use of com.facebook.presto.hive.functions.type.ObjectEncoder in project presto by prestodb.
the class HiveScalarFunctionInvoker method createFunctionInvoker.
public static HiveScalarFunctionInvoker createFunctionInvoker(Class<?> cls, QualifiedObjectName name, List<TypeSignature> arguments, TypeManager typeManager) {
final List<Type> argumentTypes = arguments.stream().map(typeManager::getType).collect(Collectors.toList());
try {
// Step 1: Create function instance
final GenericUDF udf = createGenericUDF(name, cls);
// Step 2: Initialize function
ObjectInspector[] inputInspectors = argumentTypes.stream().map(argumentType -> ObjectInspectors.create(argumentType, typeManager)).toArray(ObjectInspector[]::new);
ObjectInspector resultInspector = udf.initialize(inputInspectors);
// Step 3: Create invoker
Type resultType = PrestoTypes.fromObjectInspector(resultInspector, typeManager);
ObjectInputDecoder[] argumentDecoders = argumentTypes.stream().map(argumentsType -> createDecoder(argumentsType, typeManager)).toArray(ObjectInputDecoder[]::new);
ObjectEncoder resultEncoder = createEncoder(resultType, resultInspector);
Signature signature = new Signature(name, SCALAR, resultType.getTypeSignature(), arguments);
// Step 4: Create ThreadLocal GenericUDF
final ThreadLocal<GenericUDF> genericUDFSupplier = ThreadLocal.withInitial(() -> {
try (ThreadContextClassLoader ignored = new ThreadContextClassLoader(cls.getClassLoader())) {
GenericUDF ret = createGenericUDF(name, cls);
ret.initialize(inputInspectors);
return ret;
} catch (Exception e) {
throw initializationError(e);
}
});
return new HiveScalarFunctionInvoker(signature, genericUDFSupplier::get, argumentDecoders, resultEncoder);
} catch (Exception e) {
throw initializationError(e);
}
}
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