push: rework the computation of fallbackheads to be correct
The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.
The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)
In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::
e
|
d f
|/
c
|
b
|
a
The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.
I added a couple of performance related common for further investigation later
on.
$ cat >> $HGRCPATH <<EOF
> [extensions]
> convert =
> [convert]
> hg.saverev = yes
> EOF
$ glog()
> {
> hg -R "$1" log -G --template '{rev} "{desc}" files: {files}\n'
> }
$ hg init source
$ cd source
$ echo a > a
$ echo b > b
$ echo f > f
$ hg ci -d '0 0' -qAm '0: add a b f'
$ echo c > c
$ hg move f d
$ hg ci -d '1 0' -qAm '1: add c, move f to d'
$ hg copy a e
$ echo b >> b
$ hg ci -d '2 0' -qAm '2: copy e from a, change b'
$ hg up -C 0
2 files updated, 0 files merged, 3 files removed, 0 files unresolved
$ echo a >> a
$ hg ci -d '3 0' -qAm '3: change a'
$ hg merge
merging a and e to e
3 files updated, 1 files merged, 1 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -d '4 0' -qAm '4: merge 2 and 3'
$ echo a >> a
$ hg ci -d '5 0' -qAm '5: change a'
$ cd ..
Convert from null revision
$ hg convert --config convert.hg.startrev=null source full
initializing destination full repository
scanning source...
sorting...
converting...
5 0: add a b f
4 1: add c, move f to d
3 2: copy e from a, change b
2 3: change a
1 4: merge 2 and 3
0 5: change a
$ glog full
o 5 "5: change a" files: a
|
o 4 "4: merge 2 and 3" files: e
|\
| o 3 "3: change a" files: a
| |
o | 2 "2: copy e from a, change b" files: b e
| |
o | 1 "1: add c, move f to d" files: c d f
|/
o 0 "0: add a b f" files: a b f
$ rm -Rf full
Convert from zero revision
$ hg convert --config convert.hg.startrev=0 source full
initializing destination full repository
scanning source...
sorting...
converting...
5 0: add a b f
4 1: add c, move f to d
3 2: copy e from a, change b
2 3: change a
1 4: merge 2 and 3
0 5: change a
$ glog full
o 5 "5: change a" files: a
|
o 4 "4: merge 2 and 3" files: e
|\
| o 3 "3: change a" files: a
| |
o | 2 "2: copy e from a, change b" files: b e
| |
o | 1 "1: add c, move f to d" files: c d f
|/
o 0 "0: add a b f" files: a b f
Convert from merge parent
$ hg convert --config convert.hg.startrev=1 source conv1
initializing destination conv1 repository
scanning source...
sorting...
converting...
3 1: add c, move f to d
2 2: copy e from a, change b
1 4: merge 2 and 3
0 5: change a
$ glog conv1
o 3 "5: change a" files: a
|
o 2 "4: merge 2 and 3" files: a e
|
o 1 "2: copy e from a, change b" files: b e
|
o 0 "1: add c, move f to d" files: a b c d
$ cd conv1
$ hg up -q
Check copy preservation
$ hg st -C --change 2 e
M e
$ hg st -C --change 1 e
A e
a
$ hg st -C --change 0 a
A a
(It seems like a bug in log that the following doesn't show rev 1.)
$ hg log --follow --copies e
changeset: 2:8d3c3fe67bb7
user: test
date: Thu Jan 01 00:00:04 1970 +0000
summary: 4: merge 2 and 3
changeset: 0:23c3be426dce
user: test
date: Thu Jan 01 00:00:01 1970 +0000
summary: 1: add c, move f to d
Check copy removal on missing parent
$ hg log --follow --copies d
changeset: 0:23c3be426dce
user: test
date: Thu Jan 01 00:00:01 1970 +0000
summary: 1: add c, move f to d
$ hg cat -r tip a b
a
a
a
b
b
$ hg -q verify
$ cd ..
Convert from merge
$ hg convert --config convert.hg.startrev=4 source conv4
initializing destination conv4 repository
scanning source...
sorting...
converting...
1 4: merge 2 and 3
0 5: change a
$ glog conv4
o 1 "5: change a" files: a
|
o 0 "4: merge 2 and 3" files: a b c d e
$ cd conv4
$ hg up -C
5 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg cat -r tip a b
a
a
a
b
b
$ hg -q verify
$ cd ..
Convert from revset in convert.hg.revs
$ hg convert --config convert.hg.revs='3:4+0' source revsetrepo
initializing destination revsetrepo repository
scanning source...
sorting...
converting...
2 0: add a b f
1 3: change a
0 4: merge 2 and 3
$ glog revsetrepo
o 2 "4: merge 2 and 3" files: b c d e f
|
o 1 "3: change a" files: a
|
o 0 "0: add a b f" files: a b f
Convert from specified revs
$ hg convert --rev 3 --rev 2 source multiplerevs
initializing destination multiplerevs repository
scanning source...
sorting...
converting...
3 0: add a b f
2 1: add c, move f to d
1 2: copy e from a, change b
0 3: change a
$ glog multiplerevs
o 3 "3: change a" files: a
|
| o 2 "2: copy e from a, change b" files: b e
| |
| o 1 "1: add c, move f to d" files: c d f
|/
o 0 "0: add a b f" files: a b f
Convert in multiple steps that doesn't overlap - the link to the parent is
preserved anyway
$ hg convert --config convert.hg.revs=::1 source multistep
initializing destination multistep repository
scanning source...
sorting...
converting...
1 0: add a b f
0 1: add c, move f to d
$ hg convert --config convert.hg.revs=2 source multistep
scanning source...
sorting...
converting...
0 2: copy e from a, change b
$ glog multistep
o 2 "2: copy e from a, change b" files: b e
|
o 1 "1: add c, move f to d" files: c d f
|
o 0 "0: add a b f" files: a b f