Examples with ObjectInputDecoder com.facebook.presto.hive.functions.type.ObjectInputDecoder used on opensource projects

Example 1 with ObjectInputDecoder

use of com.facebook.presto.hive.functions.type.ObjectInputDecoder 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);
    }
}