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

222 lines
5.3 KiB
C++

//
// UUID.h
//
// $Id: //poco/1.4/Foundation/include/Poco/UUID.h#2 $
//
// Library: Foundation
// Package: UUID
// Module: UUID
//
// Definition of the UUID class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_UUID_INCLUDED
#define Foundation_UUID_INCLUDED
#include "Poco/Foundation.h"
namespace Poco {
class Foundation_API UUID
/// A UUID is an identifier that is unique across both space and time,
/// with respect to the space of all UUIDs. Since a UUID is a fixed
/// size and contains a time field, it is possible for values to
/// rollover (around A.D. 3400, depending on the specific algorithm
/// used). A UUID can be used for multiple purposes, from tagging
/// objects with an extremely short lifetime, to reliably identifying
/// very persistent objects across a network.
///
/// This class implements a Universal Unique Identifier,
/// 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://www.ics.uci.edu/~ejw/authoring/uuid-guid/draft-leach-uuids-guids-01.txt)
/// and also http://tools.ietf.org/html/draft-mealling-uuid-urn-05
{
public:
enum Version
{
UUID_TIME_BASED = 0x01,
UUID_DCE_UID = 0x02,
UUID_NAME_BASED = 0x03,
UUID_RANDOM = 0x04,
UUID_NAME_BASED_SHA1 = 0x05
};
UUID();
/// Creates a nil (all zero) UUID.
UUID(const UUID& uuid);
/// Copy constructor.
explicit UUID(const std::string& uuid);
/// Parses the UUID from a string.
explicit UUID(const char* uuid);
/// Parses the UUID from a string.
~UUID();
/// Destroys the UUID.
UUID& operator = (const UUID& uuid);
/// Assignment operator.
void swap(UUID& uuid);
/// Swaps the UUID with another one.
void parse(const std::string& uuid);
/// Parses the UUID from its string representation.
bool tryParse(const std::string& uuid);
/// Tries to interpret the given string as an UUID.
/// If the UUID is syntactically valid, assigns the
/// members and returns true. Otherwise leaves the
/// object unchanged and returns false.
std::string toString() const;
/// Returns a string representation of the UUID consisting
/// of groups of hexadecimal digits separated by hyphens.
void copyFrom(const char* buffer);
/// Copies the UUID (16 bytes) from a buffer or byte array.
/// The UUID fields are expected to be
/// stored in network byte order.
/// The buffer need not be aligned.
void copyTo(char* buffer) const;
/// Copies the UUID to the buffer. The fields
/// are in network byte order.
/// The buffer need not be aligned.
/// There must have room for at least 16 bytes.
Version version() const;
/// Returns the version of the UUID.
int variant() const;
/// Returns the variant number of the UUID:
/// - 0 reserved for NCS backward compatibility
/// - 2 the Leach-Salz variant (used by this class)
/// - 6 reserved, Microsoft Corporation backward compatibility
/// - 7 reserved for future definition
bool operator == (const UUID& uuid) const;
bool operator != (const UUID& uuid) const;
bool operator < (const UUID& uuid) const;
bool operator <= (const UUID& uuid) const;
bool operator > (const UUID& uuid) const;
bool operator >= (const UUID& uuid) const;
bool isNull() const;
/// Returns true iff the UUID is nil (in other words,
/// consists of all zeros).
static const UUID& null();
/// Returns a null/nil UUID.
static const UUID& dns();
/// Returns the namespace identifier for the DNS namespace.
static const UUID& uri();
/// Returns the namespace identifier for the URI (former URL) namespace.
static const UUID& oid();
/// Returns the namespace identifier for the OID namespace.
static const UUID& x500();
/// Returns the namespace identifier for the X500 namespace.
protected:
UUID(UInt32 timeLow, UInt32 timeMid, UInt32 timeHiAndVersion, UInt16 clockSeq, UInt8 node[]);
UUID(const char* bytes, Version version);
int compare(const UUID& uuid) const;
static void appendHex(std::string& str, UInt8 n);
static void appendHex(std::string& str, UInt16 n);
static void appendHex(std::string& str, UInt32 n);
static Int16 nibble(char hex);
void fromNetwork();
void toNetwork();
private:
UInt32 _timeLow;
UInt16 _timeMid;
UInt16 _timeHiAndVersion;
UInt16 _clockSeq;
UInt8 _node[6];
friend class UUIDGenerator;
};
//
// inlines
//
inline bool UUID::operator == (const UUID& uuid) const
{
return compare(uuid) == 0;
}
inline bool UUID::operator != (const UUID& uuid) const
{
return compare(uuid) != 0;
}
inline bool UUID::operator < (const UUID& uuid) const
{
return compare(uuid) < 0;
}
inline bool UUID::operator <= (const UUID& uuid) const
{
return compare(uuid) <= 0;
}
inline bool UUID::operator > (const UUID& uuid) const
{
return compare(uuid) > 0;
}
inline bool UUID::operator >= (const UUID& uuid) const
{
return compare(uuid) >= 0;
}
inline UUID::Version UUID::version() const
{
return Version(_timeHiAndVersion >> 12);
}
inline bool UUID::isNull() const
{
return compare(null()) == 0;
}
inline void swap(UUID& u1, UUID& u2)
{
u1.swap(u2);
}
} // namespace Poco
#endif // Foundation_UUID_INCLUDED