be/src/exprs/function/function_string_concat.h

Source
// 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.

#pragma once

#include <fmt/format.h>

#include <cstddef>
#include <cstring>
#include <string>
#include <string_view>
#include <vector>

#include "common/status.h"
#include "core/assert_cast.h"
#include "core/block/block.h"
#include "core/block/column_numbers.h"
#include "core/column/column.h"
#include "core/column/column_array.h"
#include "core/column/column_const.h"
#include "core/column/column_nullable.h"
#include "core/column/column_string.h"
#include "core/column/column_vector.h"
#include "core/data_type/data_type_array.h"
#include "core/data_type/data_type_nullable.h"
#include "core/data_type/data_type_number.h"
#include "core/data_type/data_type_string.h"
#include "core/memcpy_small.h"
#include "core/string_ref.h"
#include "exec/common/stringop_substring.h"
#include "exec/common/template_helpers.hpp"
#include "exec/common/util.hpp"
#include "exprs/function/function.h"
#include "exprs/function/function_helpers.h"
#include "exprs/function_context.h"
#include "util/simd/vstring_function.h"

namespace doris {
#include "common/compile_check_avoid_begin.h"

class FunctionStringConcat : public IFunction {
public:
    struct ConcatState {
        bool use_state = false;
        std::string tail;
    };

    static constexpr auto name = "concat";
    static FunctionPtr create() { return std::make_shared<FunctionStringConcat>(); }
    String get_name() const override { return name; }
    size_t get_number_of_arguments() const override { return 0; }
    bool is_variadic() const override { return true; }

    DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {
        return std::make_shared<DataTypeString>();
    }

    Status open(FunctionContext* context, FunctionContext::FunctionStateScope scope) override {
        if (scope == FunctionContext::THREAD_LOCAL) {
            return Status::OK();
        }
        std::shared_ptr<ConcatState> state = std::make_shared<ConcatState>();

        context->set_function_state(scope, state);

        state->use_state = true;

        // Optimize function calls like this:
        // concat(col, "123", "abc", "456") -> tail = "123abc456"
        for (size_t i = 1; i < context->get_num_args(); i++) {
            const auto* column_string = context->get_constant_col(i);
            if (column_string == nullptr) {
                state->use_state = false;
                return IFunction::open(context, scope);
            }
            auto string_vale = column_string->column_ptr->get_data_at(0);
            if (string_vale.data == nullptr) {
                // For concat(col, null), it is handled by default_implementation_for_nulls
                state->use_state = false;
                return IFunction::open(context, scope);
            }

            state->tail.append(string_vale.begin(), string_vale.size);
        }

        // The reserve is used here to allow the usage of memcpy_small_allow_read_write_overflow15 below.
        state->tail.reserve(state->tail.size() + 16);

        return IFunction::open(context, scope);
    }

    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,
                        uint32_t result, size_t input_rows_count) const override {
        DCHECK_GE(arguments.size(), 1);

        if (arguments.size() == 1) {
            block.get_by_position(result).column = block.get_by_position(arguments[0]).column;
            return Status::OK();
        }
        auto* concat_state = reinterpret_cast<ConcatState*>(
                context->get_function_state(FunctionContext::FRAGMENT_LOCAL));
        if (!concat_state) {
            return Status::RuntimeError("funciton context for function '{}' must have ConcatState;",
                                        get_name());
        }
        if (concat_state->use_state) {
            const auto& [col, is_const] =
                    unpack_if_const(block.get_by_position(arguments[0]).column);
            const auto* col_str = assert_cast<const ColumnString*>(col.get());
            if (is_const) {
                return execute_const<true>(concat_state, block, col_str, result, input_rows_count);
            } else {
                return execute_const<false>(concat_state, block, col_str, result, input_rows_count);
            }

        } else {
            return execute_vecotr(block, arguments, result, input_rows_count);
        }
    }

    Status execute_vecotr(Block& block, const ColumnNumbers& arguments, uint32_t result,
                          size_t input_rows_count) const {
        int argument_size = arguments.size();
        std::vector<ColumnPtr> argument_columns(argument_size);

        std::vector<const ColumnString::Offsets*> offsets_list(argument_size);
        std::vector<const ColumnString::Chars*> chars_list(argument_size);
        std::vector<bool> is_const_args(argument_size);

        for (int i = 0; i < argument_size; ++i) {
            const auto& [col, is_const] =
                    unpack_if_const(block.get_by_position(arguments[i]).column);

            const auto* col_str = assert_cast<const ColumnString*>(col.get());
            offsets_list[i] = &col_str->get_offsets();
            chars_list[i] = &col_str->get_chars();
            is_const_args[i] = is_const;
        }

        auto res = ColumnString::create();
        auto& res_data = res->get_chars();
        auto& res_offset = res->get_offsets();

        res_offset.resize(input_rows_count);
        size_t res_reserve_size = 0;
        for (size_t i = 0; i < argument_size; ++i) {
            if (is_const_args[i]) {
                res_reserve_size += (*offsets_list[i])[0] * input_rows_count;
            } else {
                res_reserve_size += (*offsets_list[i])[input_rows_count - 1];
            }
        }

        ColumnString::check_chars_length(res_reserve_size, 0);

        res_data.resize(res_reserve_size);

        auto* data = res_data.data();
        size_t dst_offset = 0;

        for (size_t i = 0; i < input_rows_count; ++i) {
            for (size_t j = 0; j < argument_size; ++j) {
                const auto& current_offsets = *offsets_list[j];
                const auto& current_chars = *chars_list[j];
                auto idx = index_check_const(i, is_const_args[j]);
                const auto size = current_offsets[idx] - current_offsets[idx - 1];
                if (size > 0) {
                    memcpy_small_allow_read_write_overflow15(
                            data + dst_offset, current_chars.data() + current_offsets[idx - 1],
                            size);
                    dst_offset += size;
                }
            }
            res_offset[i] = dst_offset;
        }

        block.get_by_position(result).column = std::move(res);
        return Status::OK();
    }

    template <bool is_const>
    Status execute_const(ConcatState* concat_state, Block& block, const ColumnString* col_str,
                         uint32_t result, size_t input_rows_count) const {
        // using tail optimize

        auto res = ColumnString::create();
        auto& res_data = res->get_chars();
        auto& res_offset = res->get_offsets();
        res_offset.resize(input_rows_count);

        size_t res_reserve_size = 0;
        if constexpr (is_const) {
            res_reserve_size = col_str->get_offsets()[0] * input_rows_count;
        } else {
            res_reserve_size = col_str->get_offsets()[input_rows_count - 1];
        }
        res_reserve_size += concat_state->tail.size() * input_rows_count;

        ColumnString::check_chars_length(res_reserve_size, 0);
        res_data.resize(res_reserve_size);

        const auto& tail = concat_state->tail;
        auto* data = res_data.data();
        size_t dst_offset = 0;

        for (size_t i = 0; i < input_rows_count; ++i) {
            const auto idx = index_check_const<is_const>(i);
            StringRef str_val = col_str->get_data_at(idx);
            // copy column
            memcpy_small_allow_read_write_overflow15(data + dst_offset, str_val.data, str_val.size);
            dst_offset += str_val.size;
            // copy tail
            memcpy_small_allow_read_write_overflow15(data + dst_offset, tail.data(), tail.size());
            dst_offset += tail.size();
            res_offset[i] = dst_offset;
        }
        block.get_by_position(result).column = std::move(res);
        return Status::OK();
    }
};

class FunctionStringElt : public IFunction {
public:
    static constexpr auto name = "elt";
    static FunctionPtr create() { return std::make_shared<FunctionStringElt>(); }
    String get_name() const override { return name; }
    size_t get_number_of_arguments() const override { return 0; }
    bool is_variadic() const override { return true; }

    DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {
        return make_nullable(std::make_shared<DataTypeString>());
    }
    bool use_default_implementation_for_nulls() const override { return false; }

    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,
                        uint32_t result, size_t input_rows_count) const override {
        int arguent_size = arguments.size();
        int num_children = arguent_size - 1;
        auto res = ColumnString::create();

        if (auto const_column = check_and_get_column<ColumnConst>(
                    *block.get_by_position(arguments[0]).column)) {
            auto data = const_column->get_data_at(0);
            // return NULL, pos is null or pos < 0 or pos > num_children
            auto is_null = data.data == nullptr;
            auto pos = is_null ? 0 : *(Int32*)data.data;
            is_null = pos <= 0 || pos > num_children;

            auto null_map = ColumnUInt8::create(input_rows_count, is_null);
            if (is_null) {
                res->insert_many_defaults(input_rows_count);
            } else {
                auto& target_column = block.get_by_position(arguments[pos]).column;
                if (auto target_const_column = check_and_get_column<ColumnConst>(*target_column)) {
                    auto target_data = target_const_column->get_data_at(0);
                    // return NULL, no target data
                    if (target_data.data == nullptr) {
                        null_map = ColumnUInt8::create(input_rows_count, true);
                        res->insert_many_defaults(input_rows_count);
                    } else {
                        res->insert_data_repeatedly(target_data.data, target_data.size,
                                                    input_rows_count);
                    }
                } else if (auto target_nullable_column =
                                   check_and_get_column<ColumnNullable>(*target_column)) {
                    auto& target_null_map = target_nullable_column->get_null_map_data();
                    VectorizedUtils::update_null_map(
                            assert_cast<ColumnUInt8&>(*null_map).get_data(), target_null_map);

                    auto& target_str_column = assert_cast<const ColumnString&>(
                            target_nullable_column->get_nested_column());
                    res->get_chars().assign(target_str_column.get_chars().begin(),
                                            target_str_column.get_chars().end());
                    res->get_offsets().assign(target_str_column.get_offsets().begin(),
                                              target_str_column.get_offsets().end());
                } else {
                    auto& target_str_column = assert_cast<const ColumnString&>(*target_column);
                    res->get_chars().assign(target_str_column.get_chars().begin(),
                                            target_str_column.get_chars().end());
                    res->get_offsets().assign(target_str_column.get_offsets().begin(),
                                              target_str_column.get_offsets().end());
                }
            }
            block.get_by_position(result).column =
                    ColumnNullable::create(std::move(res), std::move(null_map));
        } else if (auto pos_null_column = check_and_get_column<ColumnNullable>(
                           *block.get_by_position(arguments[0]).column)) {
            auto& pos_column =
                    assert_cast<const ColumnInt32&>(pos_null_column->get_nested_column());
            auto& pos_null_map = pos_null_column->get_null_map_data();
            auto null_map = ColumnUInt8::create(input_rows_count, false);
            auto& res_null_map = assert_cast<ColumnUInt8&>(*null_map).get_data();

            for (size_t i = 0; i < input_rows_count; ++i) {
                auto pos = pos_column.get_element(i);
                res_null_map[i] =
                        pos_null_map[i] || pos <= 0 || pos > num_children ||
                        block.get_by_position(arguments[pos]).column->get_data_at(i).data ==
                                nullptr;
                if (res_null_map[i]) {
                    res->insert_default();
                } else {
                    auto insert_data = block.get_by_position(arguments[pos]).column->get_data_at(i);
                    res->insert_data(insert_data.data, insert_data.size);
                }
            }
            block.get_by_position(result).column =
                    ColumnNullable::create(std::move(res), std::move(null_map));
        } else {
            auto& pos_column =
                    assert_cast<const ColumnInt32&>(*block.get_by_position(arguments[0]).column);
            auto null_map = ColumnUInt8::create(input_rows_count, false);
            auto& res_null_map = assert_cast<ColumnUInt8&>(*null_map).get_data();

            for (size_t i = 0; i < input_rows_count; ++i) {
                auto pos = pos_column.get_element(i);
                res_null_map[i] =
                        pos <= 0 || pos > num_children ||
                        block.get_by_position(arguments[pos]).column->get_data_at(i).data ==
                                nullptr;
                if (res_null_map[i]) {
                    res->insert_default();
                } else {
                    auto insert_data = block.get_by_position(arguments[pos]).column->get_data_at(i);
                    res->insert_data(insert_data.data, insert_data.size);
                }
            }
            block.get_by_position(result).column =
                    ColumnNullable::create(std::move(res), std::move(null_map));
        }
        return Status::OK();
    }
};

// concat_ws (string,string....) or (string, Array)
// TODO: avoid use fmtlib
class FunctionStringConcatWs : public IFunction {
public:
    using Chars = ColumnString::Chars;
    using Offsets = ColumnString::Offsets;

    static constexpr auto name = "concat_ws";
    static FunctionPtr create() { return std::make_shared<FunctionStringConcatWs>(); }
    String get_name() const override { return name; }
    size_t get_number_of_arguments() const override { return 0; }
    bool is_variadic() const override { return true; }

    DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {
        const IDataType* first_type = arguments[0].get();
        if (first_type->is_nullable()) {
            return make_nullable(std::make_shared<DataTypeString>());
        } else {
            return std::make_shared<DataTypeString>();
        }
    }
    bool use_default_implementation_for_nulls() const override { return false; }

    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,
                        uint32_t result, size_t input_rows_count) const override {
        DCHECK_GE(arguments.size(), 2);
        auto null_map = ColumnUInt8::create(input_rows_count, 0);
        // we create a zero column to simply implement
        auto const_null_map = ColumnUInt8::create(input_rows_count, 0);
        auto res = ColumnString::create();
        bool is_null_type = block.get_by_position(arguments[0]).type.get()->is_nullable();
        size_t argument_size = arguments.size();
        std::vector<const Offsets*> offsets_list(argument_size);
        std::vector<const Chars*> chars_list(argument_size);
        std::vector<const ColumnUInt8::Container*> null_list(argument_size);

        std::vector<ColumnPtr> argument_columns(argument_size);
        std::vector<ColumnPtr> argument_null_columns(argument_size);

        for (size_t i = 0; i < argument_size; ++i) {
            argument_columns[i] =
                    block.get_by_position(arguments[i]).column->convert_to_full_column_if_const();
            if (const auto* nullable =
                        check_and_get_column<const ColumnNullable>(*argument_columns[i])) {
                // Danger: Here must dispose the null map data first! Because
                // argument_columns[i]=nullable->get_nested_column_ptr(); will release the mem
                // of column nullable mem of null map
                null_list[i] = &nullable->get_null_map_data();
                argument_null_columns[i] = nullable->get_null_map_column_ptr();
                argument_columns[i] = nullable->get_nested_column_ptr();
            } else {
                null_list[i] = &const_null_map->get_data();
            }

            if (is_column<ColumnArray>(argument_columns[i].get())) {
                continue;
            }

            const auto* col_str = assert_cast<const ColumnString*>(argument_columns[i].get());
            offsets_list[i] = &col_str->get_offsets();
            chars_list[i] = &col_str->get_chars();
        }

        auto& res_data = res->get_chars();
        auto& res_offset = res->get_offsets();
        res_offset.resize(input_rows_count);

        VectorizedUtils::update_null_map(null_map->get_data(), *null_list[0]);
        fmt::memory_buffer buffer;
        std::vector<std::string_view> views;

        if (is_column<ColumnArray>(argument_columns[1].get())) {
            // Determine if the nested type of the array is String
            const auto& array_column = reinterpret_cast<const ColumnArray&>(*argument_columns[1]);
            if (!array_column.get_data().is_column_string()) {
                return Status::NotSupported(
                        fmt::format("unsupported nested array of type {} for function {}",
                                    is_column_nullable(array_column.get_data())
                                            ? array_column.get_data().get_name()
                                            : array_column.get_data().get_name(),
                                    get_name()));
            }
            // Concat string in array
            _execute_array(input_rows_count, array_column, buffer, views, offsets_list, chars_list,
                           null_list, res_data, res_offset);

        } else {
            // Concat string
            _execute_string(input_rows_count, argument_size, buffer, views, offsets_list,
                            chars_list, null_list, res_data, res_offset);
        }
        if (is_null_type) {
            block.get_by_position(result).column =
                    ColumnNullable::create(std::move(res), std::move(null_map));
        } else {
            block.get_by_position(result).column = std::move(res);
        }
        return Status::OK();
    }

private:
    void _execute_array(const size_t& input_rows_count, const ColumnArray& array_column,
                        fmt::memory_buffer& buffer, std::vector<std::string_view>& views,
                        const std::vector<const Offsets*>& offsets_list,
                        const std::vector<const Chars*>& chars_list,
                        const std::vector<const ColumnUInt8::Container*>& null_list,
                        Chars& res_data, Offsets& res_offset) const {
        // Get array nested column
        const UInt8* array_nested_null_map = nullptr;
        ColumnPtr array_nested_column = nullptr;

        if (is_column_nullable(array_column.get_data())) {
            const auto& array_nested_null_column =
                    reinterpret_cast<const ColumnNullable&>(array_column.get_data());
            // String's null map in array
            array_nested_null_map =
                    array_nested_null_column.get_null_map_column().get_data().data();
            array_nested_column = array_nested_null_column.get_nested_column_ptr();
        } else {
            array_nested_column = array_column.get_data_ptr();
        }

        const auto& string_column = reinterpret_cast<const ColumnString&>(*array_nested_column);
        const Chars& string_src_chars = string_column.get_chars();
        const auto& src_string_offsets = string_column.get_offsets();
        const auto& src_array_offsets = array_column.get_offsets();
        size_t current_src_array_offset = 0;

        // Concat string in array
        for (size_t i = 0; i < input_rows_count; ++i) {
            auto& sep_offsets = *offsets_list[0];
            auto& sep_chars = *chars_list[0];
            auto& sep_nullmap = *null_list[0];

            if (sep_nullmap[i]) {
                res_offset[i] = res_data.size();
                current_src_array_offset += src_array_offsets[i] - src_array_offsets[i - 1];
                continue;
            }

            int sep_size = sep_offsets[i] - sep_offsets[i - 1];
            const char* sep_data = reinterpret_cast<const char*>(&sep_chars[sep_offsets[i - 1]]);

            std::string_view sep(sep_data, sep_size);
            buffer.clear();
            views.clear();

            for (auto next_src_array_offset = src_array_offsets[i];
                 current_src_array_offset < next_src_array_offset; ++current_src_array_offset) {
                const auto current_src_string_offset =
                        current_src_array_offset ? src_string_offsets[current_src_array_offset - 1]
                                                 : 0;
                size_t bytes_to_copy =
                        src_string_offsets[current_src_array_offset] - current_src_string_offset;
                const char* ptr =
                        reinterpret_cast<const char*>(&string_src_chars[current_src_string_offset]);

                if (array_nested_null_map == nullptr ||
                    !array_nested_null_map[current_src_array_offset]) {
                    views.emplace_back(ptr, bytes_to_copy);
                }
            }

            fmt::format_to(buffer, "{}", fmt::join(views, sep));

            StringOP::push_value_string(std::string_view(buffer.data(), buffer.size()), i, res_data,
                                        res_offset);
        }
    }

    void _execute_string(const size_t& input_rows_count, const size_t& argument_size,
                         fmt::memory_buffer& buffer, std::vector<std::string_view>& views,
                         const std::vector<const Offsets*>& offsets_list,
                         const std::vector<const Chars*>& chars_list,
                         const std::vector<const ColumnUInt8::Container*>& null_list,
                         Chars& res_data, Offsets& res_offset) const {
        // Concat string
        for (size_t i = 0; i < input_rows_count; ++i) {
            auto& sep_offsets = *offsets_list[0];
            auto& sep_chars = *chars_list[0];
            auto& sep_nullmap = *null_list[0];
            if (sep_nullmap[i]) {
                res_offset[i] = res_data.size();
                continue;
            }

            int sep_size = sep_offsets[i] - sep_offsets[i - 1];
            const char* sep_data = reinterpret_cast<const char*>(&sep_chars[sep_offsets[i - 1]]);

            std::string_view sep(sep_data, sep_size);
            buffer.clear();
            views.clear();
            for (size_t j = 1; j < argument_size; ++j) {
                auto& current_offsets = *offsets_list[j];
                auto& current_chars = *chars_list[j];
                auto& current_nullmap = *null_list[j];
                int size = current_offsets[i] - current_offsets[i - 1];
                const char* ptr =
                        reinterpret_cast<const char*>(&current_chars[current_offsets[i - 1]]);
                if (!current_nullmap[i]) {
                    views.emplace_back(ptr, size);
                }
            }
            fmt::format_to(buffer, "{}", fmt::join(views, sep));
            StringOP::push_value_string(std::string_view(buffer.data(), buffer.size()), i, res_data,
                                        res_offset);
        }
    }
};

class FunctionStringRepeat : public IFunction {
public:
    static constexpr auto name = "repeat";
    static FunctionPtr create() { return std::make_shared<FunctionStringRepeat>(); }
    String get_name() const override { return name; }
    size_t get_number_of_arguments() const override { return 2; }
    // should set NULL value of nested data to default,
    // as iff it's not inited and invalid, the repeat result of length is so large cause overflow
    bool need_replace_null_data_to_default() const override { return true; }

    DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {
        return make_nullable(std::make_shared<DataTypeString>());
    }
    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,
                        uint32_t result, size_t input_rows_count) const override {
        DCHECK_EQ(arguments.size(), 2);
        auto res = ColumnString::create();
        auto null_map = ColumnUInt8::create();

        ColumnPtr argument_ptr[2];
        argument_ptr[0] =
                block.get_by_position(arguments[0]).column->convert_to_full_column_if_const();
        argument_ptr[1] = block.get_by_position(arguments[1]).column;

        if (const auto* col1 = check_and_get_column<ColumnString>(*argument_ptr[0])) {
            if (const auto* col2 = check_and_get_column<ColumnInt32>(*argument_ptr[1])) {
                RETURN_IF_ERROR(vector_vector(col1->get_chars(), col1->get_offsets(),
                                              col2->get_data(), res->get_chars(),
                                              res->get_offsets(), null_map->get_data()));
                block.replace_by_position(
                        result, ColumnNullable::create(std::move(res), std::move(null_map)));
                return Status::OK();
            } else if (const auto* col2_const =
                               check_and_get_column<ColumnConst>(*argument_ptr[1])) {
                DCHECK(check_and_get_column<ColumnInt32>(col2_const->get_data_column()));
                int repeat = col2_const->get_int(0);
                if (repeat <= 0) {
                    null_map->get_data().resize_fill(input_rows_count, 0);
                    res->insert_many_defaults(input_rows_count);
                } else {
                    vector_const(col1->get_chars(), col1->get_offsets(), repeat, res->get_chars(),
                                 res->get_offsets(), null_map->get_data());
                }
                block.replace_by_position(
                        result, ColumnNullable::create(std::move(res), std::move(null_map)));
                return Status::OK();
            }
        }

        return Status::RuntimeError("repeat function get error param: {}, {}",
                                    argument_ptr[0]->get_name(), argument_ptr[1]->get_name());
    }

    Status vector_vector(const ColumnString::Chars& data, const ColumnString::Offsets& offsets,
                         const ColumnInt32::Container& repeats, ColumnString::Chars& res_data,
                         ColumnString::Offsets& res_offsets,
                         ColumnUInt8::Container& null_map) const {
        size_t input_row_size = offsets.size();

        fmt::memory_buffer buffer;
        res_offsets.resize(input_row_size);
        null_map.resize_fill(input_row_size, 0);
        for (ssize_t i = 0; i < input_row_size; ++i) {
            buffer.clear();
            const char* raw_str = reinterpret_cast<const char*>(&data[offsets[i - 1]]);
            size_t size = offsets[i] - offsets[i - 1];
            int repeat = repeats[i];
            if (repeat <= 0) {
                StringOP::push_empty_string(i, res_data, res_offsets);
            } else {
                ColumnString::check_chars_length(repeat * size + res_data.size(), 0);
                for (int j = 0; j < repeat; ++j) {
                    buffer.append(raw_str, raw_str + size);
                }
                StringOP::push_value_string(std::string_view(buffer.data(), buffer.size()), i,
                                            res_data, res_offsets);
            }
        }
        return Status::OK();
    }

    // TODO: 1. use pmr::vector<char> replace fmt_buffer may speed up the code
    //       2. abstract the `vector_vector` and `vector_const`
    //       3. rethink we should use `DEFAULT_MAX_STRING_SIZE` to bigger here
    void vector_const(const ColumnString::Chars& data, const ColumnString::Offsets& offsets,
                      int repeat, ColumnString::Chars& res_data, ColumnString::Offsets& res_offsets,
                      ColumnUInt8::Container& null_map) const {
        size_t input_row_size = offsets.size();

        fmt::memory_buffer buffer;
        res_offsets.resize(input_row_size);
        null_map.resize_fill(input_row_size, 0);
        for (ssize_t i = 0; i < input_row_size; ++i) {
            buffer.clear();
            const char* raw_str = reinterpret_cast<const char*>(&data[offsets[i - 1]]);
            size_t size = offsets[i] - offsets[i - 1];
            ColumnString::check_chars_length(repeat * size + res_data.size(), 0);

            for (int j = 0; j < repeat; ++j) {
                buffer.append(raw_str, raw_str + size);
            }
            StringOP::push_value_string(std::string_view(buffer.data(), buffer.size()), i, res_data,
                                        res_offsets);
        }
    }
};

template <typename Impl>
class FunctionStringPad : public IFunction {
public:
    static constexpr auto name = Impl::name;
    static FunctionPtr create() { return std::make_shared<FunctionStringPad>(); }
    String get_name() const override { return name; }
    size_t get_number_of_arguments() const override { return 3; }

    DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {
        return make_nullable(std::make_shared<DataTypeString>());
    }

    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,
                        uint32_t result, size_t input_rows_count) const override {
        DCHECK_GE(arguments.size(), 3);
        auto null_map = ColumnUInt8::create(input_rows_count, 0);
        // we create a zero column to simply implement
        auto const_null_map = ColumnUInt8::create(input_rows_count, 0);
        auto res = ColumnString::create();

        ColumnPtr col[3];
        bool col_const[3];
        for (size_t i = 0; i < 3; ++i) {
            std::tie(col[i], col_const[i]) =
                    unpack_if_const(block.get_by_position(arguments[i]).column);
        }
        auto& null_map_data = null_map->get_data();
        auto& res_offsets = res->get_offsets();
        auto& res_chars = res->get_chars();
        res_offsets.resize(input_rows_count);

        const auto* strcol = assert_cast<const ColumnString*>(col[0].get());
        const auto& strcol_offsets = strcol->get_offsets();
        const auto& strcol_chars = strcol->get_chars();

        const auto* col_len = assert_cast<const ColumnInt32*>(col[1].get());
        const auto& col_len_data = col_len->get_data();

        const auto* padcol = assert_cast<const ColumnString*>(col[2].get());
        const auto& padcol_offsets = padcol->get_offsets();
        const auto& padcol_chars = padcol->get_chars();
        std::visit(
                [&](auto str_const, auto len_const, auto pad_const) {
                    execute_utf8<str_const, len_const, pad_const>(
                            strcol_offsets, strcol_chars, col_len_data, padcol_offsets,
                            padcol_chars, res_offsets, res_chars, null_map_data, input_rows_count);
                },
                make_bool_variant(col_const[0]), make_bool_variant(col_const[1]),
                make_bool_variant(col_const[2]));

        block.get_by_position(result).column =
                ColumnNullable::create(std::move(res), std::move(null_map));
        return Status::OK();
    }

    template <bool str_const, bool len_const, bool pad_const>
    void execute_utf8(const ColumnString::Offsets& strcol_offsets,
                      const ColumnString::Chars& strcol_chars,
                      const ColumnInt32::Container& col_len_data,
                      const ColumnString::Offsets& padcol_offsets,
                      const ColumnString::Chars& padcol_chars, ColumnString::Offsets& res_offsets,
                      ColumnString::Chars& res_chars, ColumnUInt8::Container& null_map_data,
                      size_t input_rows_count) const {
        std::vector<size_t> pad_index;
        size_t const_pad_char_size = 0;
        // If pad_const = true, initialize pad_index only once.
        // The same logic applies to the if constexpr (!pad_const) condition below.
        if constexpr (pad_const) {
            const_pad_char_size = simd::VStringFunctions::get_char_len(
                    (const char*)padcol_chars.data(), padcol_offsets[0], pad_index);
        }

        fmt::memory_buffer buffer;
        buffer.resize(strcol_chars.size());
        size_t buffer_len = 0;

        for (size_t i = 0; i < input_rows_count; ++i) {
            if constexpr (!pad_const) {
                pad_index.clear();
            }
            const auto len = col_len_data[index_check_const<len_const>(i)];
            if (len < 0) {
                // return NULL when input length is invalid number
                null_map_data[i] = true;
                res_offsets[i] = buffer_len;
            } else {
                const auto str_idx = index_check_const<str_const>(i);
                const int str_len = strcol_offsets[str_idx] - strcol_offsets[str_idx - 1];
                const auto* str_data = &strcol_chars[strcol_offsets[str_idx - 1]];
                const auto pad_idx = index_check_const<pad_const>(i);
                const int pad_len = padcol_offsets[pad_idx] - padcol_offsets[pad_idx - 1];
                const auto* pad_data = &padcol_chars[padcol_offsets[pad_idx - 1]];

                auto [iterate_byte_len, iterate_char_len] =
                        simd::VStringFunctions::iterate_utf8_with_limit_length(
                                (const char*)str_data, (const char*)str_data + str_len, len);
                // If iterate_char_len equals len, it indicates that the str length is greater than or equal to len
                if (iterate_char_len == len) {
                    buffer.resize(buffer_len + iterate_byte_len);
                    memcpy(buffer.data() + buffer_len, str_data, iterate_byte_len);
                    buffer_len += iterate_byte_len;
                    res_offsets[i] = buffer_len;
                    continue;
                }
                size_t pad_char_size;
                if constexpr (!pad_const) {
                    pad_char_size = simd::VStringFunctions::get_char_len((const char*)pad_data,
                                                                         pad_len, pad_index);
                } else {
                    pad_char_size = const_pad_char_size;
                }

                // make compatible with mysql. return empty string if pad is empty
                if (pad_char_size == 0) {
                    res_offsets[i] = buffer_len;
                    continue;
                }
                const size_t str_char_size = iterate_char_len;
                const size_t pad_times = (len - str_char_size) / pad_char_size;
                const size_t pad_remainder_len = pad_index[(len - str_char_size) % pad_char_size];
                const size_t new_capacity = str_len + size_t(pad_times + 1) * pad_len;
                ColumnString::check_chars_length(buffer_len + new_capacity, i);
                buffer.resize(buffer_len + new_capacity);
                if constexpr (!Impl::is_lpad) {
                    memcpy(buffer.data() + buffer_len, str_data, str_len);
                    buffer_len += str_len;
                }
                // Prepend chars of pad.
                StringOP::fast_repeat((uint8_t*)buffer.data() + buffer_len, pad_data, pad_len,
                                      pad_times);
                buffer_len += pad_times * pad_len;

                memcpy(buffer.data() + buffer_len, pad_data, pad_remainder_len);
                buffer_len += pad_remainder_len;

                if constexpr (Impl::is_lpad) {
                    memcpy(buffer.data() + buffer_len, str_data, str_len);
                    buffer_len += str_len;
                }
                res_offsets[i] = buffer_len;
            }
        }
        res_chars.insert(buffer.data(), buffer.data() + buffer_len);
    }
};

#include "common/compile_check_avoid_end.h"
} // namespace doris

Coverage Report

Created: 2026-04-14 20:14