view tests/test-pager.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

  $ cat >> fakepager.py <<EOF
  > import sys
  > printed = False
  > for line in sys.stdin:
  >     sys.stdout.write('paged! %r\n' % line)
  >     printed = True
  > if not printed:
  >     sys.stdout.write('paged empty output!\n')
  > EOF

Enable ui.formatted because pager won't fire without it, and set up
pager and tell it to use our fake pager that lets us see when the
pager was running.
  $ cat >> $HGRCPATH <<EOF
  > [ui]
  > formatted = yes
  > color = no
  > [pager]
  > pager = "$PYTHON" $TESTTMP/fakepager.py
  > EOF

  $ hg init repo
  $ cd repo
  $ echo a >> a
  $ hg add a
  $ hg ci -m 'add a'
  $ for x in `"$PYTHON" $TESTDIR/seq.py 1 10`; do
  >   echo a $x >> a
  >   hg ci -m "modify a $x"
  > done

By default diff and log are paged, but id is not:

  $ hg diff -c 2 --pager=yes
  paged! 'diff -r f4be7687d414 -r bce265549556 a\n'
  paged! '--- a/a\tThu Jan 01 00:00:00 1970 +0000\n'
  paged! '+++ b/a\tThu Jan 01 00:00:00 1970 +0000\n'
  paged! '@@ -1,2 +1,3 @@\n'
  paged! ' a\n'
  paged! ' a 1\n'
  paged! '+a 2\n'

  $ hg log --limit 2
  paged! 'changeset:   10:46106edeeb38\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'
  paged! 'changeset:   9:6dd8ea7dd621\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 9\n'
  paged! '\n'

  $ hg id
  46106edeeb38 tip

We can control the pager from the config

  $ hg log --limit 1 --config 'ui.paginate=False'
  changeset:   10:46106edeeb38
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify a 10
  
  $ hg log --limit 1 --config 'ui.paginate=0'
  changeset:   10:46106edeeb38
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify a 10
  
  $ hg log --limit 1 --config 'ui.paginate=1'
  paged! 'changeset:   10:46106edeeb38\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'

explicit --pager=on should take precedence over other configurations
(issue5580)

  $ cat >> $HGRCPATH <<EOF
  > [ui]
  > paginate = false
  > EOF
  $ hg log --limit 1 --pager=on
  paged! 'changeset:   10:46106edeeb38\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'

  $ cat >> $HGRCPATH <<EOF
  > [ui]
  > # true is default value of ui.paginate
  > paginate = true
  > EOF
  $ hg log --limit 1 --pager=off
  changeset:   10:46106edeeb38
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify a 10
  

We can enable the pager on id:

BROKEN: should be paged
  $ hg --config pager.attend-id=yes id
  46106edeeb38 tip

Setting attend-$COMMAND to a false value works, even with pager in
core:
  $ hg --config pager.attend-diff=no diff -c 2
  diff -r f4be7687d414 -r bce265549556 a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,2 +1,3 @@
   a
   a 1
  +a 2

Command aliases should have same behavior as main command

  $ hg history --limit 2
  paged! 'changeset:   10:46106edeeb38\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'
  paged! 'changeset:   9:6dd8ea7dd621\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 9\n'
  paged! '\n'

Abbreviated command alias should also be paged

  $ hg hist -l 1
  paged! 'changeset:   10:46106edeeb38\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'

Attend for an abbreviated command does not work

  $ hg --config pager.attend-ident=true ident
  46106edeeb38 tip

  $ hg --config extensions.pager= --config pager.attend-ident=true ident
  46106edeeb38 tip

Pager should not start if stdout is not a tty.

  $ hg log -l1 -q --config ui.formatted=False
  10:46106edeeb38

Pager should be disabled if pager.pager is empty (otherwise the output would
be silently lost.)

  $ hg log -l1 -q --config pager.pager=
  10:46106edeeb38

Pager with color enabled allows colors to come through by default,
even though stdout is no longer a tty.
  $ cat >> $HGRCPATH <<EOF
  > [ui]
  > color = always
  > [color]
  > mode = ansi
  > EOF
  $ hg log --limit 3
  paged! '\x1b[0;33mchangeset:   10:46106edeeb38\x1b[0m\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'
  paged! '\x1b[0;33mchangeset:   9:6dd8ea7dd621\x1b[0m\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 9\n'
  paged! '\n'
  paged! '\x1b[0;33mchangeset:   8:cff05a6312fe\x1b[0m\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 8\n'
  paged! '\n'

#if no-chg
An invalid pager command name is reported sensibly if we don't have to
use shell=True in the subprocess call:
  $ hg log --limit 3 --config pager.pager=this-command-better-never-exist
  missing pager command 'this-command-better-never-exist', skipping pager
  \x1b[0;33mchangeset:   10:46106edeeb38\x1b[0m (esc)
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify a 10
  
  \x1b[0;33mchangeset:   9:6dd8ea7dd621\x1b[0m (esc)
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify a 9
  
  \x1b[0;33mchangeset:   8:cff05a6312fe\x1b[0m (esc)
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify a 8
  
#endif

A complicated pager command gets worse behavior. Bonus points if you can
improve this.
  $ hg log --limit 3 \
  >   --config pager.pager='this-command-better-never-exist --seriously' \
  >  2>/dev/null || true

Pager works with shell aliases.

  $ cat >> $HGRCPATH <<EOF
  > [alias]
  > echoa = !echo a
  > EOF

  $ hg echoa
  a
BROKEN: should be paged
  $ hg --config pager.attend-echoa=yes echoa
  a

Pager works with hg aliases including environment variables.

  $ cat >> $HGRCPATH <<'EOF'
  > [alias]
  > printa = log -T "$A\n" -r 0
  > EOF

  $ A=1 hg --config pager.attend-printa=yes printa
  paged! '1\n'
  $ A=2 hg --config pager.attend-printa=yes printa
  paged! '2\n'

Something that's explicitly attended is still not paginated if the
pager is globally set to off using a flag:
  $ A=2 hg --config pager.attend-printa=yes printa --pager=no
  2

Pager should not override the exit code of other commands

  $ cat >> $TESTTMP/fortytwo.py <<'EOF'
  > from mercurial import commands, registrar
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > @command(b'fortytwo', [], b'fortytwo', norepo=True)
  > def fortytwo(ui, *opts):
  >     ui.write(b'42\n')
  >     return 42
  > EOF

  $ cat >> $HGRCPATH <<'EOF'
  > [extensions]
  > fortytwo = $TESTTMP/fortytwo.py
  > EOF

  $ hg fortytwo --pager=on
  paged! '42\n'
  [42]

A command that asks for paging using ui.pager() directly works:
  $ hg blame a
  paged! ' 0: a\n'
  paged! ' 1: a 1\n'
  paged! ' 2: a 2\n'
  paged! ' 3: a 3\n'
  paged! ' 4: a 4\n'
  paged! ' 5: a 5\n'
  paged! ' 6: a 6\n'
  paged! ' 7: a 7\n'
  paged! ' 8: a 8\n'
  paged! ' 9: a 9\n'
  paged! '10: a 10\n'
but not with HGPLAIN
  $ HGPLAIN=1 hg blame a
   0: a
   1: a 1
   2: a 2
   3: a 3
   4: a 4
   5: a 5
   6: a 6
   7: a 7
   8: a 8
   9: a 9
  10: a 10
explicit flags work too:
  $ hg blame --pager=no a
   0: a
   1: a 1
   2: a 2
   3: a 3
   4: a 4
   5: a 5
   6: a 6
   7: a 7
   8: a 8
   9: a 9
  10: a 10

A command with --output option:

  $ hg cat -r0 a
  paged! 'a\n'
  $ hg cat -r0 a --output=-
  paged! 'a\n'
  $ hg cat -r0 a --output=out

  $ hg export -r0
  paged! '# HG changeset patch\n'
  paged! '# User test\n'
  paged! '# Date 0 0\n'
  paged! '#      Thu Jan 01 00:00:00 1970 +0000\n'
  paged! '# Node ID 1f0dee641bb7258c56bd60e93edfa2405381c41e\n'
  paged! '# Parent  0000000000000000000000000000000000000000\n'
  paged! 'add a\n'
  paged! '\n'
  paged! '\x1b[0;1mdiff -r 000000000000 -r 1f0dee641bb7 a\x1b[0m\n'
  paged! '\x1b[0;31;1m--- /dev/null\tThu Jan 01 00:00:00 1970 +0000\x1b[0m\n'
  paged! '\x1b[0;32;1m+++ b/a\tThu Jan 01 00:00:00 1970 +0000\x1b[0m\n'
  paged! '\x1b[0;35m@@ -0,0 +1,1 @@\x1b[0m\n'
  paged! '\x1b[0;32m+a\x1b[0m\n'
  $ hg export -r0 -o -
  paged! '# HG changeset patch\n'
  paged! '# User test\n'
  paged! '# Date 0 0\n'
  paged! '#      Thu Jan 01 00:00:00 1970 +0000\n'
  paged! '# Node ID 1f0dee641bb7258c56bd60e93edfa2405381c41e\n'
  paged! '# Parent  0000000000000000000000000000000000000000\n'
  paged! 'add a\n'
  paged! '\n'
  paged! '\x1b[0;1mdiff -r 000000000000 -r 1f0dee641bb7 a\x1b[0m\n'
  paged! '\x1b[0;31;1m--- /dev/null\tThu Jan 01 00:00:00 1970 +0000\x1b[0m\n'
  paged! '\x1b[0;32;1m+++ b/a\tThu Jan 01 00:00:00 1970 +0000\x1b[0m\n'
  paged! '\x1b[0;35m@@ -0,0 +1,1 @@\x1b[0m\n'
  paged! '\x1b[0;32m+a\x1b[0m\n'
  $ hg export -r0 -o out

  $ rm out

Put annotate in the ignore list for pager:
  $ cat >> $HGRCPATH <<EOF
  > [pager]
  > ignore = annotate
  > EOF
  $ hg blame a
   0: a
   1: a 1
   2: a 2
   3: a 3
   4: a 4
   5: a 5
   6: a 6
   7: a 7
   8: a 8
   9: a 9
  10: a 10

During pushbuffer, pager should not start:
  $ cat > $TESTTMP/pushbufferpager.py <<EOF
  > def uisetup(ui):
  >     ui.pushbuffer()
  >     ui.pager(b'mycmd')
  >     ui.write(b'content\n')
  >     ui.write(ui.popbuffer())
  > EOF

  $ echo append >> a
  $ hg --config extensions.pushbuffer=$TESTTMP/pushbufferpager.py status --color=off
  content
  paged! 'M a\n'

Environment variables like LESS and LV are set automatically:
  $ cat > $TESTTMP/printlesslv.py <<EOF
  > from __future__ import absolute_import
  > import os
  > import sys
  > sys.stdin.read()
  > for name in ['LESS', 'LV']:
  >     sys.stdout.write(('%s=%s\n') % (name, os.environ.get(name, '-')))
  > sys.stdout.flush()
  > EOF

  $ cat >> $HGRCPATH <<EOF
  > [alias]
  > noop = log -r 0 -T ''
  > [ui]
  > formatted=1
  > [pager]
  > pager = "$PYTHON" $TESTTMP/printlesslv.py
  > EOF
  $ unset LESS
  $ unset LV
  $ hg noop --pager=on
  LESS=FRX
  LV=-c
  $ LESS=EFGH hg noop --pager=on
  LESS=EFGH
  LV=-c