Mercurial > cpython-lru_cache-weakref
diff Modules/itertoolsmodule.c @ 30773:95fd55545cac legacy-trunk
Improvements to coding for itertools.tee():
* Add error checking code to PyList_Append() call.
* Replace PyObject_CallMethod(to->outbasket, "pop", NULL) with equivalent
in-line code. Inlining is important here because the search for the
pop method will occur for every element returned by the iterator.
* Make tee's dealloc() a little smarter. If the trailing iterator is
being deallocated, then the queue data is no longer needed and can
be freed.
| author | Raymond Hettinger <python@rcn.com> |
|---|---|
| date | Sat, 25 Oct 2003 06:37:47 +0000 |
| parents | b948e775a79e |
| children | 225d848a5f96 |
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--- a/Modules/itertoolsmodule.c Fri Oct 24 20:09:23 2003 +0000 +++ b/Modules/itertoolsmodule.c Sat Oct 25 06:37:47 2003 +0000 @@ -46,6 +46,7 @@ { teeobject *to = lz->tee; PyObject *result, *tmp; + int n; if (lz->num_seen == to->num_seen) { /* This instance is leading, use iter to get more data */ @@ -53,7 +54,10 @@ if (result == NULL) return NULL; if (to->save_mode) - PyList_Append(to->inbasket, result); + if(PyList_Append(to->inbasket, result) == -1){ + Py_DECREF(result); + return NULL; + } to->num_seen++; lz->num_seen++; return result; @@ -66,18 +70,37 @@ to->outbasket = to->inbasket; to->inbasket = tmp; PyList_Reverse(to->outbasket); - assert(PyList_GET_SIZE(to->outbasket) > 0); } + /* Pop result from to->outbasket */ + n = PyList_GET_SIZE(to->outbasket); + assert(n>0); + result = PyList_GET_ITEM(to->outbasket, n-1); + Py_INCREF(result); + if (PyList_SetSlice(to->outbasket, n-1, n, NULL) == -1) { + Py_DECREF(result); + return NULL; + } lz->num_seen++; - return PyObject_CallMethod(to->outbasket, "pop", NULL); + return result; } static void ii_dealloc(iiobject *ii) { + teeobject *to = ii->tee; + int n; + PyObject_GC_UnTrack(ii); ii->tee->save_mode = 0; /* Stop saving data */ + if (ii->num_seen < to->num_seen) { + /* It is the trailing iterator being freed; this means + that the stored queue data is no longer needed */ + n = PyList_GET_SIZE(to->inbasket); + PyList_SetSlice(to->inbasket, 0, n, NULL); + n = PyList_GET_SIZE(to->outbasket); + PyList_SetSlice(to->outbasket, 0, n, NULL); + } Py_XDECREF(ii->tee); PyObject_GC_Del(ii); }