mbeckerle commented on a change in pull request #273: WIP: Add User Defined Functions Capability URL: https://github.com/apache/incubator-daffodil/pull/273#discussion_r334638556
########## 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}" + Review comment: When you log this way, constructing the string separately, you defeat an important optimization. This string need not even be constructed if logging is off, or the log level is insufficient to warrant outputting this message. log is a macro actually so that if the logging is off or loglevel insufficient, none of the arguments are even evaluated. So it costs almost nothing to use log. For this and the internationalization reason described above, you really should do this as log(LogLevel.Warning, "string with %s things %s in it", args, args, args) If you want to put a string together with mkString, do it within the arglist of the log call, so that it will not happen if no logging is being done. ---------------------------------------------------------------- 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
