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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.
*/
#pragma once
#include <boost/algorithm/string.hpp>
#include <boost/optional.hpp>
#include <map>
#include <ostream>
#include <set>
#include <utility>
#include "mongo/bson/oid.h"
#include "mongo/client/sdam/sdam_datatypes.h"
#include "mongo/db/repl/optime.h"
#include "mongo/platform/basic.h"
#include "mongo/rpc/topology_version_gen.h"
#include "mongo/util/clock_source.h"
namespace mongo::sdam {
class ServerDescription {
ServerDescription() = delete;
public:
/**
* Construct an unknown ServerDescription with default values except the server's address.
*/
ServerDescription(ServerAddress address)
: _address(std::move(address)), _type(ServerType::kUnknown) {}
/**
* Build a new ServerDescription according to the rules of the SDAM spec based on the
* last RTT to the server and isMaster response.
*/
ServerDescription(ClockSource* clockSource,
const IsMasterOutcome& isMasterOutcome,
boost::optional<IsMasterRTT> lastRtt = boost::none,
boost::optional<TopologyVersion> topologyVersion = boost::none,
boost::optional<int> poolResetCounter = boost::none);
/**
* This determines if a server description is equivalent according to the Server Discovery and
* Monitoring specification. Members marked with (=) are used to determine equality. Note that
* these members do not include RTT or the server's address.
*/
bool isEquivalent(const ServerDescription& other) const;
// server identity
const ServerAddress& getAddress() const;
ServerType getType() const;
const boost::optional<ServerAddress>& getMe() const;
const boost::optional<std::string>& getSetName() const;
const std::map<std::string, std::string>& getTags() const;
void appendBsonTags(BSONObjBuilder& builder) const;
// network attributes
const boost::optional<std::string>& getError() const;
const boost::optional<IsMasterRTT>& getRtt() const;
const boost::optional<int>& getLogicalSessionTimeoutMinutes() const;
int getPoolResetCounter();
// server capabilities
int getMinWireVersion() const;
int getMaxWireVersion() const;
bool isDataBearingServer() const;
bool isStreamable() const;
// server 'time'
const Date_t getLastUpdateTime() const;
const boost::optional<Date_t>& getLastWriteDate() const;
const boost::optional<repl::OpTime>& getOpTime() const;
// topology membership
const boost::optional<ServerAddress>& getPrimary() const;
const std::set<ServerAddress>& getHosts() const;
const std::set<ServerAddress>& getPassives() const;
const std::set<ServerAddress>& getArbiters() const;
const boost::optional<int>& getSetVersion() const;
const boost::optional<OID>& getElectionId() const;
const boost::optional<TopologyVersion>& getTopologyVersion() const;
const boost::optional<TopologyDescriptionPtr> getTopologyDescription();
BSONObj toBson() const;
std::string toString() const;
ServerDescriptionPtr cloneWithRTT(IsMasterRTT rtt);
private:
/**
* Classify the server's type based on the ismaster response.
* @param isMaster - reply information for the ismaster command
*/
void parseTypeFromIsMaster(const BSONObj isMaster);
void calculateRtt(const IsMasterRTT currentRtt, const boost::optional<IsMasterRTT> lastRtt);
void saveLastWriteInfo(BSONObj lastWriteBson);
void storeHostListIfPresent(const std::string key,
const BSONObj response,
std::set<ServerAddress>& destination);
void saveHosts(const BSONObj response);
void saveTags(BSONObj tagsObj);
void saveElectionId(BSONElement electionId);
void saveTopologyVersion(BSONElement topologyVersionField);
void saveStreamable(BSONElement streamableField);
static inline const std::string kIsDbGrid = "isdbgrid";
static inline const double kRttAlpha = 0.2;
// address: the hostname or IP, and the port number, that the client connects to. Note that this
// is not the server's ismaster.me field, in the case that the server reports an address
// different from the address the client uses.
ServerAddress _address;
// topologyVersion: the server's topology version. Updated upon a significant topology change.
boost::optional<TopologyVersion> _topologyVersion;
// error: information about the last error related to this server. Default null.
boost::optional<std::string> _error;
// roundTripTime: the duration of the ismaster call. Default null.
boost::optional<IsMasterRTT> _rtt;
// lastWriteDate: a 64-bit BSON datetime or null. The "lastWriteDate" from the server's most
// recent ismaster response.
boost::optional<Date_t> _lastWriteDate;
// opTime: an ObjectId or null. The last opTime reported by the server; an ObjectId or null.
// (Only mongos and shard servers record this field when monitoring config servers as replica
// sets.)
boost::optional<repl::OpTime> _opTime;
// (=) type: a ServerType enum value. Default Unknown.
ServerType _type;
// (=) minWireVersion, maxWireVersion: the wire protocol version range supported by the server.
// Both default to 0. Use min and maxWireVersion only to determine compatibility.
int _minWireVersion = 0;
int _maxWireVersion = 0;
// (=) me: The hostname or IP, and the port number, that this server was configured with in the
// replica set. Default null.
boost::optional<ServerAddress> _me;
// (=) hosts, passives, arbiters: Sets of addresses. This server's opinion of the replica set's
// members, if any. These hostnames are normalized to lower-case. Default empty. The client
// monitors all three types of servers in a replica set.
std::set<ServerAddress> _hosts;
std::set<ServerAddress> _passives;
std::set<ServerAddress> _arbiters;
// (=) tags: map from string to string. Default empty.
std::map<std::string, std::string> _tags;
// (=) setName: string or null. Default null.
boost::optional<std::string> _setName;
// (=) setVersion: integer or null. Default null.
boost::optional<int> _setVersion;
// (=) electionId: an ObjectId, if this is a MongoDB 2.6+ replica set member that believes it is
// primary. See using setVersion and electionId to detect stale primaries. Default null.
boost::optional<OID> _electionId;
// (=) primary: an address. This server's opinion of who the primary is. Default null.
boost::optional<ServerAddress> _primary;
// lastUpdateTime: when this server was last checked. Default "infinity ago".
boost::optional<Date_t> _lastUpdateTime = Date_t::min();
// (=) logicalSessionTimeoutMinutes: integer or null. Default null.
boost::optional<int> _logicalSessionTimeoutMinutes;
// (=) streamable: whether this server can stream isMaster responses. Default false.
bool _streamable = false;
// (=) poolResetCounter: integer, default 0. Initialized when client first creates connection
// pool for server. Incremented on network error or timeout.
int _poolResetCounter = 0;
// The topology description of that we are a part of
boost::optional<std::weak_ptr<TopologyDescription>> _topologyDescription;
friend class TopologyDescription;
friend class ServerDescriptionBuilder;
};
bool operator==(const mongo::sdam::ServerDescription& a, const mongo::sdam::ServerDescription& b);
bool operator!=(const mongo::sdam::ServerDescription& a, const mongo::sdam::ServerDescription& b);
std::ostream& operator<<(std::ostream& os, const ServerDescriptionPtr& description);
std::ostream& operator<<(std::ostream& os, const ServerDescription& description);
}; // namespace mongo::sdam
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