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
$ cat >> $HGRCPATH << EOF
> [extensions]
> show =
> EOF
$ hg init repo0
$ cd repo0
Empty repo / no checkout results in error
$ hg show stack
abort: stack view only available when there is a working directory
[255]
Stack displays single draft changeset as root revision
$ echo 0 > foo
$ hg -q commit -A -m 'commit 0'
$ hg show stack
@ 9f17 commit 0
Stack displays multiple draft changesets
$ echo 1 > foo
$ hg commit -m 'commit 1'
$ echo 2 > foo
$ hg commit -m 'commit 2'
$ echo 3 > foo
$ hg commit -m 'commit 3'
$ echo 4 > foo
$ hg commit -m 'commit 4'
$ hg show stack
@ 2737 commit 4
o d1a6 commit 3
o 128c commit 2
o 181c commit 1
o 9f17 commit 0
Public parent of draft base is displayed, separated from stack
$ hg phase --public -r 0
$ hg show stack
@ 2737 commit 4
o d1a6 commit 3
o 128c commit 2
o 181c commit 1
/ (stack base)
o 9f17 commit 0
$ hg phase --public -r 1
$ hg show stack
@ 2737 commit 4
o d1a6 commit 3
o 128c commit 2
/ (stack base)
o 181c commit 1
Draft descendants are shown
$ hg -q up 2
$ hg show stack
o 2737 commit 4
o d1a6 commit 3
@ 128c commit 2
/ (stack base)
o 181c commit 1
$ hg -q up 3
$ hg show stack
o 2737 commit 4
@ d1a6 commit 3
o 128c commit 2
/ (stack base)
o 181c commit 1
working dir on public changeset should display special message
$ hg -q up 1
$ hg show stack
(empty stack; working directory parent is a published changeset)
Branch point in descendants displayed at top of graph
$ hg -q up 3
$ echo b > foo
$ hg commit -m 'commit 5 (new dag branch)'
created new head
$ hg -q up 2
$ hg show stack
\ / (multiple children)
|
o d1a6 commit 3
@ 128c commit 2
/ (stack base)
o 181c commit 1
$ cd ..
Base is stopped at merges
$ hg init merge-base
$ cd merge-base
$ echo 0 > foo
$ hg -q commit -A -m initial
$ echo h1 > foo
$ hg commit -m 'head 1'
$ hg -q up 0
$ echo h2 > foo
$ hg -q commit -m 'head 2'
$ hg phase --public -r 0:tip
$ hg -q up 1
$ hg merge -t :local 2
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg commit -m 'merge heads'
TODO doesn't yet handle case where wdir is a draft merge
$ hg show stack
@ 8ee9 merge heads
/ (stack base)
o 5947 head 1
$ echo d1 > foo
$ hg commit -m 'draft 1'
$ echo d2 > foo
$ hg commit -m 'draft 2'
$ hg show stack
@ 430d draft 2
o 787b draft 1
/ (stack base)
o 8ee9 merge heads
$ cd ..
Now move on to stacks when there are more commits after the base branchpoint
$ hg init public-rebase
$ cd public-rebase
$ echo 0 > foo
$ hg -q commit -A -m 'base'
$ hg phase --public -r .
$ echo d1 > foo
$ hg commit -m 'draft 1'
$ echo d2 > foo
$ hg commit -m 'draft 2'
$ hg -q up 0
$ echo 1 > foo
$ hg commit -m 'new 1'
created new head
$ echo 2 > foo
$ hg commit -m 'new 2'
$ hg -q up 2
Newer draft heads don't impact output
$ hg show stack
@ eaff draft 2
o 2b21 draft 1
/ (stack base)
o b66b base
Newer public heads are rendered
$ hg phase --public -r '::tip'
$ hg show stack
o baa4 new 2
/ (2 commits ahead)
:
: (stack head)
: @ eaff draft 2
: o 2b21 draft 1
:/ (stack base)
o b66b base
If rebase is available, we show a hint how to rebase to that head
$ hg --config extensions.rebase= show stack
o baa4 new 2
/ (2 commits ahead; hg rebase --source 2b21 --dest baa4)
:
: (stack head)
: @ eaff draft 2
: o 2b21 draft 1
:/ (stack base)
o b66b base
Similar tests but for multiple heads
$ hg -q up 0
$ echo h2 > foo
$ hg -q commit -m 'new head 2'
$ hg phase --public -r .
$ hg -q up 2
$ hg show stack
o baa4 new 2
/ (2 commits ahead)
: o 9a84 new head 2
:/ (1 commits ahead)
:
: (stack head)
: @ eaff draft 2
: o 2b21 draft 1
:/ (stack base)
o b66b base
$ hg --config extensions.rebase= show stack
o baa4 new 2
/ (2 commits ahead; hg rebase --source 2b21 --dest baa4)
: o 9a84 new head 2
:/ (1 commits ahead; hg rebase --source 2b21 --dest 9a84)
:
: (stack head)
: @ eaff draft 2
: o 2b21 draft 1
:/ (stack base)
o b66b base