Handle the case where we don't have a common ancestor

This commit is contained in:
Erik Johnston 2014-09-08 20:13:27 +01:00
parent 2eaa199e6a
commit 942d8412c4
2 changed files with 42 additions and 9 deletions

View File

@ -174,7 +174,9 @@ class StateHandler(object):
n = new_branch[-1]
c = current_branch[-1]
if n.pdu_id == c.pdu_id and n.origin == c.origin:
common_ancestor = n.pdu_id == c.pdu_id and n.origin == c.origin
if common_ancestor:
# We found a common ancestor!
if len(current_branch) == 1:
@ -185,10 +187,12 @@ class StateHandler(object):
# We didn't find a common ancestor. This is probably fine.
pass
result = self._do_conflict_res(new_branch, current_branch)
result = self._do_conflict_res(
new_branch, current_branch, common_ancestor
)
defer.returnValue(result)
def _do_conflict_res(self, new_branch, current_branch):
def _do_conflict_res(self, new_branch, current_branch, common_ancestor):
conflict_res = [
self._do_power_level_conflict_res,
self._do_chain_length_conflict_res,
@ -196,7 +200,9 @@ class StateHandler(object):
]
for algo in conflict_res:
new_res, curr_res = algo(new_branch, current_branch)
new_res, curr_res = algo(
new_branch, current_branch, common_ancestor
)
if new_res < curr_res:
defer.returnValue(False)
@ -205,23 +211,26 @@ class StateHandler(object):
raise Exception("Conflict resolution failed.")
def _do_power_level_conflict_res(self, new_branch, current_branch):
def _do_power_level_conflict_res(self, new_branch, current_branch,
common_ancestor):
max_power_new = max(
new_branch[:-1],
new_branch[:-1] if common_ancestor else new_branch,
key=lambda t: t.power_level
).power_level
max_power_current = max(
current_branch[:-1],
current_branch[:-1] if common_ancestor else current_branch,
key=lambda t: t.power_level
).power_level
return (max_power_new, max_power_current)
def _do_chain_length_conflict_res(self, new_branch, current_branch):
def _do_chain_length_conflict_res(self, new_branch, current_branch,
common_ancestor):
return (len(new_branch), len(current_branch))
def _do_hash_conflict_res(self, new_branch, current_branch):
def _do_hash_conflict_res(self, new_branch, current_branch,
common_ancestor):
new_str = "".join([p.pdu_id + p.origin for p in new_branch])
c_str = "".join([p.pdu_id + p.origin for p in current_branch])

View File

@ -440,6 +440,30 @@ class StateTestCase(unittest.TestCase):
self.assertEqual(1, self.persistence.update_current_state.call_count)
@defer.inlineCallbacks
def test_no_common_ancestor(self):
# We do a direct overwriting of the old state, i.e., the new state
# points to the old state.
old_pdu = new_fake_pdu_entry("A", "test", "mem", "x", None, 5)
new_pdu = new_fake_pdu_entry("B", "test", "mem", "x", None, 10)
self.persistence.get_unresolved_state_tree.return_value = (
(ReturnType([new_pdu], [old_pdu]), None)
)
is_new = yield self.state.handle_new_state(new_pdu)
self.assertTrue(is_new)
self.persistence.get_unresolved_state_tree.assert_called_once_with(
new_pdu
)
self.assertEqual(1, self.persistence.update_current_state.call_count)
self.assertFalse(self.replication.get_pdu.called)
@defer.inlineCallbacks
def test_new_event(self):
event = Mock()