public static Field toArrowField()

in paimon-arrow/src/main/java/org/apache/paimon/arrow/ArrowUtils.java [95:190]
91 lines of code
5 McCabe index (conditional complexity)

    public static Field toArrowField(String fieldName, int fieldId, DataType dataType, int depth) {
        FieldType fieldType = dataType.accept(ArrowFieldTypeConversion.ARROW_FIELD_TYPE_VISITOR);
        fieldType =
                new FieldType(
                        fieldType.isNullable(),
                        fieldType.getType(),
                        fieldType.getDictionary(),
                        Collections.singletonMap(PARQUET_FIELD_ID, String.valueOf(fieldId)));
        List<Field> children = null;
        if (dataType instanceof ArrayType) {
            Field field =
                    toArrowField(
                            ListVector.DATA_VECTOR_NAME,
                            fieldId,
                            ((ArrayType) dataType).getElementType(),
                            depth + 1);
            FieldType typeInner = field.getFieldType();
            field =
                    new Field(
                            field.getName(),
                            new FieldType(
                                    typeInner.isNullable(),
                                    typeInner.getType(),
                                    typeInner.getDictionary(),
                                    Collections.singletonMap(
                                            PARQUET_FIELD_ID,
                                            String.valueOf(
                                                    SpecialFields.getArrayElementFieldId(
                                                            fieldId, depth + 1)))),
                            field.getChildren());
            children = Collections.singletonList(field);
        } else if (dataType instanceof MapType) {
            MapType mapType = (MapType) dataType;

            Field keyField =
                    toArrowField(
                            MapVector.KEY_NAME, fieldId, mapType.getKeyType().notNull(), depth + 1);
            FieldType keyType = keyField.getFieldType();
            keyField =
                    new Field(
                            keyField.getName(),
                            new FieldType(
                                    keyType.isNullable(),
                                    keyType.getType(),
                                    keyType.getDictionary(),
                                    Collections.singletonMap(
                                            PARQUET_FIELD_ID,
                                            String.valueOf(
                                                    SpecialFields.getMapKeyFieldId(
                                                            fieldId, depth + 1)))),
                            keyField.getChildren());

            Field valueField =
                    toArrowField(
                            MapVector.VALUE_NAME,
                            fieldId,
                            mapType.getValueType().notNull(),
                            depth + 1);
            FieldType valueType = valueField.getFieldType();
            valueField =
                    new Field(
                            valueField.getName(),
                            new FieldType(
                                    valueType.isNullable(),
                                    valueType.getType(),
                                    valueType.getDictionary(),
                                    Collections.singletonMap(
                                            PARQUET_FIELD_ID,
                                            String.valueOf(
                                                    SpecialFields.getMapValueFieldId(
                                                            fieldId, depth + 1)))),
                            valueField.getChildren());

            FieldType structType =
                    new FieldType(
                            false,
                            Types.MinorType.STRUCT.getType(),
                            null,
                            Collections.singletonMap(PARQUET_FIELD_ID, String.valueOf(fieldId)));
            Field mapField =
                    new Field(
                            MapVector.DATA_VECTOR_NAME,
                            // data vector, key vector and value vector CANNOT be null
                            structType,
                            Arrays.asList(keyField, valueField));

            children = Collections.singletonList(mapField);
        } else if (dataType instanceof RowType) {
            RowType rowType = (RowType) dataType;
            children = new ArrayList<>();
            for (DataField field : rowType.getFields()) {
                children.add(toArrowField(field.name(), field.id(), field.type(), 0));
            }
        }
        return new Field(fieldName, fieldType, children);
    }