outgoing: rework the handling of the `missingroots` case to be faster
The previous implementation was slow, to the point it was taking a significant
amount of `hg bundle --type none-streamv2` call. We rework the code to compute
the same value much faster, making the operation disappear from the `hg bundle
--type none-streamv2` profile. Someone would remark that producing a streamclone
does not requires an `outgoing` object. However that is a matter for another
day. There is other user of `missingroots` (non stream `hg bundle` call for
example), and they will also benefit from this rework.
We implement an old TODO in the process, directly computing the missing and
common attribute as we have most element at hand already.
### benchmark.name = hg.command.bundle
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.revs = all
# benchmark.variants.type = none-streamv2
## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog
before: 7.750458
after: 6.665565 (-14.00%, -1.08)
## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog
before: 0.700229
after: 0.496050 (-29.16%, -0.20)
## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
before: 346.508952
after: 316.749699 (-8.59%, -29.76)
## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog
before: 3.401700
after: 2.915810 (-14.28%, -0.49)
## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog
before: 1.870798
after: 1.461583 (-21.87%, -0.41)
note: this whole `missingroots` of outgoing has a limited number of callers and
could likely be replace by something simpler (like taking an explicit
"missing_revs" set for example). However this is a wider change and we focus on
a small impact, quick rework that does not change the API for now.
Set up repo
$ cat << EOF >> $HGRCPATH
> [ui]
> origbackuppath=.hg/origbackups
> [merge]
> checkunknown=warn
> EOF
$ hg init repo
$ cd repo
$ echo base > base
$ hg add base
$ hg commit -m "base"
Make a dir named b that contains a file, and a file named d
$ mkdir -p b
$ echo c1 > b/c
$ echo d1 > d
$ hg add b/c d
$ hg commit -m "c1"
$ hg bookmark c1
Peform an update that causes b/c to be backed up
$ hg up -q 0
$ mkdir -p b
$ echo c2 > b/c
$ hg up --verbose c1
resolving manifests
b/c: replacing untracked file
getting b/c
creating directory: $TESTTMP/repo/.hg/origbackups/b
getting d
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark c1)
$ test -f .hg/origbackups/b/c
Make files named b and d
$ hg up -q 0
$ echo b1 > b
$ echo d2 > d
$ hg add b d
$ hg commit -m b1
created new head
$ hg bookmark b1
Perform an update that causes b to be backed up - it should replace the backup b dir
$ hg up -q 0
$ echo b2 > b
$ hg up --verbose b1
resolving manifests
b: replacing untracked file
getting b
removing conflicting directory: $TESTTMP/repo/.hg/origbackups/b
getting d
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark b1)
$ test -f .hg/origbackups/b
Perform an update the causes b/c to be backed up again - it should replace the backup b file
$ hg up -q 0
$ mkdir b
$ echo c3 > b/c
$ hg up --verbose c1
resolving manifests
b/c: replacing untracked file
getting b/c
creating directory: $TESTTMP/repo/.hg/origbackups/b
removing conflicting file: $TESTTMP/repo/.hg/origbackups/b
getting d
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark c1)
$ test -d .hg/origbackups/b
Cause two symlinks to be backed up that points to a valid location from the backup dir
$ hg up -q 0
$ mkdir ../sym-link-target
#if symlink
$ ln -s ../../../sym-link-target b
$ ln -s ../../../sym-link-target d
#else
$ touch b d
#endif
$ hg up b1
b: replacing untracked file
d: replacing untracked file
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark b1)
#if symlink
$ readlink.py .hg/origbackups/b
.hg/origbackups/b -> ../../../sym-link-target
#endif
Perform an update that causes b/c and d to be backed up again - b/c should not go into the target dir
$ hg up -q 0
$ mkdir b
$ echo c4 > b/c
$ echo d3 > d
$ hg up --verbose c1
resolving manifests
b/c: replacing untracked file
d: replacing untracked file
getting b/c
creating directory: $TESTTMP/repo/.hg/origbackups/b
removing conflicting file: $TESTTMP/repo/.hg/origbackups/b
getting d
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark c1)
$ cat .hg/origbackups/b/c
c4
$ cat .hg/origbackups/d
d3
$ ls ../sym-link-target
Incorrectly configure origbackuppath to be under a file
$ echo data > .hg/badorigbackups
$ hg up -q 0
$ mkdir b
$ echo c5 > b/c
$ hg up --verbose c1 --config ui.origbackuppath=.hg/badorigbackups
resolving manifests
b/c: replacing untracked file
getting b/c
creating directory: $TESTTMP/repo/.hg/badorigbackups/b
removing conflicting file: $TESTTMP/repo/.hg/badorigbackups
getting d
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark c1)
$ ls .hg/badorigbackups/b
c