branchcache: lazily validate nodes from the branchmap
On my personal hg-repository with 365 entries in .hg/cache/branch2, following
are the numbers for perfbranchmapload.
Before this patch:
! wall 0.000866 comb 0.000000 user 0.000000 sys 0.000000 (best of 2680)
! wall 0.001525 comb 0.000000 user 0.000000 sys 0.000000 (max of 2680)
! wall 0.001107 comb 0.001097 user 0.001086 sys 0.000011 (avg of 2680)
! wall 0.001104 comb 0.000000 user 0.000000 sys 0.000000 (median of 2680)
With this patch:
! wall 0.000530 comb 0.000000 user 0.000000 sys 0.000000 (best of 4240)
! wall 0.001078 comb 0.000000 user 0.000000 sys 0.000000 (max of 4240)
! wall 0.000696 comb 0.000693 user 0.000677 sys 0.000017 (avg of 4240)
! wall 0.000690 comb 0.000000 user 0.000000 sys 0.000000 (median of 4240)
On our internal repository with ~20k entries in branchcache, I see improvement
from 0.125 sec to 0.066 sec which is 47% speed up.
The above are the numbers of perfbranchmapload which shows how much time we
saved by not validating the nodes. But we need to validate some nodes. Following
are timings of some mercurial operations which have speed up because of this
lazy validation of nodes:
No-op `hg update` on our internal repository (Avg on 4 runs):
Before: 0.540 secs
After: 0.430 secs
Setting a branch name which already exists without --force (Avg of 4 runs):
Before: 0.510 secs
After: 0.250 secs
I ran the ASV performance suite and was unable to see any improvements except
there was improvement of perfdirstatewrite() on netbeans which I think was not
related.
I looked into the commit code, the command which I am trying to speedup, it
looks like it uses revbranchcache to update the branchcache.
Differential Revision: https://phab.mercurial-scm.org/D6208
$ . "$TESTDIR/histedit-helpers.sh"
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ initrepo ()
> {
> hg init r
> cd r
> for x in a b c d e f ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> }
$ initrepo
log before edit
$ hg log --graph
@ changeset: 5:652413bf663e
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:e860deea161a
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:055a42cdd887
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:177f92b77385
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
edit the history
$ hg histedit 177f92b77385 --commands - 2>&1 << EOF | fixbundle
> drop 177f92b77385 c
> pick e860deea161a e
> pick 652413bf663e f
> pick 055a42cdd887 d
> EOF
log after edit
$ hg log --graph
@ changeset: 4:f518305ce889
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 3:a4f7421b80f7
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 2:ee283cb5f2d5
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
Check histedit_source
$ hg log --debug --rev f518305ce889
changeset: 4:f518305ce889c07cb5bd05522176d75590ef3324
tag: tip
phase: draft
parent: 3:a4f7421b80f79fcc59fff01bcbf4a53d127dd6d3
parent: -1:0000000000000000000000000000000000000000
manifest: 4:d3d4f51c157ff242c32ff745d4799aaa26ccda44
user: test
date: Thu Jan 01 00:00:00 1970 +0000
files+: d
extra: branch=default
extra: histedit_source=055a42cdd88768532f9cf79daa407fc8d138de9b
description:
d
manifest after edit
$ hg manifest
a
b
d
e
f
Drop the last changeset
$ hg histedit ee283cb5f2d5 --commands - 2>&1 << EOF | fixbundle
> pick ee283cb5f2d5 e
> pick a4f7421b80f7 f
> drop f518305ce889 d
> EOF
$ hg log --graph
@ changeset: 3:a4f7421b80f7
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 2:ee283cb5f2d5
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
$ hg histedit cb9a9f314b8b --commands - 2>&1 << EOF | fixbundle
> pick cb9a9f314b8b a
> pick ee283cb5f2d5 e
> EOF
hg: parse error: missing rules for changeset a4f7421b80f7
(use "drop a4f7421b80f7" to discard, see also: 'hg help -e histedit.config')
$ hg --config histedit.dropmissing=True histedit cb9a9f314b8b --commands - 2>&1 << EOF | fixbundle
> EOF
hg: parse error: no rules provided
(use strip extension to remove commits)
$ hg --config histedit.dropmissing=True histedit cb9a9f314b8b --commands - 2>&1 << EOF | fixbundle
> pick cb9a9f314b8b a
> pick ee283cb5f2d5 e
> EOF
$ hg log --graph
@ changeset: 1:e99c679bf03e
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a