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
#require svn svn-bindings
$ cat >> $HGRCPATH <<EOF
> [extensions]
> convert =
> EOF
$ svnadmin create svn-repo
$ svnadmin load -q svn-repo < "$TESTDIR/svn/branches.svndump"
Convert trunk and branches
$ cat > branchmap <<EOF
> old3 newbranch
>
>
> EOF
$ hg convert --branchmap=branchmap --datesort -r 10 svn-repo A-hg
initializing destination A-hg repository
scanning source...
sorting...
converting...
10 init projA
9 hello
8 branch trunk, remove c and dir
7 change a
6 change b
5 move and update c
4 move and update c
3 change b again
2 move to old2
1 move back to old
0 last change to a
Test template keywords
$ hg -R A-hg log --template '{rev} {svnuuid}{svnpath}@{svnrev}\n'
10 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@10
9 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@9
8 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old2@8
7 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@7
6 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@6
5 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@6
4 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@5
3 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@4
2 644ede6c-2b81-4367-9dc8-d786514f2cde/branches/old@3
1 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@2
0 644ede6c-2b81-4367-9dc8-d786514f2cde/trunk@1
Convert again
$ hg convert --branchmap=branchmap --datesort svn-repo A-hg
scanning source...
sorting...
converting...
0 branch trunk@1 into old3
$ cd A-hg
$ hg log -G --template 'branch={branches} {rev} {desc|firstline} files: {files}\n'
o branch=newbranch 11 branch trunk@1 into old3 files:
|
| o branch= 10 last change to a files: a
| |
| | o branch=old 9 move back to old files:
| | |
| | o branch=old2 8 move to old2 files:
| | |
| | o branch=old 7 change b again files: b
| | |
| o | branch= 6 move and update c files: b
| | |
| | o branch=old 5 move and update c files: c
| | |
| | o branch=old 4 change b files: b
| | |
| o | branch= 3 change a files: a
| | |
| | o branch=old 2 branch trunk, remove c and dir files: c
| |/
| o branch= 1 hello files: a b c dir/e
|/
o branch= 0 init projA files:
$ hg branches
newbranch 11:a6d7cc050ad1
default 10:6e2b33404495
old 9:1b494af68c0b
old2 8:5be40b8dcbf6 (inactive)
$ hg tags -q
tip
$ cd ..
Test hg failing to call itself
$ HG=foobar hg convert svn-repo B-hg 2>&1 | grep abort
abort: Mercurial failed to run itself, check hg executable is in PATH
Convert 'trunk' to branch other than 'default'
$ cat > branchmap <<EOF
> default hgtrunk
>
>
> EOF
$ hg convert --branchmap=branchmap --datesort -r 10 svn-repo C-hg
initializing destination C-hg repository
scanning source...
sorting...
converting...
10 init projA
9 hello
8 branch trunk, remove c and dir
7 change a
6 change b
5 move and update c
4 move and update c
3 change b again
2 move to old2
1 move back to old
0 last change to a
$ cd C-hg
$ hg branches --template '{branch}\n'
hgtrunk
old
old2
$ cd ..