# Copyright (C) Dnspython Contributors, see LICENSE for text of ISC license """Serial Number Arthimetic from RFC 1982""" class Serial: def __init__(self, value: int, bits: int = 32): self.value = value % 2**bits self.bits = bits def __repr__(self): return f"dns.serial.Serial({self.value}, {self.bits})" def __eq__(self, other): if isinstance(other, int): other = Serial(other, self.bits) elif not isinstance(other, Serial) or other.bits != self.bits: return NotImplemented return self.value == other.value def __ne__(self, other): if isinstance(other, int): other = Serial(other, self.bits) elif not isinstance(other, Serial) or other.bits != self.bits: return NotImplemented return self.value != other.value def __lt__(self, other): if isinstance(other, int): other = Serial(other, self.bits) elif not isinstance(other, Serial) or other.bits != self.bits: return NotImplemented if self.value < other.value and other.value - self.value < 2 ** (self.bits - 1): return True elif self.value > other.value and self.value - other.value > 2 ** ( self.bits - 1 ): return True else: return False def __le__(self, other): return self == other or self < other def __gt__(self, other): if isinstance(other, int): other = Serial(other, self.bits) elif not isinstance(other, Serial) or other.bits != self.bits: return NotImplemented if self.value < other.value and other.value - self.value > 2 ** (self.bits - 1): return True elif self.value > other.value and self.value - other.value < 2 ** ( self.bits - 1 ): return True else: return False def __ge__(self, other): return self == other or self > other def __add__(self, other): v = self.value if isinstance(other, Serial): delta = other.value elif isinstance(other, int): delta = other else: raise ValueError if abs(delta) > (2 ** (self.bits - 1) - 1): raise ValueError v += delta v = v % 2**self.bits return Serial(v, self.bits) def __iadd__(self, other): v = self.value if isinstance(other, Serial): delta = other.value elif isinstance(other, int): delta = other else: raise ValueError if abs(delta) > (2 ** (self.bits - 1) - 1): raise ValueError v += delta v = v % 2**self.bits self.value = v return self def __sub__(self, other): v = self.value if isinstance(other, Serial): delta = other.value elif isinstance(other, int): delta = other else: raise ValueError if abs(delta) > (2 ** (self.bits - 1) - 1): raise ValueError v -= delta v = v % 2**self.bits return Serial(v, self.bits) def __isub__(self, other): v = self.value if isinstance(other, Serial): delta = other.value elif isinstance(other, int): delta = other else: raise ValueError if abs(delta) > (2 ** (self.bits - 1) - 1): raise ValueError v -= delta v = v % 2**self.bits self.value = v return self