slinkydeveloper commented on a change in pull request #17522: URL: https://github.com/apache/flink/pull/17522#discussion_r737514777
########## File path: flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/functions/casting/rules/ArrayToArrayCastRule.java ########## @@ -0,0 +1,213 @@ +/* + * 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.planner.functions.casting.rules; + +import org.apache.flink.table.data.ArrayData; +import org.apache.flink.table.data.GenericArrayData; +import org.apache.flink.table.planner.functions.casting.CastCodeBlock; +import org.apache.flink.table.planner.functions.casting.CastRulePredicate; +import org.apache.flink.table.planner.functions.casting.CastRuleProvider; +import org.apache.flink.table.planner.functions.casting.CodeGeneratorCastRule; +import org.apache.flink.table.types.logical.ArrayType; +import org.apache.flink.table.types.logical.DistinctType; +import org.apache.flink.table.types.logical.LogicalType; +import org.apache.flink.table.types.logical.LogicalTypeRoot; + +import static org.apache.flink.table.planner.codegen.CodeGenUtils.className; +import static org.apache.flink.table.planner.codegen.CodeGenUtils.newName; +import static org.apache.flink.table.planner.functions.casting.rules.CastRuleUtils.functionCall; +import static org.apache.flink.table.types.logical.utils.LogicalTypeChecks.getFieldCount; +import static org.apache.flink.table.types.logical.utils.LogicalTypeChecks.getPrecision; +import static org.apache.flink.table.types.logical.utils.LogicalTypeChecks.getScale; + +/** Array to array casting rule. */ +public class ArrayToArrayCastRule + extends AbstractNullAwareCodeGeneratorCastRule<ArrayData, ArrayData> { + + public static final ArrayToArrayCastRule INSTANCE = new ArrayToArrayCastRule(); + + private ArrayToArrayCastRule() { + super( + CastRulePredicate.builder() + .predicate( + (input, target) -> + input.getTypeRoot() == LogicalTypeRoot.ARRAY + && target.getTypeRoot() == LogicalTypeRoot.ARRAY + && isValidArrayCasting( + ((ArrayType) input).getElementType(), + ((ArrayType) target).getElementType())) + .build()); + } + + private static boolean isValidArrayCasting( + LogicalType innerInputType, LogicalType innerTargetType) { + return CastRuleProvider.resolve(innerInputType, innerTargetType) != null; + } + + @SuppressWarnings("rawtypes") + @Override + protected String generateCodeBlockInternal( + CodeGeneratorCastRule.Context context, + String inputTerm, + String returnVariable, + LogicalType inputLogicalType, + LogicalType targetLogicalType) { + LogicalType innerInputType = ((ArrayType) inputLogicalType).getElementType(); + LogicalType innerTargetType = ((ArrayType) targetLogicalType).getElementType(); + + String innerTargetTypeTerm = arrayElementType(innerTargetType); + String arraySize = inputTerm + ".size()"; + String objArrayTerm = newName("objArray"); + + CodeGeneratorCastRule<?, ?> innerCastRule = + (CodeGeneratorCastRule) CastRuleProvider.resolve(innerInputType, innerTargetType); + + StringBuilder result = new StringBuilder(); + result.append( + innerTargetTypeTerm + + "[] " + + objArrayTerm + + " = new " + + innerTargetTypeTerm + + "[" + + arraySize + + "];\n"); + + result.append("for (int i = 0; i < " + arraySize + "; i++) {\n"); + CastCodeBlock codeBlock = + innerCastRule.generateCodeBlock( + context, + inputTerm + "." + getArrayElement(innerInputType, "i"), + innerInputType.copy(false), // Null check is done at the array access level + innerTargetType); + + String innerElementCode = + codeBlock.getCode() + + "\n" + + objArrayTerm + + "[i] = " + + codeBlock.getReturnTerm() + + ";\n"; + + // Add null check if inner type is nullable + if (innerInputType.isNullable()) { + result.append("if (" + inputTerm + ".isNullAt(i)) {\n") + .append(objArrayTerm + "[i] = null;\n") + .append("} else {\n") + .append(innerElementCode) + .append("}\n"); + } else { + result.append(innerElementCode); + } + + result.append("}\n"); + + result.append( + returnVariable + + " = new " + + className(GenericArrayData.class) + + "(" + + objArrayTerm + + ");\n"); + + return result.toString(); + } + + private static String arrayElementType(LogicalType t) { Review comment: I couldn't find any, we have `boxedTypeTermForType` and `primitiveTypeTermForType` but the issue here is that, unless I'm using a primitive, I need a `Object[]` type. Let me know if you have another idea in mind for that. -- 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: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
