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/**
* Copyright (C) 2019-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include "mongo/db/exec/sbe/expressions/expression.h"
#include "mongo/db/exec/sbe/stages/stages.h"
#include "mongo/db/exec/sbe/vm/vm.h"
namespace mongo::sbe {
/**
* Evaluates a set of expressions and stores the results into corresponding output slots. This is
* unrelated to projections in MQL. The set of (slot, expression) pairs are passed in the 'projects'
* slot map.
*
* Debug string representation:
*
* project [slot_1 = expr_1, ..., slot_n = expr_n] childStage
*/
class ProjectStage final : public PlanStage {
public:
ProjectStage(std::unique_ptr<PlanStage> input,
value::SlotMap<std::unique_ptr<EExpression>> projects,
PlanNodeId planNodeId,
bool participateInTrialRunTracking = true);
std::unique_ptr<PlanStage> clone() const final;
void prepare(CompileCtx& ctx) final;
value::SlotAccessor* getAccessor(CompileCtx& ctx, value::SlotId slot) final;
void open(bool reOpen) final;
PlanState getNext() final;
void close() final;
std::unique_ptr<PlanStageStats> getStats(bool includeDebugInfo) const final;
const SpecificStats* getSpecificStats() const final;
std::vector<DebugPrinter::Block> debugPrint() const final;
size_t estimateCompileTimeSize() const final;
protected:
void doSaveState(bool relinquishCursor) final;
private:
const value::SlotMap<std::unique_ptr<EExpression>> _projects;
value::SlotMap<std::pair<std::unique_ptr<vm::CodeFragment>, value::OwnedValueAccessor>> _fields;
vm::ByteCode _bytecode;
bool _compiled{false};
};
template <typename... Ts>
inline auto makeProjectStage(std::unique_ptr<PlanStage> input, PlanNodeId nodeId, Ts&&... pack) {
return makeS<ProjectStage>(std::move(input), makeEM(std::forward<Ts>(pack)...), nodeId);
}
} // namespace mongo::sbe
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