gustavodemorais commented on code in PR #27901: URL: https://github.com/apache/flink/pull/27901#discussion_r3094266872
########## flink-table/flink-table-common/src/main/java/org/apache/flink/table/types/inference/strategies/FromChangelogTypeStrategy.java: ########## @@ -0,0 +1,253 @@ +/* + * 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.flink.table.types.inference.strategies; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.table.api.DataTypes; +import org.apache.flink.table.api.DataTypes.Field; +import org.apache.flink.table.api.ValidationException; +import org.apache.flink.table.functions.TableSemantics; +import org.apache.flink.table.types.DataType; +import org.apache.flink.table.types.inference.CallContext; +import org.apache.flink.table.types.inference.InputTypeStrategy; +import org.apache.flink.table.types.inference.TypeStrategy; +import org.apache.flink.table.types.logical.LogicalTypeFamily; +import org.apache.flink.types.ColumnList; +import org.apache.flink.types.RowKind; + +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.Optional; +import java.util.Set; +import java.util.stream.Collectors; + +/** Type strategies for the {@code FROM_CHANGELOG} process table function. */ +@Internal +public final class FromChangelogTypeStrategy { + + private static final String DEFAULT_OP_COLUMN_NAME = "op"; + + private static final Set<String> VALID_ROW_KIND_NAMES = + Set.of("INSERT", "UPDATE_BEFORE", "UPDATE_AFTER", "DELETE"); + + // -------------------------------------------------------------------------------------------- + // Input validation + // -------------------------------------------------------------------------------------------- + + public static final InputTypeStrategy INPUT_TYPE_STRATEGY = + new ValidationOnlyInputTypeStrategy() { + @Override + public Optional<List<DataType>> inferInputTypes( + final CallContext callContext, final boolean throwOnFailure) { + return validateInputs(callContext, throwOnFailure); + } + }; + + // -------------------------------------------------------------------------------------------- + // Output type inference + // -------------------------------------------------------------------------------------------- + + public static final TypeStrategy OUTPUT_TYPE_STRATEGY = + callContext -> { + final TableSemantics tableSemantics = + callContext + .getTableSemantics(0) + .orElseThrow( + () -> + new ValidationException( + "First argument must be a table for FROM_CHANGELOG.")); + + final String opColumnName = resolveOpColumnName(callContext); + + final List<Field> outputFields = buildOutputFields(tableSemantics, opColumnName); + + return Optional.of(DataTypes.ROW(outputFields).notNull()); + }; + private static final String UPDATE_BEFORE = RowKind.UPDATE_BEFORE.name(); + private static final String UPDATE_AFTER = RowKind.UPDATE_AFTER.name(); + + // -------------------------------------------------------------------------------------------- + // Helpers + // -------------------------------------------------------------------------------------------- + + @SuppressWarnings("rawtypes") + private static Optional<List<DataType>> validateInputs( + final CallContext callContext, final boolean throwOnFailure) { + Optional<List<DataType>> error; + + error = validateTableArg(callContext, throwOnFailure); Review Comment: Beautiful 🙂 -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
