view tests/test-rename-dir-merge.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

  $ hg init t
  $ cd t

  $ mkdir a
  $ echo foo > a/a
  $ echo bar > a/b
  $ hg ci -Am "0"
  adding a/a
  adding a/b

  $ hg co -C 0
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg mv a b
  moving a/a to b/a
  moving a/b to b/b
  $ hg ci -m "1 mv a/ b/"

  $ hg co -C 0
  2 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo baz > a/c
  $ echo quux > a/d
  $ hg add a/c
  $ hg ci -m "2 add a/c"
  created new head

  $ hg merge --debug 1
    unmatched files in local:
     a/c
    unmatched files in other:
     b/a
     b/b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a/a' -> dst: 'b/a' 
     src: 'a/b' -> dst: 'b/b' 
    checking for directory renames
     discovered dir src: 'a/' -> dst: 'b/'
     pending file src: 'a/c' -> dst: 'b/c'
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: f9b20c0d4c51, local: ce36d17b18fb+, remote: 397f8b00a740
   a/a: other deleted -> r
  removing a/a
   a/b: other deleted -> r
  removing a/b
   b/a: remote created -> g
  getting b/a
   b/b: remote created -> g
  getting b/b
   b/c: remote directory rename - move from a/c -> dm
  moving a/c to b/c
  3 files updated, 0 files merged, 2 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ echo a/* b/*
  a/d b/a b/b b/c
  $ hg st -C
  M b/a
  M b/b
  A b/c
    a/c
  R a/a
  R a/b
  R a/c
  ? a/d
  $ hg ci -m "3 merge 2+1"
  $ hg debugrename b/c
  b/c renamed from a/c:354ae8da6e890359ef49ade27b68bbc361f3ca88

  $ hg co -C 1
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge --debug 2
    unmatched files in local:
     b/a
     b/b
    unmatched files in other:
     a/c
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     src: 'a/a' -> dst: 'b/a' 
     src: 'a/b' -> dst: 'b/b' 
    checking for directory renames
     discovered dir src: 'a/' -> dst: 'b/'
     pending file src: 'a/c' -> dst: 'b/c'
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: f9b20c0d4c51, local: 397f8b00a740+, remote: ce36d17b18fb
  starting 4 threads for background file closing (?)
   b/c: local directory rename - get from a/c -> dg
  getting a/c to b/c
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ echo a/* b/*
  a/d b/a b/b b/c
  $ hg st -C
  A b/c
    a/c
  ? a/d
  $ hg ci -m "4 merge 1+2"
  created new head
  $ hg debugrename b/c
  b/c renamed from a/c:354ae8da6e890359ef49ade27b68bbc361f3ca88

Local directory rename with conflicting file added in remote source directory
and untracked in local target directory.

  $ hg co -qC 1
  $ echo target > b/c
  $ hg merge 2
  b/c: untracked file differs
  abort: untracked files in working directory differ from files in requested revision
  [255]
  $ cat b/c
  target
but it should succeed if the content matches
  $ hg cat -r 2 a/c > b/c
  $ hg merge 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st -C
  A b/c
    a/c
  ? a/d

Local directory rename with conflicting file added in remote source directory
and committed in local target directory.

  $ hg co -qC 1
  $ echo target > b/c
  $ hg add b/c
  $ hg commit -qm 'new file in target directory'
  $ hg merge 2
  merging b/c and a/c to b/c
  warning: conflicts while merging b/c! (edit, then use 'hg resolve --mark')
  0 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]
  $ hg st -A
  M b/c
    a/c
  ? a/d
  ? b/c.orig
  C b/a
  C b/b
  $ cat b/c
  <<<<<<< working copy: f1c50ca4f127 - test: new file in target directory
  target
  =======
  baz
  >>>>>>> merge rev:    ce36d17b18fb - test: 2 add a/c
  $ rm b/c.orig

Remote directory rename with conflicting file added in remote target directory
and committed in local source directory.

  $ hg co -qC 2
  $ hg st -A
  ? a/d
  C a/a
  C a/b
  C a/c
  $ hg merge 5
  merging a/c and b/c to b/c
  warning: conflicts while merging b/c! (edit, then use 'hg resolve --mark')
  2 files updated, 0 files merged, 2 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]
  $ hg st -A
  M b/a
  M b/b
  M b/c
    a/c
  R a/a
  R a/b
  R a/c
  ? a/d
  ? b/c.orig
  $ cat b/c
  <<<<<<< working copy: ce36d17b18fb - test: 2 add a/c
  baz
  =======
  target
  >>>>>>> merge rev:    f1c50ca4f127 - test: new file in target directory

Second scenario with two repos:

  $ cd ..
  $ hg init r1
  $ cd r1
  $ mkdir a
  $ echo foo > a/f
  $ hg add a
  adding a/f
  $ hg ci -m "a/f == foo"
  $ cd ..

  $ hg clone r1 r2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd r2
  $ hg mv a b
  moving a/f to b/f
  $ echo foo1 > b/f
  $ hg ci -m" a -> b, b/f == foo1"
  $ cd ..

  $ cd r1
  $ mkdir a/aa
  $ echo bar > a/aa/g
  $ hg add a/aa
  adding a/aa/g
  $ hg ci -m "a/aa/g"
  $ hg pull ../r2
  pulling from ../r2
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  new changesets 7d51ed18da25
  1 local changesets published
  (run 'hg heads' to see heads, 'hg merge' to merge)

  $ hg merge
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg st -C
  M b/f
  A b/aa/g
    a/aa/g
  R a/aa/g
  R a/f

  $ cd ..

Test renames to separate directories

  $ hg init a
  $ cd a
  $ mkdir a
  $ touch a/s
  $ touch a/t
  $ hg ci -Am0
  adding a/s
  adding a/t

Add more files

  $ touch a/s2
  $ touch a/t2
  $ hg ci -Am1
  adding a/s2
  adding a/t2

Do moves on a branch

  $ hg up 0
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ mkdir s
  $ mkdir t
  $ hg mv a/s s
  $ hg mv a/t t
  $ hg ci -Am2
  created new head
  $ hg st --copies --change .
  A s/s
    a/s
  A t/t
    a/t
  R a/s
  R a/t

Merge shouldn't move s2, t2

  $ hg merge
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M a/s2
  M a/t2

Try the merge in the other direction. It may or may not be appropriate for
status to list copies here.

  $ hg up -C 1
  4 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg merge
  2 files updated, 0 files merged, 2 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M s/s
  M t/t
  R a/s
  R a/t