slinkydeveloper commented on a change in pull request #17658: URL: https://github.com/apache/flink/pull/17658#discussion_r742261221
########## File path: flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/functions/casting/rules/MapToStringCastRule.java ########## @@ -0,0 +1,227 @@ +/* + * 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.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.LogicalType; +import org.apache.flink.table.types.logical.LogicalTypeFamily; +import org.apache.flink.table.types.logical.LogicalTypeRoot; +import org.apache.flink.table.types.logical.MapType; + +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.codegen.CodeGenUtils.rowFieldReadAccess; +import static org.apache.flink.table.planner.codegen.calls.BuiltInMethods.BINARY_STRING_DATA_FROM_STRING; +import static org.apache.flink.table.planner.functions.casting.rules.CastRuleUtils.constructorCall; +import static org.apache.flink.table.planner.functions.casting.rules.CastRuleUtils.functionCall; +import static org.apache.flink.table.planner.functions.casting.rules.CastRuleUtils.methodCall; +import static org.apache.flink.table.planner.functions.casting.rules.CastRuleUtils.strLiteral; + +/** {@link LogicalTypeRoot#MAP} to {@link LogicalTypeFamily#CHARACTER_STRING} cast rule. */ +public class MapToStringCastRule extends AbstractNullAwareCodeGeneratorCastRule<ArrayData, String> { + + public static final MapToStringCastRule INSTANCE = new MapToStringCastRule(); + + private MapToStringCastRule() { + super( + CastRulePredicate.builder() + .predicate( + (input, target) -> + input.is(LogicalTypeRoot.MAP) + && target.is(LogicalTypeFamily.CHARACTER_STRING) + && CastRuleProvider.exists( + ((MapType) input).getKeyType(), target) + && CastRuleProvider.exists( + ((MapType) input).getValueType(), target)) + .build()); + } + + /* Example generated code for MAP<STRING, INTERVAL MONTH>: + + isNull$0 = _myInputIsNull; + if (!isNull$0) { + org.apache.flink.table.data.ArrayData keys$2 = _myInput.keyArray(); + org.apache.flink.table.data.ArrayData values$3 = _myInput.valueArray(); + builder$1.delete(0, builder$1.length()); + builder$1.append("{"); + for (int i$4 = 0; i$4 < _myInput.size(); i$4++) { + if (i$4 != 0) { + builder$1.append(", "); + } + org.apache.flink.table.data.binary.BinaryStringData key$5 = org.apache.flink.table.data.binary.BinaryStringData.EMPTY_UTF8; + boolean keyIsNull$6 = keys$2.isNullAt(i$4); + int value$7 = -1; + boolean valueIsNull$8 = values$3.isNullAt(i$4); + if (!keyIsNull$6) { + key$5 = ((org.apache.flink.table.data.binary.BinaryStringData) keys$2.getString(i$4)); + builder$1.append(key$5); + } else { + builder$1.append("NULL"); + } + builder$1.append("="); + if (!valueIsNull$8) { + value$7 = values$3.getInt(i$4); + result$2 = org.apache.flink.table.data.binary.BinaryStringData.fromString(org.apache.flink.table.utils.DateTimeUtils.intervalYearMonthToString(value$7)); + builder$1.append(result$2); + } else { + builder$1.append("NULL"); + } + } + builder$1.append("}"); + result$1 = org.apache.flink.table.data.binary.BinaryStringData.fromString(builder$1.toString()); + } else { + result$1 = org.apache.flink.table.data.binary.BinaryStringData.EMPTY_UTF8; + } + + */ + @Override + protected String generateCodeBlockInternal( + CodeGeneratorCastRule.Context context, + String inputTerm, + String returnVariable, + LogicalType inputLogicalType, + LogicalType targetLogicalType) { + final LogicalType keyType = ((MapType) inputLogicalType).getKeyType(); + final LogicalType valueType = ((MapType) inputLogicalType).getValueType(); + + final String builderTerm = newName("builder"); + context.declareClassField( + className(StringBuilder.class), builderTerm, constructorCall(StringBuilder.class)); + + final String keyArrayTerm = newName("keys"); + final String valueArrayTerm = newName("values"); + + return new CastRuleUtils.CodeWriter() + .declStmt(ArrayData.class, keyArrayTerm, methodCall(inputTerm, "keyArray")) + .declStmt(ArrayData.class, valueArrayTerm, methodCall(inputTerm, "valueArray")) + .stmt(methodCall(builderTerm, "delete", 0, methodCall(builderTerm, "length"))) + .stmt(methodCall(builderTerm, "append", strLiteral("{"))) + .forStmt( + methodCall(inputTerm, "size"), + (indexTerm, loopBodyWriter) -> { + String keyTerm = newName("key"); + String keyIsNullTerm = newName("keyIsNull"); + String valueTerm = newName("value"); + String valueIsNullTerm = newName("valueIsNull"); + + CastCodeBlock keyCast = + CastRuleProvider.generateCodeBlock( + context, + keyTerm, + keyIsNullTerm, + // Null check is done at the key array access level + keyType.copy(false), + targetLogicalType); + CastCodeBlock valueCast = + CastRuleProvider.generateCodeBlock( + context, + valueTerm, + valueIsNullTerm, + // Null check is done at the value array access level + valueType.copy(false), + targetLogicalType); + + loopBodyWriter + // Write the comma + .ifStmt( + indexTerm + " != 0", + thenBodyWriter -> + thenBodyWriter.stmt( + methodCall( + builderTerm, + "append", + strLiteral(", ")))) + // Declare key and values variables + .declPrimitiveStmt(keyType, keyTerm) + .declStmt( + boolean.class, + keyIsNullTerm, + methodCall(keyArrayTerm, "isNullAt", indexTerm)) + .declPrimitiveStmt(valueType, valueTerm) + .declStmt( + boolean.class, + valueIsNullTerm, + methodCall(valueArrayTerm, "isNullAt", indexTerm)) + // Execute casting if inner key/value not null + .ifStmt( + "!" + keyIsNullTerm, + thenBodyWriter -> + thenBodyWriter + // If key not null, extract it and + // execute the cast + .assignStmt( + keyTerm, + rowFieldReadAccess( + indexTerm, + keyArrayTerm, + keyType)) + .append(keyCast) + .stmt( + methodCall( + builderTerm, + "append", + keyCast + .getReturnTerm())), + elseBodyWriter -> + elseBodyWriter.stmt( + methodCall( + builderTerm, + "append", + strLiteral("NULL")))) Review comment: This PR doesn't deal with `<NULL>`, because that's user facing (see `PrintUtils#NULL_COLUMN`), the next PR (for FLINK-24685) will deal with it. For `NULL`, I've added a constant in `PrintUtils` -- 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]
