be/src/vec/functions/function_python_udf.h

// Licensed to the Apache Software Foundation (ASF) under one
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// 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
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// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

#pragma once

#include <gen_cpp/Types_types.h>

#include <functional>
#include <memory>

#include "common/status.h"
#include "udf/udf.h"
#include "vec/core/block.h"
#include "vec/core/column_numbers.h"
#include "vec/core/columns_with_type_and_name.h"
#include "vec/core/types.h"
#include "vec/data_types/data_type.h"
#include "vec/functions/function.h"

namespace doris::vectorized {

class PythonUDFPreparedFunction : public PreparedFunctionImpl {
public:
    using execute_call_back = std::function<Status(FunctionContext* context, Block& block,
                                                   const ColumnNumbers& arguments, uint32_t result,
                                                   size_t input_rows_count)>;

    explicit PythonUDFPreparedFunction(const execute_call_back& func, const std::string& name)
            : callback_function(func), name(name) {}

    String get_name() const override { return name; }

protected:
    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,
                        uint32_t result, size_t input_rows_count) const override {
        return callback_function(context, block, arguments, result, input_rows_count);
    }

    bool use_default_implementation_for_nulls() const override { return false; }

private:
    execute_call_back callback_function;
    std::string name;
};

class PythonFunctionCall : public IFunctionBase {
public:
    PythonFunctionCall(const TFunction& fn, const DataTypes& argument_types,
                       const DataTypePtr& return_type);

    static FunctionBasePtr create(const TFunction& fn, const ColumnsWithTypeAndName& argument_types,
                                  const DataTypePtr& return_type) {
        DataTypes data_types(argument_types.size());
        for (size_t i = 0; i < argument_types.size(); ++i) {
            data_types[i] = argument_types[i].type;
        }
        return std::make_shared<PythonFunctionCall>(fn, data_types, return_type);
    }

    /// Get the main function name.
    String get_name() const override { return _fn.name.function_name; }

    const DataTypes& get_argument_types() const override { return _argument_types; }
    const DataTypePtr& get_return_type() const override { return _return_type; }

    PreparedFunctionPtr prepare(FunctionContext* context, const Block& sample_block,
                                const ColumnNumbers& arguments, uint32_t result) const override {
        return std::make_shared<PythonUDFPreparedFunction>(
                [this](auto&& PH1, auto&& PH2, auto&& PH3, auto&& PH4, auto&& PH5) {
                    return PythonFunctionCall::execute_impl(
                            std::forward<decltype(PH1)>(PH1), std::forward<decltype(PH2)>(PH2),
                            std::forward<decltype(PH3)>(PH3), std::forward<decltype(PH4)>(PH4),
                            std::forward<decltype(PH5)>(PH5));
                },
                _fn.name.function_name);
    }

    Status open(FunctionContext* context, FunctionContext::FunctionStateScope scope) override;

    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,
                        uint32_t result, size_t input_rows_count) const;

    Status close(FunctionContext* context, FunctionContext::FunctionStateScope scope) override;

    bool is_use_default_implementation_for_constants() const override { return true; }

    bool is_udf_function() const override { return true; }

private:
    const TFunction& _fn;
    const DataTypes _argument_types;
    const DataTypePtr _return_type {nullptr};
};

} // namespace doris::vectorized