ClickHouse/src/Processors/Formats/Impl/ArrowColumnToCHColumn.h

#pragma once
#include "config_formats.h"

#if USE_ARROW || USE_ORC || USE_PARQUET

#include <DataTypes/IDataType.h>
#include <DataTypes/DataTypesNumber.h>
#include <DataTypes/DataTypeDate.h>
#include <DataTypes/DataTypeDateTime.h>
#include <DataTypes/DataTypeString.h>
#include <arrow/type.h>
#include <Columns/ColumnVector.h>
#include <arrow/table.h>
#include <arrow/array.h>
#include <arrow/buffer.h>
#include <Processors/Chunk.h>
#include <Core/Block.h>

namespace DB
{

    class ArrowColumnToCHColumn
    {
    private:

#    define FOR_ARROW_NUMERIC_TYPES(M) \
        M(arrow::Type::UINT8, DB::UInt8) \
        M(arrow::Type::INT8, DB::Int8) \
        M(arrow::Type::UINT16, DB::UInt16) \
        M(arrow::Type::INT16, DB::Int16) \
        M(arrow::Type::UINT32, DB::UInt32) \
        M(arrow::Type::INT32, DB::Int32) \
        M(arrow::Type::UINT64, DB::UInt64) \
        M(arrow::Type::INT64, DB::Int64) \
        M(arrow::Type::HALF_FLOAT, DB::Float32) \
        M(arrow::Type::FLOAT, DB::Float32) \
        M(arrow::Type::DOUBLE, DB::Float64)

#    define FOR_ARROW_INDEXES_TYPES(M) \
        M(arrow::Type::UINT8, DB::UInt8) \
        M(arrow::Type::INT8, DB::UInt8) \
        M(arrow::Type::UINT16, DB::UInt16) \
        M(arrow::Type::INT16, DB::UInt16) \
        M(arrow::Type::UINT32, DB::UInt32) \
        M(arrow::Type::INT32, DB::UInt32) \
        M(arrow::Type::UINT64, DB::UInt64) \
        M(arrow::Type::INT64, DB::UInt64)

        /// Map {column name : dictionary column}.
        /// To avoid converting dictionary from Arrow Dictionary
        /// to LowCardinality every chunk we save it and reuse.
        std::unordered_map<std::string, ColumnPtr> dictionary_values;

    public:

        void arrowTableToCHChunk(Chunk & res, std::shared_ptr<arrow::Table> & table,
                                        const Block & header, std::string format_name);
    };
}
#endif