misc/scripts/detect_cycle.py
author Sylvain Thénault <sylvain.thenault@logilab.fr>
Fri, 18 Dec 2015 09:07:33 +0100
changeset 11030 c1fdd22232d1
parent 10589 7c23b7de2b8d
permissions -rw-r--r--
[server] always monkeypatch QuerierHelper to handle dates and times on SQLite The patch prevents problems due to a SQLite bug causing some values to be returned as strings instead of properly typed objects. This should probably be improved to use SQLite connection hooks. But the major improvement is that the monkeypatch is now done all the time, and not just for tests.

from __future__ import print_function

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))