ClickHouse/src/Functions/polygonsDistance.cpp

#include <Functions/FunctionFactory.h>
#include <Functions/geometryConverters.h>

#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/polygon.hpp>

#include <common/logger_useful.h>

#include <Columns/ColumnArray.h>
#include <Columns/ColumnTuple.h>
#include <Columns/ColumnConst.h>
#include <Columns/ColumnsNumber.h>
#include <DataTypes/DataTypesNumber.h>
#include <DataTypes/DataTypeArray.h>
#include <DataTypes/DataTypeTuple.h>
#include <DataTypes/DataTypeCustomGeo.h>

#include <memory>
#include <utility>

namespace DB
{

namespace ErrorCodes
{
    extern const int TOO_FEW_ARGUMENTS_FOR_FUNCTION;
    extern const int BAD_ARGUMENTS;
    extern const int ILLEGAL_TYPE_OF_ARGUMENT;
    extern const int ILLEGAL_COLUMN;
}


using CoordinateType = Float64;
using Point = boost::geometry::model::d2::point_xy<CoordinateType>;
using Polygon = boost::geometry::model::polygon<Point, false>;
using MultiPolygon = boost::geometry::model::multi_polygon<Float64Polygon>;
using Box = boost::geometry::model::box<Point>;


class FunctionPolygonsDistance : public IFunction
{
public:
    static inline const char * name = "polygonsDistance";

    explicit FunctionPolygonsDistance() = default;

    static FunctionPtr create(const Context &)
    {
        return std::make_shared<FunctionPolygonsDistance>();
    }

    String getName() const override
    {
        return name;
    }

    bool isVariadic() const override
    {
        return false;
    }

    size_t getNumberOfArguments() const override
    {
        return 2;
    }

    DataTypePtr getReturnTypeImpl(const DataTypes &) const override
    {
        return std::make_shared<DataTypeFloat64>();
    }

    void executeImpl(Block & block, const ColumnNumbers & arguments, size_t result, size_t input_rows_count) override
    {
        auto get_parser = [&block, &arguments] (size_t i) {
            const auto * const_col =
                checkAndGetColumn<ColumnConst>(block.getByPosition(arguments[i]).column.get());

            bool is_const = static_cast<bool>(const_col);

            return std::pair<bool, GeometryFromColumnParser>{is_const, is_const ?
                makeGeometryFromColumnParser(ColumnWithTypeAndName(const_col->getDataColumnPtr(), block.getByPosition(arguments[i]).type, block.getByPosition(arguments[i]).name)) :
                makeGeometryFromColumnParser(block.getByPosition(arguments[i]))};
        };

        auto [is_first_polygon_const, first_parser] = get_parser(0);
        auto first_container = createContainer(first_parser);

        auto [is_second_polygon_const, second_parser] = get_parser(1);
        auto second_container = createContainer(second_parser);

        auto res_column = ColumnFloat64::create();

        for (size_t i = 0; i < input_rows_count; i++)
        {
            if (!is_first_polygon_const || i == 0)
                get(first_parser, first_container, i);
            if (!is_second_polygon_const || i == 0)
                get(second_parser, second_container, i);

            bool distance = boost::geometry::distance(
                boost::get<Float64MultiPolygon>(first_container),
                boost::get<Float64MultiPolygon>(second_container));

            res_column->insertValue(distance);
        }

        block.getByPosition(result).column = std::move(res_column);
    }

    bool useDefaultImplementationForConstants() const override
    {
        return true;
    }
};


void registerFunctionPolygonsDistance(FunctionFactory & factory)
{
    factory.registerFunction<FunctionPolygonsDistance>();
}

}