[session] deprecate `hijack_user` method
The semantic of this method is wicked and lead to very hard violation of sanity.
(multiple transaction using the very same cursors). We deprecated the API to be
able to drop it as soon as possible.
The method was added long ago for some notification trick. It is not needed
since we sent notification on ``postcommit_event``.
(closes #2781782)
try:
rtype, = __args__
except ValueError:
print 'USAGE: cubicweb-ctl shell <instance> detect_cycle.py -- <relation type>'
print
graph = {}
for fromeid, toeid in rql('Any X,Y WHERE X %s Y' % rtype):
graph.setdefault(fromeid, []).append(toeid)
from logilab.common.graph import get_cycles
for cycle in get_cycles(graph):
print 'cycle', '->'.join(str(n) for n in cycle)