view tests/test-issue3084.t @ 42621:99ebde4fec99

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 "largefiles =" >> $HGRCPATH

Create the repository outside $HOME since largefiles write to
$HOME/.cache/largefiles.

  $ hg init test
  $ cd test
  $ echo "root" > root
  $ hg add root
  $ hg commit -m "Root commit" --config extensions.largefiles=!

Ensure that .hg/largefiles isn't created before largefiles are added
#if unix-permissions
  $ chmod 555 .hg
#endif
  $ hg status
#if unix-permissions
  $ chmod 755 .hg
#endif

  $ test -f .hg/largefiles
  [1]

  $ echo "large" > foo
  $ hg add --large foo
  $ hg commit -m "Add foo as a largefile"

  $ hg update -r 0
  getting changed largefiles
  0 largefiles updated, 1 removed
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo "normal" > foo
  $ hg add foo
  $ hg commit -m "Add foo as normal file"
  created new head

Normal file in the working copy, keeping the normal version:

  $ echo "n" | hg merge --config ui.interactive=Yes
  remote turned local normal file foo into a largefile
  use (l)argefile or keep (n)ormal file? n
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg status
  $ cat foo
  normal

Normal file in the working copy, keeping the largefile version:

  $ hg update -q -C
  $ echo "l" | hg merge --config ui.interactive=Yes
  remote turned local normal file foo into a largefile
  use (l)argefile or keep (n)ormal file? l
  getting changed largefiles
  1 largefiles updated, 0 removed
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg status
  M foo

  $ hg diff --nodates
  diff -r fa129ab6b5a7 .hglf/foo
  --- /dev/null
  +++ b/.hglf/foo
  @@ -0,0 +1,1 @@
  +7f7097b041ccf68cc5561e9600da4655d21c6d18
  diff -r fa129ab6b5a7 foo
  --- a/foo
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -normal

  $ cat foo
  large

Largefile in the working copy, keeping the normal version:

  $ hg update -q -C -r 1
  $ echo "n" | hg merge --config ui.interactive=Yes
  remote turned local largefile foo into a normal file
  keep (l)argefile or use (n)ormal file? n
  getting changed largefiles
  0 largefiles updated, 0 removed
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg status
  M foo

  $ hg diff --nodates
  diff -r ff521236428a .hglf/foo
  --- a/.hglf/foo
  +++ /dev/null
  @@ -1,1 +0,0 @@
  -7f7097b041ccf68cc5561e9600da4655d21c6d18
  diff -r ff521236428a foo
  --- /dev/null
  +++ b/foo
  @@ -0,0 +1,1 @@
  +normal

  $ cat foo
  normal

Largefile in the working copy, keeping the largefile version:

  $ hg update -q -C -r 1
  $ echo "l" | hg merge --config ui.interactive=Yes
  remote turned local largefile foo into a normal file
  keep (l)argefile or use (n)ormal file? l
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg status

  $ cat foo
  large

Whatever ... commit something so we can invoke merge when updating

  $ hg commit -m '3: Merge'

Updating from largefile to normal - no reason to prompt

  $ hg up -r 2
  getting changed largefiles
  0 largefiles updated, 0 removed
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ cat foo
  normal

(the update above used to leave the working dir in a very weird state - clean it
  $ hg up -qr null
  $ hg up -qr 2
)

Updating from normal to largefile - no reason to prompt

  $ hg up -r 3
  getting changed largefiles
  1 largefiles updated, 0 removed
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ cat foo
  large

  $ cd ..


Systematic testing of merges involving largefiles:

Ancestor: normal  Parent: normal-id  Parent: large   result: large
Ancestor: normal  Parent: normal2    Parent: large   result: ?
Ancestor: large   Parent: large-id   Parent: normal  result: normal
Ancestor: large   Parent: large2     Parent: normal  result: ?

All cases should try merging both ways.

Prepare test repo:

  $ hg init merges
  $ cd merges

prepare cases with "normal" ancestor:

  $ hg up -qr null
  $ echo normal > f
  $ hg ci -Aqm "normal-ancestor"
  $ hg tag -l "normal-ancestor"
  $ touch f2
  $ hg ci -Aqm "normal-id"
  $ hg tag -l "normal-id"
  $ echo normal2 > f
  $ hg ci -m "normal2"
  $ hg tag -l "normal2"
  $ echo normal > f
  $ hg ci -Aqm "normal-same"
  $ hg tag -l "normal-same"
  $ hg up -qr "normal-ancestor"
  $ hg rm f
  $ echo large > f
  $ hg add --large f
  $ hg ci -qm "large"
  $ hg tag -l "large"

prepare cases with "large" ancestor:

  $ hg up -qr null
  $ echo large > f
  $ hg add --large f
  $ hg ci -qm "large-ancestor"
  $ hg tag -l "large-ancestor"
  $ touch f2
  $ hg ci -Aqm "large-id"
  $ hg tag -l "large-id"
  $ echo large2 > f
  $ hg ci -m "large2"
  $ hg tag -l "large2"
  $ echo large > f
  $ hg ci -Aqm "large-same"
  $ hg tag -l "large-same"
  $ hg up -qr "large-ancestor"
  $ hg rm f
  $ echo normal > f
  $ hg ci -qAm "normal"
  $ hg tag -l "normal"

  $ hg log -GT '{tags}'
  @  normal tip
  |
  | o  large-same
  | |
  | o  large2
  | |
  | o  large-id
  |/
  o  large-ancestor
  
  o  large
  |
  | o  normal-same
  | |
  | o  normal2
  | |
  | o  normal-id
  |/
  o  normal-ancestor
  


Ancestor: normal  Parent: normal-id  Parent: large   result: large

  $ hg up -Cqr normal-id
  $ hg merge -r large
  getting changed largefiles
  1 largefiles updated, 0 removed
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  large

swap

  $ hg up -Cqr large
  $ hg merge -r normal-id
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  large

Ancestor: normal  Parent: normal-same  Parent: large   result: large

  $ hg up -Cqr normal-same
  $ hg merge -r large
  getting changed largefiles
  1 largefiles updated, 0 removed
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  large

swap

  $ hg up -Cqr large
  $ hg merge -r normal-same
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  large

Ancestor: normal  Parent: normal2  Parent: large   result: ?
(annoying extra prompt ... but it do not do any serious harm)

  $ hg up -Cqr normal2
  $ hg merge -r large
  remote turned local normal file f into a largefile
  use (l)argefile or keep (n)ormal file? l
  getting changed largefiles
  1 largefiles updated, 0 removed
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  large

  $ hg up -Cqr normal2
  $ echo n | hg merge -r large --config ui.interactive=Yes
  remote turned local normal file f into a largefile
  use (l)argefile or keep (n)ormal file? n
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  normal2

swap

  $ hg up -Cqr large
  $ hg merge -r normal2
  remote turned local largefile f into a normal file
  keep (l)argefile or use (n)ormal file? l
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  large

  $ hg up -Cqr large
  $ echo n | hg merge -r normal2 --config ui.interactive=Yes
  remote turned local largefile f into a normal file
  keep (l)argefile or use (n)ormal file? n
  getting changed largefiles
  0 largefiles updated, 0 removed
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  normal2

Ancestor: large   Parent: large-id   Parent: normal  result: normal

  $ hg up -Cqr large-id
  $ hg merge -r normal
  getting changed largefiles
  0 largefiles updated, 0 removed
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  normal

swap

  $ hg up -Cqr normal
  $ hg merge -r large-id
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  normal

Ancestor: large   Parent: large-same   Parent: normal  result: normal

  $ hg up -Cqr large-same
  $ hg merge -r normal
  getting changed largefiles
  0 largefiles updated, 0 removed
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  normal

swap

  $ hg up -Cqr normal
  $ hg merge -r large-same
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  normal

Ancestor: large   Parent: large2   Parent: normal  result: ?
(annoying extra prompt ... but it do not do any serious harm)

  $ hg up -Cqr large2
  $ hg merge -r normal
  remote turned local largefile f into a normal file
  keep (l)argefile or use (n)ormal file? l
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  large2

  $ hg up -Cqr large2
  $ echo n | hg merge -r normal --config ui.interactive=Yes
  remote turned local largefile f into a normal file
  keep (l)argefile or use (n)ormal file? n
  getting changed largefiles
  0 largefiles updated, 0 removed
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  normal

swap

  $ hg up -Cqr normal
  $ hg merge -r large2
  remote turned local normal file f into a largefile
  use (l)argefile or keep (n)ormal file? l
  getting changed largefiles
  1 largefiles updated, 0 removed
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  large2

  $ hg up -Cqr normal
  $ echo n | hg merge -r large2 --config ui.interactive=Yes
  remote turned local normal file f into a largefile
  use (l)argefile or keep (n)ormal file? n
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ cat f
  normal

  $ cd ..