Add google-endpoints to third_party/.

third_party/google-endpoints/rsa/parallel.py

+# -*- 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
+#
+#      https://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_odd_int(nbits)
+
+        # 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
+    try:
+        procs = [mp.Process(target=_find_prime, args=(nbits, pipe_send))
+                 for _ in range(poolsize)]
+        # Start processes
+        for p in procs:
+            p.start()
+
+        result = pipe_recv.recv()
+    finally:
+        pipe_recv.close()
+        pipe_send.close()
+
+    # Terminate processes
+    for p in procs:
+        p.terminate()
+
+    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')