implementation, the aggregate object is reused through the calculation, thus it can have aggregation-related state.

Field Summary

Fields

Modifier and Type	Field	Description
java.lang.Class<?>	accumulatorType
java.lang.reflect.Method	addMethod
java.lang.Class<?>	declaringClass
java.lang.reflect.Method	initMethod
boolean	isStatic
java.lang.reflect.Method	mergeMethod
private java.util.List<FunctionParameter>	parameters
java.lang.reflect.Method	resultMethod
java.lang.Class<?>	resultType
com.google.common.collect.ImmutableList<java.lang.Class<?>>	valueTypes

Constructor Summary

Constructors

Modifier	Constructor	Description
private	AggregateFunctionImpl(java.lang.Class<?> declaringClass, java.util.List<FunctionParameter> params, java.util.List<java.lang.Class<?>> valueTypes, java.lang.Class<?> accumulatorType, java.lang.Class<?> resultType, java.lang.reflect.Method initMethod, java.lang.reflect.Method addMethod, java.lang.reflect.Method mergeMethod, java.lang.reflect.Method resultMethod)	Private constructor; use create(java.lang.Class<?>).

Method Summary

Modifier and Type	Method	Description
static AggregateFunctionImpl	create(java.lang.Class<?> clazz)	Creates an aggregate function, or returns null.
AggImplementor	getImplementor(boolean windowContext)	Returns implementor that translates the function to linq4j expression.
java.util.List<FunctionParameter>	getParameters()	Returns the parameters of this function.
RelDataType	getReturnType(RelDataTypeFactory typeFactory)	Returns the return type of this function, constructed using the given type factory.

Methods inherited from class java.lang.Object

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

Field Detail

isStatic

public final boolean isStatic

initMethod

public final java.lang.reflect.Method initMethod

addMethod

public final java.lang.reflect.Method addMethod

mergeMethod

public final java.lang.reflect.Method mergeMethod

resultMethod

public final java.lang.reflect.Method resultMethod

valueTypes

public final com.google.common.collect.ImmutableList<java.lang.Class<?>> valueTypes

parameters

private final java.util.List<FunctionParameter> parameters

accumulatorType

public final java.lang.Class<?> accumulatorType

resultType

public final java.lang.Class<?> resultType

declaringClass

public final java.lang.Class<?> declaringClass

Constructor Detail

AggregateFunctionImpl

private AggregateFunctionImpl(java.lang.Class<?> declaringClass,
                              java.util.List<FunctionParameter> params,
                              java.util.List<java.lang.Class<?>> valueTypes,
                              java.lang.Class<?> accumulatorType,
                              java.lang.Class<?> resultType,
                              java.lang.reflect.Method initMethod,
                              java.lang.reflect.Method addMethod,
                              java.lang.reflect.Method mergeMethod,
                              java.lang.reflect.Method resultMethod)

Private constructor; use create(java.lang.Class<?>).

Method Detail

create

public static AggregateFunctionImpl create(java.lang.Class<?> clazz)

Creates an aggregate function, or returns null.

getParameters

public java.util.List<FunctionParameter> getParameters()

Description copied from interface: Function

Returns the parameters of this function.

Specified by:

getParameters in interface Function

Returns:

Parameters; never null

getReturnType

public RelDataType getReturnType(RelDataTypeFactory typeFactory)

Description copied from interface: AggregateFunction

Returns the return type of this function, constructed using the given type factory.

Specified by:

getReturnType in interface AggregateFunction

Parameters:

typeFactory - Type factory

getImplementor

public AggImplementor getImplementor(boolean windowContext)

Description copied from interface: ImplementableAggFunction

Returns implementor that translates the function to linq4j expression.

Specified by:

getImplementor in interface ImplementableAggFunction

Parameters:

windowContext - true when aggregate is used in window context

Returns:

implementor that translates the function to linq4j expression.