twisted.names._rfc1982.SerialNumber

class documentation

class SerialNumber(FancyStrMixin): (source)

Constructor: SerialNumber(number, serialBits)

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An RFC1982 Serial Number.

This class implements RFC1982 DNS Serial Number Arithmetic.

SNA is used in DNS and specifically in DNSSEC as defined in RFC4034 in the DNSSEC Signature Expiration and Inception Fields.

See Also
https://tools.ietf.org/html/rfc1982
https://tools.ietf.org/html/rfc4034
Class Method fromRFC4034DateString Create an SerialNumber instance from a date string in format 'YYYYMMDDHHMMSS' described in RFC4034 3.2.
Method __add__ Allow addition with another SerialNumber instance.
Method __eq__ Allow rich equality comparison with another SerialNumber instance.
Method __ge__ Allow greater than or equal comparison with another SerialNumber instance.
Method __gt__ Allow greater than comparison with another SerialNumber instance.
Method __hash__ Allow SerialNumber instances to be hashed for use as dict keys.
Method __init__ Construct an SerialNumber instance.
Method __int__ No summary
Method __le__ Allow less than or equal comparison with another SerialNumber instance.
Method __lt__ Allow less than comparison with another SerialNumber instance.
Method __str__ Return a string representation of this SerialNumber instance.
Method toRFC4034DateString Calculate a date by treating the current SerialNumber value as a UNIX timestamp and return a date string in the format described in RFC4034 3.2.
Class Variable showAttributes Undocumented
Method _convertOther Check that a foreign object is suitable for use in the comparison or arithmetic magic methods of this SerialNumber instance. Raise TypeError if not.
Instance Variable _halfRing Half _modulo. If another SerialNumber value is larger than this, it would lead to a wrapped value which is larger than the first and comparisons are therefore ambiguous.
Instance Variable _maxAdd Half _modulo plus 1. If another SerialNumber value is larger than this, it would lead to a wrapped value which is larger than the first. Comparisons with the original value would therefore be ambiguous.
Instance Variable _modulo The value at which wrapping will occur.
Instance Variable _number See number of __init__.
Instance Variable _serialBits See serialBits of __init__.
@classmethod
def fromRFC4034DateString(cls, utcDateString): (source)

Create an SerialNumber instance from a date string in format 'YYYYMMDDHHMMSS' described in RFC4034 3.2.

The SerialNumber instance stores the date as a 32bit UNIX timestamp.

Parameters
utcDateString:unicodeA UTC date/time string of format YYMMDDhhmmss which will be converted to seconds since the UNIX epoch.
Returns
An SerialNumber instance containing the supplied date as a 32bit UNIX timestamp.
See Also
https://tools.ietf.org/html/rfc4034#section-3.1.5
def __add__(self, other: object) -> SerialNumber: (source)

Allow addition with another SerialNumber instance.

Serial numbers may be incremented by the addition of a positive integer n, where n is taken from the range of integers [0 .. (2^(SERIAL_BITS - 1) - 1)]. For a sequence number s, the result of such an addition, s', is defined as

s' = (s + n) modulo (2 ^ SERIAL_BITS)

where the addition and modulus operations here act upon values that are non-negative values of unbounded size in the usual ways of integer arithmetic.

Addition of a value outside the range [0 .. (2^(SERIAL_BITS - 1) - 1)] is undefined.

Raises
ArithmeticErrorIf other is more than _maxAdd ie more than half the maximum value of this serial number.
See Also
http://tools.ietf.org/html/rfc1982#section-3.1
def __eq__(self, other: object) -> bool: (source)

Allow rich equality comparison with another SerialNumber instance.

def __ge__(self, other: object) -> bool: (source)

Allow greater than or equal comparison with another SerialNumber instance.

def __gt__(self, other: object) -> bool: (source)

Allow greater than comparison with another SerialNumber instance.

def __hash__(self): (source)

Allow SerialNumber instances to be hashed for use as dict keys.

Returns
intUndocumented
def __init__(self, number: int, serialBits: int = 32): (source)

Construct an SerialNumber instance.

Parameters
number:intAn int which will be stored as the modulo number % 2 ^ serialBits
serialBits:intThe size of the serial number space. The power of two which results in one larger than the largest integer corresponding to a serial number value.
def __int__(self): (source)
Returns
intThe integer value of this SerialNumber instance.
def __le__(self, other: object) -> bool: (source)

Allow less than or equal comparison with another SerialNumber instance.

def __lt__(self, other: object) -> bool: (source)

Allow less than comparison with another SerialNumber instance.

def __str__(self) -> str: (source)
overrides twisted.python.util.FancyStrMixin.__str__

Return a string representation of this SerialNumber instance.

Returns
nativeStringUndocumented
def toRFC4034DateString(self): (source)

Calculate a date by treating the current SerialNumber value as a UNIX timestamp and return a date string in the format described in RFC4034 3.2.

Returns
The date string.
showAttributes: tuple = (source)
overrides twisted.python.util.FancyStrMixin.showAttributes

Undocumented

def _convertOther(self, other: object) -> SerialNumber: (source)

Check that a foreign object is suitable for use in the comparison or arithmetic magic methods of this SerialNumber instance. Raise TypeError if not.

Parameters
other:objectThe foreign object to be checked.
Returns
SerialNumberother after compatibility checks and possible coercion.
Raises
TypeErrorIf other is not compatible.
_halfRing: int = (source)

Half _modulo. If another SerialNumber value is larger than this, it would lead to a wrapped value which is larger than the first and comparisons are therefore ambiguous.

_maxAdd = (source)

Half _modulo plus 1. If another SerialNumber value is larger than this, it would lead to a wrapped value which is larger than the first. Comparisons with the original value would therefore be ambiguous.

_modulo = (source)

The value at which wrapping will occur.

_number: int = (source)

See number of __init__.

_serialBits = (source)

See serialBits of __init__.