contrib/dumprevlog

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.

#!/usr/bin/env python
# Dump revlogs as raw data stream
# $ find .hg/store/ -name "*.i" | xargs dumprevlog > repo.dump

import sys
from mercurial import revlog, node, util

for fp in (sys.stdin, sys.stdout, sys.stderr):
    util.setbinary(fp)

for f in sys.argv[1:]:
    binopen = lambda fn: open(fn, 'rb')
    r = revlog.revlog(binopen, f)
    print "file:", f
    for i in r:
        n = r.node(i)
        p = r.parents(n)
        d = r.revision(n)
        print "node:", node.hex(n)
        print "linkrev:", r.linkrev(i)
        print "parents:", node.hex(p[0]), node.hex(p[1])
        print "length:", len(d)
        print "-start-"
        print d
        print "-end-"