ClickHouse/contrib/libpoco/Foundation/include/Poco/UUIDGenerator.h

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//
// UUIDGenerator.h
//
// $Id: //poco/1.4/Foundation/include/Poco/UUIDGenerator.h#1 $
//
// Library: Foundation
// Package: UUID
// Module: UUID
//
// Definition of the UUIDGenerator class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_UUIDGenerator_INCLUDED
#define Foundation_UUIDGenerator_INCLUDED
#include "Poco/Foundation.h"
#include "Poco/UUID.h"
#include "Poco/Mutex.h"
#include "Poco/Random.h"
#include "Poco/Timestamp.h"
#include "Poco/Environment.h"
namespace Poco {
class DigestEngine;
class Foundation_API UUIDGenerator
/// This class implements a generator for Universal Unique Identifiers,
/// as specified in Appendix A of the DCE 1.1 Remote Procedure
/// Call Specification (http://www.opengroup.org/onlinepubs/9629399/),
/// RFC 2518 (WebDAV), section 6.4.1 and the UUIDs and GUIDs internet
/// draft by Leach/Salz from February, 1998
/// (http://ftp.ics.uci.edu/pub/ietf/webdav/uuid-guid/draft-leach-uuids-guids-01.txt)
{
public:
UUIDGenerator();
/// Creates the UUIDGenerator.
~UUIDGenerator();
/// Destroys the UUIDGenerator.
UUID create();
/// Creates a new time-based UUID, using the MAC address of
/// one of the system's ethernet adapters.
///
/// Throws a SystemException if no MAC address can be
/// obtained.
UUID createFromName(const UUID& nsid, const std::string& name);
/// Creates a name-based UUID.
UUID createFromName(const UUID& nsid, const std::string& name, DigestEngine& de);
/// Creates a name-based UUID, using the given digest engine.
///
/// Note: in order to create a standard-compliant UUID, the given DigestEngine
/// must be either an instance of MD5Engine or SHA1Engine. The version field of
/// the UUID will be set accordingly.
UUID createFromName(const UUID& nsid, const std::string& name, DigestEngine& de, UUID::Version version);
/// Creates a name-based UUID, using the given digest engine and version.
UUID createRandom();
/// Creates a random UUID.
UUID createOne();
/// Tries to create and return a time-based UUID (see create()), and,
/// if that does not work due to the unavailability of a MAC address,
/// creates and returns a random UUID (see createRandom()).
///
/// The UUID::version() method can be used to determine the actual kind of
/// the UUID generated.
static UUIDGenerator& defaultGenerator();
/// Returns a reference to the default UUIDGenerator.
protected:
Timestamp::UtcTimeVal timeStamp();
void getNode();
private:
FastMutex _mutex;
Random _random;
Timestamp _lastTime;
int _ticks;
Environment::NodeId _node;
bool _haveNode;
UUIDGenerator(const UUIDGenerator&);
UUIDGenerator& operator = (const UUIDGenerator&);
};
} // namespace Poco
#endif // Foundation_UUIDGenerator_INCLUDED