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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.
*/
#include "mongo/platform/basic.h"
#include "mongo/bson/bsonobj.h"
#include "mongo/bson/bsonobjbuilder.h"
#include "mongo/db/commands.h"
#include "mongo/db/commands/map_reduce_gen.h"
#include "mongo/db/query/cursor_response.h"
#include "mongo/db/query/getmore_request.h"
#include "mongo/s/commands/cluster_map_reduce_agg.h"
namespace mongo {
// Exhaust the cursor from the aggregation response and extract results and statistics.
std::vector<BSONObj> getAllAggregationResults(OperationContext* opCtx,
const std::string& dbname,
CursorResponse& response) {
CursorId cursorId = response.getCursorId();
auto fullBatch = response.releaseBatch();
while (cursorId != 0) {
GetMoreRequest request(
response.getNSS(), cursorId, boost::none, boost::none, boost::none, boost::none);
BSONObj getMoreResponse = CommandHelpers::runCommandDirectly(
opCtx, OpMsgRequest::fromDBAndBody(dbname, request.toBSON()));
auto getMoreCursorResponse = CursorResponse::parseFromBSONThrowing(getMoreResponse);
auto nextBatch = getMoreCursorResponse.releaseBatch();
fullBatch.insert(fullBatch.end(), nextBatch.begin(), nextBatch.end());
cursorId = getMoreCursorResponse.getCursorId();
}
return fullBatch;
}
bool runAggregationMapReduce(OperationContext* opCtx,
const std::string& dbname,
const BSONObj& cmd,
std::string& errmsg,
BSONObjBuilder& result) {
// Pretend we have built the appropriate pipeline and aggregation request.
auto mrRequest = MapReduce::parse(IDLParserErrorContext("MapReduce"), cmd);
const BSONObj aggRequest =
fromjson(str::stream() << "{aggregate: '" << mrRequest.getNamespace().coll()
<< "', pipeline: [ { $group: { _id: { user: \"$user\" },"
<< "count: { $sum: 1 } } } ], cursor: {}}");
BSONObj aggResult = CommandHelpers::runCommandDirectly(
opCtx, OpMsgRequest::fromDBAndBody(dbname, std::move(aggRequest)));
bool inMemory = mrRequest.getOutOptions().getOutputType() == OutputType::InMemory;
std::string outColl = mrRequest.getOutOptions().getCollectionName();
// Either inline response specified or we have an output collection.
invariant(inMemory ^ !outColl.empty());
auto cursorResponse = CursorResponse::parseFromBSONThrowing(aggResult);
auto completeBatch = getAllAggregationResults(opCtx, dbname, cursorResponse);
[[maybe_unused]] CursorResponse completeCursor(
cursorResponse.getNSS(), cursorResponse.getCursorId(), std::move(completeBatch));
return true;
}
} // namespace mongo
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