refactor to make the avro schema more readable

Author: anniewang-db

hudi/src/main/scala/org/apache/spark/sql/delta/hudi/HudiSchemaUtils.scala

@@ -34,17 +34,16 @@ object HudiSchemaUtils extends DeltaLogging {
      * corresponding Avro type.
      */
     def transform[E <: DataType](elem: E, isNullable: Boolean, currentPath: String): Schema =
-      elem match {
+    elem match {
       case StructType(fields) =>
 
         val avroFields: util.List[Schema.Field] = fields.map(f =>
           new Schema.Field(
             f.name,
-            transform(f.dataType, f.nullable,
-              if (currentPath.isEmpty) f.name else s"$currentPath.${f.name}"),
+            transform(f.dataType, f.nullable, s"$currentPath.${f.name}"),
             f.getComment().orNull)).toList.asJava
         finalizeSchema(
-          Schema.createRecord(elem.typeName, null, currentPath, false, avroFields),
+          Schema.createRecord(currentPath, null, null, false, avroFields),
           isNullable)
       // TODO: Add List and Map support: https://github.com/delta-io/delta/issues/2738
       case ArrayType(elementType, containsNull) =>
@@ -59,7 +58,7 @@ object HudiSchemaUtils extends DeltaLogging {
         throw new UnsupportedOperationException(s"Cannot convert Delta type $other to Hudi")
     }
 
-    transform(deltaSchema, false, "")
+    transform(deltaSchema, false, "root")
   }
 
   private def finalizeSchema(targetSchema: Schema, isNullable: Boolean): Schema = {