revisionbranchcache: fall back to slow path if starting readonly (issue4531)
Transitioning to Mercurial versions with revision branch cache could be slow as
long as all operations were readonly (revset queries) and the cache would be
populated but not written back.
Instead, fall back to using the consistently slow path when readonly and the
cache doesn't exist yet. That avoids the overhead of populating the cache
without writing it back.
If not readonly, it will still populate all missing entries initially. That
avoids repeated writing of the cache file with small updates, and it also makes
sure a fully populated cache available for the readonly operations.
#require no-msys # MSYS will translate web paths as if they were file paths
This is a test of the wire protocol over CGI-based hgweb.
initialize repository
$ hg init test
$ cd test
$ echo a > a
$ hg ci -Ama
adding a
$ cd ..
$ cat >hgweb.cgi <<HGWEB
> #
> # An example CGI script to use hgweb, edit as necessary
> import cgitb
> cgitb.enable()
> from mercurial import demandimport; demandimport.enable()
> from mercurial.hgweb import hgweb
> from mercurial.hgweb import wsgicgi
> application = hgweb("test", "Empty test repository")
> wsgicgi.launch(application)
> HGWEB
$ chmod 755 hgweb.cgi
try hgweb request
$ . "$TESTDIR/cgienv"
$ QUERY_STRING="cmd=changegroup&roots=0000000000000000000000000000000000000000"; export QUERY_STRING
$ python hgweb.cgi >page1 2>&1
$ python "$TESTDIR/md5sum.py" page1
1f424bb22ec05c3c6bc866b6e67efe43 page1
make sure headers are sent even when there is no body
$ QUERY_STRING="cmd=listkeys&namespace=nosuchnamespace" python hgweb.cgi
Status: 200 Script output follows\r (esc)
Content-Type: application/mercurial-0.1\r (esc)
Content-Length: 0\r (esc)
\r (esc)