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/**
* Copyright (C) 2017 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* 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 GNU Affero General 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/executor/task_executor.h"
#include "mongo/s/query/cluster_client_cursor_params.h"
#include "mongo/s/query/router_exec_stage.h"
namespace mongo {
/**
* Uses a RouterStageMerge to merge results, and monitors the merged stream for special
* sentinel documents which indicate the the set of cursors needs to be updated. When the
* sentinel is detected, removes it from the stream and updates the set of cursors.
*
* cmdToRunOnNewShards: Command to execute on the new shard to open the cursor.
*/
class RouterStageUpdateOnAddShard final : public RouterExecStage {
public:
RouterStageUpdateOnAddShard(OperationContext* opCtx,
executor::TaskExecutor* executor,
ClusterClientCursorParams* params,
std::vector<ShardId> shardIds,
BSONObj cmdToRunOnNewShards);
StatusWith<ClusterQueryResult> next(ExecContext) final;
private:
/**
* Establish the new cursors and tell the RouterStageMerge about them.
* obj: The BSONObj which triggered the establishment of the new cursors
*/
void addNewShardCursors(BSONObj obj);
/**
* Open the cursors on the new shards.
*/
std::vector<RemoteCursor> establishShardCursorsOnNewShards(const BSONObj& newShardDetectedObj);
ClusterClientCursorParams* _params;
std::vector<ShardId> _shardIds;
BSONObj _cmdToRunOnNewShards;
};
}
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