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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 "mongo/s/database_version_gen.h"
namespace mongo {
/**
* This class is used to represent a specific version of a Database.
*
* Currently it is implemented as a (uuid, timestamp, lastMod) triplet, where the
* timestamp is optional in versions prior 4.9. The uuid is going to be removed soon,
* since they are not comparable.
*
*/
class DatabaseVersion : public DatabaseVersionBase {
public:
/**
* The name for the database version information field, which shard-aware commands should
* include if they want to convey database version.
*/
static constexpr StringData kDatabaseVersionField = "databaseVersion"_sd;
using DatabaseVersionBase::getTimestamp;
DatabaseVersion() = default;
explicit DatabaseVersion(const BSONObj& obj) {
DatabaseVersionBase::parseProtected(IDLParserContext("DatabaseVersion"), obj);
}
explicit DatabaseVersion(const DatabaseVersionBase& dbv) : DatabaseVersionBase(dbv) {}
/**
* Constructor of a DatabaseVersion based on epochs and timestamps
*/
DatabaseVersion(mongo::UUID uuid, mongo::Timestamp timestamp)
: DatabaseVersionBase(timestamp, 1 /* lastMod */) {
setUuid(uuid);
}
// Returns a new hardcoded DatabaseVersion value, which is used to distinguish databases that do
// not have entries in the sharding catalog, namely 'config' and 'admin'.
static DatabaseVersion makeFixed();
// Returns a new DatabaseVersion with just the lastMod incremented. This indicates that the
// database changed primary, as opposed to being dropped and recreated.
DatabaseVersion makeUpdated() const;
/**
* It returns true if the Timestamp and lastmod of both versions are the same.
*/
bool operator==(const DatabaseVersion& other) const {
return getTimestamp() == other.getTimestamp() && getLastMod() == other.getLastMod();
}
bool operator!=(const DatabaseVersion& other) const {
return !(*this == other);
}
bool operator<(const DatabaseVersion& other) const;
bool operator>(const DatabaseVersion& other) const {
return other < *this;
}
bool operator<=(const DatabaseVersion& other) const {
return !(*this > other);
}
bool operator>=(const DatabaseVersion& other) const {
return !(*this < other);
}
bool isFixed() const {
return getLastMod() == 0;
}
UUID getUuid() const {
return *DatabaseVersionBase::getUuid();
}
std::string toString() const;
};
inline std::ostream& operator<<(std::ostream& s, const DatabaseVersion& v) {
return s << v.toString();
}
inline StringBuilder& operator<<(StringBuilder& s, const DatabaseVersion& v) {
return s << v.toString();
}
} // namespace mongo
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