def __init__(self, context, completekey="tab", stdin=None, stdout=None):
cmd.Cmd.__init__(self, completekey=completekey, stdin=stdin, stdout=stdout)
ConnectCmdShell.__init__(self, context)
ActionCmdShell.__init__(self, context)
ShowCmdShell.__init__(self, context)
ListCmdShell.__init__(self, context)
UpdateCmdShell.__init__(self, context)
RemoveCmdShell.__init__(self, context)
AddCmdShell.__init__(self, context)
DisconnectCmdShell.__init__(self, context)
ConsoleCmdShell.__init__(self, context)
PingCmdShell.__init__(self, context)
StatusCmdShell.__init__(self, context)
ClearCmdShell.__init__(self, context)
FileCmdShell.__init__(self, context)
HistoryCmdShell.__init__(self, context)
InfoCmdShell.__init__(self, context)
SummaryCmdShell.__init__(self, context)
CapabilitiesCmdShell.__init__(self, context)
self.__last_output = ""
self.__input_buffer = ""
self.__last_status = -1
self.onError = Event() # triggered when error occurs
self.onInit = Event() # triggered on init()
self.onExit = Event() # triggered on exit
self.onPromptChange = Event() # triggered onPromptChange
self.onSigInt = Event() # triggered on SigInt fault
self.__prompt_manager = PromptManager(self)
self.__register_sys_listeners()
self.__register_dfsm_callbacks()
self.__init_promt()
cmd.Cmd.doc_header = self.context.settings.get("ovirt-shell:commands")
cmd.Cmd.undoc_header = self.context.settings.get("ovirt-shell:misc_commands")
cmd.Cmd.intro = self.__get_intro()
readline.set_completer_delims(" ")
signal.signal(signal.SIGINT, self.__handler)
self.onInit.fire()
def __init__(self, context, completekey='tab', stdin=None, stdout=None):
cmd.Cmd.__init__(self,
completekey=completekey,
stdin=stdin,
stdout=stdout)
ConnectCmdShell.__init__(self, context)
ActionCmdShell.__init__(self, context)
ShowCmdShell.__init__(self, context)
ListCmdShell.__init__(self, context)
UpdateCmdShell.__init__(self, context)
RemoveCmdShell.__init__(self, context)
AddCmdShell.__init__(self, context)
DisconnectCmdShell.__init__(self, context)
ConsoleCmdShell.__init__(self, context)
PingCmdShell.__init__(self, context)
StatusCmdShell.__init__(self, context)
ClearCmdShell.__init__(self, context)
FileCmdShell.__init__(self, context)
HistoryCmdShell.__init__(self, context)
InfoCmdShell.__init__(self, context)
SummaryCmdShell.__init__(self, context)
CapabilitiesCmdShell.__init__(self, context)
self.__last_output = ''
self.__input_buffer = ''
self.__last_status = -1
self.onError = Event() # triggered when error occurs
self.onInit = Event() # triggered on init()
self.onExit = Event() # triggered on exit
self.onPromptChange = Event() # triggered onPromptChange
self.onSigInt = Event() # triggered on SigInt fault
self.__prompt_manager = PromptManager(self)
self.__register_sys_listeners()
self.__register_dfsm_callbacks()
self.__init_promt()
cmd.Cmd.doc_header = self.context.settings.get('ovirt-shell:commands')
cmd.Cmd.undoc_header = self.context.settings.get(
'ovirt-shell:misc_commands')
cmd.Cmd.intro = self.__get_intro()
readline.set_completer_delims(' ')
signal.signal(signal.SIGINT, self.__handler)
self.onInit.fire()
class FiniteStateMachine(object):
'''
The Deterministic Finite-State Automata (DFSA)
=========== state maintains logic ===========
A=(A, Q, l, q0, F)
A is alphabetic
_
Q is a finite set of states |_|
_ _
l is a state transition function |_| -> |_|
_
q0 is a initial state ->|_|
=====
F is a set of final states || ||
=====
L = {ab^n E A* : n >= 0}
e.g:
--b-------------------------
| |
--- ===== ---- |
->|q0|-a--->||q1||-a-->|q2|<---
-- ===== ----
| ^ | ^
b | a,b |
| | | |
----- -----
A = ({{a, b}, {q0,q1,q2},l,{q0}, {q1})
e.g: l=(q0,a)=q1 l=(q1,b)=q1
=========== usage ===========
from ovirtcli.state.finitestatemachine import FiniteStateMachine
from ovirtcli.state.dfsaevent import DFSAEvent
from ovirtcli.state.dfsastate import DFSAState
1. define the callback for events, with callback you can either
perform onEvent actions or block the StateMachine till your
action is accomplished.
def onConnectCallback(self, **kwargs):
print "connect callback with:\n%s\n\n" % kwargs['event']
def onDisconnectCallback(self, **kwargs):
print "disconnect callback:\n%s\n\n" % kwargs['event']
2. define the StateMachine
class Test(object):
def run(self):
sm = FiniteStateMachine( # define the StateMachine
events=[ # define events
DFSAEvent( # define StateMachine event
name='disconnect', # event name
sources=[ # source states from which this event is eligible
DFSAState.Connected,
DFSAState.Unauthorized
],
destination=DFSAState.Disconnected, # destination event state
callbacks=[self.onDisconnectCallback]), # callbacks to invoke after
# this events is triggered
DFSAEvent(
name='connect',
sources=[
DFSAState.Disconnected,
DFSAState.Unauthorized
],
destination=DFSAState.Connected,
callbacks=[self.onConnectCallback]),
DFSAEvent(
name='unauthorized',
sources=[
DFSAState.Connected
],
destination=DFSAState.Unauthorized,
callbacks=[]),
]
)
3. StateMachine has own events:
- onBeforeApplyState: triggered Before ApplyState occurs
- onAfterApplyState : triggered After ApplyState occurs
- onStateChange, : triggered on any StateChange
- onBeforeEvent : triggered Before Event processed
- onAfterEvent : triggered After Event processed
- onCanMove : triggered when CanMove() check is invoked
you can register to them using event patter:
sm.onBeforeEvent += OnBeforeEventListener()
NOTE:
- EventListener must to implement IListener interface
- All events are provided with 'event' argument to maintain the state
between the events, in some case extra data can be provided such as
[source, destination, result, ...] depending on event's context.
- callbacks can be registered later calling sm.add_callback(DFSAState.X, your_method)
4. trigger events on StateMachine
sm.connect() # 'connect' event
# print sm; print "\n"
sm.disconnect() 'disconnect' event
# print sm; print "\n"
sm.unauthorized() 'unauthorized' event
# print sm; print "\n"
...
Test().run()
'''
__metaclass__ = Singleton
# @Requires([DFSAEvent], DFSAEvent)
# TODO: support multi-parameters definition ^
def __init__(self, events, inital_state=DFSAEvent(
name='disconnected',
sources=[],
destination=DFSAState.DISCONNECTED,
description='init'
)
):
'''
@param events: the list of DFSA events
@param inital_state: the inital state of DFSA (optional)
'''
assert events != None
self.__id = id(self)
self.__current_state_obj = None
self.__current_state = None
self.__origin_state = None
self.__origin_state_object = None
self.__events = {} # future use
self.onBeforeApplyState = Event()
self.onAfterApplyState = Event()
self.onStateChange = Event()
self.onBeforeEvent = Event()
self.onAfterEvent = Event()
self.onCanMove = Event()
self.__register_events(events)
self.__resolve_inital_state(inital_state)
# @Requires(DFSAEvent)
def __apply_state(self, event):
"""
applying state
@raise StateError: when event.destination state is
not applicable from the current_state
"""
if self.can_move(event):
self.onBeforeApplyState.fire(
event=event,
source=self.get_current_state(),
destination=event.get_destination()
)
self.onStateChange.fire(
event=event,
source=self.get_current_state(),
destination=event.get_destination()
)
old_state = self.get_current_state()
self.__origin_state_object = self.__current_state_obj
self.__current_state_obj = event
self.__origin_state = self.__current_state
self.__current_state = event.get_destination()
self.onAfterApplyState.fire(
event=event,
source=old_state,
destination=self.get_current_state()
)
else:
self.__raise_state_error(event)
@Requires([DFSAEvent])
def __register_events(self, events):
"""
registers events
@param events: the list of events to register
"""
self.__events = {}
for event in events:
self.__do_add_event(event)
# @Requires(DFSAEvent)
def __produce_event_method(self, event):
"""
produces event method
@param eevent: event for which the method should
be procured
"""
def event_method(**kwargs):
if self.get_current_state() != event.get_destination():
self.onBeforeEvent.fire(event=event)
self.__apply_state(event)
if event.get_callbacks():
for callback in event.get_callbacks():
# TODO: consider passing all **kwargs
callback(event=event)
self.onAfterEvent.fire(event=event)
else:
return
return event_method
# @Requires(DFSAEvent)
def __raise_state_error(self, event):
"""
@raise StateError: when event.destination state is
not applicable from the current_state
"""
raise StateError(
destination=event,
current=self.get_current_state()
)
def __raise_unknown_event(self, name):
"""
@raise UnknownEventError: when is not registered
"""
raise UnknownEventError(name=name)
# @Requires(DFSAEvent)
def __do_add_event(self, event):
"""
registers new event in DFSM
@param event: event to register
"""
self.__events[event.get_name()] = event
setattr(
self,
event.get_name(),
self.__produce_event_method(event)
)
# @Requires(types.StringType)
def __get_event(self, state):
name = str(DFSAState(state)).lower()
if name in self.__events.keys():
return self.__events[name]
self.__raise_unknown_event(name)
def __str__(self):
return 'FiniteStateMachine: %s, current state: %s' % (
str(self.__id),
DFSAState(self.get_current_state())
)
@Requires(DFSAEvent)
def add_event(self, event):
"""
adds or overrides DFSAEvent event to/in DFSA
@param event: the DFSAEvent to add/override
"""
self.__do_add_event(event)
# @Requires(types.StringType, types.MethodType)
def add_callback(self, state, callback):
"""
adds new callback to event
@param state: the state to which you would
like to add a callback
@param callback: the method to register
"""
self.__get_event(state) \
.get_callbacks() \
.append(callback)
def get_current_state(self):
"""
@return: the current State of DFSA
"""
return self.__current_state
def get_origin_state(self):
"""
@return: the origin State of DFSA
"""
return self.__origin_state
def get_origin_state_event(self):
"""
@return: the origin State of DFSA
"""
return self.__origin_state_object
@Requires(DFSAEvent)
def can_move(self, event):
"""
checks if DFSA can move to the given event.destination
@param event: the destination DFSAEvent
"""
if not self.__current_state_obj:
result = True # can happen during init only!
# TODO: consider restricting this behavior
else:
result = self.__current_state in event.get_sources()
self.onCanMove.fire(
event=event,
source=self.get_current_state(),
destination=event.get_destination(),
result=result
)
return result
def rollback(self):
"""
performs a rollback to the origin state
"""
self.__apply_state(self.get_origin_state_event())
def __resolve_inital_state(self, inital_state):
"""
resolves initial state of DFSA
if user has defined same state as default one and DFSA can move to it -
it will be used, otherwise default state will be set as a initial.
"""
if self.__events.has_key(inital_state.get_name()) and \
self.can_move(inital_state):
self.__apply_state(
self.__events.get(
inital_state.get_name()
)
)
else:
self.__apply_state(inital_state)
def __init__(self, events, inital_state=DFSAEvent(
name='disconnected',
sources=[],
destination=DFSAState.DISCONNECTED,
description='init'
)
):
'''
@param events: the list of DFSA events
@param inital_state: the inital state of DFSA (optional)
'''
assert events != None
self.__id = id(self)
self.__current_state_obj = None
self.__current_state = None
self.__origin_state = None
self.__origin_state_object = None
self.__events = {} # future use
self.onBeforeApplyState = Event()
self.onAfterApplyState = Event()
self.onStateChange = Event()
self.onBeforeEvent = Event()
self.onAfterEvent = Event()
self.onCanMove = Event()
self.__register_events(events)
self.__resolve_inital_state(inital_state)
class EngineShell(
cmd.Cmd,
ConnectCmdShell,
ActionCmdShell,
ShowCmdShell,
ListCmdShell,
UpdateCmdShell,
RemoveCmdShell,
AddCmdShell,
DisconnectCmdShell,
ConsoleCmdShell,
PingCmdShell,
StatusCmdShell,
ClearCmdShell,
FileCmdShell,
HistoryCmdShell,
InfoCmdShell,
SummaryCmdShell,
CapabilitiesCmdShell,
):
OFF_LINE_CONTENT = [ConnectCmdShell.NAME, HelpCommand.name, "exit", "EOF"]
############################# INIT #################################
def __init__(self, context, completekey="tab", stdin=None, stdout=None):
cmd.Cmd.__init__(self, completekey=completekey, stdin=stdin, stdout=stdout)
ConnectCmdShell.__init__(self, context)
ActionCmdShell.__init__(self, context)
ShowCmdShell.__init__(self, context)
ListCmdShell.__init__(self, context)
UpdateCmdShell.__init__(self, context)
RemoveCmdShell.__init__(self, context)
AddCmdShell.__init__(self, context)
DisconnectCmdShell.__init__(self, context)
ConsoleCmdShell.__init__(self, context)
PingCmdShell.__init__(self, context)
StatusCmdShell.__init__(self, context)
ClearCmdShell.__init__(self, context)
FileCmdShell.__init__(self, context)
HistoryCmdShell.__init__(self, context)
InfoCmdShell.__init__(self, context)
SummaryCmdShell.__init__(self, context)
CapabilitiesCmdShell.__init__(self, context)
self.__last_output = ""
self.__input_buffer = ""
self.__last_status = -1
self.onError = Event() # triggered when error occurs
self.onInit = Event() # triggered on init()
self.onExit = Event() # triggered on exit
self.onPromptChange = Event() # triggered onPromptChange
self.onSigInt = Event() # triggered on SigInt fault
self.__prompt_manager = PromptManager(self)
self.__register_sys_listeners()
self.__register_dfsm_callbacks()
self.__init_promt()
cmd.Cmd.doc_header = self.context.settings.get("ovirt-shell:commands")
cmd.Cmd.undoc_header = self.context.settings.get("ovirt-shell:misc_commands")
cmd.Cmd.intro = self.__get_intro()
readline.set_completer_delims(" ")
signal.signal(signal.SIGINT, self.__handler)
self.onInit.fire()
############################ SHELL ##################################
def cmdloop(self, intro=None, clear=True):
try:
if clear:
self.do_clear("")
return cmd.Cmd.cmdloop(self, intro)
except KeyboardInterrupt:
return self.cmdloop(intro="^C", clear=False)
except Exception, e:
self._error(str(e))
return self.cmdloop(intro, clear=False)
class EngineShell(cmd.Cmd, ConnectCmdShell, ActionCmdShell, \
ShowCmdShell, ListCmdShell, UpdateCmdShell, \
RemoveCmdShell, AddCmdShell, DisconnectCmdShell, \
ConsoleCmdShell, PingCmdShell, StatusCmdShell, \
ClearCmdShell, FileCmdShell, HistoryCmdShell, \
InfoCmdShell, SummaryCmdShell, CapabilitiesCmdShell):
OFF_LINE_CONTENT = [ConnectCmdShell.NAME, HelpCommand.name, 'exit', "EOF"]
############################# INIT #################################
def __init__(self, context, completekey='tab', stdin=None, stdout=None):
cmd.Cmd.__init__(self,
completekey=completekey,
stdin=stdin,
stdout=stdout)
ConnectCmdShell.__init__(self, context)
ActionCmdShell.__init__(self, context)
ShowCmdShell.__init__(self, context)
ListCmdShell.__init__(self, context)
UpdateCmdShell.__init__(self, context)
RemoveCmdShell.__init__(self, context)
AddCmdShell.__init__(self, context)
DisconnectCmdShell.__init__(self, context)
ConsoleCmdShell.__init__(self, context)
PingCmdShell.__init__(self, context)
StatusCmdShell.__init__(self, context)
ClearCmdShell.__init__(self, context)
FileCmdShell.__init__(self, context)
HistoryCmdShell.__init__(self, context)
InfoCmdShell.__init__(self, context)
SummaryCmdShell.__init__(self, context)
CapabilitiesCmdShell.__init__(self, context)
self.__last_output = ''
self.__input_buffer = ''
self.__last_status = -1
self.onError = Event() # triggered when error occurs
self.onInit = Event() # triggered on init()
self.onExit = Event() # triggered on exit
self.onPromptChange = Event() # triggered onPromptChange
self.onSigInt = Event() # triggered on SigInt fault
self.__prompt_manager = PromptManager(self)
self.__register_sys_listeners()
self.__register_dfsm_callbacks()
self.__init_promt()
cmd.Cmd.doc_header = self.context.settings.get('ovirt-shell:commands')
cmd.Cmd.undoc_header = self.context.settings.get(
'ovirt-shell:misc_commands')
cmd.Cmd.intro = self.__get_intro()
readline.set_completer_delims(' ')
signal.signal(signal.SIGINT, self.__handler)
self.onInit.fire()
############################ SHELL ##################################
def cmdloop(self, intro=None, clear=True):
try:
if clear: self.do_clear('')
return cmd.Cmd.cmdloop(self, intro)
except KeyboardInterrupt:
return self.cmdloop(intro="^C", clear=False)
except Exception, e:
self._error(str(e))
return self.cmdloop(intro, clear=False)
