nooneuse commented on code in PR #63143: URL: https://github.com/apache/doris/pull/63143#discussion_r3257130887
########## be/src/exprs/aggregate/aggregate_function_datasketches_hll_union_agg.h: ########## @@ -0,0 +1,177 @@ +// 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 <stddef.h> + +#include <DataSketches/hll.hpp> +#include <boost/iterator/iterator_facade.hpp> +#include <memory> +#include <type_traits> +#include <vector> + +#include "common/compiler_util.h" // IWYU pragma: keep +#include "core/assert_cast.h" +#include "core/column/column.h" +#include "core/column/column_vector.h" +#include "core/data_type/data_type_number.h" +#include "core/data_type/define_primitive_type.h" +#include "core/field.h" +#include "core/string_ref.h" +#include "core/types.h" +#include "core/uint128.h" +#include "exec/common/hash_table/hash.h" +#include "exec/common/hash_table/phmap_fwd_decl.h" +#include "exprs/aggregate/aggregate_function.h" +#include "util/var_int.h" +template <typename T> +struct HashCRC32; +namespace doris { +class Arena; +class BufferReadable; +class BufferWritable; +template <PrimitiveType T> +class ColumnDecimal; +/// datasketches_hll_union_agg +template <PrimitiveType T> +struct AggregateFunctionHllSketchData { + /** We set the default LgK to 12, + * as this value is used as a performance baseline in the relevant documentation. + * (https://datasketches.apache.org/docs/HLL/HllPerformance.html) + */ + static const uint8_t DEFAULT_LOG_K = 12; + std::unique_ptr<datasketches::hll_union> hll_union_data; + static String get_name() { return "datasketches_hll_union_agg"; } + void merge(const datasketches::hll_sketch& sketch_data) { + if (hll_union_data == nullptr) { + hll_union_data = + std::make_unique<datasketches::hll_union>(sketch_data.get_lg_config_k()); + } + try { + hll_union_data->update(sketch_data); + } catch (...) { + throw Exception(ErrorCode::INTERNAL_ERROR, + "Internal error happened when update HLL sketch."); + } + } + void reset() { + if (hll_union_data != nullptr) { + hll_union_data->reset(); + } + hll_union_data = nullptr; + } + void write_sketch(BufferWritable& buf, const datasketches::hll_sketch& sk) const { + auto serialized_bytes = sk.serialize_compact(); + StringRef d(serialized_bytes.data(), serialized_bytes.size()); + buf.write_binary(d); + } + void write(BufferWritable& buf) const { + if (hll_union_data == nullptr) { + /** Using DEFAULT_LOG_K(12) here is surely sufficient, + * because in this case the union that actually needs to be serialized should contain no data. + */ + datasketches::hll_union u(DEFAULT_LOG_K); + write_sketch(buf, u.get_result()); + return; + } + try { + auto cache = hll_union_data->get_result(); + write_sketch(buf, cache); + } catch (...) { + throw Exception(ErrorCode::INTERNAL_ERROR, + "Internal error happened when serialize HLL sketch."); + } + } + void read(BufferReadable& buf) { + StringRef d; + buf.read_binary(d); + try { + auto cache = datasketches::hll_sketch::deserialize(d.data, d.size); + merge(cache); + } catch (...) { + throw Exception(ErrorCode::CORRUPTION, "HLL sketch data corrupted when read."); + } + } + int64_t get_result() const { + if (hll_union_data != nullptr) { + try { + return static_cast<int64_t>(hll_union_data->get_estimate()); + } catch (...) { + throw Exception(ErrorCode::INTERNAL_ERROR, + "Internal error happened when get HLL sketch estimate."); + } + } + return 0; + } +}; +namespace detail { +/** The structure for the delegation work to add one element to the `datasketches_hll_union_agg` aggregate functions. + * Used for partial specialization to add strings. + */ +template <PrimitiveType T, typename Data> +struct OneAdder { + static void ALWAYS_INLINE add(Data& data, const IColumn& column, size_t row_num) { + if constexpr (is_string_type(T) || is_varbinary(T)) { + StringRef value = column.get_data_at(row_num); + if (value.empty()) { + return; + } + try { + datasketches::hll_sketch sketch_data = + datasketches::hll_sketch::deserialize(value.begin(), value.size); + data.merge(sketch_data); + } catch (...) { + throw Exception(ErrorCode::CORRUPTION, "HLL sketch data corrupted when add."); + } + } + } +}; +} // namespace detail +/// Calculates the number of different values approximately using hll sketch. +template <PrimitiveType T, typename Data> +class AggregateFunctionDataSketchesHllUnionAgg final + : public IAggregateFunctionDataHelper<Data, + AggregateFunctionDataSketchesHllUnionAgg<T, Data>>, + VarargsExpression, + NotNullableAggregateFunction { +public: + AggregateFunctionDataSketchesHllUnionAgg(const DataTypes& argument_types_) + : IAggregateFunctionDataHelper<Data, AggregateFunctionDataSketchesHllUnionAgg<T, Data>>( + argument_types_) {} + String get_name() const override { return Data::get_name(); } + DataTypePtr get_return_type() const override { return std::make_shared<DataTypeInt64>(); } + void reset(AggregateDataPtr __restrict place) const override { this->data(place).reset(); } + void add(AggregateDataPtr __restrict place, const IColumn** columns, ssize_t row_num, + Arena&) const override { + detail::OneAdder<T, Data>::add(this->data(place), *columns[0], row_num); + } + void merge(AggregateDataPtr __restrict place, ConstAggregateDataPtr rhs, + Arena&) const override { + this->data(place).merge(this->data(rhs).hll_union_data->get_result(datasketches::HLL_8)); Review Comment: I added a null pointer check here. -- This is an automated message from the Apache Git Service. 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