#include #include #include #include #include #include #include #include #include namespace DB { namespace ErrorCodes { extern const int LOGICAL_ERROR; } NativeBlockOutputStream::NativeBlockOutputStream( WriteBuffer & ostr_, UInt64 client_revision_, const Block & header_, bool remove_low_cardinality_, WriteBuffer * index_ostr_, size_t initial_size_of_file_) : ostr(ostr_), client_revision(client_revision_), header(header_), index_ostr(index_ostr_), initial_size_of_file(initial_size_of_file_), remove_low_cardinality(remove_low_cardinality_) { if (index_ostr) { ostr_concrete = typeid_cast(&ostr); if (!ostr_concrete) throw Exception("When need to write index for NativeBlockOutputStream, ostr must be CompressedWriteBuffer.", ErrorCodes::LOGICAL_ERROR); } } void NativeBlockOutputStream::flush() { ostr.next(); } void NativeBlockOutputStream::writeData(const IDataType & type, const ColumnPtr & column, WriteBuffer & ostr, size_t offset, size_t limit) { /** If there are columns-constants - then we materialize them. * (Since the data type does not know how to serialize / deserialize constants.) */ ColumnPtr full_column = column->convertToFullColumnIfConst(); IDataType::SerializeBinaryBulkSettings settings; settings.getter = [&ostr](IDataType::SubstreamPath) -> WriteBuffer * { return &ostr; }; settings.position_independent_encoding = false; settings.low_cardinality_max_dictionary_size = 0; IDataType::SerializeBinaryBulkStatePtr state; type.serializeBinaryBulkStatePrefix(settings, state); type.serializeBinaryBulkWithMultipleStreams(*full_column, offset, limit, settings, state); type.serializeBinaryBulkStateSuffix(settings, state); } void NativeBlockOutputStream::write(const Block & block) { /// Additional information about the block. if (client_revision > 0) block.info.write(ostr); block.checkNumberOfRows(); /// Dimensions size_t columns = block.columns(); size_t rows = block.rows(); writeVarUInt(columns, ostr); writeVarUInt(rows, ostr); /** The index has the same structure as the data stream. * But instead of column values, it contains a mark that points to the location in the data file where this part of the column is located. */ if (index_ostr) { writeVarUInt(columns, *index_ostr); writeVarUInt(rows, *index_ostr); } for (size_t i = 0; i < columns; ++i) { /// For the index. MarkInCompressedFile mark; if (index_ostr) { ostr_concrete->next(); /// Finish compressed block. mark.offset_in_compressed_file = initial_size_of_file + ostr_concrete->getCompressedBytes(); mark.offset_in_decompressed_block = ostr_concrete->getRemainingBytes(); } ColumnWithTypeAndName column = block.safeGetByPosition(i); /// Send data to old clients without low cardinality type. if (remove_low_cardinality || (client_revision && client_revision < DBMS_MIN_REVISION_WITH_LOW_CARDINALITY_TYPE)) { column.column = recursiveRemoveLowCardinality(column.column); column.type = recursiveRemoveLowCardinality(column.type); } /// Name writeStringBinary(column.name, ostr); /// Type String type_name = column.type->getName(); /// For compatibility, we will not send explicit timezone parameter in DateTime data type /// to older clients, that cannot understand it. if (client_revision < DBMS_MIN_REVISION_WITH_TIME_ZONE_PARAMETER_IN_DATETIME_DATA_TYPE && startsWith(type_name, "DateTime(")) type_name = "DateTime"; writeStringBinary(type_name, ostr); /// Data if (rows) /// Zero items of data is always represented as zero number of bytes. writeData(*column.type, column.column, ostr, 0, 0); if (index_ostr) { writeStringBinary(column.name, *index_ostr); writeStringBinary(column.type->getName(), *index_ostr); writeBinary(mark.offset_in_compressed_file, *index_ostr); writeBinary(mark.offset_in_decompressed_block, *index_ostr); } } } }