Method SerializeHeader

query/common/hll.go:871–941

SerializeHeader serialize HLL header -----------query result 0------------------- [uint8] num_enum_columns [uint8] bytes per dim ... [padding for 8 bytes] [uint32] result_size [uint32] raw_dim_values_vector_length [uint8] dim_index_0... [uint8] dim_index_n [padding for 8 bytes] [

()

//
// 	 <end of header>
func (builder *HLLDataWriter) SerializeHeader() error {
	writer := utils.NewBufferWriter(builder.Buffer)

	// num_enum_columns
	if err := writer.AppendUint8(uint8(len(builder.EnumDicts))); err != nil {
		return err
	}

	// bytes per dim
	if err := writer.Append([]byte(builder.NumDimsPerDimWidth[:])); err != nil {
		return err
	}
	writer.AlignBytes(8)

	// result_size
	if err := writer.AppendUint32(builder.ResultSize); err != nil {
		return err
	}

	// raw_dim_values_vector_length
	if err := writer.AppendUint32(builder.PaddedRawDimValuesVectorLength); err != nil {
		return err
	}

	// dim_indexes
	for _, dimIndex := range builder.DimIndexes {
		if err := writer.AppendUint8(uint8(dimIndex)); err != nil {
			return err
		}
	}
	writer.AlignBytes(8)

	// data_types
	for _, dataType := range builder.DataTypes {
		if err := writer.AppendUint32(uint32(dataType)); err != nil {
			return err
		}
	}
	writer.AlignBytes(8)

	// Write enum cases.
	for dimIdx, enumCases := range builder.EnumDicts {
		enumCasesBytes := CalculateEnumCasesBytes(enumCases)
		if err := writer.AppendUint32(enumCasesBytes); err != nil {
			return err
		}

		if err := writer.AppendUint16(uint16(dimIdx)); err != nil {
			return err
		}

		// padding
		writer.SkipBytes(2)

		var enumCaseBytesWritten uint32
		for _, enumCase := range enumCases {
			if err := writer.Append([]byte(enumCase)); err != nil {
				return err