posix: give checklink a fast path that cache the check file and is read only
util.checklink would create a symlink and remove it again. That would sometimes
happen multiple times. Write operations are relatively expensive and give disk
tear and noise for applications monitoring file system activity.
Instead of creating a symlink and deleting it again, just create it once and
leave it in .hg/cache/check-link . If the file exists, just verify that
os.islink reports true. We will assume that this check is as good as symlink
creation not failing.
Note: The symlink left in .hg/cache has to resolve to a file - otherwise 'make
dist' will fail ...
test-symlink-os-yes-fs-no.py does some monkey patching to simulate a platform
without symlink support. The slightly different testing method requires
additional monkeying.
$ echo 'raise Exception("bit bucket overflow")' > badext.py
$ abspathexc=`pwd`/badext.py
$ cat >baddocext.py <<EOF
> """
> baddocext is bad
> """
> EOF
$ abspathdoc=`pwd`/baddocext.py
$ cat <<EOF >> $HGRCPATH
> [extensions]
> gpg =
> hgext.gpg =
> badext = $abspathexc
> baddocext = $abspathdoc
> badext2 =
> EOF
$ hg -q help help 2>&1 |grep extension
*** failed to import extension badext from $TESTTMP/badext.py: bit bucket overflow
*** failed to import extension badext2: No module named badext2
show traceback
$ hg -q help help --traceback 2>&1 | egrep ' extension|^Exception|Traceback|ImportError'
*** failed to import extension badext from $TESTTMP/badext.py: bit bucket overflow
Traceback (most recent call last):
Exception: bit bucket overflow
*** failed to import extension badext2: No module named badext2
Traceback (most recent call last):
ImportError: No module named badext2
names of extensions failed to load can be accessed via extensions.notloaded()
$ cat <<EOF > showbadexts.py
> from mercurial import cmdutil, commands, extensions
> cmdtable = {}
> command = cmdutil.command(cmdtable)
> @command('showbadexts', norepo=True)
> def showbadexts(ui, *pats, **opts):
> ui.write('BADEXTS: %s\n' % ' '.join(sorted(extensions.notloaded())))
> EOF
$ hg --config extensions.badexts=showbadexts.py showbadexts 2>&1 | grep '^BADEXTS'
BADEXTS: badext badext2
show traceback for ImportError of hgext.name if debug is set
(note that --debug option isn't applied yet when loading extensions)
$ (hg -q help help --traceback --config ui.debug=True 2>&1) \
> | grep -v '^ ' \
> | egrep 'extension..[^p]|^Exception|Traceback|ImportError|not import'
*** failed to import extension badext from $TESTTMP/badext.py: bit bucket overflow
Traceback (most recent call last):
Exception: bit bucket overflow
could not import hgext.badext2 (No module named *badext2): trying hgext3rd.badext2 (glob)
Traceback (most recent call last):
ImportError: No module named *badext2 (glob)
could not import hgext3rd.badext2 (No module named *badext2): trying badext2 (glob)
Traceback (most recent call last):
ImportError: No module named *badext2 (glob)
*** failed to import extension badext2: No module named badext2
Traceback (most recent call last):
ImportError: No module named badext2
confirm that there's no crash when an extension's documentation is bad
$ hg help --keyword baddocext
*** failed to import extension badext from $TESTTMP/badext.py: bit bucket overflow
*** failed to import extension badext2: No module named badext2
Topics:
extensions Using Additional Features