cambyzju commented on a change in pull request #8597: URL: https://github.com/apache/incubator-doris/pull/8597#discussion_r834881751
########## File path: be/src/vec/functions/array/function_array_element.h ########## @@ -0,0 +1,247 @@ +// 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. +// This file is copied from +// https://github.com/ClickHouse/ClickHouse/blob/master/src/Functions/array/arrayElement.cpp +// and modified by Doris +#pragma once + +#include <string_view> + +#include "vec/columns/column_array.h" +#include "vec/columns/column_const.h" +#include "vec/columns/column_string.h" +#include "vec/data_types/data_type_array.h" +#include "vec/data_types/data_type_number.h" +#include "vec/functions/function.h" +#include "vec/functions/function_helpers.h" + +namespace doris::vectorized { + +class FunctionArrayElement : public IFunction { +public: + static constexpr auto name = "element_at"; + static FunctionPtr create() { return std::make_shared<FunctionArrayElement>(); } + + /// Get function name. + String get_name() const override { return name; } + + bool is_variadic() const override { return false; } + + size_t get_number_of_arguments() const override { return 2; } + + DataTypePtr get_return_type_impl(const DataTypes& arguments) const override { + DCHECK(is_array(arguments[0])) + << "first argument for function: " << name << " should be DataTypeArray"; + DCHECK(is_integer(arguments[1])) + << "second argument for function: " << name << " should be Integer"; + return make_nullable( + check_and_get_data_type<DataTypeArray>(arguments[0].get())->get_nested_type()); + } + + Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments, + size_t result, size_t input_rows_count) override { + auto dst_null_column = ColumnUInt8::create(input_rows_count); + UInt8* dst_null_map = dst_null_column->get_data().data(); + const UInt8* src_null_map = nullptr; + ColumnsWithTypeAndName args; + auto col_left = block.get_by_position(arguments[0]); + if (col_left.column->is_nullable()) { + auto null_col = check_and_get_column<ColumnNullable>(*col_left.column); + src_null_map = null_col->get_null_map_column().get_data().data(); + args = {{null_col->get_nested_column_ptr(), remove_nullable(col_left.type), + col_left.name}, + block.get_by_position(arguments[1])}; + } else { + args = {col_left, block.get_by_position(arguments[1])}; + } + + auto result_type = remove_nullable( + check_and_get_data_type<DataTypeArray>(args[0].type.get())->get_nested_type()); + + auto res_column = _perform(args, result_type, input_rows_count, src_null_map, dst_null_map); + if (!res_column) { + return Status::RuntimeError( + fmt::format("unsupported types for function {}({}, {})", get_name(), + block.get_by_position(arguments[0]).type->get_name(), + block.get_by_position(arguments[1]).type->get_name())); + } + block.replace_by_position( + result, ColumnNullable::create(std::move(res_column), std::move(dst_null_column))); + return Status::OK(); + } + +private: + ColumnPtr _perform(const ColumnsWithTypeAndName& arguments, const DataTypePtr& result_type, + size_t input_rows_count, const UInt8* src_null_map, UInt8* dst_null_map) { + ColumnPtr res; + if (!((res = _execute_number<Int8>(arguments, result_type, input_rows_count, src_null_map, + dst_null_map)) || + (res = _execute_number<Int16>(arguments, result_type, input_rows_count, src_null_map, + dst_null_map)) || + (res = _execute_number<Int32>(arguments, result_type, input_rows_count, src_null_map, + dst_null_map)) || + (res = _execute_number<Int64>(arguments, result_type, input_rows_count, src_null_map, + dst_null_map)) || + (res = _execute_number<Float32>(arguments, result_type, input_rows_count, + src_null_map, dst_null_map)) || + (res = _execute_number<Float64>(arguments, result_type, input_rows_count, + src_null_map, dst_null_map)) || + (res = _execute_string(arguments, result_type, input_rows_count, src_null_map, + dst_null_map)))) { + return nullptr; + } + return res; + } + + ColumnPtr _execute_string(const ColumnsWithTypeAndName& arguments, + const DataTypePtr& result_type, size_t input_rows_count, + const UInt8* src_null_map, UInt8* dst_null_map) { + // check array nested column type and get data + auto array_column = check_and_get_column<ColumnArray>(*arguments[0].column); + DCHECK(array_column != nullptr); + const ColumnString* nested_column = nullptr; + const UInt8* nested_null_map = nullptr; + auto nested_null_column = check_and_get_column<ColumnNullable>(array_column->get_data()); + if (nested_null_column) { + nested_null_map = nested_null_column->get_null_map_column().get_data().data(); + nested_column = + check_and_get_column<ColumnString>(nested_null_column->get_nested_column()); + } else { + nested_column = check_and_get_column<ColumnString>(array_column->get_data()); + } + if (!nested_column) { + return nullptr; + } + const auto& offsets = array_column->get_offsets(); + const auto& src_str_offs = nested_column->get_offsets(); + const auto& src_str_chars = nested_column->get_chars(); + + // prepare return data + auto dst = ColumnString::create(); + auto& dst_str_offs = dst->get_offsets(); + dst_str_offs.resize(input_rows_count); + auto& dst_str_chars = dst->get_chars(); + dst_str_chars.reserve(src_str_chars.size()); + + // process + for (size_t row = 0; row < input_rows_count; ++row) { + size_t off = offsets[row - 1]; + size_t len = offsets[row] - off; + auto index = arguments[1].column->get_int(row); + // array is nullable + bool null_flag = bool(src_null_map && src_null_map[row]); + // calc index in nested column + if (!null_flag && index > 0 && index <= len) { + index += off - 1; + } else if (!null_flag && index < 0 && -index <= len) { + index += off + len; + } else { + null_flag = true; + } + // nested column nullable check + if (!null_flag && nested_null_map && nested_null_map[index]) { + null_flag = true; + } + // actual string copy + if (!null_flag) { + DCHECK(index >= 0 && index < src_str_offs.size()); + dst_null_map[row] = false; + auto element_size = src_str_offs[index] - src_str_offs[index - 1]; + dst_str_offs[row] = dst_str_offs[row - 1] + element_size; + auto src_string_pos = src_str_offs[index - 1]; + auto dst_string_pos = dst_str_offs[row - 1]; + dst_str_chars.resize(dst_string_pos + element_size); + memcpy(&dst_str_chars[dst_string_pos], &src_str_chars[src_string_pos], + element_size); + } else { + dst_null_map[row] = true; + dst_str_offs[row] = dst_str_offs[row - 1]; + } + } + + VLOG_DEBUG << "function:" << get_name() << ", array type:" << arguments[0].type->get_name() + << ", index type:" << arguments[1].type->get_name() + << ", result type:" << result_type->get_name(); + return dst; + } + + template <typename ElementDataType> + ColumnPtr _execute_number(const ColumnsWithTypeAndName& arguments, + const DataTypePtr& result_type, size_t input_rows_count, + const UInt8* src_null_map, UInt8* dst_null_map) { + // check array nested column type and get data + auto array_column = check_and_get_column<ColumnArray>(*arguments[0].column); + DCHECK(array_column != nullptr); + const ColumnVector<ElementDataType>* nested_column = nullptr; + const UInt8* nested_null_map = nullptr; + auto nested_null_column = check_and_get_column<ColumnNullable>(array_column->get_data()); Review comment: ColumnNullable( // the array may be null or not ColumnArray( ColumnNullable( // nested element may be null or not ColumnInt8))) for example: ``` > select * from array_test; +------+------+--------+ | k1 | k2 | k3 | +------+------+--------+ | 3 | NULL | NULL | | 1 | 2 | [1, 2, NULL] | | 4 | NULL | [] | +------+------+--------+ ``` row 1 : array is null (outer ColumnNullable) row 2: one element of the array is null (inner ColumnNullable) -- This is an automated message from the Apache Git Service. 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