New submission from INADA Naoki <songofaca...@gmail.com>: Currently, functools.lru_cache implement own doubly-linked list.
But it is inefficient than OrderedDict because each link node is GC object. So it may eat more memory and take longer GC time. I added two private C API for OrderedDict and make lru_cache use it. * _PyODict_LRUGetItem(): Similar to PyDict_GetItemWithHash() + od.move_to_end(last=True). * _PyODict_PopItem(): Similar to odict.popitem(). Why I didn't implement C version of move_to_end() is to reduce lookup. _PyODict_LRUGetItem(key) lookup key once while od[key]; od.move_to_end(key) lookup key twice. I'll benchmark it and report result here. ---------- components: Interpreter Core messages: 308980 nosy: inada.naoki priority: normal severity: normal status: open title: Make OrderedDict can be used for LRU from C versions: Python 3.7 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue32422> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
