scmutil: add file object wrapper class to check ambiguity at closing
In Mercurial source tree, opening a file in "a"/"a+" mode like below
doesn't specify atomictemp=True for vfs, and this avoids file stat
ambiguity check by atomictempfile.
- writing changes out in revlog layer uses "a+" mode
- truncation in repair.strip() uses "a" mode
- truncation in transaction._playback() uses "a" mode
If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).
1. append data to revlog-style file (and close transaction)
2. discard appended data by truncation (strip or rollback)
3. append same size but different data to revlog-style file again
Therefore, cache validation doesn't work after (3) as expected.
This patch adds file object wrapper class checkambigatclosing to check
(and get rid of) ambiguity at closing. It is used by vfs in subsequent
patch.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
BTW, checkambigatclosing is tested in test-filecache.py, even though
it doesn't use filecache itself, because filecache assumes that file
stat ambiguity never occurs (and there is no another test-*.py related
to filecache).
hide outer repo
$ hg init
Use hgrc within $TESTTMP
$ HGRCPATH=`pwd`/hgrc
$ export HGRCPATH
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
hg: parse 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 (glob)
# path aliases to other clones of this repo in URLs or filesystem paths
# (see 'hg help config.paths' for more info)
#
# default-push = ssh://jdoe@example.net/hg/jdoes-fork
# my-fork = ssh://jdoe@example.net/hg/jdoes-fork
# my-clone = /home/jdoe/jdoes-clone
[ui]
# name and email (local to this repository, optional), e.g.
# username = Jane Doe <jdoe@example.com>
$ hg paths
default = $TESTTMP/foo%bar (glob)
$ hg showconfig
bundle.mainreporoot=$TESTTMP/foobar (glob)
extensions.chgserver= (?)
paths.default=$TESTTMP/foo%bar (glob)
$ cd ..
issue1829: wrong indentation
$ echo '[foo]' > $HGRC
$ echo ' x = y' >> $HGRC
$ hg version
hg: parse error at $TESTTMP/hgrc:2: x = y
unexpected leading whitespace
[255]
$ $PYTHON -c "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) 2005-2016 Matt Mackall and others
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
extensions.chgserver= (?)
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=$TESTTMP
extensions.chgserver= (?)
ui.username=$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 defaults.identify
abort: only one config item permitted
[255]
$ hg showconfig alias.log defaults.identify
abort: only one config item permitted
[255]
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
--config: extensions.chgserver= (?)
$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: extensions.chgserver= (?)
--config: ui.traceback=True
--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('plain: %r\n' % ui.plain())
> return orig(ui, repo, *values, **opts)
> def uisetup(ui):
> extensions.wrapcommand(commands.table, '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: extensions.chgserver= (?)
--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: extensions.chgserver= (?)
--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: extensions.chgserver= (?)
--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 (glob)