Function encodeDataTypeImpl

src/DataTypes/DataTypesBinaryEncoding.cpp:315–541

template <bool encode_for_hash_calculation>
void encodeDataTypeImpl(const DataTypePtr & type, WriteBuffer & buf)
{
    /// First, write the BinaryTypeIndex byte.
    auto binary_type_index = getBinaryTypeIndex(type);
    buf.write(UInt8(binary_type_index));
    /// Then, write additional information depending on the data type.
    switch (binary_type_index)
    {
        case BinaryTypeIndex::DateTimeWithTimezone:
        {
            const auto & datetime_type = assert_cast<const DataTypeDateTime &>(*type);
            writeStringBinary(getDateLUTTimeZone(datetime_type.getTimeZone()), buf);
            break;
        }
        case BinaryTypeIndex::DateTime64UTC:
        {
            const auto & datetime64_type = assert_cast<const DataTypeDateTime64 &>(*type);
            /// Maximum scale for DateTime64 is 9, so we can write it as 1 byte.
            buf.write(UInt8(datetime64_type.getScale()));
            break;
        }
        case BinaryTypeIndex::DateTime64WithTimezone:
        {
            const auto & datetime64_type = assert_cast<const DataTypeDateTime64 &>(*type);
            buf.write(UInt8(datetime64_type.getScale()));
            writeStringBinary(getDateLUTTimeZone(datetime64_type.getTimeZone()), buf);
            break;
        }
        case BinaryTypeIndex::Time64:
        {
            const auto & time64_type = assert_cast<const DataTypeTime64 &>(*type);
            /// Maximum scale for Time64 is 9, so we can write it as 1 byte.
            buf.write(UInt8(time64_type.getScale()));
            break;
        }
        case BinaryTypeIndex::FixedString:
        {
            const auto & fixed_string_type = assert_cast<const DataTypeFixedString &>(*type);
            writeVarUInt(fixed_string_type.getN(), buf);
            break;
        }
        case BinaryTypeIndex::Enum8:
        {
            encodeEnumValues<Int8>(type, buf);
            break;
        }
        case BinaryTypeIndex::Enum16:
        {
            encodeEnumValues<Int16>(type, buf);
            break;
        }
        case BinaryTypeIndex::Decimal32:
        {
            encodeDecimal<Decimal32>(type, buf);
            break;
        }
        case BinaryTypeIndex::Decimal64:
        {