| Index: third_party/google-endpoints/Crypto/Util/_number_new.py
|
| diff --git a/third_party/google-endpoints/Crypto/Util/_number_new.py b/third_party/google-endpoints/Crypto/Util/_number_new.py
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..b040025f38801d877aa767c49b84abeeedd2fa1c
|
| --- /dev/null
|
| +++ b/third_party/google-endpoints/Crypto/Util/_number_new.py
|
| @@ -0,0 +1,119 @@
|
| +# -*- coding: ascii -*-
|
| +#
|
| +# Util/_number_new.py : utility functions
|
| +#
|
| +# Written in 2008 by Dwayne C. Litzenberger <dlitz@dlitz.net>
|
| +#
|
| +# ===================================================================
|
| +# The contents of this file are dedicated to the public domain. To
|
| +# the extent that dedication to the public domain is not available,
|
| +# everyone is granted a worldwide, perpetual, royalty-free,
|
| +# non-exclusive license to exercise all rights associated with the
|
| +# contents of this file for any purpose whatsoever.
|
| +# No rights are reserved.
|
| +#
|
| +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
|
| +# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
| +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
|
| +# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
|
| +# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
|
| +# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
|
| +# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
| +# SOFTWARE.
|
| +# ===================================================================
|
| +
|
| +## NOTE: Do not import this module directly. Import these functions from Crypto.Util.number.
|
| +
|
| +__revision__ = "$Id$"
|
| +__all__ = ['ceil_shift', 'ceil_div', 'floor_div', 'exact_log2', 'exact_div']
|
| +
|
| +import sys
|
| +if sys.version_info[0] == 2 and sys.version_info[1] == 1:
|
| + from Crypto.Util.py21compat import *
|
| +
|
| +def ceil_shift(n, b):
|
| + """Return ceil(n / 2**b) without performing any floating-point or division operations.
|
| +
|
| + This is done by right-shifting n by b bits and incrementing the result by 1
|
| + if any '1' bits were shifted out.
|
| + """
|
| + if not isinstance(n, (int, long)) or not isinstance(b, (int, long)):
|
| + raise TypeError("unsupported operand type(s): %r and %r" % (type(n).__name__, type(b).__name__))
|
| +
|
| + assert n >= 0 and b >= 0 # I haven't tested or even thought about negative values
|
| + mask = (1L << b) - 1
|
| + if n & mask:
|
| + return (n >> b) + 1
|
| + else:
|
| + return n >> b
|
| +
|
| +def ceil_div(a, b):
|
| + """Return ceil(a / b) without performing any floating-point operations."""
|
| +
|
| + if not isinstance(a, (int, long)) or not isinstance(b, (int, long)):
|
| + raise TypeError("unsupported operand type(s): %r and %r" % (type(a).__name__, type(b).__name__))
|
| +
|
| + (q, r) = divmod(a, b)
|
| + if r:
|
| + return q + 1
|
| + else:
|
| + return q
|
| +
|
| +def floor_div(a, b):
|
| + if not isinstance(a, (int, long)) or not isinstance(b, (int, long)):
|
| + raise TypeError("unsupported operand type(s): %r and %r" % (type(a).__name__, type(b).__name__))
|
| +
|
| + (q, r) = divmod(a, b)
|
| + return q
|
| +
|
| +def exact_log2(num):
|
| + """Find and return an integer i >= 0 such that num == 2**i.
|
| +
|
| + If no such integer exists, this function raises ValueError.
|
| + """
|
| +
|
| + if not isinstance(num, (int, long)):
|
| + raise TypeError("unsupported operand type: %r" % (type(num).__name__,))
|
| +
|
| + n = long(num)
|
| + if n <= 0:
|
| + raise ValueError("cannot compute logarithm of non-positive number")
|
| +
|
| + i = 0
|
| + while n != 0:
|
| + if (n & 1) and n != 1:
|
| + raise ValueError("No solution could be found")
|
| + i += 1
|
| + n >>= 1
|
| + i -= 1
|
| +
|
| + assert num == (1L << i)
|
| + return i
|
| +
|
| +def exact_div(p, d, allow_divzero=False):
|
| + """Find and return an integer n such that p == n * d
|
| +
|
| + If no such integer exists, this function raises ValueError.
|
| +
|
| + Both operands must be integers.
|
| +
|
| + If the second operand is zero, this function will raise ZeroDivisionError
|
| + unless allow_divzero is true (default: False).
|
| + """
|
| +
|
| + if not isinstance(p, (int, long)) or not isinstance(d, (int, long)):
|
| + raise TypeError("unsupported operand type(s): %r and %r" % (type(p).__name__, type(d).__name__))
|
| +
|
| + if d == 0 and allow_divzero:
|
| + n = 0
|
| + if p != n * d:
|
| + raise ValueError("No solution could be found")
|
| + else:
|
| + (n, r) = divmod(p, d)
|
| + if r != 0:
|
| + raise ValueError("No solution could be found")
|
| +
|
| + assert p == n * d
|
| + return n
|
| +
|
| +# vim:set ts=4 sw=4 sts=4 expandtab:
|
|
|