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 rep; cd rep
$ touch empty-file
$ "$PYTHON" -c 'for x in range(10000): print(x)' > large-file
$ hg addremove
adding empty-file
adding large-file
$ hg commit -m A
$ rm large-file empty-file
$ "$PYTHON" -c 'for x in range(10,10000): print(x)' > another-file
$ hg addremove -s50
adding another-file
removing empty-file
removing large-file
recording removal of large-file as rename to another-file (99% similar)
$ hg commit -m B
comparing two empty files caused ZeroDivisionError in the past
$ hg update -C 0
2 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ rm empty-file
$ touch another-empty-file
$ hg addremove -s50
adding another-empty-file
removing empty-file
$ cd ..
$ hg init rep2; cd rep2
$ "$PYTHON" -c 'for x in range(10000): print(x)' > large-file
$ "$PYTHON" -c 'for x in range(50): print(x)' > tiny-file
$ hg addremove
adding large-file
adding tiny-file
$ hg commit -m A
$ "$PYTHON" -c 'for x in range(70): print(x)' > small-file
$ rm tiny-file
$ rm large-file
$ hg addremove -s50
removing large-file
adding small-file
removing tiny-file
recording removal of tiny-file as rename to small-file (82% similar)
$ hg commit -m B
should be sorted by path for stable result
$ for i in `"$PYTHON" $TESTDIR/seq.py 0 9`; do
> cp small-file $i
> done
$ rm small-file
$ hg addremove
adding 0
adding 1
adding 2
adding 3
adding 4
adding 5
adding 6
adding 7
adding 8
adding 9
removing small-file
recording removal of small-file as rename to 0 (100% similar)
recording removal of small-file as rename to 1 (100% similar)
recording removal of small-file as rename to 2 (100% similar)
recording removal of small-file as rename to 3 (100% similar)
recording removal of small-file as rename to 4 (100% similar)
recording removal of small-file as rename to 5 (100% similar)
recording removal of small-file as rename to 6 (100% similar)
recording removal of small-file as rename to 7 (100% similar)
recording removal of small-file as rename to 8 (100% similar)
recording removal of small-file as rename to 9 (100% similar)
$ hg commit -m '10 same files'
pick one from many identical files
$ cp 0 a
$ rm `"$PYTHON" $TESTDIR/seq.py 0 9`
$ hg addremove
removing 0
removing 1
removing 2
removing 3
removing 4
removing 5
removing 6
removing 7
removing 8
removing 9
adding a
recording removal of 0 as rename to a (100% similar)
$ hg revert -aq
pick one from many similar files
$ cp 0 a
$ for i in `"$PYTHON" $TESTDIR/seq.py 0 9`; do
> echo $i >> $i
> done
$ hg commit -m 'make them slightly different'
$ rm `"$PYTHON" $TESTDIR/seq.py 0 9`
$ hg addremove -s50
removing 0
removing 1
removing 2
removing 3
removing 4
removing 5
removing 6
removing 7
removing 8
removing 9
adding a
recording removal of 0 as rename to a (99% similar)
$ hg commit -m 'always the same file should be selected'
should all fail
$ hg addremove -s foo
abort: similarity must be a number
[255]
$ hg addremove -s -1
abort: similarity must be between 0 and 100
[255]
$ hg addremove -s 1e6
abort: similarity must be between 0 and 100
[255]
$ cd ..
Issue1527: repeated addremove causes Abort
$ hg init rep3; cd rep3
$ mkdir d
$ echo a > d/a
$ hg add d/a
$ hg commit -m 1
$ mv d/a d/b
$ hg addremove -s80
removing d/a
adding d/b
recording removal of d/a as rename to d/b (100% similar)
$ hg debugstate
r 0 0 1970-01-01 00:00:00 d/a
a 0 -1 unset d/b
copy: d/a -> d/b
$ mv d/b c
no copies found here (since the target isn't in d
$ hg addremove -s80 d
removing d/b
copies here
$ hg addremove -s80
adding c
recording removal of d/a as rename to c (100% similar)
$ cd ..