| /* |
| * 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.samza.sql.udfs; |
| |
| import org.apache.samza.config.Config; |
| import org.apache.samza.context.Context; |
| |
| |
| /** |
| * The base class for the Scalar UDFs. All the scalar UDF classes needs to extend this. |
| * The number and type of arguments for the method annotated with {@link SamzaSqlUdfMethod} in the UDF class should match the number and type of fields |
| * used while invoking this UDF in SQL statement. |
| * Say for e.g. User creates a UDF class with signature int execute(int var1, String var2). It can be used in a SQL query |
| * select myudf(id, name) from profile |
| * In the above query, Profile should contain fields named 'id' of INTEGER/NUMBER type and 'name' of type VARCHAR/CHARACTER |
| */ |
| public interface ScalarUdf { |
| /** |
| * Udfs can implement this method to perform any initialization that they may need. |
| * @param udfConfig Config specific to the udf. |
| * @param context Samza application and framework context |
| */ |
| void init(Config udfConfig, Context context); |
| } |