ClickHouse/src/AggregateFunctions/AggregateFunctionGroupBitmap.h

#pragma once

#include <Columns/ColumnVector.h>
#include <Common/assert_cast.h>
#include <AggregateFunctions/IAggregateFunction.h>
#include <DataTypes/DataTypesNumber.h>
#include <Columns/ColumnAggregateFunction.h>

// TODO include this last because of a broken roaring header. See the comment
// inside.
#include <AggregateFunctions/AggregateFunctionGroupBitmapData.h>

namespace DB
{

/// Counts bitmap operation on numbers.
template <typename T, typename Data>
class AggregateFunctionBitmap final : public IAggregateFunctionDataHelper<Data, AggregateFunctionBitmap<T, Data>>
{
public:
    AggregateFunctionBitmap(const DataTypePtr & type)
            : IAggregateFunctionDataHelper<Data, AggregateFunctionBitmap<T, Data>>({type}, {}) {}

    String getName() const override { return Data::name(); }

    DataTypePtr getReturnType() const override
    {
        return std::make_shared<DataTypeNumber<T>>();
    }

    void add(AggregateDataPtr place, const IColumn ** columns, size_t row_num, Arena *) const override
    {
        this->data(place).rbs.add(assert_cast<const ColumnVector<T> &>(*columns[0]).getData()[row_num]);
    }

    void merge(AggregateDataPtr place, ConstAggregateDataPtr rhs, Arena *) const override
    {
        this->data(place).rbs.merge(this->data(rhs).rbs);
    }

    void serialize(ConstAggregateDataPtr place, WriteBuffer & buf) const override
    {
        this->data(place).rbs.write(buf);
    }

    void deserialize(AggregateDataPtr place, ReadBuffer & buf, Arena *) const override
    {
        this->data(place).rbs.read(buf);
    }

    void insertResultInto(AggregateDataPtr place, IColumn & to) const override
    {
        assert_cast<ColumnVector<T> &>(to).getData().push_back(this->data(place).rbs.size());
    }
};


template <typename T, typename Data, typename Policy>
class AggregateFunctionBitmapL2 final : public IAggregateFunctionDataHelper<Data, AggregateFunctionBitmapL2<T, Data, Policy>>
{
public:
    AggregateFunctionBitmapL2(const DataTypePtr & type)
            : IAggregateFunctionDataHelper<Data, AggregateFunctionBitmapL2<T, Data, Policy>>({type}, {}){}

    String getName() const override { return Data::name(); }

    DataTypePtr getReturnType() const override
    {
        return std::make_shared<DataTypeNumber<T>>();
    }

    void add(AggregateDataPtr place, const IColumn ** columns, size_t row_num, Arena *) const override
    {
        Data & data_lhs = this->data(place);
        const Data & data_rhs = this->data(assert_cast<const ColumnAggregateFunction &>(*columns[0]).getData()[row_num]);
        if (!data_lhs.doneFirst)
        {
            data_lhs.doneFirst = true;
            data_lhs.rbs.rb_or(data_rhs.rbs);
        }
        else
        {
            Policy::apply(data_lhs, data_rhs);
        }
    }

    void merge(AggregateDataPtr place, ConstAggregateDataPtr rhs, Arena *) const override
    {
        Data & data_lhs = this->data(place);
        const Data & data_rhs = this->data(rhs);

        if (!data_rhs.doneFirst)
            return;

        if (!data_lhs.doneFirst)
        {
            data_lhs.doneFirst = true;
            data_lhs.rbs.rb_or(data_rhs.rbs);
        }
        else
        {
            Policy::apply(data_lhs, data_rhs);
        }
    }

    void serialize(ConstAggregateDataPtr place, WriteBuffer & buf) const override
    {
        this->data(place).rbs.write(buf);
    }

    void deserialize(AggregateDataPtr place, ReadBuffer & buf, Arena *) const override
    {
        this->data(place).rbs.read(buf);
    }

    void insertResultInto(AggregateDataPtr place, IColumn & to) const override
    {
        assert_cast<ColumnVector<T> &>(to).getData().push_back(this->data(place).rbs.size());
    }
};

template <typename Data>
class BitmapAndPolicy
{
public:
    static void apply(Data& lhs, const Data& rhs)
    {
        lhs.rbs.rb_and(rhs.rbs);
    }
};

template <typename Data>
class BitmapOrPolicy
{
public:
    static void apply(Data& lhs, const Data& rhs)
    {
        lhs.rbs.rb_or(rhs.rbs);
    }
};

template <typename Data>
class BitmapXorPolicy
{
public:
    static void apply(Data& lhs, const Data& rhs)
    {
        lhs.rbs.rb_xor(rhs.rbs);
    }
};

template <typename T, typename Data>
using AggregateFunctionBitmapL2And = AggregateFunctionBitmapL2<T, Data, BitmapAndPolicy<Data> >;

template <typename T, typename Data>
using AggregateFunctionBitmapL2Or = AggregateFunctionBitmapL2<T, Data, BitmapOrPolicy<Data> >;

template <typename T, typename Data>
using AggregateFunctionBitmapL2Xor = AggregateFunctionBitmapL2<T, Data, BitmapXorPolicy<Data> >;

}