org.apache.flink.table.functions

Interface SpecializedFunction.ExpressionEvaluator

All Superinterfaces:

Serializable

All Known Implementing Classes:

DefaultExpressionEvaluator

Enclosing interface:

SpecializedFunction

@PublicEvolving
public static interface SpecializedFunction.ExpressionEvaluator
extends Serializable

Serializable factory that can be passed into a UserDefinedFunction for evaluating previously defined expression during runtime.

See Also:

SpecializedFunction.ExpressionEvaluatorFactory.createEvaluator(Expression, DataType, DataTypes.Field...), SpecializedFunction.ExpressionEvaluatorFactory.createEvaluator(BuiltInFunctionDefinition, DataType, DataType...)

Method Summary

Modifier and Type	Method and Description
default void	close() Closes the runtime implementation for expression evaluation.
MethodHandle	open(FunctionContext context) Creates and initializes runtime implementation for expression evaluation.

Method Detail

open

MethodHandle open(FunctionContext context)

Creates and initializes runtime implementation for expression evaluation. The returned MethodHandle should be stored in a transient variable and can be invoked via MethodHandle.invokeExact(Object...) using the conversion classes previously defined via the passed DataTypes.

This method should be called in UserDefinedFunction.open(FunctionContext).

close

default void close()

Closes the runtime implementation for expression evaluation. It performs clean up work.

This method should be called in UserDefinedFunction.close().