[Python-checkins] CVS: python/dist/src/Lib/test test_hash.py,NONE,1.1

[Fred L. Drake]

Update of /cvsroot/python/python/dist/src/Lib/test
In directory slayer.i.sourceforge.net:/tmp/cvs-serv3837/Lib/test

Added Files:
	test_hash.py 
Log Message:
This patch addresses two main issues: (1) There exist some non-fatal
errors in some of the hash algorithms. For exmaple, in float_hash and
complex_hash a certain part of the value is not included in the hash
calculation. See Tim's, Guido's, and my discussion of this on
python-dev in May under the title "fix float_hash and complex_hash for
64-bit *nix"

(2) The hash algorithms that use pointers (e.g. func_hash, code_hash)
are universally not correct on Win64 (they assume that sizeof(long) ==
sizeof(void*))

As well, this patch significantly cleans up the hash code. It adds the
two function _Py_HashDouble and _PyHash_VoidPtr that the various
hashing routine are changed to use.

These help maintain the hash function invariant: (a==b) =>
(hash(a)==hash(b))) I have added Lib/test/test_hash.py and
Lib/test/output/test_hash to test this for some cases.


--- NEW FILE ---
# test the invariant that
#   iff a==b then hash(a)==hash(b)
#

import test_support


def same_hash(*objlist):
	# hash each object given an raise TestFailed if
	# the hash values are not all the same
	hashed = map(hash, objlist)
	for h in hashed[1:]:
		if h != hashed[0]:
			raise TestFailed, "hashed values differ: %s" % `objlist`



same_hash(1, 1L, 1.0, 1.0+0.0j)
same_hash(int(1), long(1), float(1), complex(1))

same_hash(long(1.23e300), float(1.23e300))

same_hash(float(0.5), complex(0.5, 0.0))