Added parallel.py module and ability to use multiprocessing when generating keys

1 files changed, 92 insertions, 0 deletions

diff --git a/rsa/parallel.py b/rsa/parallel.py
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+# -*- 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.
+
+'''
+
+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'
+