Function parse_special_datum

cpp/deeplake_pg/utils.hpp:554–712

}

inline parsed_special_datum_result parse_special_datum(Datum d, Oid attr_typeid)
{
    parsed_special_datum_result result;

    if (!can_make_special_datum(attr_typeid)) {
        return result;
    }

    if (is_string_type(attr_typeid)) {
        // For string types, parse the formatted string: "magic table_id row_id column_id"
        text* txt = DatumGetTextP(d);
        if (txt == nullptr) {
            return result;
        }

        const char* data = VARDATA(txt);
        size_t len = VARSIZE(txt) - VARHDRSZ;

        result = parse_space_separated_values(data, len);

    } else if (type_is_array(attr_typeid)) {
        // For array types, check the first element for magic and parse accordingly
        ArrayType* arr = DatumGetArrayTypeP(d);
        if (arr == nullptr) {
            return result;
        }

        int ndims = ARR_NDIM(arr);
        if (ndims != 1) {
            return result;
        }

        int* dims = ARR_DIMS(arr);
        if (dims[0] < 4) {
            return result;
        }

        switch (attr_typeid) {
        case INT2ARRAYOID: {
            if (dims[0] != 8)
                return result;

            int16* data = (int16*)ARR_DATA_PTR(arr);

            // Reconstruct magic number from first two elements
            int32_t magic = static_cast<int32_t>(data[0]) | (static_cast<int32_t>(data[1]) << 16);
            if (magic != g_not_fetched_magic) {
                return result;
            }

            // Reconstruct table_id and row_id from split parts
            uint32_t table_id = static_cast<uint32_t>(data[2]) | (static_cast<uint32_t>(data[3]) << 16);
            int64_t row_id = static_cast<int64_t>(data[4]) | (static_cast<int64_t>(data[5]) << 16) |
                             (static_cast<int64_t>(data[6]) << 32);

            result.is_valid = true;
            result.table_id = table_id;
            result.row_id = row_id;