Repository navigation
Optimize update_keyword_args() function #72032
Description
| BPO | 27845 |
|---|---|
| Nosy | @vstinner, @serhiy-storchaka |
Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.
Show more details
GitHub fields:
assignee = None
closed_at = <Date 2016-09-28.22:05:09.527>
created_at = <Date 2016-08-23.21:44:34.855>
labels = ['performance']
title = 'Optimize update_keyword_args() function'
updated_at = <Date 2016-09-28.22:05:09.526>
user = 'https://github.com/vstinner'bugs.python.org fields:
activity = <Date 2016-09-28.22:05:09.526>
actor = 'serhiy.storchaka'
assignee = 'none'
closed = True
closed_date = <Date 2016-09-28.22:05:09.527>
closer = 'serhiy.storchaka'
components = []
creation = <Date 2016-08-23.21:44:34.855>
creator = 'vstinner'
dependencies = []
files = []
hgrepos = []
issue_num = 27845
keywords = []
message_count = 3.0
messages = ['273518', '273681', '276023']
nosy_count = 2.0
nosy_names = ['vstinner', 'serhiy.storchaka']
pr_nums = []
priority = 'normal'
resolution = 'out of date'
stage = 'resolved'
status = 'closed'
superseder = None
type = 'performance'
url = 'https://bugs.python.org/issue27845'
versions = ['Python 3.6']
Activity
vstinner commentedon Aug 23, 2016
In the review of my issue bpo-27830 "Add _PyObject_FastCallKeywords(): pass keyword arguments as (key, value) pairs", Antoine Pitrou wrote about _PyStack_AsDict():
"It's a pity that you're doing two dict lookups per keyword argument.
Another strategy would be to check that
PyDict_Size() == nkat the end, and if not, try to find the duplicate keyword."https://bugs.python.org/review/27830/diff/18203/Objects/abstract.c#newcode2326_Objects/abstract.c:2326
In fact, I simply copied code from update_keyword_args(), helper function used by do_call() and ext_do_call() in Python/ceval.c.
This function is quite old, the last major change was made in 2001:
---
changeset: 15711:2481b5fe86d6
branch: legacy-trunk
user: Jeremy Hylton <jeremy@alum.mit.edu>
date: Wed Jan 03 23:52:36 2001 +0000
files: Python/ceval.c
description:
Revised implementation of CALL_FUNCTION and friends.
More revision still needed.
(...)
---
But this change just moved code. It looks like the real code was in fact added by this change made in 2000:
---
changeset: 12082:603db0d0aed1
branch: legacy-trunk
user: Jeremy Hylton <jeremy@alum.mit.edu>
date: Tue Mar 28 23:49:17 2000 +0000
files: Grammar/Grammar Include/opcode.h Lib/dis.py Misc/ACKS Python/ceval.c Python/compile.c Python/graminit.c
description:
slightly modified version of Greg Ewing's extended call syntax patch
executive summary:
Instead of typing 'apply(f, args, kwargs)' you can type 'f(*arg, **kwargs)'.
Some file-by-file details follow.
(...)
---
vstinner commentedon Aug 25, 2016
See also the issue bpo-27358: "BUILD_MAP_UNPACK_WITH_CALL is slow.
vstinner commentedon Sep 12, 2016
_PyStack_AsDict() doesn't check anymore if keys are unique.
BUILD_MAP_UNPACK and BUILD_MAP_UNPACK_WITH_CALL opcodes now use PyDict_Update() to combine mappings and _PyDictView_Intersect() to check if keys are unique.
I don't know if there is still something to optimize. The opcode changed the method to C and Python functions (FASTCALL) changed a lot recently ;-)
I suggest to close the issue.