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.
This commit is contained in:
Fred Drake 2000-06-29 19:17:04 +00:00
parent b46696c0ed
commit 13634cf7a4
10 changed files with 126 additions and 49 deletions

View file

@ -172,7 +172,7 @@ static long
meth_hash(a)
PyCFunctionObject *a;
{
long x;
long x,y;
if (a->m_self == NULL)
x = 0;
else {
@ -180,7 +180,13 @@ meth_hash(a)
if (x == -1)
return -1;
}
return x ^ (long) a->m_ml->ml_meth;
y = _Py_HashPointer(a->m_ml->ml_meth);
if (y == -1)
return -1;
x ^= y;
if (x == -1)
x = -2;
return x;
}
PyTypeObject PyCFunction_Type = {