bpo-40889: Optimize dict.items() ^ dict.items() (GH-20718)
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index c4d5da5..1bb8cfd 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -4409,9 +4409,99 @@
return result;
}
+static PyObject *
+dictitems_xor(PyObject *self, PyObject *other)
+{
+ assert(PyDictItems_Check(self));
+ assert(PyDictItems_Check(other));
+ PyObject *d1 = (PyObject *)((_PyDictViewObject *)self)->dv_dict;
+ PyObject *d2 = (PyObject *)((_PyDictViewObject *)other)->dv_dict;
+
+ PyObject *temp_dict = PyDict_Copy(d1);
+ if (temp_dict == NULL) {
+ return NULL;
+ }
+ PyObject *result_set = PySet_New(NULL);
+ if (result_set == NULL) {
+ Py_CLEAR(temp_dict);
+ return NULL;
+ }
+
+ PyObject *key = NULL, *val1 = NULL, *val2 = NULL;
+ Py_ssize_t pos = 0;
+ Py_hash_t hash;
+
+ while (_PyDict_Next(d2, &pos, &key, &val2, &hash)) {
+ Py_INCREF(key);
+ Py_INCREF(val2);
+ val1 = _PyDict_GetItem_KnownHash(temp_dict, key, hash);
+
+ int to_delete;
+ if (val1 == NULL) {
+ if (PyErr_Occurred()) {
+ goto error;
+ }
+ to_delete = 0;
+ }
+ else {
+ Py_INCREF(val1);
+ to_delete = PyObject_RichCompareBool(val1, val2, Py_EQ);
+ if (to_delete < 0) {
+ goto error;
+ }
+ }
+
+ if (to_delete) {
+ if (_PyDict_DelItem_KnownHash(temp_dict, key, hash) < 0) {
+ goto error;
+ }
+ }
+ else {
+ PyObject *pair = PyTuple_Pack(2, key, val2);
+ if (pair == NULL) {
+ goto error;
+ }
+ if (PySet_Add(result_set, pair) < 0) {
+ Py_DECREF(pair);
+ goto error;
+ }
+ Py_DECREF(pair);
+ }
+ Py_DECREF(key);
+ Py_XDECREF(val1);
+ Py_DECREF(val2);
+ }
+ key = val1 = val2 = NULL;
+
+ _Py_IDENTIFIER(items);
+ PyObject *remaining_pairs = _PyObject_CallMethodIdNoArgs(temp_dict,
+ &PyId_items);
+ if (remaining_pairs == NULL) {
+ goto error;
+ }
+ if (_PySet_Update(result_set, remaining_pairs) < 0) {
+ Py_DECREF(remaining_pairs);
+ goto error;
+ }
+ Py_DECREF(temp_dict);
+ Py_DECREF(remaining_pairs);
+ return result_set;
+
+error:
+ Py_XDECREF(temp_dict);
+ Py_XDECREF(result_set);
+ Py_XDECREF(key);
+ Py_XDECREF(val1);
+ Py_XDECREF(val2);
+ return NULL;
+}
+
static PyObject*
dictviews_xor(PyObject* self, PyObject *other)
{
+ if (PyDictItems_Check(self) && PyDictItems_Check(other)) {
+ return dictitems_xor(self, other);
+ }
PyObject *result = dictviews_to_set(self);
if (result == NULL) {
return NULL;