view tests/test-hgrc.t @ 47010:76ae43d5b1db stable

repoview: fix memory leak of filtered repo classes

The leak occurs in long-running server processes with
extensions, and is measured at 110kB per request.

Before this change, the contents of the `_filteredrepotypes`
cache are not properly garbage collected, despite it begin
a `WeakKeyDictionary`.

Extensions have a tendency to generate a new repository class
for each `localrepo` instantiation. Server processes based
on `hgwebdir_mod` will instantiate a new `localrepo` for each
HTTP request that involves a repository.

As a result, with a testing process that repeatedly opens a
repository with several extensions activated
(`topic` notably among them), we see a steady increase in
resident memory of 110kB per repository instantiation before this
change. This is also true, if we call `gc.collect()` at each
instantiation, like `hgwebdir_mod` does, or not.

The cause of the leak is that the *values* aren't weak references.
This change uses `weakref.ref` for the values, and this makes
in our measurements the resident size increase drop to 5kB per
repository instantiation, with no explicit call of `gc.collect()`
at all.
There is currently no reason to believe that this remaining leak
of 5kB is related to or even due to Mercurial core.

We've also seen evidence that `ui.ui` instances weren't properly
garbage collected before the change (with the change, they are).
This could explain why the figures are relatively high.

In theory, the collection of weak references could lead to
much more misses in the cache, so we measured the impact on
the original case that was motivation for introducing that cache
in 7e89bd0cfb86 (see also issue5043): `hg convert` of the
mozilla-central repository. The bad news here is that there is a
major memory leak there, both with and without the present changeset.
There were no more cache misses, and we could see no
more memory leak with this change: the resident size after importing
roughly 100000 changesets was at 12.4GB before, and 12.5GB after.
The small increase is mentioned for completeness only, and we
believe that it should be ignored, at least as long as the main
leak isn't fixed. At less than 1% of the main leak, even finding out
whether it is merely noise would be wasteful.

Original context where this was spotted and first mitigated:
  https://foss.heptapod.net/heptapod/heptapod/-/issues/466

The leak reduction was also obtained in Heptapod inner HTTP server,
which amounts to the same as `hgwebdir_mod` for these questions.

The measurements done with Python 3.9, similar figures seen with 3.8.
More work on our side would be needed to give measurements with 2.7,
because of testing server process does not support it.

Use hgrc within $TESTTMP

  $ HGRCPATH=`pwd`/hgrc
  $ export HGRCPATH

hide outer repo
  $ hg init

Use an alternate var for scribbling on hgrc to keep check-code from
complaining about the important settings we may be overwriting:

  $ HGRC=`pwd`/hgrc
  $ export HGRC

Basic syntax error

  $ echo "invalid" > $HGRC
  $ hg version
  config error at $TESTTMP/hgrc:1: invalid
  [255]
  $ echo "" > $HGRC

Issue1199: Can't use '%' in hgrc (eg url encoded username)

  $ hg init "foo%bar"
  $ hg clone "foo%bar" foobar
  updating to branch default
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd foobar
  $ cat .hg/hgrc
  # example repository config (see 'hg help config' for more info)
  [paths]
  default = $TESTTMP/foo%bar
  
  # path aliases to other clones of this repo in URLs or filesystem paths
  # (see 'hg help config.paths' for more info)
  #
  # default:pushurl = ssh://[e-mail]/hg/jdoes-fork
  # my-fork         = ssh://[e-mail]/hg/jdoes-fork
  # my-clone        = /home/jdoe/jdoes-clone
  
  [ui]
  # name and email (local to this repository, optional), e.g.
  # username = Jane Doe <[e-mail]>
  $ hg paths
  default = $TESTTMP/foo%bar
  $ hg showconfig
  bundle.mainreporoot=$TESTTMP/foobar
  paths.default=$TESTTMP/foo%bar
  $ cd ..

Check %include

  $ echo '[section]' > $TESTTMP/included
  $ echo 'option = value' >> $TESTTMP/included
  $ echo '%include $TESTTMP/included' >> $HGRC
  $ hg showconfig section
  section.option=value
#if unix-permissions no-root
  $ chmod u-r $TESTTMP/included
  $ hg showconfig section
  config error at $TESTTMP/hgrc:2: cannot include $TESTTMP/included (Permission denied*) (glob)
  [255]
#endif

issue1829: wrong indentation

  $ echo '[foo]' > $HGRC
  $ echo '  x = y' >> $HGRC
  $ hg version
  config error at $TESTTMP/hgrc:2: unexpected leading whitespace:   x = y
  [255]

  $ "$PYTHON" -c "from __future__ import print_function; print('[foo]\nbar = a\n b\n c \n  de\n fg \nbaz = bif cb \n')" \
  > > $HGRC
  $ hg showconfig foo
  foo.bar=a\nb\nc\nde\nfg
  foo.baz=bif cb

  $ FAKEPATH=/path/to/nowhere
  $ export FAKEPATH
  $ echo '%include $FAKEPATH/no-such-file' > $HGRC
  $ hg version
  Mercurial Distributed SCM (version *) (glob)
  (see https://mercurial-scm.org for more information)
  
  Copyright (C) 2005-* Olivia Mackall and others (glob)
  This is free software; see the source for copying conditions. There is NO
  warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  $ unset FAKEPATH

make sure global options given on the cmdline take precedence

  $ hg showconfig --config ui.verbose=True --quiet
  bundle.mainreporoot=$TESTTMP
  ui.verbose=False
  ui.debug=False
  ui.quiet=True

  $ touch foobar/untracked
  $ cat >> foobar/.hg/hgrc <<EOF
  > [ui]
  > verbose=True
  > EOF
  $ hg -R foobar st -q

username expansion

  $ olduser=$HGUSER
  $ unset HGUSER

  $ FAKEUSER='John Doe'
  $ export FAKEUSER
  $ echo '[ui]' > $HGRC
  $ echo 'username = $FAKEUSER' >> $HGRC

  $ hg init usertest
  $ cd usertest
  $ touch bar
  $ hg commit --addremove --quiet -m "added bar"
  $ hg log --template "{author}\n"
  John Doe
  $ cd ..

  $ hg showconfig
  bundle.mainreporoot=$TESTTMP
  ui.username=$FAKEUSER

  $ unset FAKEUSER
  $ HGUSER=$olduser
  $ export HGUSER

showconfig with multiple arguments

  $ echo "[alias]" > $HGRC
  $ echo "log = log -g" >> $HGRC
  $ echo "[defaults]" >> $HGRC
  $ echo "identify = -n" >> $HGRC
  $ hg showconfig alias defaults
  alias.log=log -g
  defaults.identify=-n
  $ hg showconfig alias alias
  alias.log=log -g
  $ hg showconfig alias.log alias.log
  alias.log=log -g
  $ hg showconfig alias defaults.identify
  alias.log=log -g
  defaults.identify=-n
  $ hg showconfig alias.log defaults.identify
  alias.log=log -g
  defaults.identify=-n

HGPLAIN

  $ echo "[ui]" > $HGRC
  $ echo "debug=true" >> $HGRC
  $ echo "fallbackencoding=ASCII" >> $HGRC
  $ echo "quiet=true" >> $HGRC
  $ echo "slash=true" >> $HGRC
  $ echo "traceback=true" >> $HGRC
  $ echo "verbose=true" >> $HGRC
  $ echo "style=~/.hgstyle" >> $HGRC
  $ echo "logtemplate={node}" >> $HGRC
  $ echo "[defaults]" >> $HGRC
  $ echo "identify=-n" >> $HGRC
  $ echo "[alias]" >> $HGRC
  $ echo "log=log -g" >> $HGRC

customized hgrc

  $ hg showconfig
  read config from: $TESTTMP/hgrc
  $TESTTMP/hgrc:13: alias.log=log -g
  repo: bundle.mainreporoot=$TESTTMP
  $TESTTMP/hgrc:11: defaults.identify=-n
  $TESTTMP/hgrc:2: ui.debug=true
  $TESTTMP/hgrc:3: ui.fallbackencoding=ASCII
  $TESTTMP/hgrc:4: ui.quiet=true
  $TESTTMP/hgrc:5: ui.slash=true
  $TESTTMP/hgrc:6: ui.traceback=true
  $TESTTMP/hgrc:7: ui.verbose=true
  $TESTTMP/hgrc:8: ui.style=~/.hgstyle
  $TESTTMP/hgrc:9: ui.logtemplate={node}

plain hgrc

  $ HGPLAIN=; export HGPLAIN
  $ hg showconfig --config ui.traceback=True --debug
  read config from: $TESTTMP/hgrc
  repo: bundle.mainreporoot=$TESTTMP
  --config: ui.traceback=True
  --verbose: ui.verbose=False
  --debug: ui.debug=True
  --quiet: ui.quiet=False

with environment variables

  $ PAGER=p1 EDITOR=e1 VISUAL=e2 hg showconfig --debug
  read config from: $TESTTMP/hgrc
  repo: bundle.mainreporoot=$TESTTMP
  $PAGER: pager.pager=p1
  $VISUAL: ui.editor=e2
  --verbose: ui.verbose=False
  --debug: ui.debug=True
  --quiet: ui.quiet=False

plain mode with exceptions

  $ cat > plain.py <<EOF
  > from mercurial import commands, extensions
  > def _config(orig, ui, repo, *values, **opts):
  >     ui.write(b'plain: %r\n' % ui.plain())
  >     return orig(ui, repo, *values, **opts)
  > def uisetup(ui):
  >     extensions.wrapcommand(commands.table, b'config', _config)
  > EOF
  $ echo "[extensions]" >> $HGRC
  $ echo "plain=./plain.py" >> $HGRC
  $ HGPLAINEXCEPT=; export HGPLAINEXCEPT
  $ hg showconfig --config ui.traceback=True --debug
  plain: True
  read config from: $TESTTMP/hgrc
  repo: bundle.mainreporoot=$TESTTMP
  $TESTTMP/hgrc:15: extensions.plain=./plain.py
  --config: ui.traceback=True
  --verbose: ui.verbose=False
  --debug: ui.debug=True
  --quiet: ui.quiet=False
  $ unset HGPLAIN
  $ hg showconfig --config ui.traceback=True --debug
  plain: True
  read config from: $TESTTMP/hgrc
  repo: bundle.mainreporoot=$TESTTMP
  $TESTTMP/hgrc:15: extensions.plain=./plain.py
  --config: ui.traceback=True
  --verbose: ui.verbose=False
  --debug: ui.debug=True
  --quiet: ui.quiet=False
  $ HGPLAINEXCEPT=i18n; export HGPLAINEXCEPT
  $ hg showconfig --config ui.traceback=True --debug
  plain: True
  read config from: $TESTTMP/hgrc
  repo: bundle.mainreporoot=$TESTTMP
  $TESTTMP/hgrc:15: extensions.plain=./plain.py
  --config: ui.traceback=True
  --verbose: ui.verbose=False
  --debug: ui.debug=True
  --quiet: ui.quiet=False

source of paths is not mangled

  $ cat >> $HGRCPATH <<EOF
  > [paths]
  > foo = bar
  > EOF
  $ hg showconfig --debug paths
  plain: True
  read config from: $TESTTMP/hgrc
  $TESTTMP/hgrc:17: paths.foo=$TESTTMP/bar

Test we can skip the user configuration

  $ cat >> .hg/hgrc <<EOF
  > [paths]
  > elephant = babar
  > EOF
  $ hg path
  elephant = $TESTTMP/babar
  foo = $TESTTMP/bar
  $ HGRCSKIPREPO=1 hg path
  foo = $TESTTMP/bar

  $ cat >> .hg/hgrc <<EOF
  > [broken
  > EOF

  $ hg path
  config error at $TESTTMP/.hg/hgrc:3: [broken
  [255]
  $ HGRCSKIPREPO=1 hg path
  foo = $TESTTMP/bar

Check that hgweb respect HGRCSKIPREPO=1

  $ hg serve -n test -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
  config error at $TESTTMP/.hg/hgrc:3: [broken
  [255]
  $ test -f hg.pid && (cat hg.pid >> $DAEMON_PIDS)
  [1]
  $ killdaemons.py
  $ test -f access.log && cat access.log
  [1]
  $ test -f errors.log && cat errors.log
  [1]

  $ HGRCSKIPREPO=1 hg serve -n test -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
  $ cat hg.pid >> $DAEMON_PIDS
  $ killdaemons.py
  $ cat access.log
  $ cat errors.log

Check that zeroconf respect HGRCSKIPREPO=1

  $ hg paths --config extensions.zeroconf=
  config error at $TESTTMP/.hg/hgrc:3: [broken
  [255]
  $ HGRCSKIPREPO=1 hg paths --config extensions.zeroconf=
  foo = $TESTTMP/bar