/usr/share/pyshared/pysnmp/nextid.py is in python-pysnmp4 4.2.2-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 | # Return a next value in a reasonably MT-safe manner
import random
random.seed()
class Integer:
def __init__(self, maximum, increment=256):
self.__maximum = maximum
if increment >= maximum:
increment = maximum
self.__increment = increment
self.__threshold = increment//2
e = random.randrange(self.__maximum - self.__increment)
self.__bank = list(range(e, e+self.__increment))
def __repr__(self):
return '%s(%d, %d)' % (
self.__class__.__name__,
self.__maximum,
self.__increment
)
def __call__(self):
v = self.__bank.pop(0)
if v % self.__threshold:
return v
else:
# this is MT-safe unless too many (~ increment/2) threads
# bump into this code simultaneously
e = self.__bank[-1]+1
if e > self.__maximum:
e = 0
self.__bank.extend(range(e, e+self.__threshold))
return v
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