diff options
| -rw-r--r-- | Objects/listobject.c | 155 |
1 files changed, 71 insertions, 84 deletions
diff --git a/Objects/listobject.c b/Objects/listobject.c index a34810e..1bf0b80 100644 --- a/Objects/listobject.c +++ b/Objects/listobject.c @@ -324,7 +324,6 @@ list_contains(PyListObject *a, PyObject *el) return cmp; } - static PyObject * list_item(PyListObject *a, int i) { @@ -686,7 +685,6 @@ listextend_internal(PyListObject *self, PyObject *b) return 0; } - static PyObject * list_inplace_concat(PyListObject *self, PyObject *other) { @@ -704,16 +702,70 @@ list_inplace_concat(PyListObject *self, PyObject *other) static PyObject * listextend(PyListObject *self, PyObject *b) { + PyObject *it; /* iter(v) */ + int m; /* size of self */ + int n; /* guess for size of b */ + int mn; /* m + n */ + int i; - b = PySequence_Fast(b, "list.extend() argument must be iterable"); - if (!b) - return NULL; + /* Special cases: + 1) lists and tuples which can use PySequence_Fast ops + 2) extending self to self requires making a copy first + */ + if (PyList_CheckExact(b) || PyTuple_CheckExact(b) || (PyObject *)self == b) { + b = PySequence_Fast(b, "argument must be iterable"); + if (!b) + return NULL; + if (listextend_internal(self, b) < 0) + return NULL; + Py_RETURN_NONE; + } - if (listextend_internal(self, b) < 0) + it = PyObject_GetIter(b); + if (it == NULL) return NULL; - Py_INCREF(Py_None); - return Py_None; + /* Guess a result list size. */ + n = PyObject_Size(b); + if (n < 0) { + PyErr_Clear(); + n = 8; /* arbitrary */ + } + m = self->ob_size; + mn = m + n; + if (list_resize(self, mn) == -1) + goto error; + memset(&(self->ob_item[m]), 0, sizeof(*self->ob_item) * n); + + /* Run iterator to exhaustion. */ + for (i = m; ; i++) { + PyObject *item = PyIter_Next(it); + if (item == NULL) { + if (PyErr_Occurred()) + goto error; + break; + } + if (i < mn) + PyList_SET_ITEM(self, i, item); /* steals ref */ + else { + int status = ins1(self, self->ob_size, item); + Py_DECREF(item); /* append creates a new ref */ + if (status < 0) + goto error; + } + } + + /* Cut back result list if initial guess was too large. */ + if (i < mn && self != NULL) { + if (list_ass_slice(self, i, mn, (PyObject *)NULL) != 0) + goto error; + } + Py_DECREF(it); + Py_RETURN_NONE; + + error: + Py_DECREF(it); + return NULL; } static PyObject * @@ -2220,78 +2272,6 @@ list_richcompare(PyObject *v, PyObject *w, int op) return PyObject_RichCompare(vl->ob_item[i], wl->ob_item[i], op); } -/* Adapted from newer code by Tim */ -static int -list_fill(PyListObject *result, PyObject *v) -{ - PyObject *it; /* iter(v) */ - int n; /* guess for result list size */ - int i; - - n = result->ob_size; - - /* Special-case list(a_list), for speed. */ - if (PyList_Check(v)) { - if (v == (PyObject *)result) - return 0; /* source is destination, we're done */ - return list_ass_slice(result, 0, n, v); - } - - /* Empty previous contents */ - if (n != 0) { - if (list_ass_slice(result, 0, n, (PyObject *)NULL) != 0) - return -1; - } - - /* Get iterator. There may be some low-level efficiency to be gained - * by caching the tp_iternext slot instead of using PyIter_Next() - * later, but premature optimization is the root etc. - */ - it = PyObject_GetIter(v); - if (it == NULL) - return -1; - - /* Guess a result list size. */ - n = PyObject_Size(v); - if (n < 0) { - PyErr_Clear(); - n = 8; /* arbitrary */ - } - if (list_resize(result, n) == -1) - goto error; - memset(result->ob_item, 0, sizeof(*result->ob_item) * n); - - /* Run iterator to exhaustion. */ - for (i = 0; ; i++) { - PyObject *item = PyIter_Next(it); - if (item == NULL) { - if (PyErr_Occurred()) - goto error; - break; - } - if (i < n) - PyList_SET_ITEM(result, i, item); /* steals ref */ - else { - int status = ins1(result, result->ob_size, item); - Py_DECREF(item); /* append creates a new ref */ - if (status < 0) - goto error; - } - } - - /* Cut back result list if initial guess was too large. */ - if (i < n && result != NULL) { - if (list_ass_slice(result, i, n, (PyObject *)NULL) != 0) - goto error; - } - Py_DECREF(it); - return 0; - - error: - Py_DECREF(it); - return -1; -} - static int list_init(PyListObject *self, PyObject *args, PyObject *kw) { @@ -2300,10 +2280,17 @@ list_init(PyListObject *self, PyObject *args, PyObject *kw) if (!PyArg_ParseTupleAndKeywords(args, kw, "|O:list", kwlist, &arg)) return -1; - if (arg != NULL) - return list_fill(self, arg); - if (self->ob_size > 0) - return list_ass_slice(self, 0, self->ob_size, (PyObject*)NULL); + /* Empty previous contents */ + if (self->ob_size != 0) { + if (list_ass_slice(self, 0, self->ob_size, (PyObject *)NULL) != 0) + return -1; + } + if (arg != NULL) { + PyObject *rv = listextend(self, arg); + if (rv == NULL) + return -1; + Py_DECREF(rv); + } return 0; } |