walterddr commented on a change in pull request #9355: [FLINK-13577][ml] Add an util class to build result row and generate … URL: https://github.com/apache/flink/pull/9355#discussion_r329372857
########## File path: flink-ml-parent/flink-ml-lib/src/main/java/org/apache/flink/ml/common/utils/OutputColsHelper.java ########## @@ -0,0 +1,190 @@ +/* + * 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.typeinfo.TypeInformation; +import org.apache.flink.table.api.TableSchema; +import org.apache.flink.types.Row; + +import org.apache.commons.lang3.ArrayUtils; + +import java.io.Serializable; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.HashSet; + +/** + * Util for generating output schema. + * + * <p>Need following information: + * 1) data schema + * 2) output column names + * 3) output column types + * 4) keep column names + * + * <p>The following roles are followed: + * 1)If reserved columns is null, then reserve all columns from the origin dataSet. + * 2)If some of the reserved column names are the same as output column names, then they are + * replaced by the output at value and type, but with the kept column names have their order kept. + * 3)[result columns] = ([reserve columns] subtract [output columns]) + [output columns] + * + */ +public class OutputColsHelper implements Serializable { + private transient String[] dataColNames; + private transient TypeInformation[] dataColTypes; + private transient String[] outputColNames; + private transient TypeInformation[] outputColTypes; + + private int resultLength; + private int[] reservedColIndices; + private int[] reservedToResultIndices; + private int[] outputToResultIndices; + + public OutputColsHelper(TableSchema dataSchema, String outputColName, TypeInformation outputColType) { + this(dataSchema, outputColName, outputColType, null); + } + + public OutputColsHelper(TableSchema dataSchema, String outputColName, TypeInformation outputColType, + String[] reservedColNames) { + this(dataSchema, new String[] {outputColName}, new TypeInformation[] {outputColType}, reservedColNames); + } + + public OutputColsHelper(TableSchema dataSchema, String[] outputColNames, TypeInformation[] outputColTypes) { + this(dataSchema, outputColNames, outputColTypes, null); + } + + public OutputColsHelper(TableSchema dataSchema, String[] outputColNames, TypeInformation[] outputColTypes, + String[] reservedColNames) { + this.dataColNames = dataSchema.getFieldNames(); + this.dataColTypes = dataSchema.getFieldTypes(); + this.outputColNames = outputColNames; + this.outputColTypes = outputColTypes; + + HashSet <String> toReservedCols = new HashSet <>( + Arrays.asList( + reservedColNames == null ? this.dataColNames : reservedColNames + ) + ); + + ArrayList <Integer> reservedColIndices = new ArrayList <>(toReservedCols.size()); + ArrayList <Integer> reservedColToResultIndex = new ArrayList <>(toReservedCols.size()); + outputToResultIndices = new int[outputColNames.length]; + Arrays.fill(outputToResultIndices, -1); + int index = 0; + for (int i = 0; i < dataColNames.length; i++) { + int key = ArrayUtils.indexOf(outputColNames, dataColNames[i]); + if (key >= 0) { + outputToResultIndices[key] = index++; + continue; + } + if (toReservedCols.contains(dataColNames[i])) { + reservedColIndices.add(i); + reservedColToResultIndex.add(index++); + } + } + for (int i = 0; i < outputToResultIndices.length; i++) { + if (outputToResultIndices[i] == -1) { + outputToResultIndices[i] = index++; + } + } + this.resultLength = index; + this.reservedColIndices = new int[reservedColIndices.size()]; + this.reservedToResultIndices = new int[reservedColIndices.size()]; + for (int i = 0; i < this.reservedColIndices.length; i++) { + this.reservedColIndices[i] = reservedColIndices.get(i); + this.reservedToResultIndices[i] = reservedColToResultIndex.get(i); + } + } + + /** + * Get the reserved colNames, the result is [reserve columns] subtract [output columns]. + * + * @return the reserved colNames. + */ + public String[] getReservedColNames() { + String[] reservedColNames = new String[reservedColIndices.length]; + for (int i = 0; i < reservedColIndices.length; i++) { + reservedColNames[i] = dataColNames[reservedColIndices[i]]; + } + return reservedColNames; + } + + /** + * Get the final table schema. [result columns] = ([reserve columns] subtract [output columns]) + [output columns] + * + * @return the table schema. + */ + public TableSchema getResultSchema() { + String[] resultColNames = new String[resultLength]; + TypeInformation[] resultColTypes = new TypeInformation[resultLength]; + for (int i = 0; i < reservedColIndices.length; i++) { + resultColNames[reservedToResultIndices[i]] = dataColNames[reservedColIndices[i]]; + resultColTypes[reservedToResultIndices[i]] = dataColTypes[reservedColIndices[i]]; + } + for (int i = 0; i < outputToResultIndices.length; i++) { + resultColNames[outputToResultIndices[i]] = outputColNames[i]; + resultColTypes[outputToResultIndices[i]] = outputColTypes[i]; + } + return new TableSchema(resultColNames, resultColTypes); + } + + /** + * Get the outputting row, which is a combination of input data and output data. + * + * @param data input data + * @param output output data + * @return The outputting row, which is a combination of reserved input data and prediction result. + */ + public Row getResultRow(Row data, Row output) { + int numOutputs = outputToResultIndices.length; + if (output.getArity() != numOutputs) { + throw new IllegalArgumentException("Invalid output size"); + } + Row result = new Row(resultLength); + for (int i = 0; i < reservedColIndices.length; i++) { + result.setField(reservedToResultIndices[i], data.getField(reservedColIndices[i])); + } + for (int i = 0; i < numOutputs; i++) { + result.setField(outputToResultIndices[i], output.getField(i)); + } + return result; + } + + /** + * Get the outputting row, which is a combination of input data and output data. + * The difference with getResultRow is that it's single column output. + * + * @param data input data + * @param output output data + * @return + */ + public Row getResultRowSingle(Row data, Object output) { Review comment: do we really need this API? it seems like the following are identical ``` getResultRowSingle(someData, myObj); getResultRow(someData, Row.of(myObj)); ``` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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