view tests/test-update-atomic.t @ 51576:de5bf3fe0233

revset: stop serializing node when using "%ln"

Turning hundred of thousand of node from node to hex and back can be slow… what
about we stop doing it?

In many case were we are using node id we should be using revision id. However
this is not a good reason to have a stupidly slow implementation of "%ln".

This caught my attention again because the phase discovery during push make an
extensive use of "%ln" or huge set. In absolute, that phase discovery probably
should use "%ld" and need to improves its algorithmic complexity, but improving
"%ln" seems simple and long overdue. This greatly speeds up `hg push` on
repository with many drafts.

Here are some relevant poulpe benchmarks:

### data-env-vars.name                             = mozilla-try-2023-03-22-zstd-sparse-revlog
  # benchmark.name                                 = hg.command.push
  # bin-env-vars.hg.flavor                         = default
  # bin-env-vars.hg.py-re2-module                  = default
  # benchmark.variants.explicit-rev                = all-out-heads
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.protocol                    = ssh
  # benchmark.variants.reuse-external-delta-parent = default

 ## benchmark.variants.revs                        = any-1-extra-rev
before: 44.235070
after:  20.416329 (-53.85%, -23.82)
 ## benchmark.variants.revs                        = any-100-extra-rev
before: 49.234697
after:  26.519829 (-46.14%, -22.71)



### benchmark.name                = hg.command.bundle
  # bin-env-vars.hg.flavor        = default
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.revs       = all
  # benchmark.variants.type       = none-streamv2
 ## data-env-vars.name            = heptapod-public-2024-03-25-zstd-sparse-revlog
before:  10.138396
after:    7.750458  (-23.55%, -2.39)
 ## data-env-vars.name            = mercurial-public-2024-03-22-zstd-sparse-revlog
before:   1.263859
after:    0.700229  (-44.60%, -0.56)
 ## data-env-vars.name            = mozilla-try-2023-03-22-zstd-sparse-revlog
before: 399.484481
after:  346.5089 (-13.26%, -52.98)
 ## data-env-vars.name            = pypy-2024-03-22-zstd-sparse-revlog
before:   4.540080
after:    3.401700  (-25.07%, -1.14)
 ## data-env-vars.name            = tryton-public-2024-03-22-zstd-sparse-revlog
before:   2.975765
after:    1.870798  (-37.13%, -1.10)

#require execbit unix-permissions no-chg

Checking that experimental.atomic-file works.

  $ cat > $TESTTMP/show_mode.py <<EOF
  > import os
  > import stat
  > import sys
  > ST_MODE = stat.ST_MODE
  > 
  > for file_path in sys.argv[1:]:
  >     file_stat = os.stat(file_path)
  >     octal_mode = oct(file_stat[ST_MODE] & 0o777).replace('o', '')
  >     print("%s:%s" % (file_path, octal_mode))
  > 
  > EOF

  $ hg init repo
  $ cd repo

  $ cat > .hg/showwrites.py <<EOF
  > from mercurial import pycompat
  > from mercurial.utils import stringutil
  > def uisetup(ui):
  >   from mercurial import vfs
  >   class newvfs(vfs.vfs):
  >     def __call__(self, *args, **kwargs):
  >       print(pycompat.sysstr(stringutil.pprint(
  >           ('vfs open', args, sorted(list(kwargs.items()))))))
  >       return super(newvfs, self).__call__(*args, **kwargs)
  >   vfs.vfs = newvfs
  > EOF

  $ for v in a1 a2 b1 b2 c ro; do echo $v > $v; done
  $ chmod +x b*
  $ hg commit -Aqm _

# We check that
# - the changes are actually atomic
# - that permissions are correct (all 4 cases of (executable before) * (executable after))
# - that renames work, though they should be atomic anyway
# - that it works when source files are read-only (but directories are read-write still)

  $ for v in a1 a2 b1 b2 ro; do echo changed-$v > $v; done
  $ chmod -x *1; chmod +x *2
  $ hg rename c d
  $ hg commit -qm _

Check behavior without update.atomic-file

  $ hg update -r 0 -q
  $ hg update -r 1 --config extensions.showwrites=.hg/showwrites.py 2>&1 | grep "a1'.*wb"
  ('vfs open', ('a1', 'wb'), [('atomictemp', False), ('backgroundclose', True)])

  $ "$PYTHON" $TESTTMP/show_mode.py *
  a1:0644
  a2:0755
  b1:0644
  b2:0755
  d:0644
  ro:0644

Add a second revision for the ro file so we can test update when the file is
present or not

  $ echo "ro" > ro

  $ hg commit -qm _

Check behavior without update.atomic-file first

  $ hg update -C -r 0 -q

  $ hg update -r 1
  6 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ "$PYTHON" $TESTTMP/show_mode.py *
  a1:0644
  a2:0755
  b1:0644
  b2:0755
  d:0644
  ro:0644

Manually reset the mode of the read-only file

  $ chmod a-w ro

  $ "$PYTHON" $TESTTMP/show_mode.py ro
  ro:0444

Now the file is present, try to update and check the permissions of the file

  $ hg up -r 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ "$PYTHON" $TESTTMP/show_mode.py ro
  ro:0644

# The file which was read-only is now writable in the default behavior

Check behavior with update.atomic-files


  $ cat >> .hg/hgrc <<EOF
  > [experimental]
  > update.atomic-file = true
  > EOF

  $ hg update -C -r 0 -q
  $ hg update -r 1 --config extensions.showwrites=.hg/showwrites.py 2>&1 | grep "a1'.*wb"
  ('vfs open', ('a1', 'wb'), [('atomictemp', True), ('backgroundclose', True)])
  $ hg st -A --rev 1
  C a1
  C a2
  C b1
  C b2
  C d
  C ro

Check the file permission after update
  $ "$PYTHON" $TESTTMP/show_mode.py *
  a1:0644
  a2:0755
  b1:0644
  b2:0755
  d:0644
  ro:0644

Manually reset the mode of the read-only file

  $ chmod a-w ro

  $ "$PYTHON" $TESTTMP/show_mode.py ro
  ro:0444

Now the file is present, try to update and check the permissions of the file

  $ hg update -r 2 --traceback
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ "$PYTHON" $TESTTMP/show_mode.py ro
  ro:0644

# The behavior is the same as without atomic update