amaliujia commented on a change in pull request #13200: URL: https://github.com/apache/beam/pull/13200#discussion_r512938754
########## File path: sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/UdfProvider.java ########## @@ -0,0 +1,39 @@ +/* + * 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.beam.sdk.extensions.sql; + +import java.lang.reflect.Method; +import java.util.Collections; +import java.util.Map; +import org.apache.beam.sdk.transforms.Combine; + +/** + * Provider for user-defined functions written in Java. Implementations should be annotated with + * {@link com.google.auto.service.AutoService}. + */ +public interface UdfProvider { + /** Maps function names to scalar function implementations. */ + default Map<String, Method> userDefinedScalarFunctions() { Review comment: I can see why you think `Method` have too many things that might not relevant. Ideally we only need users to provide function signature (including function name) , which are enough to 1) offer required information to SQL parser 2) locate the right implementation in the user jar. The reason we still use `Method`, is because that current UDF implementation asks for a `Method`: [1] [2] [3]. So as we will need to construct a `Method` eventually, it doesn't seem a bad choice to expose it in the interface. [1]: https://github.com/apache/beam/blob/5076255fda1700f0d3ac2a9e5e73372bdf3c59dd/sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/impl/ScalarFunctionImpl.java#L96 [2]: https://github.com/apache/beam/blob/master/sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/impl/ScalarFunctionImpl.java#L111 [3]: https://github.com/apache/beam/blob/master/sdks/java/extensions/sql/zetasql/src/main/java/org/apache/beam/sdk/extensions/sql/zetasql/translation/SqlOperators.java#L195 ---------------------------------------------------------------- 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
