541 lines
20 KiB
Python
541 lines
20 KiB
Python
r"""UUID objects (universally unique identifiers) according to RFC 4122.
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This module provides immutable UUID objects (class UUID) and the functions
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uuid1(), uuid3(), uuid4(), uuid5() for generating version 1, 3, 4, and 5
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UUIDs as specified in RFC 4122.
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If all you want is a unique ID, you should probably call uuid1() or uuid4().
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Note that uuid1() may compromise privacy since it creates a UUID containing
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the computer's network address. uuid4() creates a random UUID.
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Typical usage:
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>>> import uuid
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# make a UUID based on the host ID and current time
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>>> uuid.uuid1()
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UUID('a8098c1a-f86e-11da-bd1a-00112444be1e')
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# make a UUID using an MD5 hash of a namespace UUID and a name
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>>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org')
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UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')
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# make a random UUID
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>>> uuid.uuid4()
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UUID('16fd2706-8baf-433b-82eb-8c7fada847da')
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# make a UUID using a SHA-1 hash of a namespace UUID and a name
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>>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org')
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UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d')
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# make a UUID from a string of hex digits (braces and hyphens ignored)
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>>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}')
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# convert a UUID to a string of hex digits in standard form
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>>> str(x)
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'00010203-0405-0607-0809-0a0b0c0d0e0f'
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# get the raw 16 bytes of the UUID
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>>> x.bytes
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'\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f'
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# make a UUID from a 16-byte string
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>>> uuid.UUID(bytes=x.bytes)
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UUID('00010203-0405-0607-0809-0a0b0c0d0e0f')
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"""
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__author__ = 'Ka-Ping Yee <ping@zesty.ca>'
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RESERVED_NCS, RFC_4122, RESERVED_MICROSOFT, RESERVED_FUTURE = [
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'reserved for NCS compatibility', 'specified in RFC 4122',
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'reserved for Microsoft compatibility', 'reserved for future definition']
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class UUID(object):
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"""Instances of the UUID class represent UUIDs as specified in RFC 4122.
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UUID objects are immutable, hashable, and usable as dictionary keys.
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Converting a UUID to a string with str() yields something in the form
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'12345678-1234-1234-1234-123456789abc'. The UUID constructor accepts
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five possible forms: a similar string of hexadecimal digits, or a tuple
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of six integer fields (with 32-bit, 16-bit, 16-bit, 8-bit, 8-bit, and
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48-bit values respectively) as an argument named 'fields', or a string
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of 16 bytes (with all the integer fields in big-endian order) as an
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argument named 'bytes', or a string of 16 bytes (with the first three
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fields in little-endian order) as an argument named 'bytes_le', or a
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single 128-bit integer as an argument named 'int'.
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UUIDs have these read-only attributes:
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bytes the UUID as a 16-byte string (containing the six
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integer fields in big-endian byte order)
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bytes_le the UUID as a 16-byte string (with time_low, time_mid,
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and time_hi_version in little-endian byte order)
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fields a tuple of the six integer fields of the UUID,
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which are also available as six individual attributes
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and two derived attributes:
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time_low the first 32 bits of the UUID
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time_mid the next 16 bits of the UUID
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time_hi_version the next 16 bits of the UUID
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clock_seq_hi_variant the next 8 bits of the UUID
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clock_seq_low the next 8 bits of the UUID
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node the last 48 bits of the UUID
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time the 60-bit timestamp
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clock_seq the 14-bit sequence number
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hex the UUID as a 32-character hexadecimal string
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int the UUID as a 128-bit integer
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urn the UUID as a URN as specified in RFC 4122
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variant the UUID variant (one of the constants RESERVED_NCS,
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RFC_4122, RESERVED_MICROSOFT, or RESERVED_FUTURE)
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version the UUID version number (1 through 5, meaningful only
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when the variant is RFC_4122)
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"""
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def __init__(self, hex=None, bytes=None, bytes_le=None, fields=None,
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int=None, version=None):
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r"""Create a UUID from either a string of 32 hexadecimal digits,
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a string of 16 bytes as the 'bytes' argument, a string of 16 bytes
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in little-endian order as the 'bytes_le' argument, a tuple of six
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integers (32-bit time_low, 16-bit time_mid, 16-bit time_hi_version,
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8-bit clock_seq_hi_variant, 8-bit clock_seq_low, 48-bit node) as
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the 'fields' argument, or a single 128-bit integer as the 'int'
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argument. When a string of hex digits is given, curly braces,
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hyphens, and a URN prefix are all optional. For example, these
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expressions all yield the same UUID:
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UUID('{12345678-1234-5678-1234-567812345678}')
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UUID('12345678123456781234567812345678')
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UUID('urn:uuid:12345678-1234-5678-1234-567812345678')
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UUID(bytes='\x12\x34\x56\x78'*4)
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UUID(bytes_le='\x78\x56\x34\x12\x34\x12\x78\x56' +
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'\x12\x34\x56\x78\x12\x34\x56\x78')
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UUID(fields=(0x12345678, 0x1234, 0x5678, 0x12, 0x34, 0x567812345678))
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UUID(int=0x12345678123456781234567812345678)
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Exactly one of 'hex', 'bytes', 'bytes_le', 'fields', or 'int' must
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be given. The 'version' argument is optional; if given, the resulting
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UUID will have its variant and version set according to RFC 4122,
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overriding the given 'hex', 'bytes', 'bytes_le', 'fields', or 'int'.
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"""
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if [hex, bytes, bytes_le, fields, int].count(None) != 4:
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raise TypeError('need one of hex, bytes, bytes_le, fields, or int')
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if hex is not None:
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hex = hex.replace('urn:', '').replace('uuid:', '')
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hex = hex.strip('{}').replace('-', '')
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if len(hex) != 32:
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raise ValueError('badly formed hexadecimal UUID string')
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int = long(hex, 16)
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if bytes_le is not None:
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if len(bytes_le) != 16:
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raise ValueError('bytes_le is not a 16-char string')
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bytes = (bytes_le[3] + bytes_le[2] + bytes_le[1] + bytes_le[0] +
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bytes_le[5] + bytes_le[4] + bytes_le[7] + bytes_le[6] +
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bytes_le[8:])
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if bytes is not None:
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if len(bytes) != 16:
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raise ValueError('bytes is not a 16-char string')
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int = long(('%02x'*16) % tuple(map(ord, bytes)), 16)
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if fields is not None:
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if len(fields) != 6:
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raise ValueError('fields is not a 6-tuple')
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(time_low, time_mid, time_hi_version,
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clock_seq_hi_variant, clock_seq_low, node) = fields
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if not 0 <= time_low < 1<<32L:
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raise ValueError('field 1 out of range (need a 32-bit value)')
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if not 0 <= time_mid < 1<<16L:
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raise ValueError('field 2 out of range (need a 16-bit value)')
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if not 0 <= time_hi_version < 1<<16L:
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raise ValueError('field 3 out of range (need a 16-bit value)')
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if not 0 <= clock_seq_hi_variant < 1<<8L:
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raise ValueError('field 4 out of range (need an 8-bit value)')
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if not 0 <= clock_seq_low < 1<<8L:
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raise ValueError('field 5 out of range (need an 8-bit value)')
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if not 0 <= node < 1<<48L:
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raise ValueError('field 6 out of range (need a 48-bit value)')
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clock_seq = (clock_seq_hi_variant << 8L) | clock_seq_low
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int = ((time_low << 96L) | (time_mid << 80L) |
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(time_hi_version << 64L) | (clock_seq << 48L) | node)
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if int is not None:
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if not 0 <= int < 1<<128L:
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raise ValueError('int is out of range (need a 128-bit value)')
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if version is not None:
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if not 1 <= version <= 5:
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raise ValueError('illegal version number')
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# Set the variant to RFC 4122.
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int &= ~(0xc000 << 48L)
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int |= 0x8000 << 48L
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# Set the version number.
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int &= ~(0xf000 << 64L)
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int |= version << 76L
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self.__dict__['int'] = int
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def __cmp__(self, other):
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if isinstance(other, UUID):
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return cmp(self.int, other.int)
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return NotImplemented
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def __hash__(self):
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return hash(self.int)
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def __int__(self):
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return self.int
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def __repr__(self):
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return 'UUID(%r)' % str(self)
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def __setattr__(self, name, value):
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raise TypeError('UUID objects are immutable')
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def __str__(self):
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hex = '%032x' % self.int
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return '%s-%s-%s-%s-%s' % (
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hex[:8], hex[8:12], hex[12:16], hex[16:20], hex[20:])
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def get_bytes(self):
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bytes = ''
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for shift in range(0, 128, 8):
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bytes = chr((self.int >> shift) & 0xff) + bytes
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return bytes
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bytes = property(get_bytes)
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def get_bytes_le(self):
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bytes = self.bytes
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return (bytes[3] + bytes[2] + bytes[1] + bytes[0] +
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bytes[5] + bytes[4] + bytes[7] + bytes[6] + bytes[8:])
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bytes_le = property(get_bytes_le)
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def get_fields(self):
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return (self.time_low, self.time_mid, self.time_hi_version,
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self.clock_seq_hi_variant, self.clock_seq_low, self.node)
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fields = property(get_fields)
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def get_time_low(self):
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return self.int >> 96L
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time_low = property(get_time_low)
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def get_time_mid(self):
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return (self.int >> 80L) & 0xffff
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time_mid = property(get_time_mid)
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def get_time_hi_version(self):
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return (self.int >> 64L) & 0xffff
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time_hi_version = property(get_time_hi_version)
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def get_clock_seq_hi_variant(self):
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return (self.int >> 56L) & 0xff
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clock_seq_hi_variant = property(get_clock_seq_hi_variant)
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def get_clock_seq_low(self):
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return (self.int >> 48L) & 0xff
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clock_seq_low = property(get_clock_seq_low)
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def get_time(self):
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return (((self.time_hi_version & 0x0fffL) << 48L) |
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(self.time_mid << 32L) | self.time_low)
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time = property(get_time)
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def get_clock_seq(self):
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return (((self.clock_seq_hi_variant & 0x3fL) << 8L) |
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self.clock_seq_low)
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clock_seq = property(get_clock_seq)
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def get_node(self):
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return self.int & 0xffffffffffff
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node = property(get_node)
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def get_hex(self):
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return '%032x' % self.int
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hex = property(get_hex)
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def get_urn(self):
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return 'urn:uuid:' + str(self)
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urn = property(get_urn)
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def get_variant(self):
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if not self.int & (0x8000 << 48L):
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return RESERVED_NCS
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elif not self.int & (0x4000 << 48L):
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return RFC_4122
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elif not self.int & (0x2000 << 48L):
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return RESERVED_MICROSOFT
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else:
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return RESERVED_FUTURE
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variant = property(get_variant)
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def get_version(self):
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# The version bits are only meaningful for RFC 4122 UUIDs.
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if self.variant == RFC_4122:
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return int((self.int >> 76L) & 0xf)
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version = property(get_version)
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def _find_mac(command, args, hw_identifiers, get_index):
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import os
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for dir in ['', '/sbin/', '/usr/sbin']:
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executable = os.path.join(dir, command)
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if not os.path.exists(executable):
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continue
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try:
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# LC_ALL to get English output, 2>/dev/null to
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# prevent output on stderr
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cmd = 'LC_ALL=C %s %s 2>/dev/null' % (executable, args)
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pipe = os.popen(cmd)
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except IOError:
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continue
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for line in pipe:
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words = line.lower().split()
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for i in range(len(words)):
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if words[i] in hw_identifiers:
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return int(words[get_index(i)].replace(':', ''), 16)
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return None
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def _ifconfig_getnode():
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"""Get the hardware address on Unix by running ifconfig."""
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# This works on Linux ('' or '-a'), Tru64 ('-av'), but not all Unixes.
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for args in ('', '-a', '-av'):
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mac = _find_mac('ifconfig', args, ['hwaddr', 'ether'], lambda i: i+1)
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if mac:
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return mac
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import socket
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ip_addr = socket.gethostbyname(socket.gethostname())
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# Try getting the MAC addr from arp based on our IP address (Solaris).
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mac = _find_mac('arp', '-an', [ip_addr], lambda i: -1)
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if mac:
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return mac
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# This might work on HP-UX.
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mac = _find_mac('lanscan', '-ai', ['lan0'], lambda i: 0)
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if mac:
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return mac
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return None
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def _ipconfig_getnode():
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"""Get the hardware address on Windows by running ipconfig.exe."""
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import os, re
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dirs = ['', r'c:\windows\system32', r'c:\winnt\system32']
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try:
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import ctypes
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buffer = ctypes.create_string_buffer(300)
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ctypes.windll.kernel32.GetSystemDirectoryA(buffer, 300)
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dirs.insert(0, buffer.value.decode('mbcs'))
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except:
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pass
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for dir in dirs:
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try:
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pipe = os.popen(os.path.join(dir, 'ipconfig') + ' /all')
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except IOError:
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continue
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for line in pipe:
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value = line.split(':')[-1].strip().lower()
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if re.match('([0-9a-f][0-9a-f]-){5}[0-9a-f][0-9a-f]', value):
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return int(value.replace('-', ''), 16)
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def _netbios_getnode():
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"""Get the hardware address on Windows using NetBIOS calls.
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See http://support.microsoft.com/kb/118623 for details."""
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import win32wnet, netbios
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ncb = netbios.NCB()
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ncb.Command = netbios.NCBENUM
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ncb.Buffer = adapters = netbios.LANA_ENUM()
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adapters._pack()
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if win32wnet.Netbios(ncb) != 0:
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return
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adapters._unpack()
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for i in range(adapters.length):
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ncb.Reset()
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ncb.Command = netbios.NCBRESET
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ncb.Lana_num = ord(adapters.lana[i])
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if win32wnet.Netbios(ncb) != 0:
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continue
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ncb.Reset()
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ncb.Command = netbios.NCBASTAT
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ncb.Lana_num = ord(adapters.lana[i])
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ncb.Callname = '*'.ljust(16)
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ncb.Buffer = status = netbios.ADAPTER_STATUS()
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if win32wnet.Netbios(ncb) != 0:
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continue
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status._unpack()
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bytes = map(ord, status.adapter_address)
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return ((bytes[0]<<40L) + (bytes[1]<<32L) + (bytes[2]<<24L) +
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(bytes[3]<<16L) + (bytes[4]<<8L) + bytes[5])
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# Thanks to Thomas Heller for ctypes and for his help with its use here.
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# If ctypes is available, use it to find system routines for UUID generation.
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_uuid_generate_random = _uuid_generate_time = _UuidCreate = None
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try:
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import ctypes, ctypes.util
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_buffer = ctypes.create_string_buffer(16)
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# The uuid_generate_* routines are provided by libuuid on at least
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# Linux and FreeBSD, and provided by libc on Mac OS X.
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for libname in ['uuid', 'c']:
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try:
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lib = ctypes.CDLL(ctypes.util.find_library(libname))
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except:
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continue
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if hasattr(lib, 'uuid_generate_random'):
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_uuid_generate_random = lib.uuid_generate_random
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if hasattr(lib, 'uuid_generate_time'):
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_uuid_generate_time = lib.uuid_generate_time
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# On Windows prior to 2000, UuidCreate gives a UUID containing the
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# hardware address. On Windows 2000 and later, UuidCreate makes a
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# random UUID and UuidCreateSequential gives a UUID containing the
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# hardware address. These routines are provided by the RPC runtime.
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# NOTE: at least on Tim's WinXP Pro SP2 desktop box, while the last
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# 6 bytes returned by UuidCreateSequential are fixed, they don't appear
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# to bear any relationship to the MAC address of any network device
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# on the box.
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try:
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lib = ctypes.windll.rpcrt4
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except:
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lib = None
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_UuidCreate = getattr(lib, 'UuidCreateSequential',
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getattr(lib, 'UuidCreate', None))
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except:
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pass
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def _unixdll_getnode():
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"""Get the hardware address on Unix using ctypes."""
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_uuid_generate_time(_buffer)
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return UUID(bytes=_buffer.raw).node
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|
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def _windll_getnode():
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"""Get the hardware address on Windows using ctypes."""
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if _UuidCreate(_buffer) == 0:
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return UUID(bytes=_buffer.raw).node
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|
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def _random_getnode():
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"""Get a random node ID, with eighth bit set as suggested by RFC 4122."""
|
|
import random
|
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return random.randrange(0, 1<<48L) | 0x010000000000L
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|
|
_node = None
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|
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def getnode():
|
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"""Get the hardware address as a 48-bit positive integer.
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|
|
The first time this runs, it may launch a separate program, which could
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|
be quite slow. If all attempts to obtain the hardware address fail, we
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choose a random 48-bit number with its eighth bit set to 1 as recommended
|
|
in RFC 4122.
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"""
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|
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global _node
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if _node is not None:
|
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return _node
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|
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import sys
|
|
if sys.platform == 'win32':
|
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getters = [_windll_getnode, _netbios_getnode, _ipconfig_getnode]
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|
else:
|
|
getters = [_unixdll_getnode, _ifconfig_getnode]
|
|
|
|
for getter in getters + [_random_getnode]:
|
|
try:
|
|
_node = getter()
|
|
except:
|
|
continue
|
|
if _node is not None:
|
|
return _node
|
|
|
|
_last_timestamp = None
|
|
|
|
def uuid1(node=None, clock_seq=None):
|
|
"""Generate a UUID from a host ID, sequence number, and the current time.
|
|
If 'node' is not given, getnode() is used to obtain the hardware
|
|
address. If 'clock_seq' is given, it is used as the sequence number;
|
|
otherwise a random 14-bit sequence number is chosen."""
|
|
|
|
# When the system provides a version-1 UUID generator, use it (but don't
|
|
# use UuidCreate here because its UUIDs don't conform to RFC 4122).
|
|
if _uuid_generate_time and node is clock_seq is None:
|
|
_uuid_generate_time(_buffer)
|
|
return UUID(bytes=_buffer.raw)
|
|
|
|
global _last_timestamp
|
|
import time
|
|
nanoseconds = int(time.time() * 1e9)
|
|
# 0x01b21dd213814000 is the number of 100-ns intervals between the
|
|
# UUID epoch 1582-10-15 00:00:00 and the Unix epoch 1970-01-01 00:00:00.
|
|
timestamp = int(nanoseconds/100) + 0x01b21dd213814000L
|
|
if timestamp <= _last_timestamp:
|
|
timestamp = _last_timestamp + 1
|
|
_last_timestamp = timestamp
|
|
if clock_seq is None:
|
|
import random
|
|
clock_seq = random.randrange(1<<14L) # instead of stable storage
|
|
time_low = timestamp & 0xffffffffL
|
|
time_mid = (timestamp >> 32L) & 0xffffL
|
|
time_hi_version = (timestamp >> 48L) & 0x0fffL
|
|
clock_seq_low = clock_seq & 0xffL
|
|
clock_seq_hi_variant = (clock_seq >> 8L) & 0x3fL
|
|
if node is None:
|
|
node = getnode()
|
|
return UUID(fields=(time_low, time_mid, time_hi_version,
|
|
clock_seq_hi_variant, clock_seq_low, node), version=1)
|
|
|
|
def uuid3(namespace, name):
|
|
"""Generate a UUID from the MD5 hash of a namespace UUID and a name."""
|
|
import md5
|
|
hash = md5.md5(namespace.bytes + name).digest()
|
|
return UUID(bytes=hash[:16], version=3)
|
|
|
|
def uuid4():
|
|
"""Generate a random UUID."""
|
|
|
|
# When the system provides a version-4 UUID generator, use it.
|
|
if _uuid_generate_random:
|
|
_uuid_generate_random(_buffer)
|
|
return UUID(bytes=_buffer.raw)
|
|
|
|
# Otherwise, get randomness from urandom or the 'random' module.
|
|
try:
|
|
import os
|
|
return UUID(bytes=os.urandom(16), version=4)
|
|
except:
|
|
import random
|
|
bytes = [chr(random.randrange(256)) for i in range(16)]
|
|
return UUID(bytes=bytes, version=4)
|
|
|
|
def uuid5(namespace, name):
|
|
"""Generate a UUID from the SHA-1 hash of a namespace UUID and a name."""
|
|
import sha
|
|
hash = sha.sha(namespace.bytes + name).digest()
|
|
return UUID(bytes=hash[:16], version=5)
|
|
|
|
# The following standard UUIDs are for use with uuid3() or uuid5().
|
|
|
|
NAMESPACE_DNS = UUID('6ba7b810-9dad-11d1-80b4-00c04fd430c8')
|
|
NAMESPACE_URL = UUID('6ba7b811-9dad-11d1-80b4-00c04fd430c8')
|
|
NAMESPACE_OID = UUID('6ba7b812-9dad-11d1-80b4-00c04fd430c8')
|
|
NAMESPACE_X500 = UUID('6ba7b814-9dad-11d1-80b4-00c04fd430c8')
|