[issue21556] try to use hashtable in pickle

STINNER Victor added the comment: "Ah, so this means CF's patch will make the pickle memotable invisible to tracemalloc?" Currently, _Py_hashtabe uses PyMem_RawMalloc and PyMem_RawFree by default (realloc is not needed, we need to keep the previous buckets on rehash). Using _Py_hashtable_new_

[issue21556] try to use hashtable in pickle

Antoine Pitrou added the comment: > I didn't want to use the Python dict type for tracemalloc because this > type may use the Python memory allocator which would lead to reentrant > calls to tracemalloc. Ah, so this means CF's patch will make the pickle memotable invisible to tracemalloc? > It

[issue21556] try to use hashtable in pickle

STINNER Victor added the comment: > And the straightforward collision resolution in hashtable.c is much less > efficient at mitigating collisions than a Python dict's. Modules/hashtable.c comes from http://sourceforge.net/projects/libcfu/ (cfuhash type). I adapted the code for my needs (the tr

[issue21556] try to use hashtable in pickle

Antoine Pitrou added the comment: > "_Py_hashtable_hash_ptr is quite crude in that it doesn't even try to > compensate for pointer alignment, so there will automatically be many > collisions. Only one hash bucket every 8 or 16 will be used, at best." > > I chose to use _Py_HashPointer() to dro

[issue21556] try to use hashtable in pickle

STINNER Victor added the comment: "_Py_hashtable_hash_ptr is quite crude in that it doesn't even try to compensate for pointer alignment, so there will automatically be many collisions. Only one hash bucket every 8 or 16 will be used, at best." I chose to use _Py_HashPointer() to drop (shift)

[issue21556] try to use hashtable in pickle

Antoine Pitrou added the comment: > I'm saying attempt, because although it works correctly, some benchmarks are > actually slower. > I didn't profile it, so I don't know if it's due to the hashtable > implementation, function call overheads, etc. It probably shows that Python dicts (which the

[issue21556] try to use hashtable in pickle

Changes by Ned Deily : -- nosy: +alexandre.vassalotti ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: https://m

[issue21556] try to use hashtable in pickle

New submission from Charles-François Natali: This patch is an attempt at making pickle use Modules/hashtable.{h,c} instead of its hash table ad-hoc implementation for its memoization table. I'm saying attempt, because although it works correctly, some benchmarks are actually slower. I didn't pr