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/**
* Copyright (C) 2018-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/pipeline/document_source_writer.h"
namespace mongo {
/**
* Implementation for the $out aggregation stage.
*/
class DocumentSourceOut final : public DocumentSourceWriter<BSONObj> {
public:
static constexpr StringData kStageName = "$out"_sd;
static constexpr StringData kInternalStageName = "$internalOutToDifferentDB"_sd;
/**
* A "lite parsed" $out stage is similar to other stages involving foreign collections except in
* some cases the foreign collection is allowed to be sharded.
*/
class LiteParsed final : public LiteParsedDocumentSourceForeignCollection {
public:
using LiteParsedDocumentSourceForeignCollection::LiteParsedDocumentSourceForeignCollection;
static std::unique_ptr<LiteParsed> parse(const NamespaceString& nss,
const BSONElement& spec);
static std::unique_ptr<LiteParsed> parseToDifferentDB(const NamespaceString& nss,
const BSONElement& spec);
bool allowShardedForeignCollection(NamespaceString nss) const final {
return _foreignNss != nss;
}
bool allowedToPassthroughFromMongos() const final {
return false;
}
PrivilegeVector requiredPrivileges(bool isMongos, bool bypassDocumentValidation) const {
ActionSet actions{ActionType::insert, ActionType::remove};
if (bypassDocumentValidation) {
actions.addAction(ActionType::bypassDocumentValidation);
}
return {Privilege(ResourcePattern::forExactNamespace(_foreignNss), actions)};
}
ReadConcernSupportResult supportsReadConcern(repl::ReadConcernLevel level) const final {
return {
{level == repl::ReadConcernLevel::kLinearizableReadConcern,
{ErrorCodes::InvalidOptions,
"{} cannot be used with a 'linearizable' read concern level"_format(kStageName)}},
Status::OK()};
}
};
~DocumentSourceOut() override;
const char* getSourceName() const final override {
if (_toDifferentDB) {
return kInternalStageName.rawData();
}
return kStageName.rawData();
}
StageConstraints constraints(Pipeline::SplitState pipeState) const final override {
return {StreamType::kStreaming,
PositionRequirement::kLast,
HostTypeRequirement::kPrimaryShard,
DiskUseRequirement::kWritesPersistentData,
FacetRequirement::kNotAllowed,
TransactionRequirement::kNotAllowed,
LookupRequirement::kNotAllowed,
UnionRequirement::kNotAllowed};
}
Value serialize(
boost::optional<ExplainOptions::Verbosity> explain = boost::none) const final override;
/**
* Creates a new $out or $internalOutToDifferentDB stage from the given arguments.
*/
static boost::intrusive_ptr<DocumentSource> create(
NamespaceString outputNs, const boost::intrusive_ptr<ExpressionContext>& expCtx);
static boost::intrusive_ptr<DocumentSource> createAndAllowDifferentDB(
NamespaceString outputNs, const boost::intrusive_ptr<ExpressionContext>& expCtx);
/**
* Parses a $out or $internalOutToDifferentDB stage from the user-supplied BSON.
*/
static boost::intrusive_ptr<DocumentSource> createFromBson(
BSONElement elem, const boost::intrusive_ptr<ExpressionContext>& pExpCtx);
static boost::intrusive_ptr<DocumentSource> createFromBsonToDifferentDB(
BSONElement elem, const boost::intrusive_ptr<ExpressionContext>& pExpCtx);
private:
DocumentSourceOut(NamespaceString outputNs,
const boost::intrusive_ptr<ExpressionContext>& expCtx)
: DocumentSourceWriter(outputNs.db() == expCtx->ns.db() ? kStageName.rawData()
: kInternalStageName.rawData(),
std::move(outputNs),
expCtx),
_toDifferentDB(getOutputNs().db() != expCtx->ns.db()) {}
void initialize() override;
void finalize() override;
void spill(BatchedObjects&& batch) override {
DocumentSourceWriteBlock writeBlock(pExpCtx->opCtx);
auto targetEpoch = boost::none;
uassertStatusOK(pExpCtx->mongoProcessInterface->insert(
pExpCtx, _tempNs, std::move(batch), _writeConcern, targetEpoch));
}
std::pair<BSONObj, int> makeBatchObject(Document&& doc) const override {
auto obj = doc.toBson();
return {obj, obj.objsize()};
}
void waitWhileFailPointEnabled() override;
// Holds on to the original collection options and index specs so we can check they didn't
// change during computation.
BSONObj _originalOutOptions;
std::list<BSONObj> _originalIndexes;
// The temporary namespace for the $out writes.
NamespaceString _tempNs;
// Keep track of whether this document source is writing to a different DB for serialization
// purposes.
bool _toDifferentDB;
};
} // namespace mongo
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