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/**
* Copyright (C) 2021-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.
*/
#include "mongo/db/pipeline/document_source_documents.h"
#include "mongo/db/exec/projection_executor.h"
#include "mongo/db/exec/projection_executor_builder.h"
#include "mongo/db/pipeline/document_source.h"
#include "mongo/db/pipeline/document_source_project.h"
#include "mongo/db/pipeline/document_source_queue.h"
#include "mongo/db/pipeline/document_source_replace_root.h"
#include "mongo/db/pipeline/document_source_unwind.h"
#include "mongo/db/pipeline/lite_parsed_document_source.h"
#include <boost/smart_ptr/intrusive_ptr.hpp>
namespace mongo {
using boost::intrusive_ptr;
REGISTER_DOCUMENT_SOURCE(documents,
DocumentSourceDocuments::LiteParsed::parse,
DocumentSourceDocuments::createFromBson,
AllowedWithApiStrict::kAlways);
std::list<intrusive_ptr<DocumentSource>> DocumentSourceDocuments::createFromBson(
BSONElement elem, const intrusive_ptr<ExpressionContext>& expCtx) {
// genField is a temporary field to hold docs to wire $project,
// $unwind, and $replaceRoot together.
auto genField = UUID::gen().toString();
auto projectContent = BSON(genField << elem);
auto queue = DocumentSourceQueue::create(expCtx, DocumentSourceDocuments::kStageName);
queue->emplace_back(Document{});
/* Create the following pipeline from $documents: [...]
* => [ queue([{}]),
* project: {tempDocumentsField: [...]},
* unwind: "$tempDocumentsField",
* replaceWith: "$tempDocumentsField" ]
*/
return {
queue,
DocumentSourceProject::create(projectContent, expCtx, elem.fieldNameStringData()),
DocumentSourceUnwind::create(expCtx, genField, false, {}, true),
DocumentSourceReplaceRoot::create(expCtx,
ExpressionFieldPath::createPathFromString(
expCtx.get(), genField, expCtx->variablesParseState),
"elements within the array passed to $documents")};
}
} // namespace mongo
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