override def supportFileFormatRead()

in backends-velox/src/main/scala/io/glutenproject/backendsapi/velox/VeloxBackend.scala [71:137]
61 lines of code
27 McCabe index (conditional complexity)

  override def supportFileFormatRead(
      format: ReadFileFormat,
      fields: Array[StructField],
      partTable: Boolean,
      paths: Seq[String]): ValidationResult = {
    // Validate if all types are supported.
    def validateTypes(validatorFunc: PartialFunction[StructField, String]): ValidationResult = {
      // Collect unsupported types.
      val unsupportedDataTypeReason = fields.collect(validatorFunc)
      if (unsupportedDataTypeReason.isEmpty) {
        ValidationResult.ok
      } else {
        ValidationResult.notOk(
          s"Found unsupported data type in $format: ${unsupportedDataTypeReason.mkString(", ")}.")
      }
    }

    format match {
      case ParquetReadFormat =>
        val typeValidator: PartialFunction[StructField, String] = {
          // Parquet scan of nested array with struct/array as element type is unsupported in Velox.
          case StructField(_, arrayType: ArrayType, _, _)
              if arrayType.elementType.isInstanceOf[StructType] =>
            "StructType as element in ArrayType"
          case StructField(_, arrayType: ArrayType, _, _)
              if arrayType.elementType.isInstanceOf[ArrayType] =>
            "ArrayType as element in ArrayType"
          // Parquet scan of nested map with struct as key type,
          // or array type as value type is not supported in Velox.
          case StructField(_, mapType: MapType, _, _) if mapType.keyType.isInstanceOf[StructType] =>
            "StructType as Key in MapType"
          case StructField(_, mapType: MapType, _, _)
              if mapType.valueType.isInstanceOf[ArrayType] =>
            "ArrayType as Value in MapType"
        }
        validateTypes(typeValidator)
      case DwrfReadFormat => ValidationResult.ok
      case OrcReadFormat =>
        if (!GlutenConfig.getConf.veloxOrcScanEnabled) {
          ValidationResult.notOk(s"Velox ORC scan is turned off.")
        } else {
          val typeValidator: PartialFunction[StructField, String] = {
            case StructField(_, ByteType, _, _) => "ByteType not support"
            case StructField(_, arrayType: ArrayType, _, _)
                if arrayType.elementType.isInstanceOf[StructType] =>
              "StructType as element in ArrayType"
            case StructField(_, arrayType: ArrayType, _, _)
                if arrayType.elementType.isInstanceOf[ArrayType] =>
              "ArrayType as element in ArrayType"
            case StructField(_, mapType: MapType, _, _)
                if mapType.keyType.isInstanceOf[StructType] =>
              "StructType as Key in MapType"
            case StructField(_, mapType: MapType, _, _)
                if mapType.valueType.isInstanceOf[ArrayType] =>
              "ArrayType as Value in MapType"
            case StructField(_, stringType: StringType, _, metadata)
                if CharVarcharUtils
                  .getRawTypeString(metadata)
                  .getOrElse(stringType.catalogString) != stringType.catalogString =>
              CharVarcharUtils.getRawTypeString(metadata) + " not support"
            case StructField(_, TimestampType, _, _) => "TimestampType not support"
          }
          validateTypes(typeValidator)
        }
      case _ => ValidationResult.notOk(s"Unsupported file format for $format.")
    }
  }