fx19880617 commented on a change in pull request #5461: URL: https://github.com/apache/incubator-pinot/pull/5461#discussion_r437650377
########## File path: pinot-core/src/main/java/org/apache/pinot/core/operator/transform/function/CaseTransformFunction.java ########## @@ -0,0 +1,436 @@ +/** + * 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.pinot.core.operator.transform.function; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.List; +import java.util.Map; +import org.apache.pinot.core.common.DataSource; +import org.apache.pinot.core.operator.blocks.ProjectionBlock; +import org.apache.pinot.core.operator.transform.TransformResultMetadata; +import org.apache.pinot.core.plan.DocIdSetPlanNode; +import org.apache.pinot.core.util.ArrayCopyUtils; +import org.apache.pinot.spi.data.FieldSpec; + + +/** + * The <code>CaseTransformFunction</code> class implements the CASE-WHEN-THEN-ELSE transformation. + * + * The SQL Syntax is: + * CASE + * WHEN condition1 THEN result1 + * WHEN condition2 THEN result2 + * WHEN conditionN THEN resultN + * ELSE result + * END; + * + * Usage: + * case(${WHEN_STATEMENT_1}, ..., ${WHEN_STATEMENT_N}, + * ${THEN_EXPRESSION_1}, ..., ${THEN_EXPRESSION_N}, + * ${ELSE_EXPRESSION}) + * + * There are 2 * N + 1 arguments: + * <code>WHEN_STATEMENT_$i</code> is a <code>BinaryOperatorTransformFunction</code> represents <code>condition$i</code> + * <code>THEN_EXPRESSION_$i</code> is a <code>TransformFunction</code> represents <code>result$i</code> + * <code>ELSE_EXPRESSION</code> is a <code>TransformFunction</code> represents <code>result</code> + * + */ +public class CaseTransformFunction extends BaseTransformFunction { + public static final String FUNCTION_NAME = "case"; + private final List<TransformFunction> _whenStatements = new ArrayList<>(); + private final List<TransformFunction> _elseThenStatements = new ArrayList<>(); + private int _numberWhenStatements; + private TransformResultMetadata _resultMetadata; + private int[] _selectedResults; + private int[] _intResults; + private long[] _longResults; + private float[] _floatResults; + private double[] _doubleResults; + private String[] _stringResults; + + @Override + public String getName() { + return FUNCTION_NAME; + } + + @Override + public void init(List<TransformFunction> arguments, Map<String, DataSource> dataSourceMap) { + // Check that there are more than 1 arguments + if (arguments.size() % 2 != 1 || arguments.size() < 3) { + throw new IllegalArgumentException("At least 3 odd number of arguments are required for CASE-WHEN-ELSE function"); + } + _numberWhenStatements = arguments.size() / 2; + for (int i = 0; i < _numberWhenStatements; i++) { + _whenStatements.add(arguments.get(i)); + } + // Add ELSE Statement first + _elseThenStatements.add(arguments.get(_numberWhenStatements * 2)); + for (int i = _numberWhenStatements; i < _numberWhenStatements * 2; i++) { + _elseThenStatements.add(arguments.get(i)); + } + getResultMetadata(); + } + + @Override + public TransformResultMetadata getResultMetadata() { + if (_resultMetadata != null) { + return _resultMetadata; + } + FieldSpec.DataType dataType = _elseThenStatements.get(0).getResultMetadata().getDataType(); + boolean isSingleValueField = _elseThenStatements.get(0).getResultMetadata().isSingleValue(); + for (int i = 1; i < _elseThenStatements.size(); i++) { + TransformResultMetadata resultMetadata = _elseThenStatements.get(i).getResultMetadata(); + if (resultMetadata.isSingleValue() ^ isSingleValueField) { + throw new IllegalStateException( + String.format("Mixed Single/Multi Value results in expression types in THEN Clause [%s].", resultMetadata)); + } + switch (dataType) { + case INT: + switch (resultMetadata.getDataType()) { + case INT: + case LONG: + case FLOAT: + case DOUBLE: + case STRING: + dataType = resultMetadata.getDataType(); + break; + default: + throw new IllegalStateException( + String.format("Incompatible expression types in THEN Clause [%s].", resultMetadata)); + } + break; + case LONG: + switch (resultMetadata.getDataType()) { + case INT: + case LONG: + break; + case FLOAT: + case DOUBLE: + dataType = FieldSpec.DataType.DOUBLE; + break; + case STRING: + dataType = FieldSpec.DataType.STRING; + break; + default: + throw new IllegalStateException( + String.format("Incompatible expression types in THEN Clause [%s].", resultMetadata)); + } + break; + case FLOAT: + switch (resultMetadata.getDataType()) { + case INT: + case FLOAT: + break; + case LONG: + case DOUBLE: + dataType = FieldSpec.DataType.DOUBLE; + break; + case STRING: + dataType = FieldSpec.DataType.STRING; + break; + default: + throw new IllegalStateException( + String.format("Incompatible expression types in THEN Clause [%s].", resultMetadata)); + } + break; + case DOUBLE: + switch (resultMetadata.getDataType()) { + case INT: + case FLOAT: + case LONG: + case DOUBLE: + break; + case STRING: + dataType = resultMetadata.getDataType(); + break; + default: + throw new IllegalStateException( + String.format("Incompatible expression types in THEN Clause [%s].", resultMetadata)); + } + break; + case STRING: + switch (resultMetadata.getDataType()) { + case INT: + case FLOAT: + case LONG: + case DOUBLE: + case STRING: + break; + default: + throw new IllegalStateException( + String.format("Incompatible expression types in THEN Clause [%s].", resultMetadata)); + } + break; + default: + if (resultMetadata.getDataType() != dataType) { + throw new IllegalStateException( + String.format("Incompatible expression types in THEN Clause [%s].", resultMetadata)); + } + } + } + _resultMetadata = new TransformResultMetadata(dataType, true, false); + return _resultMetadata; + } + + /** + * Evaluate the ProjectionBlock for the WHEN statements, returns an array with the + * index(1 to N) of matched WHEN clause, 0 means nothing matched, so go to ELSE. + * + * @param projectionBlock + * @return + */ + private int[] getSelectedArray(ProjectionBlock projectionBlock) { + if (_selectedResults == null) { + _selectedResults = new int[DocIdSetPlanNode.MAX_DOC_PER_CALL]; + } else { + Arrays.fill(_selectedResults, 0); + } + for (int i = 0; i < _numberWhenStatements; i++) { + TransformFunction transformFunction = _whenStatements.get(i); + int[] conditions = transformFunction.transformToIntValuesSV(projectionBlock); + for (int j = 0; j < conditions.length; j++) { + if (_selectedResults[j] == 0 && conditions[j] == 1) { + _selectedResults[j] = i + 1; + } + } + } + return _selectedResults; + } + + @Override + public int[] transformToIntValuesSV(ProjectionBlock projectionBlock) { + int[] selected = getSelectedArray(projectionBlock); + if (_intResults == null) { + _intResults = new int[DocIdSetPlanNode.MAX_DOC_PER_CALL]; + } + for (int i = 0; i < _elseThenStatements.size(); i++) { + TransformFunction transformFunction = _elseThenStatements.get(i); + FieldSpec.DataType dataType = transformFunction.getResultMetadata().getDataType(); + int blockNumDocs = projectionBlock.getNumDocs(); + int[] evalInts; + if (dataType == FieldSpec.DataType.INT) { + evalInts = transformFunction.transformToIntValuesSV(projectionBlock); + } else { + evalInts = new int[blockNumDocs]; + switch (dataType) { + case LONG: + ArrayCopyUtils.copy(transformFunction.transformToLongValuesSV(projectionBlock), evalInts, blockNumDocs); + break; + case FLOAT: + ArrayCopyUtils.copy(transformFunction.transformToFloatValuesSV(projectionBlock), evalInts, blockNumDocs); + break; + case DOUBLE: + ArrayCopyUtils.copy(transformFunction.transformToDoubleValuesSV(projectionBlock), evalInts, blockNumDocs); + break; + case STRING: + ArrayCopyUtils.copy(transformFunction.transformToStringValuesSV(projectionBlock), evalInts, blockNumDocs); + break; + default: + throw new IllegalStateException(String + .format("Cannot convert result type [%s] to [INT] for transform function [%s]", dataType, + transformFunction)); + } + } Review comment: Not really, the issue is that the transform function may call IdentifierTransformFunction, which only supports one data type. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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