from test.test_support import TestFailed, verbose, verify import struct import sys ISBIGENDIAN = sys.byteorder == "big" del sys verify((struct.pack('=i', 1)[0] == chr(0)) == ISBIGENDIAN, "bigendian determination appears wrong") def string_reverse(s): chars = list(s) chars.reverse() return "".join(chars) def bigendian_to_native(value): if ISBIGENDIAN: return value else: return string_reverse(value) def simple_err(func, *args): try: func(*args) except struct.error: pass else: raise TestFailed, "%s%s did not raise struct.error" % ( func.__name__, args) def any_err(func, *args): try: func(*args) except (struct.error, OverflowError, TypeError): pass else: raise TestFailed, "%s%s did not raise error" % ( func.__name__, args) simple_err(struct.calcsize, 'Z') sz = struct.calcsize('i') if sz * 3 != struct.calcsize('iii'): raise TestFailed, 'inconsistent sizes' fmt = 'cbxxxxxxhhhhiillffd' fmt3 = '3c3b18x12h6i6l6f3d' sz = struct.calcsize(fmt) sz3 = struct.calcsize(fmt3) if sz * 3 != sz3: raise TestFailed, 'inconsistent sizes (3*%r -> 3*%d = %d, %r -> %d)' % ( fmt, sz, 3*sz, fmt3, sz3) simple_err(struct.pack, 'iii', 3) simple_err(struct.pack, 'i', 3, 3, 3) simple_err(struct.pack, 'i', 'foo') simple_err(struct.pack, 'P', 'foo') simple_err(struct.unpack, 'd', 'flap') s = struct.pack('ii', 1, 2) simple_err(struct.unpack, 'iii', s) simple_err(struct.unpack, 'i', s) c = 'a' b = 1 h = 255 i = 65535 l = 65536 f = 3.1415 d = 3.1415 for prefix in ('', '@', '<', '>', '=', '!'): for format in ('xcbhilfd', 'xcBHILfd'): format = prefix + format if verbose: print "trying:", format s = struct.pack(format, c, b, h, i, l, f, d) cp, bp, hp, ip, lp, fp, dp = struct.unpack(format, s) if (cp != c or bp != b or hp != h or ip != i or lp != l or int(100 * fp) != int(100 * f) or int(100 * dp) != int(100 * d)): # ^^^ calculate only to two decimal places raise TestFailed, "unpack/pack not transitive (%s, %s)" % ( str(format), str((cp, bp, hp, ip, lp, fp, dp))) # 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), ] for fmt, arg, big, lil, asy in tests: if verbose: print "%r %r %r %r" % (fmt, arg, big, lil) for (xfmt, exp) in [('>'+fmt, big), ('!'+fmt, big), ('<'+fmt, lil), ('='+fmt, ISBIGENDIAN and big or lil)]: res = struct.pack(xfmt, arg) if res != exp: raise TestFailed, "pack(%r, %r) -> %r # expected %r" % ( fmt, arg, res, exp) n = struct.calcsize(xfmt) if n != len(res): raise TestFailed, "calcsize(%r) -> %d # expected %d" % ( xfmt, n, len(res)) rev = struct.unpack(xfmt, res)[0] if rev != arg and not asy: raise TestFailed, "unpack(%r, %r) -> (%r,) # expected (%r,)" % ( fmt, res, rev, arg) ########################################################################### # Simple native q/Q tests. has_native_qQ = 1 try: struct.pack("q", 5) except struct.error: has_native_qQ = 0 if verbose: print "Platform has native q/Q?", has_native_qQ and "Yes." or "No." any_err(struct.pack, "Q", -1) # can't pack -1 as unsigned regardless simple_err(struct.pack, "q", "a") # can't pack string as 'q' regardless simple_err(struct.pack, "Q", "a") # ditto, but 'Q' def test_native_qQ(): 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) verify(got == native_expected, "%r-pack of %r gave %r, not %r" % (format, input, got, native_expected)) retrieved = struct.unpack(format, got)[0] verify(retrieved == input, "%r-unpack of %r gave %r, not %r" % (format, got, retrieved, input)) if has_native_qQ: test_native_qQ() ########################################################################### # Standard integer tests (bBhHiIlLqQ). import binascii class IntTester: # 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): assert len(formatpair) == 2 self.formatpair = formatpair for direction in "<>!=": for code in formatpair: format = direction + code verify(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): if verbose: print "trying std", self.formatpair, "on", x, "==", hex(x) # 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 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) verify(got == expected, "'%s'-pack of %r gave %r, not %r" % (format, x, got, expected)) # Unpack work? retrieved = unpack(format, got)[0] verify(x == retrieved, "'%s'-unpack of %r gave %r, not %r" % (format, got, retrieved, x)) # Adding any byte should cause a "too big" error. any_err(unpack, format, '\x01' + got) # Try little-endian. format = "<" + code expected = string_reverse(expected) # Pack work? got = pack(format, x) verify(got == expected, "'%s'-pack of %r gave %r, not %r" % (format, x, got, expected)) # Unpack work? retrieved = unpack(format, got)[0] verify(x == retrieved, "'%s'-unpack of %r gave %r, not %r" % (format, got, retrieved, x)) # Adding any byte should cause a "too big" error. any_err(unpack, format, '\x01' + got) else: # x is out of range -- verify pack realizes that. if code in self.BUGGY_RANGE_CHECK: if verbose: print "Skipping buggy range check for code", code else: any_err(pack, ">" + code, x) any_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) verify(got == expected, "'%s'-pack of %r gave %r, not %r" % (format, x, got, expected)) # Unpack work? retrieved = unpack(format, got)[0] verify(x == retrieved, "'%s'-unpack of %r gave %r, not %r" % (format, got, retrieved, x)) # Adding any byte should cause a "too big" error. any_err(unpack, format, '\x01' + got) # Try little-endian. format = "<" + code expected = string_reverse(expected) # Pack work? got = pack(format, x) verify(got == expected, "'%s'-pack of %r gave %r, not %r" % (format, x, got, expected)) # Unpack work? retrieved = unpack(format, got)[0] verify(x == retrieved, "'%s'-unpack of %r gave %r, not %r" % (format, got, retrieved, x)) # Adding any byte should cause a "too big" error. any_err(unpack, format, '\x01' + got) else: # x is out of range -- verify pack realizes that. if code in self.BUGGY_RANGE_CHECK: if verbose: print "Skipping buggy range check for code", code else: any_err(pack, ">" + code, x) any_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: any_err(struct.pack, direction + code, badobject) for args in [("bB", 1), ("hH", 2), ("iI", 4), ("lL", 4), ("qQ", 8)]: t = IntTester(*args) t.run() ########################################################################### # The p ("Pascal string") code. def test_p_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) if got != expected: raise TestFailed("pack(%r, %r) == %r but expected %r" % (code, input, got, expected)) (got,) = struct.unpack(code, got) if got != expectedback: raise TestFailed("unpack(%r, %r) == %r but expected %r" % (code, input, got, expectedback)) test_p_code() ########################################################################### # SF bug 705836. "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. def test_705836(): 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) verify(bigpacked == string_reverse(packed), ">f pack should be byte-reversal of f", bigpacked)[0] verify(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] verify(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) try: packed = struct.pack(">f", big) except OverflowError: pass else: TestFailed("expected OverflowError") test_705836()