def test_proposer_uses_one_proposal_at_a_time(self):
self.role.receive(Request.create(value="myval_1"), self.channel)
self.role.receive(Request.create(value="myval_2"), self.channel)
self.role.receive(Request.create(value="myval_3"), self.channel)
sent_message = self.channel.broadcast_messages[-1]
self.assertEqual(sent_message.proposal.number, 0)
def _(self, message, channel, create_reply=Response.create):
"""Learn Phase.
To learn that a value has been chosen, a learner must find out that a
proposal has been accepted by a majority of acceptors.
"""
LOG.debug("RECEIVED message {0}".format(message))
self.accepted_proposals.setdefault(message.proposal, set()) \
.add(message.sender)
minimum_quorum = len(channel.replicas) // 2 + 1
accepted_quorum = len(self.accepted_proposals.get(message.proposal))
if accepted_quorum == minimum_quorum:
# Here we reset for the next round.
self.state.write(Role.PROPOSED, self.state.read(Role.PROPOSED) \
.next())
self.state.write(Role.VALUE, None)
channel.unicast(Request.create(receiver=message.receiver,
sender=message.receiver))
self.notification.send(create_reply(proposal=message.proposal))
if accepted_quorum >= minimum_quorum:
self._ledger.append(LedgerEntry(number=message.proposal.number,
value=message.value))
reply = create_reply(proposal=message.proposal)
channel.unicast(reply)
if accepted_quorum == len(channel.replicas):
del self.accepted_proposals[message.proposal]
def send_requests(channel, host, interval=1):
for v in ["a", "b", "c", "d", "e", "f", "g", "z"]:
for n in range(1):
val = v + str(n)
channel.unicast(Request.create(sender=host, receiver=host, value=val))
time.sleep(interval)
def test_proposer_sends_initial_prepare(self):
self.role.receive(Request.create(value="myval"), self.channel)
sent_message = self.channel.broadcast_messages[-1]
self.assertTrue(type(sent_message) is Prepare)
self.assertEqual(sent_message.proposal.number, 0)
def test_proposer_doesnt_send_prepare_if_no_value_in_request(self):
self.role.receive(Request.create(), self.channel)
self.assertEqual(len(self.channel.broadcast_messages), 0)
def update(self, name, obj):
val = "{0}={1}".format(name, repr(self._serialize(obj)))
self._channel.loopback(Request.create(value=val))
def sync(self, name):
val = "READ({0})".format(name)
self._channel.loopback(Request.create(value=val))
