112 lines
3.7 KiB
C++
112 lines
3.7 KiB
C++
/*------------------------------------------------------------------------------*
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* Architecture & Implementation of DBMS *
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*------------------------------------------------------------------------------*
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* Copyright 2022 Databases and Information Systems Group TU Dortmund *
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* Visit us at *
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* http://dbis.cs.tu-dortmund.de/cms/en/home/ *
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* *
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR *
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* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, *
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR *
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* OTHER DEALINGS IN THE SOFTWARE. *
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* *
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* Authors: *
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* Maximilian Berens <maximilian.berens@tu-dortmund.de> *
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* Roland Kühn <roland.kuehn@cs.tu-dortmund.de> *
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* Jan Mühlig <jan.muehlig@tu-dortmund.de> *
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*------------------------------------------------------------------------------*
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*/
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#pragma once
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#include "unary_operator.h"
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#include <cstdint>
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#include <memory>
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#include <table/memory_table.h>
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#include <table/schema.h>
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#include <utility>
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#include <vector>
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namespace beedb::execution
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{
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/**
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* Comparator for comparing two tuples during
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* sort.
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*/
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class TupleComparator
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{
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public:
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explicit TupleComparator(const std::vector<std::pair<std::uint32_t, bool>> &indices) : _indices(indices)
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{
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}
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~TupleComparator() = default;
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bool operator()(const table::Tuple &left, const table::Tuple &right) const
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{
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for (auto &[index, is_ascending] : _indices)
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{
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const auto value_left = left.get(index);
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const auto value_right = right.get(index);
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if (is_ascending)
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{
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if (value_left < value_right)
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{
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return true;
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}
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else if (value_left > value_right)
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{
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return false;
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}
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}
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else
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{
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if (value_right < value_left)
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{
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return true;
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}
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else if (value_right > value_left)
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{
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return false;
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}
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}
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}
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return false;
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}
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private:
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const std::vector<std::pair<std::uint32_t, bool>> &_indices;
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};
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/**
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* Sorts the result provided by a child using quicksort.
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*/
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class OrderOperator final : public UnaryOperator
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{
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public:
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OrderOperator(concurrency::Transaction *transaction, const table::Schema &schema,
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std::vector<std::pair<std::uint32_t, bool>> &&order_columns);
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~OrderOperator() override = default;
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void open() override;
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util::optional<table::Tuple> next() override;
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void close() override;
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[[nodiscard]] const table::Schema &schema() const override
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{
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return _schema;
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}
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private:
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const table::Schema &_schema;
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const std::vector<std::pair<std::uint32_t, bool>> _order_columns;
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std::unique_ptr<table::MemoryTable> _result_table;
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std::size_t _stack_index = 0u;
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};
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} // namespace beedb::execution
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