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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 <boost/optional.hpp>
#include <vector>
#include "mongo/db/namespace_string.h"
namespace mongo {
class BSONObj;
class OperationContext;
/**
* Given a chunk, determines whether it can be split and returns the split points if so. This
* function is functionally equivalent to the splitVector command.
*
* If maxSplitPoints is specified and there are more than "maxSplitPoints" split points,
* only the first "maxSplitPoints" points are returned.
* If maxChunkObjects is specified then it indicates to split every "maxChunkObjects"th key.
* By default, we split so that each new chunk has approximately half the keys of the maxChunkSize
* chunk. We only split at the "maxChunkObjects"th key if it would split at a lower key count than
* the default.
* maxChunkSize is the maximum size of a chunk in megabytes. If the chunk exceeds this size, we
* should split. Although maxChunkSize and maxChunkSizeBytes are boost::optional, at least one must
* be specified.
* If force is set, split at the halfway point of the chunk. This also effectively
* makes maxChunkSize equal the size of the chunk.
*/
std::vector<BSONObj> splitVector(OperationContext* opCtx,
const NamespaceString& nss,
const BSONObj& keyPattern,
const BSONObj& min,
const BSONObj& max,
bool force,
boost::optional<long long> maxSplitPoints,
boost::optional<long long> maxChunkObjects,
boost::optional<long long> maxChunkSizeBytes);
} // namespace mongo
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