qiuxiafei commented on a change in pull request #9373: [FLINK-13596][ml] Add two utils for Table transformations URL: https://github.com/apache/flink/pull/9373#discussion_r362156769
########## File path: flink-ml-parent/flink-ml-lib/src/main/java/org/apache/flink/ml/common/utils/DataSetConversionUtil.java ########## @@ -0,0 +1,172 @@ +/* + * 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.ml.common.utils; + +import org.apache.flink.api.common.functions.MapFunction; +import org.apache.flink.api.common.typeinfo.TypeInformation; +import org.apache.flink.api.java.DataSet; +import org.apache.flink.api.java.operators.SingleInputUdfOperator; +import org.apache.flink.api.java.operators.TwoInputUdfOperator; +import org.apache.flink.api.java.typeutils.RowTypeInfo; +import org.apache.flink.ml.common.MLEnvironment; +import org.apache.flink.ml.common.MLEnvironmentFactory; +import org.apache.flink.table.api.Table; +import org.apache.flink.table.api.TableSchema; +import org.apache.flink.table.api.ValidationException; +import org.apache.flink.types.Row; + +/** + * Provide functions of conversions between DataSet and Table. + */ +public class DataSetConversionUtil { + /** + * Convert the given Table to {@link DataSet}<{@link Row}>. + * + * @param sessionId the sessionId of {@link MLEnvironmentFactory} + * @param table the Table to convert. + * @return the converted DataSet. + */ + public static DataSet <Row> fromTable(Long sessionId, Table table) { + return MLEnvironmentFactory + .get(sessionId) + .getBatchTableEnvironment() + .toDataSet(table, Row.class); + } + + /** + * Convert the given DataSet into a Table with specified TableSchema. + * + * @param sessionId the sessionId of {@link MLEnvironmentFactory} + * @param data the DataSet to convert. + * @param schema the specified TableSchema. + * @return the converted Table. + */ + public static Table toTable(Long sessionId, DataSet <Row> data, TableSchema schema) { + return toTable(sessionId, data, schema.getFieldNames(), schema.getFieldTypes()); + } + + /** + * Convert the given DataSet into a Table with specified colNames and colTypes. + * + * @param sessionId sessionId the sessionId of {@link MLEnvironmentFactory}. + * @param data the DataSet to convert. + * @param colNames the specified colNames. + * @param colTypes the specified colTypes. This variable is used only when the + * DataSet is produced by a function and Flink cannot determine + * automatically what the produced type is. + * @return the converted Table. + */ + public static Table toTable(Long sessionId, DataSet <Row> data, String[] colNames, TypeInformation <?>[] colTypes) { + return toTable(MLEnvironmentFactory.get(sessionId), data, colNames, colTypes); + } + + /** + * Convert the given DataSet into a Table with specified colNames. + * + * @param sessionId sessionId the sessionId of {@link MLEnvironmentFactory}. + * @param data the DataSet to convert. + * @param colNames the specified colNames. + * @return the converted Table. + */ + public static Table toTable(Long sessionId, DataSet <Row> data, String[] colNames) { + return toTable(MLEnvironmentFactory.get(sessionId), data, colNames); + } + + /** + * Convert the given DataSet into a Table with specified colNames and colTypes. + * + * @param session the MLEnvironment using to convert DataSet to Table. + * @param data the DataSet to convert. + * @param colNames the specified colNames. + * @param colTypes the specified colTypes. This variable is used only when the + * DataSet is produced by a function and Flink cannot determine + * automatically what the produced type is. + * @return the converted Table. + */ + public static Table toTable(MLEnvironment session, DataSet <Row> data, String[] colNames, TypeInformation <?>[] colTypes) { + try { + // Try to add row type information for the dataset to be converted. + // In most case, this keeps us from the rolling back logic in the catch block, + // which adds an unnecessary map function just in order to add row type information. + if (data instanceof SingleInputUdfOperator) { Review comment: There're two lines confuse me in `testE2E`, 1. The line `thrown.expect(ValidationException.class);` , why is an `ValidationException` expected? 2. The line `env.execute();` seems have nothing to execute because of the previous `print()` ,am I right? So I just comment them out, add the heuristic lines back and move ahead. I do reproduce the exception you mentioned, in the 3rd `toTable` invocation. I think that's because type information has been added to `input` in the 2nd invocation already. Flink complains about this when the same thing applied to the identical `input` object in the 3rd invocation. So I think at least it proves that our heuristic works. And it also reveals a corner case we missed, in which an identical `DataSet` object is passed to `toTable` more than once. UT will pass after adding `IllegalStateException` to catch block. The new `toTable` mothod now looks like: ```java public static Table toTable(MLEnvironment session, DataSet <Row> data, String[] colNames, TypeInformation <?>[] colTypes) { try { if (data instanceof SingleInputUdfOperator) { ((SingleInputUdfOperator) data).returns(new RowTypeInfo(colTypes, colNames)); } else if (data instanceof TwoInputUdfOperator) { ((TwoInputUdfOperator) data).returns(new RowTypeInfo(colTypes, colNames)); } return toTable(session, data, colNames); } catch (ValidationException | IllegalStateException ex) { // currently ValidationException will be thrown and caught for further processing. // Because the getType() API of the Transformation can only be accessed once. // This can be improve if we add "isTypeSet()" API to the Transformation class. if (null == colTypes) { throw ex; } else { DataSet <Row> t = fallbackToExplicitTypeDefine(data, colNames, colTypes); return toTable(session, t, colNames); } } ``` I just wanna make sure it ok to add another exception to the origin anti-pattern code ^_^ .. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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