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Use a known unique object for the dummy entry. 

This lets us run PyObject_RichCompareBool() without
first needing to check whether the entry is a dummy.
This commit is contained in:
Raymond Hettinger 2013-08-17 02:31:53 -07:00
parent 07b16615bc
commit 237b34b074
1 changed files with 20 additions and 25 deletions
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45
Objects/setobject.c
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@ -91,32 +91,27 @@ set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
if (entry->key == NULL || entry->key == key)
return entry;
if (entry->key == dummy)
freeslot = entry;
else {
if (entry->hash == hash) {
startkey = entry->key;
Py_INCREF(startkey);
cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
Py_DECREF(startkey);
if (cmp < 0)
return NULL;
if (table == so->table && entry->key == startkey) {
if (cmp > 0)
return entry;
}
else {
/* The compare did major nasty stuff to the
* set: start over.
*/
return set_lookkey(so, key, hash);
}
if (entry->hash == hash) {
startkey = entry->key;
Py_INCREF(startkey);
cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
Py_DECREF(startkey);
if (cmp < 0)
return NULL;
if (table == so->table && entry->key == startkey) {
if (cmp > 0)
return entry;
}
else {
/* Start over if the compare altered the set */
return set_lookkey(so, key, hash);
}
freeslot = NULL;
}
/* In the loop, key == dummy is by far (factor of 100s) the
least likely outcome, so test for that last. */
freeslot = (entry->key == dummy) ? entry : NULL;
/* In the loop, key == dummy is by far (factor of 100s)
the least likely outcome, so test for that last. */
for (perturb = hash; ; perturb >>= PERTURB_SHIFT) {
i = i * 5 + perturb + 1;
entry = &table[i & mask];
@ -127,7 +122,7 @@ set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
}
if (entry->key == key)
break;
if (entry->hash == hash && entry->key != dummy) {
if (entry->hash == hash) {
startkey = entry->key;
Py_INCREF(startkey);
cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
@ -1029,7 +1024,7 @@ make_new_set(PyTypeObject *type, PyObject *iterable)
PySetObject *so = NULL;
if (dummy == NULL) { /* Auto-initialize dummy */
dummy = PyUnicode_FromString("<dummy key>");
dummy = _PyObject_New(&PyBaseObject_Type);
if (dummy == NULL)
return NULL;
}