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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 "mongo/bson/bsonobj.h"
namespace mongo {
class BSONObjBuilder;
template <typename T>
class StatusWith;
struct WriteConcernOptions;
/**
* Returns the default write concern for migration cleanup on the donor shard and for cloning
* documents on the destination shard.
*/
class MigrationSecondaryThrottleOptions {
public:
enum SecondaryThrottleOption {
// The secondary throttle option is not set explicitly. Use the default for the service.
kDefault,
// The secondary throttle option is explicitly disabled.
kOff,
// The secondary throttle option is explicitly enabled and there potentially might be a
// write concern specified. If no write concern was specified, use the default.
kOn
};
/**
* Constructs an object with the specified secondary throttle option and no custom write
* concern.
*/
static MigrationSecondaryThrottleOptions create(SecondaryThrottleOption option);
/**
* Constructs an object with the secondary throttle enabled and with the specified write
* concern.
*/
static MigrationSecondaryThrottleOptions createWithWriteConcern(
const WriteConcernOptions& writeConcern);
/**
* Extracts the write concern settings from a BSON with the following format:
*
* {
* secondaryThrottle: <bool>, // optional
* _secondaryThrottle: <bool>, // optional
* writeConcern: <WriteConcern formatted as BSONObj> // optional
* }
*
* Note: secondaryThrottle takes precedence over _secondaryThrottle. If either of the two are
* missing, the secondaryThrottle enabled status defaults to true.
*
* Returns OK if the parse was successful.
*/
static StatusWith<MigrationSecondaryThrottleOptions> createFromCommand(const BSONObj& obj);
/*
* Same as `createFromCommand`, but throwing in case of parsing exception
*/
static MigrationSecondaryThrottleOptions parseFromBSON(const BSONObj& obj) {
return uassertStatusOK(createFromCommand(obj));
}
/**
* Extracts the secondary throttle settings from a balancer configuration document, which can
* have the following format:
*
* {
* _secondaryThrottle: <bool> | <WriteConcern formatted as BSONObj> // optional
* }
*
* If secondary throttle is not specified, uses kDefault.
*/
static StatusWith<MigrationSecondaryThrottleOptions> createFromBalancerConfig(
const BSONObj& obj);
/**
* Returns the selected secondary throttle option.
*/
SecondaryThrottleOption getSecondaryThrottle() const {
return _secondaryThrottle;
}
/**
* Returns whether secondary throttle is enabled and write concern was requested.
*/
bool isWriteConcernSpecified() const {
return _writeConcernBSON.is_initialized();
}
/**
* Returns the custom write concern, which was requested. Must only be called if
* isWriteConcernSpecified returns true.
*/
WriteConcernOptions getWriteConcern() const;
/**
* Returns a BSON representation of the current secondary throttle settings.
*/
void append(BSONObjBuilder* builder) const;
BSONObj toBSON() const;
/**
* Returns true if the options match exactly.
*/
bool operator==(const MigrationSecondaryThrottleOptions& other) const;
bool operator!=(const MigrationSecondaryThrottleOptions& other) const;
private:
MigrationSecondaryThrottleOptions(SecondaryThrottleOption secondaryThrottle,
boost::optional<BSONObj> writeConcernBSON);
// What is the state of the secondaryThrottle option (kDefault means that it has not been set)
SecondaryThrottleOption _secondaryThrottle;
// Owned BSON object with the contents of the writeConcern. If this object is set, then
// secodaryThrottle must be true.
boost::optional<BSONObj> _writeConcernBSON;
};
} // namespace mongo
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