Package dev.frostlake.executor.udf

Interface UdfLanguageRuntime

public interface UdfLanguageRuntime

Executes UDFs and stored procedures of one UdfLanguage. Runtimes are discovered as a ServiceLoader SPI (see UdfRuntimes): Java ships in the engine, while the heavyweight languages live in optional modules — frostlake-rt-js (GraalJS JavaScript), frostlake-rt-py (GraalPy Python) and frostlake-rt-scala (in-process scala-compiler) — and light up only when their module is on the classpath, so the core engine carries no GraalVM language or Scala compiler dependencies. Adding a language is "implement this interface and register the provider in META-INF/services/dev.frostlake.executor.udf.UdfLanguageRuntime".

Method Summary

Modifier and Type	Method	Description
default void	compileFunction(Function function)	Compile a FUNCTION's body at CREATE time, throwing if the routine could never run — live-verified, a Python, Java or Scala function whose body will not compile, or whose HANDLER is not in it, is refused by CREATE rather than by the first call.
default void	compileProcedure(Procedure procedure)	Compile a PROCEDURE's body at CREATE time, as compileFunction(dev.frostlake.metastore.model.Function) does for a function.
void	configure(EngineConfig config)	Engine-construction hook: receives every new engine's configuration (e.g.
Object	executeFunction(Function function, List<Object> arguments, Catalog catalog, S3PathResolver s3PathResolver)	Evaluate a scalar UDF call and return its SQL value.
Object	executeProcedure(Procedure procedure, List<Object> arguments, DatabaseEngine engine)	Execute a stored procedure call and return its result value.
ResultSet	executeTableFunction(Function function, List<Object> arguments)	Execute a table function (UDTF) call; languages without table functions throw.
UdfLanguage	language()	The language this runtime executes.

Method Details

language

UdfLanguage language()

The language this runtime executes.

configure

void configure(EngineConfig config)

Engine-construction hook: receives every new engine's configuration (e.g. python.venv). Called once per DatabaseEngine instance for every discovered runtime — implementations with JVM-wide state must be idempotent; runtimes without configuration make this a no-op.

executeFunction

Object executeFunction(Function function,
 List<Object> arguments,
 Catalog catalog,
 S3PathResolver s3PathResolver)

Evaluate a scalar UDF call and return its SQL value. The catalog and S3 resolver (either may be null) let runtimes whose handlers can live in a JAR resolve IMPORTS stage references — runtimes that only execute inline bodies ignore them.

executeProcedure

Object executeProcedure(Procedure procedure,
 List<Object> arguments,
 DatabaseEngine engine)

Execute a stored procedure call and return its result value.

executeTableFunction

ResultSet executeTableFunction(Function function,
 List<Object> arguments)

Execute a table function (UDTF) call; languages without table functions throw.

compileFunction

default void compileFunction(Function function)

Compile a FUNCTION's body at CREATE time, throwing if the routine could never run — live-verified, a Python, Java or Scala function whose body will not compile, or whose HANDLER is not in it, is refused by CREATE rather than by the first call.

The default is a deliberate no-op, and it is what JavaScript wants: live compiles no JavaScript body at all, so AS '' is created happily and only fails when called. It is also the honest answer for a language whose module is absent — an engine that cannot judge a body must accept it, exactly as the SQL-body check fails open on a construct it cannot parse.

compileProcedure

default void compileProcedure(Procedure procedure)

Compile a PROCEDURE's body at CREATE time, as compileFunction(dev.frostlake.metastore.model.Function) does for a function.

Not simply the same rule: a PYTHON procedure is NOT compiled at CREATE though a Python function is — measured both ways on the same account — so this defaults to a no-op separately rather than sharing the function's implementation.