public static ColumnReader createColumnReader()

in paimon-format/src/main/java/org/apache/paimon/format/parquet/reader/ParquetSplitReaderUtil.java [63:186]
124 lines of code
27 McCabe index (conditional complexity)

    public static ColumnReader createColumnReader(
            DataType fieldType,
            Type type,
            List<ColumnDescriptor> columnDescriptors,
            PageReadStore pages,
            int depth)
            throws IOException {
        List<ColumnDescriptor> descriptors =
                getAllColumnDescriptorByType(depth, type, columnDescriptors);
        switch (fieldType.getTypeRoot()) {
            case BOOLEAN:
                return new BooleanColumnReader(
                        descriptors.get(0), pages.getPageReader(descriptors.get(0)));
            case TINYINT:
                return new ByteColumnReader(
                        descriptors.get(0), pages.getPageReader(descriptors.get(0)));
            case DOUBLE:
                return new DoubleColumnReader(
                        descriptors.get(0), pages.getPageReader(descriptors.get(0)));
            case FLOAT:
                return new FloatColumnReader(
                        descriptors.get(0), pages.getPageReader(descriptors.get(0)));
            case INTEGER:
            case DATE:
            case TIME_WITHOUT_TIME_ZONE:
                return new IntColumnReader(
                        descriptors.get(0), pages.getPageReader(descriptors.get(0)));
            case BIGINT:
                return new LongColumnReader(
                        descriptors.get(0), pages.getPageReader(descriptors.get(0)));
            case SMALLINT:
                return new ShortColumnReader(
                        descriptors.get(0), pages.getPageReader(descriptors.get(0)));
            case CHAR:
            case VARCHAR:
            case BINARY:
            case VARBINARY:
                return new BytesColumnReader(
                        descriptors.get(0), pages.getPageReader(descriptors.get(0)));
            case TIMESTAMP_WITHOUT_TIME_ZONE:
            case TIMESTAMP_WITH_LOCAL_TIME_ZONE:
                if (descriptors.get(0).getPrimitiveType().getPrimitiveTypeName()
                        == PrimitiveType.PrimitiveTypeName.INT64) {
                    return new LongColumnReader(
                            descriptors.get(0), pages.getPageReader(descriptors.get(0)));
                }
                return new TimestampColumnReader(
                        true, descriptors.get(0), pages.getPageReader(descriptors.get(0)));
            case DECIMAL:
                switch (descriptors.get(0).getPrimitiveType().getPrimitiveTypeName()) {
                    case INT32:
                        return new IntColumnReader(
                                descriptors.get(0), pages.getPageReader(descriptors.get(0)));
                    case INT64:
                        return new LongColumnReader(
                                descriptors.get(0), pages.getPageReader(descriptors.get(0)));
                    case BINARY:
                        return new BytesColumnReader(
                                descriptors.get(0), pages.getPageReader(descriptors.get(0)));
                    case FIXED_LEN_BYTE_ARRAY:
                        return new FixedLenBytesColumnReader(
                                descriptors.get(0),
                                pages.getPageReader(descriptors.get(0)),
                                ((DecimalType) fieldType).getPrecision());
                }
            case ARRAY:
                return new ArrayColumnReader(
                        descriptors.get(0),
                        pages.getPageReader(descriptors.get(0)),
                        true,
                        descriptors.get(0).getPrimitiveType(),
                        fieldType);
            case MAP:
                MapType mapType = (MapType) fieldType;
                ArrayColumnReader mapKeyReader =
                        new ArrayColumnReader(
                                descriptors.get(0),
                                pages.getPageReader(descriptors.get(0)),
                                true,
                                descriptors.get(0).getPrimitiveType(),
                                new ArrayType(mapType.getKeyType()));
                ArrayColumnReader mapValueReader =
                        new ArrayColumnReader(
                                descriptors.get(1),
                                pages.getPageReader(descriptors.get(1)),
                                true,
                                descriptors.get(1).getPrimitiveType(),
                                new ArrayType(mapType.getValueType()));
                return new MapColumnReader(mapKeyReader, mapValueReader);
            case MULTISET:
                MultisetType multisetType = (MultisetType) fieldType;
                ArrayColumnReader multisetKeyReader =
                        new ArrayColumnReader(
                                descriptors.get(0),
                                pages.getPageReader(descriptors.get(0)),
                                true,
                                descriptors.get(0).getPrimitiveType(),
                                new ArrayType(multisetType.getElementType()));
                ArrayColumnReader multisetValueReader =
                        new ArrayColumnReader(
                                descriptors.get(1),
                                pages.getPageReader(descriptors.get(1)),
                                true,
                                descriptors.get(1).getPrimitiveType(),
                                new ArrayType(new IntType(false)));
                return new MapColumnReader(multisetKeyReader, multisetValueReader);
            case ROW:
                RowType rowType = (RowType) fieldType;
                GroupType groupType = type.asGroupType();
                List<ColumnReader> fieldReaders = new ArrayList<>();
                for (int i = 0; i < rowType.getFieldCount(); i++) {
                    fieldReaders.add(
                            createColumnReader(
                                    rowType.getTypeAt(i),
                                    groupType.getType(i),
                                    descriptors,
                                    pages,
                                    depth + 1));
                }
                return new RowColumnReader(fieldReaders);
            default:
                throw new UnsupportedOperationException(fieldType + " is not supported now.");
        }
    }