PyBitmessage/rsa/parallel.py

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2012-11-19 20:45:05 +01:00
# -*- coding: utf-8 -*-
#
# Copyright 2011 Sybren A. Stüvel <sybren@stuvel.eu>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
'''Functions for parallel computation on multiple cores.
Introduced in Python-RSA 3.1.
.. note::
Requires Python 2.6 or newer.
'''
from __future__ import print_function
import multiprocessing as mp
import rsa.prime
import rsa.randnum
def _find_prime(nbits, pipe):
while True:
integer = rsa.randnum.read_random_int(nbits)
# Make sure it's odd
integer |= 1
# Test for primeness
if rsa.prime.is_prime(integer):
pipe.send(integer)
return
def getprime(nbits, poolsize):
'''Returns a prime number that can be stored in 'nbits' bits.
Works in multiple threads at the same time.
>>> p = getprime(128, 3)
>>> rsa.prime.is_prime(p-1)
False
>>> rsa.prime.is_prime(p)
True
>>> rsa.prime.is_prime(p+1)
False
>>> from rsa import common
>>> common.bit_size(p) == 128
True
'''
(pipe_recv, pipe_send) = mp.Pipe(duplex=False)
# Create processes
procs = [mp.Process(target=_find_prime, args=(nbits, pipe_send))
for _ in range(poolsize)]
[p.start() for p in procs]
result = pipe_recv.recv()
[p.terminate() for p in procs]
return result
__all__ = ['getprime']
if __name__ == '__main__':
print('Running doctests 1000x or until failure')
import doctest
for count in range(100):
(failures, tests) = doctest.testmod()
if failures:
break
if count and count % 10 == 0:
print('%i times' % count)
print('Doctests done')