commit: improve the files field of changelog for merges
Currently, the files list of merge commits repeats all the deletions
(either actual deletions, or files that got renamed) that happened
between base and p2 of the merge. If p2 is the main branch, the list
can easily be much bigger than the change being merged.
This results in various problems worth improving:
- changelog is bigger than necessary
- `hg log directory` lists many unrelated merge commits, and `hg log
-v -r commit` frequently fills multiple screens worth of files
- it possibly slows down adjustlinkrev, by forcing it to read more
manifests, and that function can certainly be a bottleneck
- the server side of pulls can waste a lot of time simply opening the
filelogs for pointless files (the constant factors for opening even
a tiny filelog is apparently pretty bad)
So stop listing such files as described in the code. Impacted merge
commits and their descendants get a different hash than they would
have without this. This doesn't seem problematic, except for
convert. The previous commit helped with that in the hg->hg case (but
if you do svn->hg twice from scratch, hashes can still change).
The rest of the description is numbers. I don't have much to report,
because recreating the files list of existing repositories is not
easy:
- debugupgradeformat and bundle/unbundle don't recreate the list
- export/import tends to choke quickly applying patches or on
description that contain diffs,
- merge commits from the convert extension don't have the right files
list for reasons orthogonal to the current commit
- replaying the merge with hg update/hg merge/hg revert --all/hg
commit can end up failing in hg revert
- I wasn't sure that using debugsetparents + debugrebuilddirstate
would really build the right thing
I measured commit time before and after this change, in a case with no
files filtered out, several files filtered out (no difference) and 5k
files filtered out (+1% time).
Recreating the 100 more recent merges in a private repo, the
concatenated uncompressed files lists goes from 1.12MB to
0.52MB. Excluding 3 merges that are not representative, then the size
goes from 570k to 15k.
I converted part of mozilla-central, and observed file list shrinking
quite a bit too, starting at the very first merge,
733641d9feaf, going
from 550 files to 10 files (although they have relatively few merges,
so they probably wouldn't care).
Differential Revision: https://phab.mercurial-scm.org/D6613
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
make a test repository that looks like this:
o 2:28bc7b1afd6a
|
| @ 1:d7fe2034f71b
|/
o 0/62ecad8b70e5
$ hg init r0
$ cd r0
$ touch f0
$ hg ci -m0 -Aq
$ touch f1
$ hg ci -m1 -Aq
$ hg update 0 -q
$ touch f2
$ hg ci -m2 -Aq
$ hg update 1 -q
make some patches with a parent: 1:d7fe2034f71b -> p0 -> p1
$ echo cp0 >> fp0
$ hg add fp0
$ hg ci -m p0 -d "0 0"
$ hg export -r. > p0
$ hg strip -qn .
$ hg qimport p0
adding p0 to series file
$ hg qpush
applying p0
now at: p0
$ echo cp1 >> fp1
$ hg add fp1
$ hg qnew p1 -d "0 0"
$ hg qpop -aq
patch queue now empty
qpush --exact when at the parent
$ hg update 1 -q
$ hg qpush -e
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg qpush -e p0
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg qpush -e p1
applying p0
applying p1
now at: p1
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
qpush --exact when at another rev
$ hg update 0 -q
$ hg qpush -e
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 0 -q
$ hg qpush -e p0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 0 -q
$ hg qpush -e p1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
applying p0
applying p1
now at: p1
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 0 -q
$ hg qpush -ea
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
applying p0
applying p1
now at: p1
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
qpush --exact while crossing branches
$ hg update 2 -q
$ hg qpush -e
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 2 -q
$ hg qpush -e p0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
applying p0
now at: p0
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 2 -q
$ hg qpush -e p1
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
applying p0
applying p1
now at: p1
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
$ hg update 2 -q
$ hg qpush -ea
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
applying p0
applying p1
now at: p1
$ hg parents -qr qbase
1:d7fe2034f71b
$ hg qpop -aq
patch queue now empty
qpush --exact --force with changes to an unpatched file
$ hg update 1 -q
$ echo c0 >> f0
$ hg qpush -e
abort: local changes found
[255]
$ hg qpush -ef
applying p0
now at: p0
$ cat f0
c0
$ rm f0
$ touch f0
$ hg qpop -aq
patch queue now empty
$ hg update 1 -q
$ echo c0 >> f0
$ hg qpush -e p1
abort: local changes found
[255]
$ hg qpush -e p1 -f
applying p0
applying p1
now at: p1
$ cat f0
c0
$ rm f0
$ touch f0
$ hg qpop -aq
patch queue now empty
qpush --exact --force with changes to a patched file
$ hg update 1 -q
$ echo cp0-bad >> fp0
$ hg add fp0
$ hg qpush -e
abort: local changes found
[255]
$ hg qpush -ef
applying p0
file fp0 already exists
1 out of 1 hunks FAILED -- saving rejects to file fp0.rej
patch failed, unable to continue (try -v)
patch failed, rejects left in working directory
errors during apply, please fix and qrefresh p0
[2]
$ cat fp0
cp0-bad
$ cat fp0.rej
--- fp0
+++ fp0
@@ -0,0 +1,1 @@
+cp0
$ hg qpop -aqf
patch queue now empty
$ rm fp0
$ rm fp0.rej
$ hg update 1 -q
$ echo cp1-bad >> fp1
$ hg add fp1
$ hg qpush -e p1
abort: local changes found
[255]
$ hg qpush -e p1 -f
applying p0
applying p1
file fp1 already exists
1 out of 1 hunks FAILED -- saving rejects to file fp1.rej
patch failed, unable to continue (try -v)
patch failed, rejects left in working directory
errors during apply, please fix and qrefresh p1
[2]
$ cat fp1
cp1-bad
$ cat fp1.rej
--- fp1
+++ fp1
@@ -0,0 +1,1 @@
+cp1
$ hg qpop -aqf
patch queue now empty
$ hg forget fp1
$ rm fp1
$ rm fp1.rej
qpush --exact when already at a patch
$ hg update 1
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg qpush -e p0
applying p0
now at: p0
$ hg qpush -e p1
abort: cannot push --exact with applied patches
[255]
$ hg qpop -aq
patch queue now empty
qpush --exact --move should fail
$ hg qpush -e --move p1
abort: cannot use --exact and --move together
[255]
qpush --exact a patch without a parent recorded
$ hg qpush -q
now at: p0
$ grep -v '# Parent' .hg/patches/p0 > p0.new
$ mv p0.new .hg/patches/p0
$ hg qpop -aq
patch queue now empty
$ hg qpush -e
abort: p0 does not have a parent recorded
[255]
$ hg qpush -e p0
abort: p0 does not have a parent recorded
[255]
$ hg qpush -e p1
abort: p0 does not have a parent recorded
[255]
$ hg qpush -ea
abort: p0 does not have a parent recorded
[255]
$ cd ..