dongjoon-hyun commented on code in PR #41409: URL: https://github.com/apache/spark/pull/41409#discussion_r1213811989
########## connector/avro/src/main/java/org/apache/spark/sql/avro/CustomDecimal.scala: ########## @@ -0,0 +1,76 @@ +/* + * 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.spark.sql.avro + +import org.apache.avro.LogicalType +import org.apache.avro.Schema + +import org.apache.spark.sql.types.DecimalType + +object CustomDecimal { + val TYPE_NAME = "custom-decimal" +} + +// A customized logical type, which will be registered to Avro. This logical type is similar to +// Avro's builtin Decimal type, but is meant to be registered for long type. It indicates that +// the long type should be converted to Spark's Decimal type, with provided precision and scale. +private class CustomDecimal(schema: Schema) extends LogicalType(CustomDecimal.TYPE_NAME) { + val scale : Int = { + val obj = schema.getObjectProp("scale") + obj match { + case null => + throw new IllegalArgumentException(s"Invalid ${CustomDecimal.TYPE_NAME}: missing scale"); + case i : Integer => + i + case other => + throw new IllegalArgumentException(s"Expected int ${CustomDecimal.TYPE_NAME}:scale") + } + } + val precision : Int = { + val obj = schema.getObjectProp("precision") + if (obj == null) { + throw new IllegalArgumentException(s"Invalid ${CustomDecimal.TYPE_NAME}: missing precision"); + } + obj.asInstanceOf[Int] + } + val className : String = schema.getProp("className") + + override def validate(schema: Schema): Unit = { + super.validate(schema) + if (schema.getType != Schema.Type.LONG) { + throw new IllegalArgumentException( + s"${CustomDecimal.TYPE_NAME} can only be used with an underlying long type") + } + if (precision <= 0) { + throw new IllegalArgumentException(s"Invalid decimal precision: $precision" + + " (must be positive)"); + } else if (precision > DecimalType.MAX_PRECISION) { + throw new IllegalArgumentException( + s"cannot store $precision digits (max ${DecimalType.MAX_PRECISION})") + } + if (scale < 0) { + throw new IllegalArgumentException(s"Invalid decimal scale: $scale" + + " (must be positive)"); + } else if (scale > precision) { + throw new IllegalArgumentException(s"Invalid decimal scale: $scale (greater than " + + s"precision: $precision)"); + } + } + override def toString: String = + s"${CustomDecimal.TYPE_NAME}<scale: $scale, precision: $precision>" Review Comment: May I ask if where this pattern, `custom-decimal<scale: x, precision: y>`, comes? 1. I'm wondering we can simplify by removing `<scale: ` and `, precision: ` parts because it seems that we omit them previously in Spark decimal type. ```scala scala> org.apache.spark.sql.types.DecimalType(9,3).toString res13: String = DecimalType(9,3) scala> sql("select cast(1.01 as decimal(9,3))").printSchema root |-- CAST(1.01 AS DECIMAL(9,3)): decimal(9,3) (nullable = false) ``` 2. Also, we show `precision` first. ```scala scala> org.apache.spark.sql.types.DecimalType(9,3).precision res15: Int = 9 ``` -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
