beedb/include/plan/logical/node/limit_node.h

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2022-04-04 20:25:01 +02:00
/*------------------------------------------------------------------------------*
* Architecture & Implementation of DBMS *
*------------------------------------------------------------------------------*
* Copyright 2022 Databases and Information Systems Group TU Dortmund *
* Visit us at *
* http://dbis.cs.tu-dortmund.de/cms/en/home/ *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL *
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR *
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, *
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR *
* OTHER DEALINGS IN THE SOFTWARE. *
* *
* Authors: *
* Maximilian Berens <maximilian.berens@tu-dortmund.de> *
* Roland Kühn <roland.kuehn@cs.tu-dortmund.de> *
* Jan Mühlig <jan.muehlig@tu-dortmund.de> *
*------------------------------------------------------------------------------*
*/
#pragma once
#include "node_interface.h"
namespace beedb::plan::logical
{
class LimitNode final : public UnaryNode
{
public:
LimitNode(std::uint64_t limit, std::uint64_t offset) : UnaryNode("Limit"), _limit(limit), _offset(offset)
{
}
~LimitNode() override = default;
[[nodiscard]] std::uint64_t limit() const
{
return _limit;
}
[[nodiscard]] std::uint64_t offset() const
{
return _offset;
}
const Schema &check_and_emit_schema(TableMap &tables) override
{
_schema.clear();
const auto &child_schema = child()->check_and_emit_schema(tables);
std::copy(child_schema.begin(), child_schema.end(), std::back_inserter(_schema));
return _schema;
}
[[nodiscard]] const Schema &schema() const override
{
return _schema;
}
[[nodiscard]] nlohmann::json to_json() const override
{
auto json = UnaryNode::to_json();
json["data"] = std::to_string(_offset) + "," + std::to_string(_limit);
return json;
}
private:
std::uint64_t _limit;
std::uint64_t _offset;
Schema _schema;
};
} // namespace beedb::plan::logical