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# $Header: /var/local/cvsroot/4Suite/Ft/Lib/Uuid.py,v 1.8 2004/08/05 21:57:32 mbrown Exp $
"""
Functions for generating and comparing Universal Unique Identifiers
(UUIDs), based on ideas from e2fsprogs.
A UUID is essentially a 128-bit random number that has a string
representation of 28 hexadecimal digits, hyphenated in groups of
8-4-4-12. The value could be greater than the number of atoms in the
universe; it's extremely unlikely that the same number would ever be
generated twice.
UUIDs are defined by ISO/IEC 11578:1996 (Remote Procedure Call)
and The Open Group's DCE 1.1 (Distributed Computing Environment) spec
(the ISO version was based on an earlier version of the DCE spec).
See http://www.opengroup.org/onlinepubs/009629399/apdxa.htm#tagcjh_20
for the current version, and also see the expired IETF Internet-Draft
http://www.opengroup.org/dce/info/draft-leach-uuids-guids-01.txt for
a version with more informative prose and examples.
Copyright 2004 Fourthought, Inc. (USA).
Detailed license and copyright information: http://4suite.org/COPYRIGHT
Project home, documentation, distributions: http://4suite.org/
"""
import socket
from Random import GetRandomBytes
def GenerateUuid():
"""Returns a new UUID as a long int"""
result = GetRandomBytes(16)
result = result[:6] + chr((ord(result[6]) & 0x4F) | 0x40) + result[7:8] + chr((ord(result[8]) & 0xBF) | 0x80) + result[9:]
res = 0L
for i in range(16):
res = (res << 8) + ord(result[i] )
return res
def UuidAsString(uuid):
"""
Formats a long int representing a UUID as a UUID string:
32 hex digits in hyphenated groups of 8-4-4-4-12.
"""
## Python 2.0+
s = '%032x' % uuid
## Python 1.5+
#s = string.replace(string.lower('%032s' % hex(uuid)[2:-1]),' ','0')
return '%s-%s-%s-%s-%s' % (s[0:8],s[8:12],s[12:16],s[16:20],s[20:])
## Uche wants to keep this around.
## Note that it does not 0-pad the number; this needs to be fixed.
#newUuid = ''
#curUuid = uuid
#for ctr in range(16):
# num = int(curUuid & 0xFF)
# newChar = chr(num)
# curUuid = curUuid >> 8
# newUuid = newChar + newUuid
#
#uuid = newUuid
#
#result = ''
##This could of course be a function, but the overhead is undesirable
#mult = 0x1000000L
#num = 0
#ix = 0
#while mult:
# num = num + mult * ord(uuid[ix])
# mult = mult / 0x100
# ix = ix + 1
#result = result + hex(num)[2:-1] + '-'
#mult = 0x100
#num = 0
#while mult:
# num = num + mult * ord(uuid[ix])
# mult = mult / 0x100
# ix = ix + 1
#result = result + hex(num)[2:] + '-'
#mult = 0x100
#num = 0
#while mult:
# num = num + mult * ord(uuid[ix])
# mult = mult / 0x100
# ix = ix + 1
#result = result + hex(num)[2:] + '-'
#mult = 0x100
#num = 0
#while mult:
# num = num + mult * ord(uuid[ix])
# mult = mult / 0x100
# ix = ix + 1
#result = result + hex(num)[2:] + '-'
#mult = 0x1000000L
#num = 0
#while mult:
# num = num + mult * ord(uuid[ix])
# mult = mult / 0x100
# ix = ix + 1
#result = result + hex(num)[2:-1]
#mult = 0x100
#num = 0
#while mult:
# num = num + mult * ord(uuid[ix])
# mult = mult / 0x100
# ix = ix + 1
#result = result + hex(num)[2:]
#return result.lower()
def CompareUuids(u1, u2):
"""Compares, as with cmp(), two UUID strings case-insensitively"""
return cmp(u1.upper(), u2.upper())
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