// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements. See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership. The ASF licenses this file

// to you under the Apache License, Version 2.0 (the

// "License"); you may not use this file except in compliance

// with the License. You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing,

// software distributed under the License is distributed on an

// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

// KIND, either express or implied. See the License for the

// specific language governing permissions and limitations

// under the License.

#include <bitset>

#include <cstdint>

#include <exception>

#include <type_traits>

#include "common/compiler_util.h"

#include "common/status.h"

#include "core/data_type/data_type_number.h"

#include "core/types.h"

#include "exprs/function/simple_function_factory.h"

namespace doris {

template <typename Impl>

class FunctionBitShift : public IFunction {

public:

static constexpr auto name = Impl::name;

String get_name() const override { return name; }

static FunctionPtr create() { return std::make_shared<FunctionBitShift<Impl>>(); }

DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {

return std::make_shared<DataTypeInt64>();

}

size_t get_number_of_arguments() const override { return 2; }

bool use_default_implementation_for_constants() const final { return false; }

Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,

uint32_t result, size_t input_rows_count) const override {

auto& column_left = block.get_by_position(arguments[0]).column;

auto& column_right = block.get_by_position(arguments[1]).column;

bool is_const_left = is_column_const(*column_left);

bool is_const_right = is_column_const(*column_right);

ColumnPtr column_result = nullptr;

if (is_const_left && is_const_right) {

column_result = constant_constant(column_left, column_right);

} else if (is_const_left) {

column_result = constant_vector(column_left, column_right);

} else if (is_const_right) {

column_result = vector_constant(column_left, column_right);

} else {

column_result = vector_vector(column_left, column_right);

}

block.replace_by_position(result, std::move(column_result));

return Status::OK();

}

private:

ColumnPtr constant_constant(ColumnPtr column_left, ColumnPtr column_right) const {

const auto* column_left_ptr = assert_cast<const ColumnConst*>(column_left.get());

const auto* column_right_ptr = assert_cast<const ColumnConst*>(column_right.get());

ColumnPtr column_result = nullptr;

auto res = ColumnInt64::create(1);

res->get_element(0) = Impl::apply(column_left_ptr->template get_value<TYPE_BIGINT>(),

column_right_ptr->template get_value<TYPE_TINYINT>());

column_result = std::move(res);

return ColumnConst::create(std::move(column_result), column_left->size());

}

ColumnPtr vector_constant(ColumnPtr column_left, ColumnPtr column_right) const {

const auto* column_right_ptr = assert_cast<const ColumnConst*>(column_right.get());

const auto* column_left_ptr = assert_cast<const ColumnInt64*>(column_left.get());

auto column_result = ColumnInt64::create(column_left->size());

auto& a = column_left_ptr->get_data();

auto& c = column_result->get_data();

size_t size = a.size();

for (size_t i = 0; i < size; ++i) {

c[i] = Impl::apply(a[i], column_right_ptr->template get_value<TYPE_TINYINT>());

}

return column_result;

}

ColumnPtr constant_vector(ColumnPtr column_left, ColumnPtr column_right) const {

const auto* column_left_ptr = assert_cast<const ColumnConst*>(column_left.get());

const auto* column_right_ptr = assert_cast<const ColumnInt8*>(column_right.get());

auto column_result = ColumnInt64::create(column_right->size());

auto& b = column_right_ptr->get_data();

auto& c = column_result->get_data();

size_t size = b.size();

for (size_t i = 0; i < size; ++i) {

c[i] = Impl::apply(column_left_ptr->template get_value<TYPE_BIGINT>(), b[i]);

}

return column_result;

}

ColumnPtr vector_vector(ColumnPtr column_left, ColumnPtr column_right) const {

const auto* column_left_ptr = assert_cast<const ColumnInt64*>(column_left->get_ptr().get());

const auto* column_right_ptr =

assert_cast<const ColumnInt8*>(column_right->get_ptr().get());

auto column_result = ColumnInt64::create(column_left->size());

auto& a = column_left_ptr->get_data();

auto& b = column_right_ptr->get_data();

auto& c = column_result->get_data();

size_t size = a.size();

for (size_t i = 0; i < size; ++i) {

c[i] = Impl::apply(a[i], b[i]);

}

return column_result;

}

};

struct BitShiftLeftImpl {

static constexpr auto name = "bit_shift_left";

static inline Int64 apply(Int64 a, Int8 b) {

// return zero if b < 0, keep consistent with mysql

// cast to unsigned so that we can do logical shift by default, keep consistent with mysql

if (UNLIKELY(b >= 64 || b < 0)) {

return 0;

}

return static_cast<typename std::make_unsigned<Int64>::type>(a) << static_cast<Int64>(b);

}

};

struct BitShiftRightImpl {

static constexpr auto name = "bit_shift_right";

static inline Int64 apply(Int64 a, Int8 b) {

// return zero if b < 0, keep consistent with mysql

// cast to unsigned so that we can do logical shift by default, keep consistent with mysql

if (UNLIKELY(b >= 64 || b < 0)) {

return 0;

}

return static_cast<typename std::make_unsigned<Int64>::type>(a) >> static_cast<Int64>(b);

}

};

void register_function_bit_shift(SimpleFunctionFactory& factory) {

factory.register_function<FunctionBitShift<BitShiftRightImpl>>();

factory.register_function<FunctionBitShift<BitShiftLeftImpl>>();

}

} // namespace doris