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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/stages/stages.h"
#include "mongo/db/exec/sbe/values/value.h"
namespace mongo::sbe {
enum class MakeObjFieldBehavior { drop, keep };
enum class MakeObjOutputType { object, bsonObject };
/**
* Base stage for creating a bsonObject or object.
*
* Template argument 'O' indicates which output type to use.
*/
template <MakeObjOutputType O>
class MakeObjStageBase final : public PlanStage {
public:
using FieldBehavior = MakeObjFieldBehavior;
/**
* Constructor. Arguments:
* -input: Child PlanStage.
* -objSlot: The output slot.
*
* -rootSlot (optional): Slot containing an object which the return object will be based on.
* -fieldBehavior (optional): This may only be specified when 'rootSlot' is specified. Describes
* what the behavior should be for each field in 'fields'. Either "drop" or "keep".
* -fields: List of fields. What the stage does with each field depends on 'fieldBehavior'.
*
* -projectFields: List of fields which should be added to the result object using the values
* from 'projectVars'.
* -projectVars: See above.
*
* -forceNewObject, returnOldObject: Describes what the behavior should be when the resulting
* object has no fields. May either return 'Nothing', an empty object, or the object in
* 'rootSlot' unmodified.
*
* -planNodeId: Mapping to the corresponding QuerySolutionNode.
*/
MakeObjStageBase(std::unique_ptr<PlanStage> input,
value::SlotId objSlot,
boost::optional<value::SlotId> rootSlot,
boost::optional<FieldBehavior> fieldBehavior,
std::vector<std::string> fields,
std::vector<std::string> projectFields,
value::SlotVector projectVars,
bool forceNewObject,
bool returnOldObject,
PlanNodeId planNodeId);
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;
protected:
void doSaveState() final;
private:
void projectField(value::Object* obj, size_t idx);
void projectField(UniqueBSONObjBuilder* bob, size_t idx);
bool isFieldRestricted(const StringMapHashedKey& key) const {
return _fieldSet.count(key) == (*_fieldBehavior == FieldBehavior::keep ? 0 : 1);
}
void resetAlreadyProjected() {
if (!_alreadyProjected.empty()) {
std::memset(_alreadyProjected.data(),
0,
_alreadyProjected.size() *
sizeof(typename decltype(_alreadyProjected)::value_type));
}
}
void produceObject();
const value::SlotId _objSlot;
const boost::optional<value::SlotId> _rootSlot;
const boost::optional<FieldBehavior> _fieldBehavior;
const std::vector<std::string> _fields;
const std::vector<std::string> _projectFields;
const value::SlotVector _projectVars;
const bool _forceNewObject;
const bool _returnOldObject;
StringSet _fieldSet;
StringMap<size_t> _projectFieldsMap;
std::vector<std::pair<std::string, value::SlotAccessor*>> _projects;
value::OwnedValueAccessor _obj;
// Reset to all 0's on each call to getNext(). Kept here to avoid repeated allocations.
std::vector<char> _alreadyProjected;
value::SlotAccessor* _root{nullptr};
bool _compiled{false};
};
using MakeObjStage = MakeObjStageBase<MakeObjOutputType::object>;
using MakeBsonObjStage = MakeObjStageBase<MakeObjOutputType::bsonObject>;
} // namespace mongo::sbe
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