SF 560736. Optimize list iteration by filling the tp_iter slot.
diff --git a/Objects/listobject.c b/Objects/listobject.c
index 83a8c70..c2892c6 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -1682,6 +1682,8 @@
"list() -> new list\n"
"list(sequence) -> new list initialized from sequence's items";
+staticforward PyObject * list_iter(PyObject *seq);
+
PyTypeObject PyList_Type = {
PyObject_HEAD_INIT(&PyType_Type)
0,
@@ -1710,7 +1712,7 @@
(inquiry)list_clear, /* tp_clear */
list_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
- 0, /* tp_iter */
+ list_iter, /* tp_iter */
0, /* tp_iternext */
list_methods, /* tp_methods */
0, /* tp_members */
@@ -1811,3 +1813,118 @@
0, /* tp_init */
/* NOTE: This is *not* the standard list_type struct! */
};
+
+
+/*********************** List Iterator **************************/
+
+typedef struct {
+ PyObject_HEAD
+ long it_index;
+ PyObject *it_seq;
+} listiterobject;
+
+PyTypeObject PyListIter_Type;
+
+PyObject *
+list_iter(PyObject *seq)
+{
+ listiterobject *it;
+
+ if (!PyList_Check(seq)) {
+ PyErr_BadInternalCall();
+ return NULL;
+ }
+ it = PyObject_GC_New(listiterobject, &PyListIter_Type);
+ if (it == NULL)
+ return NULL;
+ it->it_index = 0;
+ Py_INCREF(seq);
+ it->it_seq = seq;
+ _PyObject_GC_TRACK(it);
+ return (PyObject *)it;
+}
+
+static void
+listiter_dealloc(listiterobject *it)
+{
+ _PyObject_GC_UNTRACK(it);
+ Py_DECREF(it->it_seq);
+ PyObject_GC_Del(it);
+}
+
+static int
+listiter_traverse(listiterobject *it, visitproc visit, void *arg)
+{
+ return visit(it->it_seq, arg);
+}
+
+
+static PyObject *
+listiter_getiter(PyObject *it)
+{
+ Py_INCREF(it);
+ return it;
+}
+
+static PyObject *
+listiter_next(PyObject *it)
+{
+ PyObject *seq;
+ PyObject *item;
+
+ assert(PyList_Check(it));
+ seq = ((listiterobject *)it)->it_seq;
+
+ if (((listiterobject *)it)->it_index < PyList_GET_SIZE(seq)) {
+ item = ((PyListObject *)(seq))->ob_item[((listiterobject *)it)->it_index++];
+ Py_INCREF(item);
+ return item;
+ }
+ return NULL;
+}
+
+static PyMethodDef listiter_methods[] = {
+ {"next", (PyCFunction)listiter_next, METH_NOARGS,
+ "it.next() -- get the next value, or raise StopIteration"},
+ {NULL, NULL} /* sentinel */
+};
+
+PyTypeObject PyListIter_Type = {
+ PyObject_HEAD_INIT(&PyType_Type)
+ 0, /* ob_size */
+ "listiterator", /* tp_name */
+ sizeof(listiterobject), /* tp_basicsize */
+ 0, /* tp_itemsize */
+ /* methods */
+ (destructor)listiter_dealloc, /* tp_dealloc */
+ 0, /* tp_print */
+ 0, /* tp_getattr */
+ 0, /* tp_setattr */
+ 0, /* tp_compare */
+ 0, /* tp_repr */
+ 0, /* tp_as_number */
+ 0, /* tp_as_sequence */
+ 0, /* tp_as_mapping */
+ 0, /* tp_hash */
+ 0, /* tp_call */
+ 0, /* tp_str */
+ PyObject_GenericGetAttr, /* tp_getattro */
+ 0, /* tp_setattro */
+ 0, /* tp_as_buffer */
+ Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */
+ 0, /* tp_doc */
+ (traverseproc)listiter_traverse, /* tp_traverse */
+ 0, /* tp_clear */
+ 0, /* tp_richcompare */
+ 0, /* tp_weaklistoffset */
+ (getiterfunc)listiter_getiter, /* tp_iter */
+ (iternextfunc)listiter_next, /* tp_iternext */
+ listiter_methods, /* tp_methods */
+ 0, /* tp_members */
+ 0, /* tp_getset */
+ 0, /* tp_base */
+ 0, /* tp_dict */
+ 0, /* tp_descr_get */
+ 0, /* tp_descr_set */
+};
+