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.
$ . "$TESTDIR/narrow-library.sh"
$ hg init master
$ cd master
$ cat >> .hg/hgrc <<EOF
> [narrow]
> serveellipses=True
> EOF
$ for x in `$TESTDIR/seq.py 10`
> do
> echo $x > "f$x"
> hg add "f$x"
> hg commit -m "Commit f$x"
> done
$ cd ..
narrow clone a couple files, f2 and f8
$ hg clone --narrow ssh://user@dummy/master narrow --include "f2" --include "f8"
requesting all changes
adding changesets
adding manifests
adding file changes
added 5 changesets with 2 changes to 2 files
new changesets *:* (glob)
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd narrow
$ ls -A
.hg
f2
f8
$ cat f2 f8
2
8
$ cd ..
change every upstream file twice
$ cd master
$ for x in `$TESTDIR/seq.py 10`
> do
> echo "update#1 $x" >> "f$x"
> hg commit -m "Update#1 to f$x" "f$x"
> done
$ for x in `$TESTDIR/seq.py 10`
> do
> echo "update#2 $x" >> "f$x"
> hg commit -m "Update#2 to f$x" "f$x"
> done
$ cd ..
look for incoming changes
$ cd narrow
$ hg incoming --limit 3
comparing with ssh://user@dummy/master
searching for changes
changeset: 5:ddc055582556
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Update#1 to f1
changeset: 6:f66eb5ad621d
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Update#1 to f2
changeset: 7:c42ecff04e99
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Update#1 to f3
Interrupting the pull is safe
$ hg --config hooks.pretxnchangegroup.bad=false pull -q
transaction abort!
rollback completed
abort: pretxnchangegroup.bad hook exited with status 1
[40]
$ hg id
223311e70a6f tip
pull new changes down to the narrow clone. Should get 8 new changesets: 4
relevant to the narrow spec, and 4 ellipsis nodes gluing them all together.
$ hg pull
pulling from ssh://user@dummy/master
searching for changes
adding changesets
adding manifests
adding file changes
added 9 changesets with 4 changes to 2 files
new changesets *:* (glob)
(run 'hg update' to get a working copy)
$ hg log -T '{rev}: {desc}\n'
13: Update#2 to f10
12: Update#2 to f8
11: Update#2 to f7
10: Update#2 to f2
9: Update#2 to f1
8: Update#1 to f8
7: Update#1 to f7
6: Update#1 to f2
5: Update#1 to f1
4: Commit f10
3: Commit f8
2: Commit f7
1: Commit f2
0: Commit f1
$ hg update tip
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
add a change and push it
$ echo "update#3 2" >> f2
$ hg commit -m "Update#3 to f2" f2
$ hg log f2 -T '{rev}: {desc}\n'
14: Update#3 to f2
10: Update#2 to f2
6: Update#1 to f2
1: Commit f2
$ hg push
pushing to ssh://user@dummy/master
searching for changes
remote: adding changesets
remote: adding manifests
remote: adding file changes
remote: added 1 changesets with 1 changes to 1 files
$ cd ..
$ cd master
$ hg log f2 -T '{rev}: {desc}\n'
30: Update#3 to f2
21: Update#2 to f2
11: Update#1 to f2
1: Commit f2
$ hg log -l 3 -T '{rev}: {desc}\n'
30: Update#3 to f2
29: Update#2 to f10
28: Update#2 to f9
Can pull into repo with a single commit
$ cd ..
$ hg clone -q --narrow ssh://user@dummy/master narrow2 --include "f1" -r 0
$ cd narrow2
$ hg pull -q -r 1
remote: abort: unexpected error: unable to resolve parent while packing '00manifest' 1 for changeset 0
transaction abort!
rollback completed
abort: pull failed on remote
[100]