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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 <functional>
#include <string>
#include <third_party/murmurhash3/MurmurHash3.h>
#include "mongo/base/data_range.h"
#include "mongo/base/status_with.h"
#include "mongo/bson/bsonelement.h"
#include "mongo/bson/bsonmisc.h"
#include "mongo/bson/bsonobj.h"
namespace mongo {
namespace repl {
class OplogEntryBase;
class ReplOperation;
} // namespace repl
namespace idl {
namespace import {
class One_UUID;
} // namespace import
} // namespace idl
/**
* A UUID is a 128-bit unique identifier, per RFC 4122, v4, using
* a secure random number generator.
*/
class UUID {
using UUIDStorage = std::array<unsigned char, 16>;
// Make the IDL generated parser a friend
friend class ConfigsvrShardCollectionResponse;
friend class ConfigsvrCommitShardCollection;
friend class ShardsvrShardCollectionResponse;
friend class DatabaseVersion;
friend class DbCheckOplogCollection;
friend class idl::import::One_UUID;
friend class LogicalSessionId;
friend class LogicalSessionToClient;
friend class LogicalSessionIdToClient;
friend class LogicalSessionFromClient;
friend class repl::OplogEntryBase;
friend class repl::ReplOperation;
friend class ResumeTokenInternal;
public:
/**
* The number of bytes contained in a UUID.
*/
static constexpr int kNumBytes = sizeof(UUIDStorage);
/**
* Generate a new random v4 UUID per RFC 4122.
*/
static UUID gen();
/**
* If the given string represents a valid UUID, constructs and returns the UUID,
* otherwise returns an error.
*/
static StatusWith<UUID> parse(const std::string& s);
/**
* If the given BSONElement represents a valid UUID, constructs and returns the UUID,
* otherwise returns an error.
*/
static StatusWith<UUID> parse(BSONElement from);
/**
* Parses a BSON document of the form { uuid: BinData(4, "...") }.
*
* For IDL.
*/
static UUID parse(const BSONObj& obj);
static UUID fromCDR(ConstDataRange cdr) {
UUID uuid;
invariant(cdr.length() == uuid._uuid.size());
memcpy(uuid._uuid.data(), cdr.data(), uuid._uuid.size());
return uuid;
}
/**
* Returns whether this string represents a valid UUID.
*/
static bool isUUIDString(const std::string& s);
/**
* Returns a ConstDataRange view of the UUID.
*/
ConstDataRange toCDR() const {
return ConstDataRange(reinterpret_cast<const char*>(_uuid.data()), _uuid.size());
}
/**
* Appends to builder as BinData(4, "...") element with the given name.
*/
void appendToBuilder(BSONObjBuilder* builder, StringData name) const;
/**
* Returns a BSON object of the form { uuid: BinData(4, "...") }.
*/
BSONObj toBSON() const;
/**
* Returns a string representation of this UUID, in hexadecimal,
* as per RFC 4122:
*
* 4 Octets - 2 Octets - 2 Octets - 2 Octets - 6 Octets
*/
std::string toString() const;
inline bool operator==(const UUID& rhs) const {
return !memcmp(&_uuid, &rhs._uuid, sizeof(_uuid));
}
inline bool operator!=(const UUID& rhs) const {
return !(*this == rhs);
}
inline bool operator<(const UUID& rhs) const {
return _uuid < rhs._uuid;
}
inline bool operator>(const UUID& rhs) const {
return _uuid > rhs._uuid;
}
inline bool operator<=(const UUID& rhs) const {
return _uuid <= rhs._uuid;
}
inline bool operator>=(const UUID& rhs) const {
return _uuid >= rhs._uuid;
}
/**
* Returns true only if the UUID is the RFC 4122 variant, v4 (random).
*/
bool isRFC4122v4() const;
/**
* Custom hasher so UUIDs can be used in unordered data structures.
*
* ex: std::unordered_set<UUID, UUID::Hash> uuidSet;
*/
struct Hash {
std::size_t operator()(const UUID& uuid) const {
uint32_t hash;
MurmurHash3_x86_32(uuid._uuid.data(), UUID::kNumBytes, 0, &hash);
return hash;
}
};
private:
UUID(const UUIDStorage& uuid) : _uuid(uuid) {}
/**
* Should never be used, as the resulting UUID will not be unique.
* The exception is in code generated by the IDL compiler, which itself ensures
* such an invalid value cannot propagate.
*/
friend class LogicalSessionId;
UUID() = default;
UUIDStorage _uuid{}; // UUID in network byte order
};
inline std::ostream& operator<<(std::ostream& s, const UUID& uuid) {
return (s << uuid.toString());
}
inline StringBuilder& operator<<(StringBuilder& s, const UUID& uuid) {
return (s << uuid.toString());
}
/**
* Supports use of UUID with the BSON macro:
* BSON("uuid" << uuid) -> { uuid: BinData(4, "...") }
*/
template <>
BSONObjBuilder& BSONObjBuilderValueStream::operator<<<UUID>(UUID value);
} // namespace mongo
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