diff options
| -rw-r--r-- | Objects/listobject.c | 76 |
1 files changed, 25 insertions, 51 deletions
diff --git a/Objects/listobject.c b/Objects/listobject.c index f34ca70..890c279 100644 --- a/Objects/listobject.c +++ b/Objects/listobject.c @@ -647,56 +647,6 @@ listappend(PyListObject *self, PyObject *v) return ins(self, (int) self->ob_size, v); } -static int -listextend_internal(PyListObject *self, PyObject *b) -{ - int selflen = PyList_GET_SIZE(self); - int blen; - register int i; - PyObject **src, **dest; - - blen = PyObject_Size(b); - if (blen == 0) { - /* short circuit when b is empty */ - Py_DECREF(b); - return 0; - } - - if (self == (PyListObject*)b) { - /* as in list_ass_slice() we must special case the - * situation: a.extend(a) - * - * XXX: I think this way ought to be faster than using - * list_slice() the way list_ass_slice() does. - */ - Py_DECREF(b); - b = PyList_New(selflen); - if (!b) - return -1; - for (i = 0; i < selflen; i++) { - PyObject *o = PyList_GET_ITEM(self, i); - Py_INCREF(o); - PyList_SET_ITEM(b, i, o); - } - } - - if (list_resize(self, selflen + blen) == -1) { - Py_DECREF(b); - return -1; - } - - /* populate the end of self with b's items */ - src = PySequence_Fast_ITEMS(b); - dest = self->ob_item + selflen; - for (i = 0; i < blen; i++) { - PyObject *o = src[i]; - Py_INCREF(o); - dest[i] = o; - } - Py_DECREF(b); - return 0; -} - static PyObject * listextend(PyListObject *self, PyObject *b) { @@ -712,11 +662,35 @@ listextend(PyListObject *self, PyObject *b) 2) extending self to self requires making a copy first */ if (PyList_CheckExact(b) || PyTuple_CheckExact(b) || (PyObject *)self == b) { + PyObject **src, **dest; b = PySequence_Fast(b, "argument must be iterable"); if (!b) return NULL; - if (listextend_internal(self, b) < 0) + n = PySequence_Fast_GET_SIZE(b); + if (n == 0) { + /* short circuit when b is empty */ + Py_DECREF(b); + Py_RETURN_NONE; + } + m = self->ob_size; + if (list_resize(self, m + n) == -1) { + Py_DECREF(b); return NULL; + } + /* note that we may still have self == b here for the + * situation a.extend(a), but the following code works + * in that case too. Just make sure to resize self + * before calling PySequence_Fast_ITEMS. + */ + /* populate the end of self with b's items */ + src = PySequence_Fast_ITEMS(b); + dest = self->ob_item + m; + for (i = 0; i < n; i++) { + PyObject *o = src[i]; + Py_INCREF(o); + dest[i] = o; + } + Py_DECREF(b); Py_RETURN_NONE; } |