obsstore: add relevantmarkers method
We add a ``relevantmarkers`` method to fetch all markers that seem relevant to a
set of nodes. See function documentation about how this set is computed. This
will let us exchange only the markers that seem "relevant" to the set of
changesets related to a push or a pull.
The approach used to define "relevant" has been successfully tested in evolve
for 6 months.
#require serve
$ hg init server
$ cd server
$ cat >> .hg/hgrc << EOF
> [extensions]
> strip=
> EOF
$ echo 1 > foo
$ hg commit -A -m 'first'
adding foo
$ echo 2 > bar
$ hg commit -A -m 'second'
adding bar
Produce a bundle to use
$ hg strip -r 1
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
saved backup bundle to $TESTTMP/server/.hg/strip-backup/ed602e697e0f-backup.hg (glob)
Serve from a bundle file
$ hg serve -R .hg/strip-backup/ed602e697e0f-backup.hg -d -p $HGPORT --pid-file=hg.pid
$ cat hg.pid >> $DAEMON_PIDS
Ensure we're serving from the bundle
$ ("$TESTDIR/get-with-headers.py" localhost:$HGPORT 'file/tip/?style=raw')
200 Script output follows
-rw-r--r-- 2 bar
-rw-r--r-- 2 foo