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
$ hg init test
$ cd test
$ echo 0 >> afile
$ hg add afile
$ hg commit -m "0.0"
$ echo 1 >> afile
$ hg commit -m "0.1"
$ echo 2 >> afile
$ hg commit -m "0.2"
$ echo 3 >> afile
$ hg commit -m "0.3"
$ hg update -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo 1 >> afile
$ hg commit -m "1.1"
created new head
$ echo 2 >> afile
$ hg commit -m "1.2"
$ echo a line > fred
$ echo 3 >> afile
$ hg add fred
$ hg commit -m "1.3"
$ hg mv afile adifferentfile
$ hg commit -m "1.3m"
$ hg update -C 3
1 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ hg mv afile anotherfile
$ hg commit -m "0.3m"
$ hg debugrevlogindex -f 1 afile
rev flag size link p1 p2 nodeid
0 0000 2 0 -1 -1 362fef284ce2
1 0000 4 1 0 -1 125144f7e028
2 0000 6 2 1 -1 4c982badb186
3 0000 8 3 2 -1 19b1fc555737
$ hg debugindex adifferentfile
rev linkrev nodeid p1 p2
0 7 2565f3199a74 000000000000 000000000000
$ hg debugindex anotherfile
rev linkrev nodeid p1 p2
0 8 2565f3199a74 000000000000 000000000000
$ hg debugindex fred
rev linkrev nodeid p1 p2
0 6 12ab3bcc5ea4 000000000000 000000000000
$ hg debugindex --manifest
rev linkrev nodeid p1 p2
0 0 43eadb1d2d06 000000000000 000000000000
1 1 8b89697eba2c 43eadb1d2d06 000000000000
2 2 626a32663c2f 8b89697eba2c 000000000000
3 3 f54c32f13478 626a32663c2f 000000000000
4 6 de68e904d169 626a32663c2f 000000000000
5 7 09bb521d218d de68e904d169 000000000000
6 8 1fde233dfb0f f54c32f13478 000000000000
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 9 changesets with 7 changes to 4 files
$ cd ..
$ for i in 0 1 2 3 4 5 6 7 8; do
> echo
> echo ---- hg clone -r "$i" test test-"$i"
> hg clone -r "$i" test test-"$i"
> cd test-"$i"
> hg verify
> cd ..
> done
---- hg clone -r 0 test test-0
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets f9ee2f85a263
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
---- hg clone -r 1 test test-1
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
new changesets f9ee2f85a263:34c2bf6b0626
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 2 changesets with 2 changes to 1 files
---- hg clone -r 2 test test-2
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
new changesets f9ee2f85a263:e38ba6f5b7e0
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 3 changesets with 3 changes to 1 files
---- hg clone -r 3 test test-3
adding changesets
adding manifests
adding file changes
added 4 changesets with 4 changes to 1 files
new changesets f9ee2f85a263:eebf5a27f8ca
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 4 changesets with 4 changes to 1 files
---- hg clone -r 4 test test-4
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
new changesets f9ee2f85a263:095197eb4973
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 2 changesets with 2 changes to 1 files
---- hg clone -r 5 test test-5
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
new changesets f9ee2f85a263:1bb50a9436a7
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 3 changesets with 3 changes to 1 files
---- hg clone -r 6 test test-6
adding changesets
adding manifests
adding file changes
added 4 changesets with 5 changes to 2 files
new changesets f9ee2f85a263:7373c1169842
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 4 changesets with 5 changes to 2 files
---- hg clone -r 7 test test-7
adding changesets
adding manifests
adding file changes
added 5 changesets with 6 changes to 3 files
new changesets f9ee2f85a263:a6a34bfa0076
updating to branch default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 5 changesets with 6 changes to 3 files
---- hg clone -r 8 test test-8
adding changesets
adding manifests
adding file changes
added 5 changesets with 5 changes to 2 files
new changesets f9ee2f85a263:aa35859c02ea
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 5 changesets with 5 changes to 2 files
$ cd test-8
$ hg pull ../test-7
pulling from ../test-7
searching for changes
adding changesets
adding manifests
adding file changes
added 4 changesets with 2 changes to 3 files (+1 heads)
new changesets 095197eb4973:a6a34bfa0076
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 9 changesets with 7 changes to 4 files
$ cd ..
$ hg clone test test-9
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd test-9
$ hg branch foobar
marked working directory as branch foobar
(branches are permanent and global, did you want a bookmark?)
$ echo file2 >> file2
$ hg add file2
$ hg commit -m "changeset9"
$ echo file3 >> file3
$ hg add file3
$ hg commit -m "changeset10"
$ cd ..
$ hg clone -r 9 -u foobar test-9 test-10
adding changesets
adding manifests
adding file changes
added 6 changesets with 6 changes to 3 files
new changesets f9ee2f85a263:7100abb79635
updating to branch foobar
2 files updated, 0 files merged, 0 files removed, 0 files unresolved