import array
import unittest
import struct
import warnings
from functools import wraps
from test.test_support import TestFailed, verbose, run_unittest
import sys
ISBIGENDIAN = sys.byteorder == "big"
IS32BIT = sys.maxsize == 0x7fffffff
del sys
try:
import _struct
except ImportError:
PY_STRUCT_RANGE_CHECKING = 0
PY_STRUCT_OVERFLOW_MASKING = 1
PY_STRUCT_FLOAT_COERCE = 2
else:
PY_STRUCT_RANGE_CHECKING = getattr(_struct, '_PY_STRUCT_RANGE_CHECKING', 0)
PY_STRUCT_OVERFLOW_MASKING = getattr(_struct, '_PY_STRUCT_OVERFLOW_MASKING', 0)
PY_STRUCT_FLOAT_COERCE = getattr(_struct, '_PY_STRUCT_FLOAT_COERCE', 0)
def string_reverse(s):
return "".join(reversed(s))
def bigendian_to_native(value):
if ISBIGENDIAN:
return value
else:
return string_reverse(value)
def with_warning_restore(func):
@wraps(func)
def decorator(*args, **kw):
with warnings.catch_warnings():
# We need this function to warn every time, so stick an
# unqualifed 'always' at the head of the filter list
warnings.simplefilter("always")
warnings.filterwarnings("error", category=DeprecationWarning)
return func(*args, **kw)
return decorator
@with_warning_restore
def deprecated_err(func, *args):
try:
func(*args)
except (struct.error, TypeError):
pass
except DeprecationWarning:
if not PY_STRUCT_OVERFLOW_MASKING:
raise TestFailed, "%s%s expected to raise DeprecationWarning" % (
func.__name__, args)
else:
raise TestFailed, "%s%s did not raise error" % (
func.__name__, args)
class StructTest(unittest.TestCase):
@with_warning_restore
def check_float_coerce(self, format, number):
# SF bug 1530559. struct.pack raises TypeError where it used to convert.
if PY_STRUCT_FLOAT_COERCE == 2:
# Test for pre-2.5 struct module
packed = struct.pack(format, number)
floored = struct.unpack(format, packed)[0]
self.assertEqual(floored, int(number),
"did not correcly coerce float to int")
return
try:
struct.pack(format, number)
except (struct.error, TypeError):
if PY_STRUCT_FLOAT_COERCE:
self.fail("expected DeprecationWarning for float coerce")
except DeprecationWarning:
if not PY_STRUCT_FLOAT_COERCE:
self.fail("expected to raise struct.error for float coerce")
else:
self.fail("did not raise error for float coerce")
def test_isbigendian(self):
self.assertEqual((struct.pack('=i', 1)[0] == chr(0)), ISBIGENDIAN)
def test_consistence(self):
self.assertRaises(struct.error, struct.calcsize, 'Z')
sz = struct.calcsize('i')
self.assertEqual(sz * 3, struct.calcsize('iii'))
fmt = 'cbxxxxxxhhhhiillffd?'
fmt3 = '3c3b18x12h6i6l6f3d3?'
sz = struct.calcsize(fmt)
sz3 = struct.calcsize(fmt3)
self.assertEqual(sz * 3, sz3)
self.assertRaises(struct.error, struct.pack, 'iii', 3)
self.assertRaises(struct.error, struct.pack, 'i', 3, 3, 3)
self.assertRaises(struct.error, struct.pack, 'i', 'foo')
self.assertRaises(struct.error, struct.pack, 'P', 'foo')
self.assertRaises(struct.error, struct.unpack, 'd', 'flap')
s = struct.pack('ii', 1, 2)
self.assertRaises(struct.error, struct.unpack, 'iii', s)
self.assertRaises(struct.error, struct.unpack, 'i', s)
def test_transitiveness(self):
c = 'a'
b = 1
h = 255
i = 65535
l = 65536
f = 3.1415
d = 3.1415
t = True
for prefix in ('', '@', '<', '>', '=', '!'):
for format in ('xcbhilfd?', 'xcBHILfd?'):
format = prefix + format
s = struct.pack(format, c, b, h, i, l, f, d, t)
cp, bp, hp, ip, lp, fp, dp, tp = struct.unpack(format, s)
self.assertEqual(cp, c)
self.assertEqual(bp, b)
self.assertEqual(hp, h)
self.assertEqual(ip, i)
self.assertEqual(lp, l)
self.assertEqual(int(100 * fp), int(100 * f))
self.assertEqual(int(100 * dp), int(100 * d))
self.assertEqual(tp, t)
def test_new_features(self):
# Test some of the new features in detail
# (format, argument, big-endian result, little-endian result, asymmetric)
tests = [
('c', 'a', 'a', 'a', 0),
('xc', 'a', '\0a', '\0a', 0),
('cx', 'a', 'a\0', 'a\0', 0),
('s', 'a', 'a', 'a', 0),
('0s', 'helloworld', '', '', 1),
('1s', 'helloworld', 'h', 'h', 1),
('9s', 'helloworld', 'helloworl', 'helloworl', 1),
('10s', 'helloworld', 'helloworld', 'helloworld', 0),
('11s', 'helloworld', 'helloworld\0', 'helloworld\0', 1),
('20s', 'helloworld', 'helloworld'+10*'\0', 'helloworld'+10*'\0', 1),
('b', 7, '\7', '\7', 0),
('b', -7, '\371', '\371', 0),
('B', 7, '\7', '\7', 0),
('B', 249, '\371', '\371', 0),
('h', 700, '\002\274', '\274\002', 0),
('h', -700, '\375D', 'D\375', 0),
('H', 700, '\002\274', '\274\002', 0),
('H', 0x10000-700, '\375D', 'D\375', 0),
('i', 70000000, '\004,\035\200', '\200\035,\004', 0),
('i', -70000000, '\373\323\342\200', '\200\342\323\373', 0),
('I', 70000000L, '\004,\035\200', '\200\035,\004', 0),
('I', 0x100000000L-70000000, '\373\323\342\200', '\200\342\323\373', 0),
('l', 70000000, '\004,\035\200', '\200\035,\004', 0),
('l', -70000000, '\373\323\342\200', '\200\342\323\373', 0),
('L', 70000000L, '\004,\035\200', '\200\035,\004', 0),
('L', 0x100000000L-70000000, '\373\323\342\200', '\200\342\323\373', 0),
('f', 2.0, '@\000\000\000', '\000\000\000@', 0),
('d', 2.0, '@\000\000\000\000\000\000\000',
'\000\000\000\000\000\000\000@', 0),
('f', -2.0, '\300\000\000\000', '\000\000\000\300', 0),
('d', -2.0, '\300\000\000\000\000\000\000\000',
'\000\000\000\000\000\000\000\300', 0),
('?', 0, '\0', '\0', 0),
('?', 3, '\1', '\1', 1),
('?', True, '\1', '\1', 0),
('?', [], '\0', '\0', 1),
('?', (1,), '\1', '\1', 1),
]
for fmt, arg, big, lil, asy in tests:
for (xfmt, exp) in [('>'+fmt, big), ('!'+fmt, big), ('<'+fmt, lil),
('='+fmt, ISBIGENDIAN and big or lil)]:
res = struct.pack(xfmt, arg)
self.assertEqual(res, exp)
self.assertEqual(struct.calcsize(xfmt), len(res))
rev = struct.unpack(xfmt, res)[0]
if rev != arg:
self.assert_(asy)
def test_native_qQ(self):
# can't pack -1 as unsigned regardless
self.assertRaises((struct.error, TypeError), struct.pack, "Q", -1)
# can't pack string as 'q' regardless
self.assertRaises(struct.error, struct.pack, "q", "a")
# ditto, but 'Q'
self.assertRaises(struct.error, struct.pack, "Q", "a")
try:
struct.pack("q", 5)
except struct.error:
# does not have native q/Q
pass
else:
bytes = struct.calcsize('q')
# The expected values here are in big-endian format, primarily
# because I'm on a little-endian machine and so this is the
# clearest way (for me) to force the code to get exercised.
for format, input, expected in (
('q', -1, '\xff' * bytes),
('q', 0, '\x00' * bytes),
('Q', 0, '\x00' * bytes),
('q', 1L, '\x00' * (bytes-1) + '\x01'),
('Q', (1L << (8*bytes))-1, '\xff' * bytes),
('q', (1L << (8*bytes-1))-1, '\x7f' + '\xff' * (bytes - 1))):
got = struct.pack(format, input)
native_expected = bigendian_to_native(expected)
self.assertEqual(got, native_expected)
retrieved = struct.unpack(format, got)[0]
self.assertEqual(retrieved, input)
def test_standard_integers(self):
# Standard integer tests (bBhHiIlLqQ).
import binascii
class IntTester(unittest.TestCase):
# XXX Most std integer modes fail to test for out-of-range.
# The "i" and "l" codes appear to range-check OK on 32-bit boxes, but
# fail to check correctly on some 64-bit ones (Tru64 Unix + Compaq C
# reported by Mark Favas).
BUGGY_RANGE_CHECK = "bBhHiIlL"
def __init__(self, formatpair, bytesize):
self.assertEqual(len(formatpair), 2)
self.formatpair = formatpair
for direction in "<>!=":
for code in formatpair:
format = direction + code
self.assertEqual(struct.calcsize(format), bytesize)
self.bytesize = bytesize
self.bitsize = bytesize * 8
self.signed_code, self.unsigned_code = formatpair
self.unsigned_min = 0
self.unsigned_max = 2L**self.bitsize - 1
self.signed_min = -(2L**(self.bitsize-1))
self.signed_max = 2L**(self.bitsize-1) - 1
def test_one(self, x, pack=struct.pack,
unpack=struct.unpack,
unhexlify=binascii.unhexlify):
# Try signed.
code = self.signed_code
if self.signed_min <= x <= self.signed_max:
# Try big-endian.
expected = long(x)
if x < 0:
expected += 1L << self.bitsize
self.assert_(expected > 0)
expected = hex(expected)[2:-1] # chop "0x" and trailing 'L'
if len(expected) & 1:
expected = "0" + expected
expected = unhexlify(expected)
expected = "\x00" * (self.bytesize - len(expected)) + expected
# Pack work?
format = ">" + code
got = pack(format, x)
self.assertEqual(got, expected)
# Unpack work?
retrieved = unpack(format, got)[0]
self.assertEqual(x, retrieved)
# Adding any byte should cause a "too big" error.
self.assertRaises((struct.error, TypeError), unpack, format,
'\x01' + got)
# Try little-endian.
format = "<" + code
expected = string_reverse(expected)
# Pack work?
got = pack(format, x)
self.assertEqual(got, expected)
# Unpack work?
retrieved = unpack(format, got)[0]
self.assertEqual(x, retrieved)
# Adding any byte should cause a "too big" error.
self.assertRaises((struct.error, TypeError), unpack, format,
'\x01' + got)
else:
# x is out of range -- verify pack realizes that.
if not PY_STRUCT_RANGE_CHECKING and code in self.BUGGY_RANGE_CHECK:
if verbose:
print "Skipping buggy range check for code", code
else:
deprecated_err(pack, ">" + code, x)
deprecated_err(pack, "<" + code, x)
# Much the same for unsigned.
code = self.unsigned_code
if self.unsigned_min <= x <= self.unsigned_max:
# Try big-endian.
format = ">" + code
expected = long(x)
expected = hex(expected)[2:-1] # chop "0x" and trailing 'L'
if len(expected) & 1:
expected = "0" + expected
expected = unhexlify(expected)
expected = "\x00" * (self.bytesize - len(expected)) + expected
# Pack work?
got = pack(format, x)
self.assertEqual(got, expected)
# Unpack work?
retrieved = unpack(format, got)[0]
self.assertEqual(x, retrieved)
# Adding any byte should cause a "too big" error.
self.assertRaises((struct.error, TypeError), unpack, format,
'\x01' + got)
# Try little-endian.
format = "<" + code
expected = string_reverse(expected)
# Pack work?
got = pack(format, x)
self.assertEqual(got, expected)
# Unpack work?
retrieved = unpack(format, got)[0]
self.assertEqual(x, retrieved)
# Adding any byte should cause a "too big" error.
self.assertRaises((struct.error, TypeError), unpack, format,
'\x01' + got)
else:
# x is out of range -- verify pack realizes that.
if not PY_STRUCT_RANGE_CHECKING and code in self.BUGGY_RANGE_CHECK:
if verbose:
print "Skipping buggy range check for code", code
else:
deprecated_err(pack, ">" + code, x)
deprecated_err(pack, "<" + code, x)
def run(self):
from random import randrange
# Create all interesting powers of 2.
values = []
for exp in range(self.bitsize + 3):
values.append(1L << exp)
# Add some random values.
for i in range(self.bitsize):
val = 0L
for j in range(self.bytesize):
val = (val << 8) | randrange(256)
values.append(val)
# Try all those, and their negations, and +-1 from them. Note
# that this tests all power-of-2 boundaries in range, and a few out
# of range, plus +-(2**n +- 1).
for base in values:
for val in -base, base:
for incr in -1, 0, 1:
x = val + incr
try:
x = int(x)
except OverflowError:
pass
self.test_one(x)
# Some error cases.
for direction in "<>":
for code in self.formatpair:
for badobject in "a string", 3+42j, randrange:
self.assertRaises((struct.error, TypeError),
struct.pack, direction + code,
badobject)
for args in [("bB", 1),
("hH", 2),
("iI", 4),
("lL", 4),
("qQ", 8)]:
t = IntTester(*args)
t.run()
def test_p_code(self):
# Test p ("Pascal string") code.
for code, input, expected, expectedback in [
('p','abc', '\x00', ''),
('1p', 'abc', '\x00', ''),
('2p', 'abc', '\x01a', 'a'),
('3p', 'abc', '\x02ab', 'ab'),
('4p', 'abc', '\x03abc', 'abc'),
('5p', 'abc', '\x03abc\x00', 'abc'),
('6p', 'abc', '\x03abc\x00\x00', 'abc'),
('1000p', 'x'*1000, '\xff' + 'x'*999, 'x'*255)]:
got = struct.pack(code, input)
self.assertEqual(got, expected)
(got,) = struct.unpack(code, got)
self.assertEqual(got, expectedback)
def test_705836(self):
# SF bug 705836. "<f" and ">f" had a severe rounding bug, where a carry
# from the low-order discarded bits could propagate into the exponent
# field, causing the result to be wrong by a factor of 2.
import math
for base in range(1, 33):
# smaller <- largest representable float less than base.
delta = 0.5
while base - delta / 2.0 != base:
delta /= 2.0
smaller = base - delta
# Packing this rounds away a solid string of trailing 1 bits.
packed = struct.pack("<f", smaller)
unpacked = struct.unpack("<f", packed)[0]
# This failed at base = 2, 4, and 32, with unpacked = 1, 2, and
# 16, respectively.
self.assertEqual(base, unpacked)
bigpacked = struct.pack(">f", smaller)
self.assertEqual(bigpacked, string_reverse(packed))
unpacked = struct.unpack(">f", bigpacked)[0]
self.assertEqual(base, unpacked)
# Largest finite IEEE single.
big = (1 << 24) - 1
big = math.ldexp(big, 127 - 23)
packed = struct.pack(">f", big)
unpacked = struct.unpack(">f", packed)[0]
self.assertEqual(big, unpacked)
# The same, but tack on a 1 bit so it rounds up to infinity.
big = (1 << 25) - 1
big = math.ldexp(big, 127 - 24)
self.assertRaises(OverflowError, struct.pack, ">f", big)
if PY_STRUCT_RANGE_CHECKING:
def test_1229380(self):
# SF bug 1229380. No struct.pack exception for some out of
# range integers
import sys
for endian in ('', '>', '<'):
for cls in (int, long):
for fmt in ('B', 'H', 'I', 'L'):
deprecated_err(struct.pack, endian + fmt, cls(-1))
deprecated_err(struct.pack, endian + 'B', cls(300))
deprecated_err(struct.pack, endian + 'H', cls(70000))
deprecated_err(struct.pack, endian + 'I', sys.maxint * 4L)
deprecated_err(struct.pack, endian + 'L', sys.maxint * 4L)
def XXXtest_1530559(self):
# XXX This is broken: see the bug report
# SF bug 1530559. struct.pack raises TypeError where it used to convert.
for endian in ('', '>', '<'):
for fmt in ('B', 'H', 'I', 'L', 'b', 'h', 'i', 'l'):
self.check_float_coerce(endian + fmt, 1.0)
self.check_float_coerce(endian + fmt, 1.5)
def test_unpack_from(self):
test_string = 'abcd01234'
fmt = '4s'
s = struct.Struct(fmt)
for cls in (str, buffer):
data = cls(test_string)
self.assertEqual(s.unpack_from(data), ('abcd',))
self.assertEqual(s.unpack_from(data, 2), ('cd01',))
self.assertEqual(s.unpack_from(data, 4), ('0123',))
for i in xrange(6):
self.assertEqual(s.unpack_from(data, i), (data[i:i+4],))
for i in xrange(6, len(test_string) + 1):
self.assertRaises(struct.error, s.unpack_from, data, i)
for cls in (str, buffer):
data = cls(test_string)
self.assertEqual(struct.unpack_from(fmt, data), ('abcd',))
self.assertEqual(struct.unpack_from(fmt, data, 2), ('cd01',))
self.assertEqual(struct.unpack_from(fmt, data, 4), ('0123',))
for i in xrange(6):
self.assertEqual(struct.unpack_from(fmt, data, i), (data[i:i+4],))
for i in xrange(6, len(test_string) + 1):
self.assertRaises(struct.error, struct.unpack_from, fmt, data, i)
def test_pack_into(self):
test_string = 'Reykjavik rocks, eow!'
writable_buf = array.array('c', ' '*100)
fmt = '21s'
s = struct.Struct(fmt)
# Test without offset
s.pack_into(writable_buf, 0, test_string)
from_buf = writable_buf.tostring()[:len(test_string)]
self.assertEqual(from_buf, test_string)
# Test with offset.
s.pack_into(writable_buf, 10, test_string)
from_buf = writable_buf.tostring()[:len(test_string)+10]
self.assertEqual(from_buf, test_string[:10] + test_string)
# Go beyond boundaries.
small_buf = array.array('c', ' '*10)
self.assertRaises(struct.error, s.pack_into, small_buf, 0, test_string)
self.assertRaises(struct.error, s.pack_into, small_buf, 2, test_string)
def test_pack_into_fn(self):
test_string = 'Reykjavik rocks, eow!'
writable_buf = array.array('c', ' '*100)
fmt = '21s'
pack_into = lambda *args: struct.pack_into(fmt, *args)
# Test without offset.
pack_into(writable_buf, 0, test_string)
from_buf = writable_buf.tostring()[:len(test_string)]
self.assertEqual(from_buf, test_string)
# Test with offset.
pack_into(writable_buf, 10, test_string)
from_buf = writable_buf.tostring()[:len(test_string)+10]
self.assertEqual(from_buf, test_string[:10] + test_string)
# Go beyond boundaries.
small_buf = array.array('c', ' '*10)
self.assertRaises(struct.error, pack_into, small_buf, 0, test_string)
self.assertRaises(struct.error, pack_into, small_buf, 2, test_string)
def test_unpack_with_buffer(self):
# SF bug 1563759: struct.unpack doens't support buffer protocol objects
data1 = array.array('B', '\x12\x34\x56\x78')
data2 = buffer('......\x12\x34\x56\x78......', 6, 4)
for data in [data1, data2]:
value, = struct.unpack('>I', data)
self.assertEqual(value, 0x12345678)
def test_bool(self):
for prefix in tuple("<>!=")+('',):
false = (), [], [], '', 0
true = [1], 'test', 5, -1, 0xffffffffL+1, 0xffffffff/2
falseFormat = prefix + '?' * len(false)
packedFalse = struct.pack(falseFormat, *false)
unpackedFalse = struct.unpack(falseFormat, packedFalse)
trueFormat = prefix + '?' * len(true)
packedTrue = struct.pack(trueFormat, *true)
unpackedTrue = struct.unpack(trueFormat, packedTrue)
self.assertEqual(len(true), len(unpackedTrue))
self.assertEqual(len(false), len(unpackedFalse))
for t in unpackedFalse:
self.assertFalse(t)
for t in unpackedTrue:
self.assertTrue(t)
packed = struct.pack(prefix+'?', 1)
self.assertEqual(len(packed), struct.calcsize(prefix+'?'))
if len(packed) != 1:
self.assertFalse(prefix, msg='encoded bool is not one byte: %r'
%packed)
for c in '\x01\x7f\xff\x0f\xf0':
self.assertTrue(struct.unpack('>?', c)[0])
if IS32BIT:
def test_crasher(self):
self.assertRaises(MemoryError, struct.pack, "357913941c", "a")
def test_main():
run_unittest(StructTest)
if __name__ == '__main__':
test_main()