private int setGetColumnsVectorSchemaRootFromFields()

in flight/flight-sql-jdbc-core/src/main/java/org/apache/arrow/driver/jdbc/ArrowDatabaseMetadata.java [1042:1157]
93 lines of code
19 McCabe index (conditional complexity)

  private int setGetColumnsVectorSchemaRootFromFields(
      final VectorSchemaRoot currentRoot,
      int insertIndex,
      final List<Field> tableColumns,
      final Text catalogName,
      final Text tableName,
      final Text schemaName,
      final Pattern columnNamePattern) {
    int ordinalIndex = 1;
    final int tableColumnsSize = tableColumns.size();

    final VarCharVector tableCatVector = (VarCharVector) currentRoot.getVector("TABLE_CAT");
    final VarCharVector tableSchemVector = (VarCharVector) currentRoot.getVector("TABLE_SCHEM");
    final VarCharVector tableNameVector = (VarCharVector) currentRoot.getVector("TABLE_NAME");
    final VarCharVector columnNameVector = (VarCharVector) currentRoot.getVector("COLUMN_NAME");
    final IntVector dataTypeVector = (IntVector) currentRoot.getVector("DATA_TYPE");
    final VarCharVector typeNameVector = (VarCharVector) currentRoot.getVector("TYPE_NAME");
    final IntVector columnSizeVector = (IntVector) currentRoot.getVector("COLUMN_SIZE");
    final IntVector decimalDigitsVector = (IntVector) currentRoot.getVector("DECIMAL_DIGITS");
    final IntVector numPrecRadixVector = (IntVector) currentRoot.getVector("NUM_PREC_RADIX");
    final IntVector nullableVector = (IntVector) currentRoot.getVector("NULLABLE");
    final IntVector ordinalPositionVector = (IntVector) currentRoot.getVector("ORDINAL_POSITION");
    final VarCharVector isNullableVector = (VarCharVector) currentRoot.getVector("IS_NULLABLE");
    final VarCharVector isAutoincrementVector =
        (VarCharVector) currentRoot.getVector("IS_AUTOINCREMENT");
    final VarCharVector isGeneratedColumnVector =
        (VarCharVector) currentRoot.getVector("IS_GENERATEDCOLUMN");
    final VarCharVector remarksVector = (VarCharVector) currentRoot.getVector("REMARKS");

    for (int i = 0; i < tableColumnsSize; i++, ordinalIndex++) {
      final Field field = tableColumns.get(i);
      final FlightSqlColumnMetadata columnMetadata =
          new FlightSqlColumnMetadata(field.getMetadata());
      final String columnName = field.getName();

      if (columnNamePattern != null && !columnNamePattern.matcher(columnName).matches()) {
        continue;
      }
      final ArrowType fieldType = field.getType();

      if (catalogName != null) {
        tableCatVector.setSafe(insertIndex, catalogName);
      }

      if (schemaName != null) {
        tableSchemVector.setSafe(insertIndex, schemaName);
      }

      if (tableName != null) {
        tableNameVector.setSafe(insertIndex, tableName);
      }

      if (columnName != null) {
        columnNameVector.setSafe(insertIndex, columnName.getBytes(CHARSET));
      }

      dataTypeVector.setSafe(insertIndex, SqlTypes.getSqlTypeIdFromArrowType(fieldType));
      byte[] typeName =
          columnMetadata.getTypeName() != null
              ? columnMetadata.getTypeName().getBytes(CHARSET)
              : SqlTypes.getSqlTypeNameFromArrowType(fieldType).getBytes(CHARSET);
      typeNameVector.setSafe(insertIndex, typeName);

      // We aren't setting COLUMN_SIZE for ROWID SQL Types, as there's no such Arrow type.
      // We aren't setting COLUMN_SIZE nor DECIMAL_DIGITS for Float/Double as their precision and
      // scale are variable.
      if (fieldType instanceof ArrowType.Decimal) {
        numPrecRadixVector.setSafe(insertIndex, BASE10_RADIX);
      } else if (fieldType instanceof ArrowType.Int) {
        numPrecRadixVector.setSafe(insertIndex, BASE10_RADIX);
      } else if (fieldType instanceof ArrowType.FloatingPoint) {
        numPrecRadixVector.setSafe(insertIndex, BASE10_RADIX);
      }

      Integer decimalDigits = columnMetadata.getScale();
      if (decimalDigits == null) {
        decimalDigits = getDecimalDigits(fieldType);
      }
      if (decimalDigits != null) {
        decimalDigitsVector.setSafe(insertIndex, decimalDigits);
      }

      Integer columnSize = columnMetadata.getPrecision();
      if (columnSize == null) {
        columnSize = getColumnSize(fieldType);
      }
      if (columnSize != null) {
        columnSizeVector.setSafe(insertIndex, columnSize);
      }

      nullableVector.setSafe(insertIndex, field.isNullable() ? 1 : 0);

      isNullableVector.setSafe(insertIndex, booleanToYesOrNo(field.isNullable()));

      Boolean autoIncrement = columnMetadata.isAutoIncrement();
      if (autoIncrement != null) {
        isAutoincrementVector.setSafe(insertIndex, booleanToYesOrNo(autoIncrement));
      } else {
        isAutoincrementVector.setSafe(insertIndex, EMPTY_BYTE_ARRAY);
      }

      String remarks = columnMetadata.getRemarks();
      if (remarks != null) {
        remarksVector.setSafe(insertIndex, remarks.getBytes(CHARSET));
      }

      // Fields also don't hold information about IS_AUTOINCREMENT and IS_GENERATEDCOLUMN,
      // so we're setting an empty string (as bytes), which means it couldn't be determined.
      isGeneratedColumnVector.setSafe(insertIndex, EMPTY_BYTE_ARRAY);

      ordinalPositionVector.setSafe(insertIndex, ordinalIndex);

      insertIndex++;
    }
    return insertIndex;
  }