mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-08-04 08:59:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 11

Issue #15402: Simplify Struct.__sizeof__ and make tests more precise.

Browse source
This commit is contained in:
Meador Inge 2012-07-28 22:32:50 -05:00
commit bb9b1c165d
2 changed files with 43 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

51
Lib/test/test_struct.py
View file

@ -3,7 +3,7 @@ import unittest
import struct
import sys
from test.support import run_unittest
from test.support import run_unittest, cpython_only
ISBIGENDIAN = sys.byteorder == "big"
IS32BIT = sys.maxsize == 0x7fffffff
@ -40,6 +40,33 @@ def bigendian_to_native(value):
return string_reverse(value)
class StructTest(unittest.TestCase):
def setUp(self):
# due to missing size_t information from struct, it is assumed that
# sizeof(Py_ssize_t) = sizeof(void*)
self.header = 'PP'
if hasattr(sys, "gettotalrefcount"):
self.header += '2P'
def check_sizeof(self, format_str, number_of_codes):
def size(fmt):
"""Wrapper around struct.calcsize which enforces the alignment
of the end of a structure to the alignment requirement of pointer.
Note: This wrapper should only be used if a pointer member is
included and no member with a size larger than a pointer exists.
"""
return struct.calcsize(fmt + '0P')
struct_obj = struct.Struct(format_str)
# The size of 'PyStructObject'
totalsize = size(self.header + '5P')
# The size taken up by the 'formatcode' dynamic array
totalsize += size('3P') * (number_of_codes + 1)
result = sys.getsizeof(struct_obj)
msg = 'wrong size for %s: got %d, expected %d' \
% (type(struct_obj), result, totalsize)
self.assertEqual(result, totalsize, msg)
def test_isbigendian(self):
self.assertEqual((struct.pack('=i', 1)[0] == 0), ISBIGENDIAN)
@ -572,15 +599,19 @@ class StructTest(unittest.TestCase):
s = struct.Struct('i')
s.__init__('ii')
def test_sizeof(self):
self.assertGreater(sys.getsizeof(struct.Struct('BHILfdspP')),
sys.getsizeof(struct.Struct('B')))
self.assertGreater(sys.getsizeof(struct.Struct('123B')),
sys.getsizeof(struct.Struct('B')))
self.assertGreater(sys.getsizeof(struct.Struct('B' * 1234)),
sys.getsizeof(struct.Struct('123B')))
self.assertGreater(sys.getsizeof(struct.Struct('1234B')),
sys.getsizeof(struct.Struct('123B')))
@cpython_only
def test__sizeof__(self):
for code in integer_codes:
self.check_sizeof(code, 1)
self.check_sizeof('BHILfdspP', 9)
self.check_sizeof('B' * 1234, 1234)
self.check_sizeof('fd', 2)
self.check_sizeof('xxxxxxxxxxxxxx', 0)
self.check_sizeof('100H', 100)
self.check_sizeof('187s', 1)
self.check_sizeof('20p', 1)
self.check_sizeof('0s', 1)
self.check_sizeof('0c', 0)
def test_main():
run_unittest(StructTest)