stevedlawrence commented on a change in pull request #273: WIP: Add User Defined Functions Capability URL: https://github.com/apache/incubator-daffodil/pull/273#discussion_r336170009
########## File path: daffodil-runtime1/src/main/scala/org/apache/daffodil/udf/UserDefinedFunctionService.scala ########## @@ -0,0 +1,185 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.daffodil.udf + +import collection.JavaConverters._ +import collection.mutable._; +import java.util.ServiceLoader +import java.util.ServiceConfigurationError +import org.apache.daffodil.util.Misc +import java.io.Serializable +import org.apache.daffodil.util.LogLevel +import org.apache.daffodil.util.Logging +import java.lang.reflect.Method + +/** + * Loads all User Defined Function Providers on the classpath once and caches them in + * following look up tables that'll be used to look up the UDFs during Schema compile time. + * + * "$namespaceURI:$fName" -> classOf[UserDefinedFunction] + * "$namespaceURI:$fName" -> UserDefinedFunctionProvider + * + * It also does validation on the providers and classes and caches any warning and errors, + * which are then reported during compile time. + * + */ +object UserDefinedFunctionService extends Logging { + val evaluateMethodName = "evaluate" + type EvaluateMethod = Method + type ParameterTypes = Array[Class[_]] + type ReturnType = Class[_] + type UdfCallingInfo = (UserDefinedFunction, EvaluateMethod, ParameterTypes, ReturnType) + type NamespaceNameKey = String + private val functionClassesLookup: HashMap[NamespaceNameKey, Class[_]] = HashMap() + private val functionProviderLookup: HashMap[NamespaceNameKey, UserDefinedFunctionProvider] = HashMap() + private val InitializedUserDefinedFunctionsCache: HashMap[NamespaceNameKey, Option[UdfCallingInfo]] = HashMap() + lazy val classUserDefinedFunctionInfo = classOf[UserDefinedFunctionInfo] + lazy val classUserDefinedFunction = classOf[UserDefinedFunction] + lazy val classJSerializable = classOf[java.io.Serializable] + lazy val currentClassPath = Misc.classPath.map(_.toString).mkString("\n") + + val loader: ServiceLoader[UserDefinedFunctionProvider] = ServiceLoader.load(classOf[UserDefinedFunctionProvider]) + + loader.asScala.map { provider => + val providerfc = provider.getUserDefinedFunctionClasses + lazy val providerClassName = provider.getClass.getName + + if (providerfc == null || providerfc.isEmpty) { + val wstr = s"User Defined Function Provider ignored: ${providerClassName}. No User Defined Functions found." + log(LogLevel.Warning, wstr) + } else { + val missingAnnotations = providerfc.filterNot(_.isAnnotationPresent(classUserDefinedFunctionInfo)) + val nonUserDefinedFunction = providerfc.filterNot(classUserDefinedFunction.isAssignableFrom(_)) + + if (!missingAnnotations.isEmpty) { + val wstr = s"User Defined Function Provider ignored: ${providerClassName}. Below must be annotated with ${classUserDefinedFunctionInfo.getName}" + + s"\n${missingAnnotations.map(_.getName).mkString("\t", "\n\t", "")}" + log(LogLevel.Warning, wstr) + } + + if (!nonUserDefinedFunction.isEmpty) { + val wstr = s"User Defined Function Provider ignored: ${providerClassName}. Below must implement ${classUserDefinedFunction.getName}" + + s"\n${nonUserDefinedFunction.map(_.getName).mkString("\t", "\n\t", "")}" + log(LogLevel.Warning, wstr) + } + + if (missingAnnotations.isEmpty && nonUserDefinedFunction.isEmpty) { + providerfc.map { fc => + val fcClassName = fc.getName + val fInfo = fc.getDeclaredAnnotation(classUserDefinedFunctionInfo) + val fns = fInfo.namespaceURI() + val fname = fInfo.name() + if (List(fns, fname).exists { p => Option(p).isEmpty || p.trim.isEmpty }) { + val wstr = s"User Defined Function ignored: ${fcClassName} from provider ${providerClassName}." + + (if (Option(fns).isEmpty || fns.trim.isEmpty) " Annotation namespace field is empty or invalid." else "") + + (if (Option(fname).isEmpty || fname.trim.isEmpty) " Annotation namespace field is empty or invalid." else "") + log(LogLevel.Warning, wstr) + } + val key = s"$fns:$fname" + if (functionProviderLookup.contains(key)) { + val estr = s"User Defined Function ignored: ${fcClassName} from provider ${providerClassName}. Duplicate $key found." + log(LogLevel.Error, estr) Review comment: 1. Yeah, since this isn't fatal until someone tries to actually use it, a warning seems reasonable. 2. I have no strong opinion one way or the other. Either keep which ever appears first or drop both seems reasonable to me. That said, the logic can get much more complicated if you try to remove dups. For example, say you do the simple thing of just removing the original and ignoring the dup when you see a dup. But imagine there are three dups. When we see the first we add it to the cach. When we see the second, it's a dup so we remove the original and ignore it. Now when we see the third, the original is gone, so we won't realize it's a dup. So the logic needs to be more complex, either rememember which ones are dups, or filter out all dups at the end, or somethign else. Personally, I'm not sure the extra logic is worth it. We'll still output a dup warning, so that should let the user know something is wrong and fix it, or there's a potential of undefined behavior. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
