def _build_convergence_loop_table():
"""
Create the ``TransitionTable`` needed by the convergence loop FSM.
:return TransitionTable: The transition table for the state machine for
converging on the cluster configuration.
"""
I = ConvergenceLoopInputs
O = ConvergenceLoopOutputs
S = ConvergenceLoopStates
table = TransitionTable()
table = table.addTransition(S.STOPPED, I.STATUS_UPDATE,
[O.STORE_INFO, O.CONVERGE], S.CONVERGING)
table = table.addTransitions(
S.CONVERGING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.STOP: ([], S.CONVERGING_STOPPING),
I.SLEEP: ([O.SCHEDULE_WAKEUP], S.SLEEPING),
})
table = table.addTransitions(
S.CONVERGING_STOPPING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.SLEEP: ([], S.STOPPED),
})
table = table.addTransitions(
S.SLEEPING, {
I.WAKEUP: ([O.CLEAR_WAKEUP, O.CONVERGE], S.CONVERGING),
I.STOP: ([O.CLEAR_WAKEUP], S.STOPPED),
I.STATUS_UPDATE:
([O.STORE_INFO, O.UPDATE_MAYBE_WAKEUP], S.SLEEPING),
})
return table
def build_convergence_loop_fsm(reactor, deployer):
"""
Create a convergence loop FSM.
:param IReactorTime reactor: Used to schedule delays in the loop.
:param IDeployer deployer: Used to discover local state and calcualte
necessary changes to match desired configuration.
"""
I = ConvergenceLoopInputs
O = ConvergenceLoopOutputs
S = ConvergenceLoopStates
table = TransitionTable()
table = table.addTransition(
S.STOPPED, I.STATUS_UPDATE, [O.STORE_INFO, O.CONVERGE], S.CONVERGING)
table = table.addTransitions(
S.CONVERGING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.STOP: ([], S.CONVERGING_STOPPING),
I.ITERATION_DONE: ([O.CONVERGE], S.CONVERGING),
})
table = table.addTransitions(
S.CONVERGING_STOPPING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.ITERATION_DONE: ([], S.STOPPED),
})
loop = ConvergenceLoop(reactor, deployer)
fsm = constructFiniteStateMachine(
inputs=I, outputs=O, states=S, initial=S.STOPPED, table=table,
richInputs=[_ClientStatusUpdate], inputContext={},
world=MethodSuffixOutputer(loop))
loop.fsm = fsm
return fsm
def build_convergence_loop_fsm(reactor, deployer):
"""
Create a convergence loop FSM.
:param IReactorTime reactor: Used to schedule delays in the loop.
:param IDeployer deployer: Used to discover local state and calcualte
necessary changes to match desired configuration.
"""
I = ConvergenceLoopInputs
O = ConvergenceLoopOutputs
S = ConvergenceLoopStates
table = TransitionTable()
table = table.addTransition(
S.STOPPED, I.STATUS_UPDATE, [O.STORE_INFO, O.CONVERGE], S.CONVERGING)
table = table.addTransitions(
S.CONVERGING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.STOP: ([], S.CONVERGING_STOPPING),
I.ITERATION_DONE: ([O.CONVERGE], S.CONVERGING),
})
table = table.addTransitions(
S.CONVERGING_STOPPING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.ITERATION_DONE: ([], S.STOPPED),
})
loop = ConvergenceLoop(reactor, deployer)
fsm = constructFiniteStateMachine(
inputs=I, outputs=O, states=S, initial=S.STOPPED, table=table,
richInputs=[_ClientStatusUpdate], inputContext={},
world=MethodSuffixOutputer(loop))
loop.fsm = fsm
return fsm
def _build_convergence_loop_table():
"""
Create the ``TransitionTable`` needed by the convergence loop FSM.
:return TransitionTable: The transition table for the state machine for
converging on the cluster configuration.
"""
I = ConvergenceLoopInputs
O = ConvergenceLoopOutputs
S = ConvergenceLoopStates
table = TransitionTable()
table = table.addTransition(
S.STOPPED, I.STATUS_UPDATE, [O.STORE_INFO, O.CONVERGE], S.CONVERGING)
table = table.addTransitions(
S.CONVERGING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.STOP: ([], S.CONVERGING_STOPPING),
I.SLEEP: ([O.SCHEDULE_WAKEUP], S.SLEEPING),
})
table = table.addTransitions(
S.CONVERGING_STOPPING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.SLEEP: ([], S.STOPPED),
})
table = table.addTransitions(
S.SLEEPING, {
I.WAKEUP: ([O.CLEAR_WAKEUP, O.CONVERGE], S.CONVERGING),
I.STOP: ([O.CLEAR_WAKEUP], S.STOPPED),
I.STATUS_UPDATE: (
[O.STORE_INFO, O.UPDATE_MAYBE_WAKEUP], S.SLEEPING),
})
return table
def build_cluster_status_fsm(convergence_loop_fsm):
"""
Create a new cluster status FSM.
The automatic reconnection logic is handled by the
``AgentLoopService``; the world object here just gets notified of
disconnects, it need schedule the reconnect itself.
:param convergence_loop_fsm: A convergence loop FSM as output by
``build_convergence_loop_fsm``.
"""
S = ClusterStatusStates
I = ClusterStatusInputs
O = ClusterStatusOutputs
table = TransitionTable()
# We may be shut down in any state, in which case we disconnect if
# necessary.
table = table.addTransitions(
S.DISCONNECTED,
{
# Store the client, then wait for cluster status to be sent
# over AMP:
I.CONNECTED_TO_CONTROL_SERVICE: ([O.STORE_CLIENT], S.IGNORANT),
I.SHUTDOWN: ([], S.SHUTDOWN),
},
)
table = table.addTransitions(
S.IGNORANT,
{
# We never told agent to start, so no need to tell it to stop:
I.DISCONNECTED_FROM_CONTROL_SERVICE: ([], S.DISCONNECTED),
# Tell agent latest cluster status, implicitly starting it:
I.STATUS_UPDATE: ([O.UPDATE_STATUS], S.KNOWLEDGEABLE),
I.SHUTDOWN: ([O.DISCONNECT], S.SHUTDOWN),
},
)
table = table.addTransitions(
S.KNOWLEDGEABLE,
{
# Tell agent latest cluster status:
I.STATUS_UPDATE: ([O.UPDATE_STATUS], S.KNOWLEDGEABLE),
I.DISCONNECTED_FROM_CONTROL_SERVICE: ([O.STOP], S.DISCONNECTED),
I.SHUTDOWN: ([O.STOP, O.DISCONNECT], S.SHUTDOWN),
},
)
table = table.addTransitions(
S.SHUTDOWN, {I.DISCONNECTED_FROM_CONTROL_SERVICE: ([], S.SHUTDOWN), I.STATUS_UPDATE: ([], S.SHUTDOWN)}
)
return constructFiniteStateMachine(
inputs=I,
outputs=O,
states=S,
initial=S.DISCONNECTED,
table=table,
richInputs=[_ConnectedToControlService, _StatusUpdate],
inputContext={},
world=MethodSuffixOutputer(ClusterStatus(convergence_loop_fsm)),
)
def test_addTransitionsDoesNotMutate(self):
"""
L{TransitionTable.addTransitions} does not change the
L{TransitionTable} it is called on.
"""
table = TransitionTable({"foo": {"bar": Transition("baz", "quux")}})
table.addTransitions("apple", {"banana": ("clementine", "date")})
self.assertEqual({"foo": {"bar": Transition("baz", "quux")}}, table.table)
def build_cluster_status_fsm(convergence_loop_fsm):
"""
Create a new cluster status FSM.
The automatic reconnection logic is handled by the
``AgentLoopService``; the world object here just gets notified of
disconnects, it need schedule the reconnect itself.
:param convergence_loop_fsm: A convergence loop FSM as output by
``build_convergence_loop_fsm``.
"""
S = ClusterStatusStates
I = ClusterStatusInputs
O = ClusterStatusOutputs
table = TransitionTable()
# We may be shut down in any state, in which case we disconnect if
# necessary.
table = table.addTransitions(
S.DISCONNECTED,
{
# Store the client, then wait for cluster status to be sent
# over AMP:
I.CONNECTED_TO_CONTROL_SERVICE: ([O.STORE_CLIENT], S.IGNORANT),
I.SHUTDOWN: ([], S.SHUTDOWN),
})
table = table.addTransitions(
S.IGNORANT,
{
# We never told agent to start, so no need to tell it to stop:
I.DISCONNECTED_FROM_CONTROL_SERVICE: ([], S.DISCONNECTED),
# Tell agent latest cluster status, implicitly starting it:
I.STATUS_UPDATE: ([O.UPDATE_STATUS], S.KNOWLEDGEABLE),
I.SHUTDOWN: ([O.DISCONNECT], S.SHUTDOWN),
})
table = table.addTransitions(
S.KNOWLEDGEABLE,
{
# Tell agent latest cluster status:
I.STATUS_UPDATE: ([O.UPDATE_STATUS], S.KNOWLEDGEABLE),
I.DISCONNECTED_FROM_CONTROL_SERVICE: ([O.STOP], S.DISCONNECTED),
I.SHUTDOWN: ([O.STOP, O.DISCONNECT], S.SHUTDOWN),
})
table = table.addTransitions(
S.SHUTDOWN, {
I.DISCONNECTED_FROM_CONTROL_SERVICE: ([], S.SHUTDOWN),
I.STATUS_UPDATE: ([], S.SHUTDOWN),
})
return constructFiniteStateMachine(
inputs=I,
outputs=O,
states=S,
initial=S.DISCONNECTED,
table=table,
richInputs=[_ConnectedToControlService, _StatusUpdate],
inputContext={},
world=MethodSuffixOutputer(ClusterStatus(convergence_loop_fsm)))
def test_addTransitionsDoesNotMutate(self):
"""
L{TransitionTable.addTransitions} does not change the
L{TransitionTable} it is called on.
"""
table = TransitionTable({"foo": {"bar": Transition("baz", "quux")}})
table.addTransitions("apple", {"banana": ("clementine", "date")})
self.assertEqual({"foo": {
"bar": Transition("baz", "quux")
}}, table.table)
def _build_cluster_status_fsm_table():
"""
Create the ``TransitionTable`` needed by the cluster status FSM.
:return TransitionTable: The transition table for the state machine for
keeping track of cluster state and configuration.
"""
S = ClusterStatusStates
I = ClusterStatusInputs
O = ClusterStatusOutputs
table = TransitionTable()
# We may be shut down in any state, in which case we disconnect if
# necessary.
table = table.addTransitions(
S.DISCONNECTED,
{
# Store the client, then wait for cluster status to be sent
# over AMP:
I.CONNECTED_TO_CONTROL_SERVICE: ([O.STORE_CLIENT], S.IGNORANT),
I.SHUTDOWN: ([], S.SHUTDOWN),
})
table = table.addTransitions(
S.IGNORANT,
{
# We never told agent to start, so no need to tell it to stop:
I.DISCONNECTED_FROM_CONTROL_SERVICE: ([], S.DISCONNECTED),
# Tell agent latest cluster status, implicitly starting it:
I.STATUS_UPDATE: ([O.UPDATE_STATUS], S.KNOWLEDGEABLE),
I.SHUTDOWN: ([O.DISCONNECT], S.SHUTDOWN),
})
table = table.addTransitions(
S.KNOWLEDGEABLE,
{
# Tell agent latest cluster status:
I.STATUS_UPDATE: ([O.UPDATE_STATUS], S.KNOWLEDGEABLE),
I.DISCONNECTED_FROM_CONTROL_SERVICE: ([O.STOP], S.DISCONNECTED),
I.SHUTDOWN: ([O.STOP, O.DISCONNECT], S.SHUTDOWN),
})
table = table.addTransitions(
S.SHUTDOWN, {
I.DISCONNECTED_FROM_CONTROL_SERVICE: ([], S.SHUTDOWN),
I.STATUS_UPDATE: ([], S.SHUTDOWN),
})
return table
def _build_cluster_status_fsm_table():
"""
Create the ``TransitionTable`` needed by the cluster status FSM.
:return TransitionTable: The transition table for the state machine for
keeping track of cluster state and configuration.
"""
S = ClusterStatusStates
I = ClusterStatusInputs
O = ClusterStatusOutputs
table = TransitionTable()
# We may be shut down in any state, in which case we disconnect if
# necessary.
table = table.addTransitions(
S.DISCONNECTED, {
# Store the client, then wait for cluster status to be sent
# over AMP:
I.CONNECTED_TO_CONTROL_SERVICE: ([O.STORE_CLIENT], S.IGNORANT),
I.SHUTDOWN: ([], S.SHUTDOWN),
})
table = table.addTransitions(
S.IGNORANT, {
# We never told agent to start, so no need to tell it to stop:
I.DISCONNECTED_FROM_CONTROL_SERVICE: ([], S.DISCONNECTED),
# Tell agent latest cluster status, implicitly starting it:
I.STATUS_UPDATE: ([O.UPDATE_STATUS], S.KNOWLEDGEABLE),
I.SHUTDOWN: ([O.DISCONNECT], S.SHUTDOWN),
})
table = table.addTransitions(
S.KNOWLEDGEABLE, {
# Tell agent latest cluster status:
I.STATUS_UPDATE: ([O.UPDATE_STATUS], S.KNOWLEDGEABLE),
I.DISCONNECTED_FROM_CONTROL_SERVICE: ([O.STOP], S.DISCONNECTED),
I.SHUTDOWN: ([O.STOP, O.DISCONNECT], S.SHUTDOWN),
})
table = table.addTransitions(
S.SHUTDOWN, {
I.DISCONNECTED_FROM_CONTROL_SERVICE: ([], S.SHUTDOWN),
I.STATUS_UPDATE: ([], S.SHUTDOWN),
})
return table
def test_addTransitions(self):
"""
L{TransitionTable.addTransitions} accepts a state and a mapping from
inputs to output, next state pairs and adds all of those transitions to
the given state to a new L{TransitionTable} which it returns.
"""
table = TransitionTable()
more = table.addTransitions(
"apple", {
"banana": ("clementine", "date"),
"eggplant": ("fig", "grape")})
self.assertEqual(
{"apple": {
"banana": Transition("clementine", "date"),
"eggplant": Transition("fig", "grape")}},
more.table)
def test_addTransitions(self):
"""
L{TransitionTable.addTransitions} accepts a state and a mapping from
inputs to output, next state pairs and adds all of those transitions to
the given state to a new L{TransitionTable} which it returns.
"""
table = TransitionTable()
more = table.addTransitions("apple", {
"banana": ("clementine", "date"),
"eggplant": ("fig", "grape")
})
self.assertEqual(
{
"apple": {
"banana": Transition("clementine", "date"),
"eggplant": Transition("fig", "grape")
}
}, more.table)
# end table def
# begin first transition
table = table.addTransition(
State.LOCKED, Input.FARE_PAID, [Output.DISENGAGE_LOCK], State.ACTIVE)
# end first transition
# begin second transition
table = table.addTransition(
State.UNLOCKED, Input.ARM_TURNED, [Output.ENGAGE_LOCK], State.ACTIVE)
# end second transition
# begin last transitions
table = table.addTransitions(
State.ACTIVE, {
Input.ARM_UNLOCKED: ([], State.UNLOCKED),
Input.ARM_LOCKED: ([], State.LOCKED),
})
# end last transitions
# begin outputer
from machinist import MethodSuffixOutputer
class Outputer(object):
def output_ENGAGE_LOCK(self, engage):
print("Engaging the lock.")
def output_DISENGAGE_LOCK(self, disengage):
print("Disengaging the lock.")
outputer = MethodSuffixOutputer(Outputer())
# end table def
# begin first transition
table = table.addTransition(State.LOCKED, Input.FARE_PAID,
[Output.DISENGAGE_LOCK], State.ACTIVE)
# end first transition
# begin second transition
table = table.addTransition(State.UNLOCKED, Input.ARM_TURNED,
[Output.ENGAGE_LOCK], State.ACTIVE)
# end second transition
# begin last transitions
table = table.addTransitions(
State.ACTIVE, {
Input.ARM_UNLOCKED: ([], State.UNLOCKED),
Input.ARM_LOCKED: ([], State.LOCKED),
})
# end last transitions
# begin outputer
from machinist import MethodSuffixOutputer
class Outputer(object):
def output_ENGAGE_LOCK(self, engage):
print("Engaging the lock.")
def output_DISENGAGE_LOCK(self, disengage):
print("Disengaging the lock.")
def build_convergence_loop_fsm(reactor, deployer):
"""
Create a convergence loop FSM.
Once cluster config+cluster state updates from control service are
received the basic loop is:
1. Discover local state.
2. Calculate ``IStateChanges`` based on local state and cluster
configuration and cluster state we received from control service.
3. Execute the change.
4. Sleep.
However, if an update is received during sleep then we calculate based
on that updated config+state whether a ``IStateChange`` needs to
happen. If it does that means this change will have impact on what we
do, so we interrupt the sleep. If calculation suggests a no-op then we
keep sleeping. Notably we do **not** do a discovery of local state
when an update is received while sleeping, since that is an expensive
operation that can involve talking to external resources. Moreover an
external update only implies external state/config changed, so we're
not interested in the latest local state in trying to decide if this
update requires us to do something; a recently cached version should
suffice.
:param IReactorTime reactor: Used to schedule delays in the loop.
:param IDeployer deployer: Used to discover local state and calcualte
necessary changes to match desired configuration.
"""
I = ConvergenceLoopInputs
O = ConvergenceLoopOutputs
S = ConvergenceLoopStates
table = TransitionTable()
table = table.addTransition(
S.STOPPED, I.STATUS_UPDATE, [O.STORE_INFO, O.CONVERGE], S.CONVERGING)
table = table.addTransitions(
S.CONVERGING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.STOP: ([], S.CONVERGING_STOPPING),
I.SLEEP: ([O.SCHEDULE_WAKEUP], S.SLEEPING),
})
table = table.addTransitions(
S.CONVERGING_STOPPING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.SLEEP: ([], S.STOPPED),
})
table = table.addTransitions(
S.SLEEPING, {
I.WAKEUP: ([O.CLEAR_WAKEUP, O.CONVERGE], S.CONVERGING),
I.STOP: ([O.CLEAR_WAKEUP], S.STOPPED),
I.STATUS_UPDATE: (
[O.STORE_INFO, O.UPDATE_MAYBE_WAKEUP], S.SLEEPING),
})
loop = ConvergenceLoop(reactor, deployer)
fsm = constructFiniteStateMachine(
inputs=I, outputs=O, states=S, initial=S.STOPPED, table=table,
richInputs=[_ClientStatusUpdate, _Sleep], inputContext={},
world=MethodSuffixOutputer(loop))
loop.fsm = fsm
return fsm
def build_convergence_loop_fsm(reactor, deployer):
"""
Create a convergence loop FSM.
Once cluster config+cluster state updates from control service are
received the basic loop is:
1. Discover local state.
2. Calculate ``IStateChanges`` based on local state and cluster
configuration and cluster state we received from control service.
3. Execute the change.
4. Sleep.
However, if an update is received during sleep then we calculate based
on that updated config+state whether a ``IStateChange`` needs to
happen. If it does that means this change will have impact on what we
do, so we interrupt the sleep. If calculation suggests a no-op then we
keep sleeping. Notably we do **not** do a discovery of local state
when an update is received while sleeping, since that is an expensive
operation that can involve talking to external resources. Moreover an
external update only implies external state/config changed, so we're
not interested in the latest local state in trying to decide if this
update requires us to do something; a recently cached version should
suffice.
:param IReactorTime reactor: Used to schedule delays in the loop.
:param IDeployer deployer: Used to discover local state and calcualte
necessary changes to match desired configuration.
"""
I = ConvergenceLoopInputs
O = ConvergenceLoopOutputs
S = ConvergenceLoopStates
table = TransitionTable()
table = table.addTransition(S.STOPPED, I.STATUS_UPDATE,
[O.STORE_INFO, O.CONVERGE], S.CONVERGING)
table = table.addTransitions(
S.CONVERGING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.STOP: ([], S.CONVERGING_STOPPING),
I.SLEEP: ([O.SCHEDULE_WAKEUP], S.SLEEPING),
})
table = table.addTransitions(
S.CONVERGING_STOPPING, {
I.STATUS_UPDATE: ([O.STORE_INFO], S.CONVERGING),
I.SLEEP: ([], S.STOPPED),
})
table = table.addTransitions(
S.SLEEPING, {
I.WAKEUP: ([O.CLEAR_WAKEUP, O.CONVERGE], S.CONVERGING),
I.STOP: ([O.CLEAR_WAKEUP], S.STOPPED),
I.STATUS_UPDATE:
([O.STORE_INFO, O.UPDATE_MAYBE_WAKEUP], S.SLEEPING),
})
loop = ConvergenceLoop(reactor, deployer)
fsm = constructFiniteStateMachine(inputs=I,
outputs=O,
states=S,
initial=S.STOPPED,
table=table,
richInputs=[_ClientStatusUpdate, _Sleep],
inputContext={},
world=MethodSuffixOutputer(loop))
loop.fsm = fsm
return fsm
ARM_TURNED = NamedConstant()
ARM_LOCKED = NamedConstant()
class TurnstileOutput(Names):
ENGAGE_LOCK = NamedConstant()
DISENGAGE_LOCK = NamedConstant()
class TurnstileState(Names):
LOCKED = NamedConstant()
UNLOCKED = NamedConstant()
ACTIVE = NamedConstant()
table = TransitionTable()
table = table.addTransitions(
TurnstileState.UNLOCKED, {
TurnstileInput.ARM_TURNED:
([TurnstileOutput.ENGAGE_LOCK], TurnstileState.ACTIVE),
})
table = table.addTransitions(
TurnstileState.ACTIVE, {
TurnstileInput.ARM_LOCKED: ([], TurnstileState.LOCKED),
TurnstileInput.ARM_UNLOCKED: ([], TurnstileState.UNLOCKED),
})
table = table.addTransitions(
TurnstileState.LOCKED, {
TurnstileInput.FARE_PAID:
([TurnstileOutput.DISENGAGE_LOCK], TurnstileState.ACTIVE),
})
class Turnstile(object):
def __init__(self, hardware):
