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_r335030092
########## 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) + } else { + functionProviderLookup += (key -> provider) + functionClassesLookup += (key -> fc) + } + } + } + } + } + + if (functionClassesLookup.isEmpty) { + log(LogLevel.Warning, "No user defined functions found. Check that UDF JARs are on classpath and that they are properly registerable by ServiceLoader.") Review comment: I would say we want to be consistent and have the same error message regardless if any UDF's are loaded. I think the easiest thing to do is to have the same "Unknown function" SDE when we do not recognnize a function, and then just have enough debug/info/warning logging that says when we ignore a UDF (and why) and which UDF's were successfully loaded that user can figure out why their particular UDF didn't work, if they intended to use a UDF. If they didn't intend to use a UDF (the most common case) then it's just a normal error and they'll probably recognize the typo. Another thing we could potentialy do (so many options when it comes to good diagnostics), is keep track of which UDF's were ignored. If a user tries to use one of those, we can output a special error. Might be overcomplicating things though. I imagine it won't be common to be ignoring UDF's--they are pretty straitforward to create, and we have pretty good documentation/examples. ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services
