view tests/test-children.t @ 44861:065421e12248

files: speed up `hg files` when no flags change display

It's not the first time I see slowness from this command slow down
tools built on top of hg.

The majority of the time is spent merely printing the result before
this change, which is clearly not how it should be (especially since
the computation of the result also looks slow).

Running `hg files` in mozilla-central:

parent revision: 1,260s
this commit: 0,683s
this commit without batching ui.write: 0,931s
this commit replacing the body of the loop with `pass`: 0,566s

This looks like a prime candidate for a rust fast path, but until
then, it seems reasonable to optimize the python.

Differential Revision: https://phab.mercurial-scm.org/D8586

test children command

  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > children =
  > EOF

init
  $ hg init t
  $ cd t

no working directory
  $ hg children

setup
  $ echo 0 > file0
  $ hg ci -qAm 0 -d '0 0'

  $ echo 1 > file1
  $ hg ci -qAm 1 -d '1 0'

  $ echo 2 >> file0
  $ hg ci -qAm 2 -d '2 0'

  $ hg co null
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo 3 > file3
  $ hg ci -qAm 3 -d '3 0'

hg children at revision 3 (tip)
  $ hg children

  $ hg co null
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

hg children at nullrev (should be 0 and 3)
  $ hg children
  changeset:   0:4df8521a7374
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  changeset:   3:e2962852269d
  tag:         tip
  parent:      -1:000000000000
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     3
  
  $ hg co 1
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

hg children at revision 1 (should be 2)
  $ hg children
  changeset:   2:8f5eea5023c2
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     2
  
  $ hg co 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

hg children at revision 2 (other head)
  $ hg children

  $ for i in null 0 1 2 3 '2^'; do
  > echo "hg children -r '$i'"
  > hg children -r $i
  > done
  hg children -r 'null'
  changeset:   0:4df8521a7374
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  changeset:   3:e2962852269d
  tag:         tip
  parent:      -1:000000000000
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     3
  
  hg children -r '0'
  changeset:   1:708c093edef0
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     1
  
  hg children -r '1'
  changeset:   2:8f5eea5023c2
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     2
  
  hg children -r '2'
  hg children -r '3'
  hg children -r '2^'
  changeset:   2:8f5eea5023c2
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     2
  

hg children -r 0 file0 (should be 2)
  $ hg children -r 0 file0
  changeset:   2:8f5eea5023c2
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     2
  

hg children -r 1 file0 (should be 2)
  $ hg children -r 1 file0
  changeset:   2:8f5eea5023c2
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     2
  

  $ hg co 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

hg children file0 at revision 0 (should be 2)
  $ hg children file0
  changeset:   2:8f5eea5023c2
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     2
  

should be compatible with templater (don't pass fctx to displayer)
  $ hg children file0 -Tdefault
  changeset:   2:8f5eea5023c2
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     2
  

  $ cd ..