be/src/vec/functions/function_fake.cpp

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// distributed with this work for additional information
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// to you under the Apache License, Version 2.0 (the
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// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
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// specific language governing permissions and limitations
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#include "vec/functions/function_fake.h"

#include <glog/logging.h>

#include <algorithm>
#include <boost/iterator/iterator_facade.hpp>
#include <ostream>
#include <string>

#include "vec/aggregate_functions/aggregate_function.h"
#include "vec/data_types/data_type_array.h"
#include "vec/data_types/data_type_jsonb.h"
#include "vec/data_types/data_type_nullable.h"
#include "vec/data_types/data_type_number.h"
#include "vec/data_types/data_type_string.h"
#include "vec/exprs/table_function/table_function.h"
#include "vec/functions/function_helpers.h"
#include "vec/functions/simple_function_factory.h"

namespace doris::vectorized {

template <typename ReturnType, bool AlwaysNullable = false>
struct FunctionFakeBaseImpl {
    static DataTypePtr get_return_type_impl(const DataTypes& arguments) {
        if constexpr (AlwaysNullable) {
            return make_nullable(std::make_shared<ReturnType>());
        }
        return std::make_shared<ReturnType>();
    }
    static std::string get_error_msg() { return "Fake function do not support execute"; }
};

struct FunctionExplode {
    static DataTypePtr get_return_type_impl(const DataTypes& arguments) {
        DCHECK(is_array(arguments[0])) << arguments[0]->get_name() << " not supported";
        return make_nullable(
                check_and_get_data_type<DataTypeArray>(arguments[0].get())->get_nested_type());
    }
    static std::string get_error_msg() { return "Fake function do not support execute"; }
};

struct FunctionEsquery {
    static DataTypePtr get_return_type_impl(const DataTypes& arguments) {
        return FunctionFakeBaseImpl<DataTypeUInt8>::get_return_type_impl(arguments);
    }
    static std::string get_error_msg() { return "esquery only supported on es table"; }
};

template <typename FunctionImpl>
void register_function(SimpleFunctionFactory& factory, const std::string& name) {
    factory.register_function<FunctionFake<FunctionImpl>>(name);
};

template <typename FunctionImpl>
void register_table_function_expand(SimpleFunctionFactory& factory, const std::string& name,
                                    const std::string& suffix) {
    factory.register_function<FunctionFake<FunctionImpl>>(name);
    factory.register_function<FunctionFake<FunctionImpl>>(name + suffix);
};

template <typename ReturnType>
void register_table_function_expand_default(SimpleFunctionFactory& factory, const std::string& name,
                                            const std::string& suffix) {
    factory.register_function<FunctionFake<FunctionFakeBaseImpl<ReturnType>>>(name);
    factory.register_function<FunctionFake<FunctionFakeBaseImpl<ReturnType, true>>>(name + suffix);
};

template <typename FunctionImpl>
void register_table_function_expand_outer(SimpleFunctionFactory& factory, const std::string& name) {
    register_table_function_expand<FunctionImpl>(factory, name, COMBINATOR_SUFFIX_OUTER);
};

template <typename ReturnType>
void register_table_function_expand_outer_default(SimpleFunctionFactory& factory,
                                                  const std::string& name) {
    register_table_function_expand_default<ReturnType>(factory, name, COMBINATOR_SUFFIX_OUTER);
};

void register_function_fake(SimpleFunctionFactory& factory) {
    register_function<FunctionEsquery>(factory, "esquery");

    register_table_function_expand_outer<FunctionExplode>(factory, "explode");

    register_table_function_expand_outer_default<DataTypeString>(factory, "explode_split");
    register_table_function_expand_outer_default<DataTypeInt32>(factory, "explode_numbers");
    register_table_function_expand_outer_default<DataTypeInt64>(factory, "explode_json_array_int");
    register_table_function_expand_outer_default<DataTypeString>(factory,
                                                                 "explode_json_array_string");
    register_table_function_expand_outer_default<DataTypeString>(factory,
                                                                 "explode_json_array_json");
    register_table_function_expand_outer_default<DataTypeFloat64>(factory,
                                                                  "explode_json_array_double");
    register_table_function_expand_outer_default<DataTypeInt64>(factory, "explode_bitmap");
}

} // namespace doris::vectorized