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from ctypes import *
import unittest
import struct
def valid_ranges(*types):
# given a sequence of numeric types, collect their _type_
# attribute, which is a single format character compatible with
# the struct module, use the struct module to calculate the
# minimum and maximum value allowed for this format.
# Returns a list of (min, max) values.
result = []
for t in types:
fmt = t._type_
size = struct.calcsize(fmt)
a = struct.unpack(fmt, ("\x00"*32)[:size])[0]
b = struct.unpack(fmt, ("\xFF"*32)[:size])[0]
c = struct.unpack(fmt, ("\x7F"+"\x00"*32)[:size])[0]
d = struct.unpack(fmt, ("\x80"+"\xFF"*32)[:size])[0]
result.append((min(a, b, c, d), max(a, b, c, d)))
return result
ArgType = type(byref(c_int(0)))
unsigned_types = [c_ubyte, c_ushort, c_uint, c_ulong]
signed_types = [c_byte, c_short, c_int, c_long, c_longlong]
bool_types = []
float_types = [c_double, c_float]
try:
c_ulonglong
c_longlong
except NameError:
pass
else:
unsigned_types.append(c_ulonglong)
signed_types.append(c_longlong)
try:
c_bool
except NameError:
pass
else:
bool_types.append(c_bool)
unsigned_ranges = valid_ranges(*unsigned_types)
signed_ranges = valid_ranges(*signed_types)
bool_values = [True, False, 0, 1, -1, 5000, 'test', [], [1]]
################################################################
class NumberTestCase(unittest.TestCase):
def test_default_init(self):
# default values are set to zero
for t in signed_types + unsigned_types + float_types:
self.assertEqual(t().value, 0)
def test_unsigned_values(self):
# the value given to the constructor is available
# as the 'value' attribute
for t, (l, h) in zip(unsigned_types, unsigned_ranges):
self.assertEqual(t(l).value, l)
self.assertEqual(t(h).value, h)
def test_signed_values(self):
# see above
for t, (l, h) in zip(signed_types, signed_ranges):
self.assertEqual(t(l).value, l)
self.assertEqual(t(h).value, h)
def test_bool_values(self):
from operator import truth
for t, v in zip(bool_types, bool_values):
self.assertEqual(t(v).value, truth(v))
def test_typeerror(self):
# Only numbers are allowed in the contructor,
# otherwise TypeError is raised
for t in signed_types + unsigned_types + float_types:
self.assertRaises(TypeError, t, "")
self.assertRaises(TypeError, t, None)
## def test_valid_ranges(self):
## # invalid values of the correct type
## # raise ValueError (not OverflowError)
## for t, (l, h) in zip(unsigned_types, unsigned_ranges):
## self.assertRaises(ValueError, t, l-1)
## self.assertRaises(ValueError, t, h+1)
def test_from_param(self):
# the from_param class method attribute always
# returns PyCArgObject instances
for t in signed_types + unsigned_types + float_types:
self.assertEqual(ArgType, type(t.from_param(0)))
def test_byref(self):
# calling byref returns also a PyCArgObject instance
for t in signed_types + unsigned_types + float_types + bool_types:
parm = byref(t())
self.assertEqual(ArgType, type(parm))
def test_floats(self):
# c_float and c_double can be created from
# Python int, long and float
class FloatLike(object):
def __float__(self):
return 2.0
f = FloatLike()
for t in float_types:
self.assertEqual(t(2.0).value, 2.0)
self.assertEqual(t(2).value, 2.0)
self.assertEqual(t(2L).value, 2.0)
self.assertEqual(t(f).value, 2.0)
def test_integers(self):
class FloatLike(object):
def __float__(self):
return 2.0
f = FloatLike()
class IntLike(object):
def __int__(self):
return 2
i = IntLike()
# integers cannot be constructed from floats,
# but from integer-like objects
for t in signed_types + unsigned_types:
self.assertRaises(TypeError, t, 3.14)
self.assertRaises(TypeError, t, f)
self.assertEqual(t(i).value, 2)
def test_sizes(self):
for t in signed_types + unsigned_types + float_types + bool_types:
try:
size = struct.calcsize(t._type_)
except struct.error:
continue
# sizeof of the type...
self.assertEqual(sizeof(t), size)
# and sizeof of an instance
self.assertEqual(sizeof(t()), size)
def test_alignments(self):
for t in signed_types + unsigned_types + float_types:
code = t._type_ # the typecode
align = struct.calcsize("c%c" % code) - struct.calcsize(code)
# alignment of the type...
self.assertEqual((code, alignment(t)),
(code, align))
# and alignment of an instance
self.assertEqual((code, alignment(t())),
(code, align))
def test_int_from_address(self):
from array import array
for t in signed_types + unsigned_types:
# the array module doesn't support all format codes
# (no 'q' or 'Q')
try:
array(t._type_)
except ValueError:
continue
a = array(t._type_, [100])
# v now is an integer at an 'external' memory location
v = t.from_address(a.buffer_info()[0])
self.assertEqual(v.value, a[0])
self.assertEqual(type(v), t)
# changing the value at the memory location changes v's value also
a[0] = 42
self.assertEqual(v.value, a[0])
def test_float_from_address(self):
from array import array
for t in float_types:
a = array(t._type_, [3.14])
v = t.from_address(a.buffer_info()[0])
self.assertEqual(v.value, a[0])
self.assertTrue(type(v) is t)
a[0] = 2.3456e17
self.assertEqual(v.value, a[0])
self.assertTrue(type(v) is t)
def test_char_from_address(self):
from ctypes import c_char
from array import array
a = array('c', 'x')
v = c_char.from_address(a.buffer_info()[0])
self.assertEqual(v.value, a[0])
self.assertTrue(type(v) is c_char)
a[0] = '?'
self.assertEqual(v.value, a[0])
# array does not support c_bool / 't'
# def test_bool_from_address(self):
# from ctypes import c_bool
# from array import array
# a = array(c_bool._type_, [True])
# v = t.from_address(a.buffer_info()[0])
# self.assertEqual(v.value, a[0])
# self.assertEqual(type(v) is t)
# a[0] = False
# self.assertEqual(v.value, a[0])
# self.assertEqual(type(v) is t)
def test_init(self):
# c_int() can be initialized from Python's int, and c_int.
# Not from c_long or so, which seems strange, abd should
# probably be changed:
self.assertRaises(TypeError, c_int, c_long(42))
def test_float_overflow(self):
import sys
big_int = int(sys.float_info.max) * 2
for t in float_types + [c_longdouble]:
self.assertRaises(OverflowError, t, big_int)
if (hasattr(t, "__ctype_be__")):
self.assertRaises(OverflowError, t.__ctype_be__, big_int)
if (hasattr(t, "__ctype_le__")):
self.assertRaises(OverflowError, t.__ctype_le__, big_int)
## def test_perf(self):
## check_perf()
from ctypes import _SimpleCData
class c_int_S(_SimpleCData):
_type_ = "i"
__slots__ = []
def run_test(rep, msg, func, arg=None):
## items = [None] * rep
items = range(rep)
from time import clock
if arg is not None:
start = clock()
for i in items:
func(arg); func(arg); func(arg); func(arg); func(arg)
stop = clock()
else:
start = clock()
for i in items:
func(); func(); func(); func(); func()
stop = clock()
print "%15s: %.2f us" % (msg, ((stop-start)*1e6/5/rep))
def check_perf():
# Construct 5 objects
from ctypes import c_int
REP = 200000
run_test(REP, "int()", int)
run_test(REP, "int(999)", int)
run_test(REP, "c_int()", c_int)
run_test(REP, "c_int(999)", c_int)
run_test(REP, "c_int_S()", c_int_S)
run_test(REP, "c_int_S(999)", c_int_S)
# Python 2.3 -OO, win2k, P4 700 MHz:
#
# int(): 0.87 us
# int(999): 0.87 us
# c_int(): 3.35 us
# c_int(999): 3.34 us
# c_int_S(): 3.23 us
# c_int_S(999): 3.24 us
# Python 2.2 -OO, win2k, P4 700 MHz:
#
# int(): 0.89 us
# int(999): 0.89 us
# c_int(): 9.99 us
# c_int(999): 10.02 us
# c_int_S(): 9.87 us
# c_int_S(999): 9.85 us
if __name__ == '__main__':
## check_perf()
unittest.main()
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