perf: make perftags clear tags cache correctly
Before this patch, "hg perftags" command doesn't measure performance
of "repo.tags()" correctly, because it doesn't clear tags cache
correctly.
9dca7653b525 replaced repo._tags with repo._tagscache, but didn't
change the code path to clear tags cache in perftags() at that time.
BTW, full history of "tags cache" is:
-
d7df759d0e97 (or 0.6) introduced repo.tagscache as the first "tags cache"
-
5614a628d173 (or 1.4) replaced repo.tagscache with repo._tags
-
9dca7653b525 (or 2.0) replaced repo._tags with repo._tagscache
-
98c867ac1330 (or 2.5) made repo._tagscache filteredpropertycache
To make perftags clear tags cache correctly, and to increase
"historical portability" of perftags, this patch examines existence of
attributes in repo object, and guess appropriate procedure to clear
tags cache.
To avoid examining existence of attributes at each repetition, this
patch makes repocleartagscachefunc() return the function, which
actually clears tags cache.
mozilla-central repo (85 tags on 308365 revs) with each Mercurial
version between before and after this patch.
==== ========= =========
ver before after
==== ========= =========
1.9 0.476062 0.466464
------- *1 -------
2.0 0.346309 0.458327
2.1 0.343106 0.454489
------- *2 -------
2.2 0.069790 0.071263
2.3 0.067829 0.069340
2.4 0.068075 0.069573
------- *3 -------
2.5 0.021896 0.022406
2.6 0.021900 0.022374
2.7 0.021883 0.022379
2.8 0.021949 0.022327
2.9 0.021877 0.022330
3.0 0.021860 0.022314
3.1 0.021869 0.022669
3.2 0.021831 0.022668
3.3 0.021809 0.022691
3.4 0.021861 0.022916
3.5 0.019335 0.020749
3.6 0.019319 0.020866
3.7 0.018781 0.020251
------- *4 -------
3.8 0.068262 0.072558
3.9 0.069682 0.073773
==== ========= =========
(*1) repo._tags was replaced with repo._tagscache at this point
"repo._tags = None" in perftags "before" this patch doesn't clear
tags cache for Mercurial 2.0 or later. This causes significant
gap of "before" between 1.9 and 2.0 .
(*2) I'm not sure about significant gap at this point, but release
note of 2.2 described "a number of significant performance
improvements for large repositories"
(*3) filtered changelog was cached in repoview as repoview.changelog
at this point (by
4d92e2d75cff)
This avoids calculation of filtered changelog at each repetition
of t().
(*4) calculation of filtered changelog was included into wall time at
this point (by
332926212ef8), again
See below for detail about this significant gap:
https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-April/083410.html
perf: replace ui.configint() by getint() for Mercurial earlier than 1.9
Before this patch, using ui.configint() prevents perf.py from
measuring performance with Mercurial earlier than 1.9 (or
fa2b596db182), because ui.configint() isn't available in such
Mercurial, even though there are some code paths for Mercurial earlier
than 1.9 in perf.py.
For example, setting "_prereadsize" attribute in perfindex() and
perfnodelookup() is effective only with hg earlier than 1.8 (or
61c9bc3da402).
This patch replaces ui.configint() invocations by newly introduced
getint().
This patch also adds check-perf-code.py an extra check entry to detect
direct usage of ui.configint() in perf.py.
BTW, this patch doesn't choose adding configint() method at runtime by
replacing ui.__class__ like below, even though this is the recommended
way to modern Mercurial extensions.
def uisetup(ui):
if not util.safehasattr(ui, 'configint'):
class uiwrap(ui.__class__):
def configint(self, section, name, ....):
....
ui.__class__ = uiwrap
Because changes to ui.__class__ by uisetup() of loaded extension have
been propagated since 1.6.1 (or
d8d0fc3988ca), the recommended way
above doesn't work as expected with Mercurial earlier than it.