Re: [gentoo-portage-dev] [PATCH 1/3] Add caching to catpkgsplit function

[Michał Górny]

Dnia June 27, 2020 6:34:13 AM UTC, Chun-Yu Shei <cshei@××××××.com> napisał(a):
>According to cProfile, catpkgsplit is called up to 1-5.5 million times
>during "emerge -uDvpU --with-bdeps=y @world". Adding a dict to cache
>its
>results reduces the time for this command from 43.53 -> 41.53 seconds
>--
>a 4.8% speedup.


Not saying caching is wrong for an interim solution but this is the kind of function where refactoring may yield even more gain.


>---
> lib/portage/versions.py | 7 +++++++
> 1 file changed, 7 insertions(+)
>
>diff --git a/lib/portage/versions.py b/lib/portage/versions.py
>index 0c21373cc..ffec316ce 100644
>--- a/lib/portage/versions.py
>+++ b/lib/portage/versions.py
>@@ -312,6 +312,7 @@ def _pkgsplit(mypkg, eapi=None):
>
> _cat_re = re.compile('^%s$' % _cat, re.UNICODE)
> _missing_cat = 'null'
>+_catpkgsplit_cache = {}
>
> def catpkgsplit(mydata, silent=1, eapi=None):
> 	"""
>@@ -331,6 +332,11 @@ def catpkgsplit(mydata, silent=1, eapi=None):
> 		return mydata.cpv_split
> 	except AttributeError:
> 		pass
>+
>+	cache_entry = _catpkgsplit_cache.get(mydata)
>+	if cache_entry is not None:
>+		return cache_entry
>+
> 	mysplit = mydata.split('/', 1)
> 	p_split = None
> 	if len(mysplit) == 1:
>@@ -343,6 +349,7 @@ def catpkgsplit(mydata, silent=1, eapi=None):
> 	if not p_split:
> 		return None
> 	retval = (cat, p_split[0], p_split[1], p_split[2])
>+	_catpkgsplit_cache[mydata] = retval
> 	return retval
>
> class _pkg_str(_unicode):


--
Best regards, 
Michał Górny