twisted.names._rfc1982.SerialNumber(FancyStrMixin, object) class documentation

Part of twisted.names._rfc1982 View Source (View In Hierarchy)

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 Alsohttps://tools.ietf.org/html/rfc1982
https://tools.ietf.org/html/rfc4034
Method __init__ Construct an SerialNumber instance.
Method __str__ Return a string representation of this SerialNumber instance.
Method __int__
Method __eq__ Allow rich equality comparison with another SerialNumber instance.
Method __ne__ Allow rich equality comparison with another SerialNumber instance.
Method __lt__ Allow less than comparison with another SerialNumber instance.
Method __gt__ Allow greater than comparison with another SerialNumber instance.
Method __le__ Allow less than or equal comparison with another SerialNumber instance.
Method __ge__ Allow greater than or equal comparison with another SerialNumber instance.
Method __add__ Allow addition with another SerialNumber instance.
Method __hash__ Allow SerialNumber instances to be hashed for use as dict keys.
Class Method fromRFC4034DateString Create an SerialNumber instance from a date string in format 'YYYYMMDDHHMMSS' described in RFC4034 3.2.
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.
Instance Variable _serialBits See serialBits of __init__.
Instance Variable _number See number of __init__.
Instance Variable _modulo The value at which wrapping will occur.
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.
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.
_serialBits =
See serialBits of __init__.
_number =
See number of __init__.
_modulo =
The value at which wrapping will occur.
_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.
_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.
def __init__(self, number, serialBits=32): (source)

Construct an SerialNumber instance.

ParametersnumberAn int which will be stored as the modulo number % 2 ^ serialBits (type: int)
serialBitsThe 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. (type: int)
def _convertOther(self, other): (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.

ParametersotherThe foreign object to be checked.
Returnsother after compatibility checks and possible coercion.
RaisesTypeError if other is not compatible.
def __str__(self): (source)
overrides twisted.python.util.FancyStrMixin.__str__

Return a string representation of this SerialNumber instance.

Returns (type: nativeString)
def __int__(self): (source)
ReturnsThe integer value of this SerialNumber instance. (type: int)
def __eq__(self, other): (source)

Allow rich equality comparison with another SerialNumber instance.

def __ne__(self, other): (source)

Allow rich equality comparison with another SerialNumber instance.

def __lt__(self, other): (source)

Allow less than comparison with another SerialNumber instance.

def __gt__(self, other): (source)

Allow greater than comparison with another SerialNumber instance.

Returns (type: bool)
def __le__(self, other): (source)

Allow less than or equal comparison with another SerialNumber instance.

Returns (type: bool)
def __ge__(self, other): (source)

Allow greater than or equal comparison with another SerialNumber instance.

Returns (type: bool)
def __add__(self, other): (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.

Returns (type: SerialNumber)
RaisesArithmeticError if other is more than _maxAdd ie more than half the maximum value of this serial number.
See Alsohttp://tools.ietf.org/html/rfc1982#section-3.1
def __hash__(self): (source)

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

Returns (type: int)
@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.

ParametersutcDateStringA UTC date/time string of format YYMMDDhhmmss which will be converted to seconds since the UNIX epoch. (type: unicode)
ReturnsAn SerialNumber instance containing the supplied date as a 32bit UNIX timestamp.
See Alsohttps://tools.ietf.org/html/rfc4034#section-3.1.5
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.

ReturnsThe date string.
API Documentation for Twisted, generated by pydoctor at 2015-05-24 20:04:00.