view tests/test-obsolete-checkheads.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

Check that obsolete properly strip heads
  $ cat >> $HGRCPATH << EOF
  > [phases]
  > # public changeset are not obsolete
  > publish=false
  > [ui]
  > logtemplate='{node|short} ({phase}) {desc|firstline}\n'
  > [experimental]
  > evolution.createmarkers=True
  > EOF
  $ mkcommit() {
  >    echo "$1" > "$1"
  >    hg add "$1"
  >    hg ci -m "add $1"
  > }
  $ getid() {
  >    hg id --debug -ir "desc('$1')"
  > }


  $ hg init remote
  $ cd remote
  $ mkcommit base
  $ hg phase --public .
  $ cd ..
  $ cp -R remote base
  $ hg clone remote local
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd local

New head replaces old head
==========================

setup
(we add the 1 flags to prevent bumped error during the test)

  $ mkcommit old
  $ hg push
  pushing to $TESTTMP/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  $ hg up -q '.^'
  $ mkcommit new
  created new head
  $ hg debugobsolete --flags 1 `getid old` `getid new`
  obsoleted 1 changesets
  $ hg log -G --hidden
  @  71e3228bffe1 (draft) add new
  |
  | x  c70b08862e08 (draft) add old
  |/
  o  b4952fcf48cf (public) add base
  
  $ cp -R ../remote ../backup1

old exists remotely as draft. It is obsoleted by new that we now push.
Push should not warn about creating new head

  $ hg push
  pushing to $TESTTMP/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)

old head is now public (public local version)
=============================================

setup

  $ rm -fr ../remote
  $ cp -R ../backup1 ../remote
  $ hg -R ../remote phase --public c70b08862e08
  $ hg pull -v
  pulling from $TESTTMP/remote
  searching for changes
  no changes found
  1 local changesets published
  $ hg log -G --hidden
  @  71e3228bffe1 (draft) add new
  |
  | o  c70b08862e08 (public) add old
  |/
  o  b4952fcf48cf (public) add base
  

Abort: old will still be an head because it's public.

  $ hg push
  pushing to $TESTTMP/remote
  searching for changes
  abort: push creates new remote head 71e3228bffe1!
  (merge or see 'hg help push' for details about pushing new heads)
  [255]

old head is now public (public remote version)
==============================================

TODO: Not implemented yet.

# setup
#
#   $ rm -fr ../remote
#   $ cp -R ../backup1 ../remote
#   $ hg -R ../remote phase --public c70b08862e08
#   $ hg phase --draft --force c70b08862e08
#   $ hg log -G --hidden
#   @  71e3228bffe1 (draft) add new
#   |
#   | x  c70b08862e08 (draft) add old
#   |/
#   o  b4952fcf48cf (public) add base
#
#
#
# Abort: old will still be an head because it's public.
#
#   $ hg push
#   pushing to $TESTTMP/remote
#   searching for changes
#   abort: push creates new remote head 71e3228bffe1!
#   (merge or see 'hg help push' for details about pushing new heads)
#   [255]

old head is obsolete but replacement is not pushed
==================================================

setup

  $ rm -fr ../remote
  $ cp -R ../backup1 ../remote
  $ hg phase --draft --force '(0::) - 0'
  $ hg up -q '.^'
  $ mkcommit other
  created new head
  $ hg log -G --hidden
  @  d7d41ccbd4de (draft) add other
  |
  | o  71e3228bffe1 (draft) add new
  |/
  | x  c70b08862e08 (draft) add old
  |/
  o  b4952fcf48cf (public) add base
  

old exists remotely as draft. It is obsoleted by new but we don't push new.
Push should abort on new head

  $ hg push -r 'desc("other")'
  pushing to $TESTTMP/remote
  searching for changes
  abort: push creates new remote head d7d41ccbd4de!
  (merge or see 'hg help push' for details about pushing new heads)
  [255]



Both precursors and successors are already know remotely. Descendant adds heads
===============================================================================

setup. (The obsolete marker is known locally only

  $ cd ..
  $ rm -rf local
  $ hg clone remote local
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd local
  $ mkcommit old
  old already tracked!
  nothing changed
  [1]
  $ hg up -q '.^'
  $ mkcommit new
  created new head
  $ hg push -f
  pushing to $TESTTMP/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  $ mkcommit desc1
  $ hg up -q '.^'
  $ mkcommit desc2
  created new head
  $ hg debugobsolete `getid old` `getid new`
  obsoleted 1 changesets
  $ hg log -G --hidden
  @  5fe37041cc2b (draft) add desc2
  |
  | o  a3ef1d111c5f (draft) add desc1
  |/
  o  71e3228bffe1 (draft) add new
  |
  | x  c70b08862e08 (draft) add old
  |/
  o  b4952fcf48cf (public) add base
  
  $ hg log -G --hidden -R ../remote
  o  71e3228bffe1 (draft) add new
  |
  | o  c70b08862e08 (draft) add old
  |/
  @  b4952fcf48cf (public) add base
  
  $ cp -R ../remote ../backup2

Push should not warn about adding new heads. We create one, but we'll delete
one anyway.

  $ hg push
  pushing to $TESTTMP/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)


Remote head is unknown but obsoleted by a local changeset
=========================================================

setup

  $ rm -fr ../remote
  $ cp -R ../backup1 ../remote
  $ cd ..
  $ rm -rf local
  $ hg clone remote local -r 0
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets b4952fcf48cf
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd local
  $ mkcommit new
  $ hg -R ../remote id --debug -r tip
  c70b08862e0838ea6d7c59c85da2f1ed6c8d67da tip
  $ hg  id --debug -r tip
  71e3228bffe1886550777233d6c97bb5a6b2a650 tip
  $ hg debugobsolete c70b08862e0838ea6d7c59c85da2f1ed6c8d67da 71e3228bffe1886550777233d6c97bb5a6b2a650
  $ hg log -G --hidden
  @  71e3228bffe1 (draft) add new
  |
  o  b4952fcf48cf (public) add base
  
  $ hg log -G --hidden -R ../remote
  o  c70b08862e08 (draft) add old
  |
  @  b4952fcf48cf (public) add base
  

We do not have enought data to take the right decision, we should fail

  $ hg push
  pushing to $TESTTMP/remote
  searching for changes
  remote has heads on branch 'default' that are not known locally: c70b08862e08
  abort: push creates new remote head 71e3228bffe1!
  (pull and merge or see 'hg help push' for details about pushing new heads)
  [255]

Pulling the missing data makes it work

  $ hg pull
  pulling from $TESTTMP/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  (1 other changesets obsolete on arrival)
  (run 'hg heads' to see heads)
  $ hg push
  pushing to $TESTTMP/remote
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)

Old head is pruned without parent data and new unrelated head added
===================================================================

setup

  $ cd ..
  $ rm -R remote local
  $ cp -R backup1 remote
  $ hg clone remote local -qr c70b08862e08
  $ cd local
  $ hg up -q '.^'
  $ mkcommit new-unrelated
  created new head
  $ hg debugobsolete `getid old`
  obsoleted 1 changesets
  $ hg log -G --hidden
  @  350a93b716be (draft) add new-unrelated
  |
  | x  c70b08862e08 (draft) add old
  |/
  o  b4952fcf48cf (public) add base
  

  $ hg push
  pushing to $TESTTMP/remote
  searching for changes
  abort: push creates new remote head 350a93b716be!
  (merge or see 'hg help push' for details about pushing new heads)
  [255]