Issue #24583: Consolidate previous set object updates into a single function

with a single entry point, named exit points at the bottom, more self-evident
refcount adjustments, and a comment describing why the pre-increment was
necessary at all.
This commit is contained in:
Raymond Hettinger 2015-07-20 07:34:05 -04:00
parent aa23fa2e21
commit ff9e18a863

View File

@ -127,17 +127,27 @@ set_lookkey(PySetObject *so, PyObject *key, Py_hash_t hash)
static int set_table_resize(PySetObject *, Py_ssize_t);
static int
_set_add_entry(PySetObject *so, PyObject *key, Py_hash_t hash)
set_add_entry(PySetObject *so, PyObject *key, Py_hash_t hash)
{
setentry *table = so->table;
setentry *table;
setentry *freeslot;
setentry *entry;
size_t perturb;
size_t mask = so->mask;
size_t i = (size_t)hash & mask; /* Unsigned for defined overflow behavior */
size_t mask;
size_t i; /* Unsigned for defined overflow behavior */
size_t j;
int cmp;
/* Pre-increment is necessary to prevent arbitrary code in the rich
comparison from deallocating the key just before the insertion. */
Py_INCREF(key);
restart:
table = so->table;
mask = so->mask;
i = (size_t)hash & mask;
entry = &table[i];
if (entry->key == NULL)
goto found_unused;
@ -160,9 +170,9 @@ _set_add_entry(PySetObject *so, PyObject *key, Py_hash_t hash)
cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
Py_DECREF(startkey);
if (cmp < 0) /* unlikely */
return -1;
goto comparison_error;
if (table != so->table || entry->key != startkey) /* unlikely */
return _set_add_entry(so, key, hash);
goto restart;
if (cmp > 0) /* likely */
goto found_active;
mask = so->mask; /* help avoid a register spill */
@ -188,9 +198,9 @@ _set_add_entry(PySetObject *so, PyObject *key, Py_hash_t hash)
cmp = PyObject_RichCompareBool(startkey, key, Py_EQ);
Py_DECREF(startkey);
if (cmp < 0)
return -1;
goto comparison_error;
if (table != so->table || entry->key != startkey)
return _set_add_entry(so, key, hash);
goto restart;
if (cmp > 0)
goto found_active;
mask = so->mask;
@ -223,22 +233,13 @@ _set_add_entry(PySetObject *so, PyObject *key, Py_hash_t hash)
entry->hash = hash;
if ((size_t)so->fill*3 < mask*2)
return 0;
if (!set_table_resize(so, so->used))
return 0;
Py_INCREF(key);
return -1;
return set_table_resize(so, so->used);
found_active:
Py_DECREF(key);
return 0;
}
static int
set_add_entry(PySetObject *so, PyObject *key, Py_hash_t hash)
{
Py_INCREF(key);
if (!_set_add_entry(so, key, hash))
return 0;
comparison_error:
Py_DECREF(key);
return -1;
}