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
$ cat >> $HGRCPATH << EOF
> [extensions]
> blackbox=
> rebase=
> mock=$TESTDIR/mockblackbox.py
>
> [experimental]
> evolution = createmarkers
> EOF
Create a repo with some tags
$ hg init repo
$ cd repo
$ echo initial > foo
$ hg -q commit -A -m initial
$ hg tag -m 'test tag' test1
$ echo first > first
$ hg -q commit -A -m first
$ hg tag -m 'test2 tag' test2
$ hg -q up -r 0
$ echo newhead > newhead
$ hg commit -A -m newhead
adding newhead
created new head
$ hg tag -m 'test head 2 tag' head2
$ hg log -G -T '{rev}:{node|short} {tags} {desc}\n'
@ 5:2942a772f72a tip test head 2 tag
|
o 4:042eb6bfcc49 head2 newhead
|
| o 3:c3cb30f2d2cd test2 tag
| |
| o 2:d75775ffbc6b test2 first
| |
| o 1:5f97d42da03f test tag
|/
o 0:55482a6fb4b1 test1 initial
Trigger tags cache population by doing something that accesses tags info
$ hg tags
tip 5:2942a772f72a
head2 4:042eb6bfcc49
test2 2:d75775ffbc6b
test1 0:55482a6fb4b1
$ cat .hg/cache/tags2-visible
5 2942a772f72a444bef4bef13874d515f50fa27b6
042eb6bfcc4909bad84a1cbf6eb1ddf0ab587d41 head2
55482a6fb4b1881fa8f746fd52cf6f096bb21c89 test1
d75775ffbc6bca1794d300f5571272879bd280da test2
Hiding a non-tip changeset should change filtered hash and cause tags recompute
$ hg debugobsolete -d '0 0' c3cb30f2d2cd0aae008cc91a07876e3c5131fd22 -u dummyuser
$ hg tags
tip 5:2942a772f72a
head2 4:042eb6bfcc49
test1 0:55482a6fb4b1
$ cat .hg/cache/tags2-visible
5 2942a772f72a444bef4bef13874d515f50fa27b6 f34fbc9a9769ba9eff5aff3d008a6b49f85c08b1
042eb6bfcc4909bad84a1cbf6eb1ddf0ab587d41 head2
55482a6fb4b1881fa8f746fd52cf6f096bb21c89 test1
$ hg blackbox -l 5
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> tags
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> 2/2 cache hits/lookups in * seconds (glob)
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> writing .hg/cache/tags2-visible with 2 tags
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> tags exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> blackbox -l 5
Hiding another changeset should cause the filtered hash to change
$ hg debugobsolete -d '0 0' d75775ffbc6bca1794d300f5571272879bd280da -u dummyuser
$ hg debugobsolete -d '0 0' 5f97d42da03fd56f3b228b03dfe48af5c0adf75b -u dummyuser
$ hg tags
tip 5:2942a772f72a
head2 4:042eb6bfcc49
$ cat .hg/cache/tags2-visible
5 2942a772f72a444bef4bef13874d515f50fa27b6 2fce1eec33263d08a4d04293960fc73a555230e4
042eb6bfcc4909bad84a1cbf6eb1ddf0ab587d41 head2
$ hg blackbox -l 5
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> tags
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> 1/1 cache hits/lookups in * seconds (glob)
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> writing .hg/cache/tags2-visible with 1 tags
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> tags exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> blackbox -l 5
Resolving tags on an unfiltered repo writes a separate tags cache
$ hg --hidden tags
tip 5:2942a772f72a
head2 4:042eb6bfcc49
test2 2:d75775ffbc6b
test1 0:55482a6fb4b1
$ cat .hg/cache/tags2
5 2942a772f72a444bef4bef13874d515f50fa27b6
042eb6bfcc4909bad84a1cbf6eb1ddf0ab587d41 head2
55482a6fb4b1881fa8f746fd52cf6f096bb21c89 test1
d75775ffbc6bca1794d300f5571272879bd280da test2
$ hg blackbox -l 5
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> --hidden tags
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> 2/2 cache hits/lookups in * seconds (glob)
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> writing .hg/cache/tags2 with 3 tags
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> --hidden tags exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob @2942a772f72a444bef4bef13874d515f50fa27b6 (5000)> blackbox -l 5