diff options
Diffstat (limited to 'sleekxmpp/xmlstream')
| -rw-r--r-- | sleekxmpp/xmlstream/scheduler.py | 2 | ||||
| -rw-r--r-- | sleekxmpp/xmlstream/statemachine.py | 152 | ||||
| -rw-r--r-- | sleekxmpp/xmlstream/xmlstream.py | 63 |
3 files changed, 178 insertions, 39 deletions
diff --git a/sleekxmpp/xmlstream/scheduler.py b/sleekxmpp/xmlstream/scheduler.py index 945d9fad..40aaf695 100644 --- a/sleekxmpp/xmlstream/scheduler.py +++ b/sleekxmpp/xmlstream/scheduler.py @@ -76,7 +76,7 @@ class Scheduler(object): if updated: self.schedule = sorted(self.schedule, key=lambda task: task.next) except KeyboardInterrupt: self.run = False - logging.debug("Qutting Scheduler thread") + logging.debug("Quitting Scheduler thread") if self.parentqueue is not None: self.parentqueue.put(('quit', None, None)) diff --git a/sleekxmpp/xmlstream/statemachine.py b/sleekxmpp/xmlstream/statemachine.py index c5f51765..c6e0ea41 100644 --- a/sleekxmpp/xmlstream/statemachine.py +++ b/sleekxmpp/xmlstream/statemachine.py @@ -10,6 +10,7 @@ import threading import time import logging + class StateMachine(object): def __init__(self, states=[]): @@ -27,7 +28,7 @@ class StateMachine(object): self.__states.append( state ) - def transition(self, from_state, to_state, wait=0.0): + def transition(self, from_state, to_state, wait=0.0, func=None, args=[], kwargs={} ): ''' Transition from the given `from_state` to the given `to_state`. This method will return `True` if the state machine is now in `to_state`. It @@ -47,25 +48,37 @@ class StateMachine(object): if thread_should_exit: return # perform actions here after successful transition - This allows the thread to be interrupted by setting `thread_should_exit=True` + This allows the thread to be responsive by setting `thread_should_exit=True`. + + The optional `func` argument allows the user to pass a callable operation which occurs + within the context of the state transition (e.g. while the state machine is locked.) + If `func` returns a True value, the transition will occur. If `func` returns a non- + True value or if an exception is thrown, the transition will not occur. Any thrown + exception is not caught by the state machine and is the caller's responsibility to handle. + If `func` completes normally, this method will return the value returned by `func.` If + values for `args` and `kwargs` are provided, they are expanded and passed like so: + `func( *args, **kwargs )`. ''' - return self.transition_any( (from_state,), to_state, wait=wait ) + return self.transition_any( (from_state,), to_state, wait=wait, + func=func, args=args, kwargs=kwargs ) + - def transition_any(self, from_states, to_state, wait=0.0): + def transition_any(self, from_states, to_state, wait=0.0, func=None, args=[], kwargs={} ): ''' Transition from any of the given `from_states` to the given `to_state`. ''' - with self.lock: - for state in from_states: - if isinstance(state,tuple) or isinstance(state,list): - raise ValueError( "State %s should be a string. Did you mean to call 'StateMachine.transition_any()?" % str(state) ) - if not state in self.__states: - raise ValueError( "StateMachine does not contain from_state %s." % state ) - if not to_state in self.__states: - raise ValueError( "StateMachine does not contain to_state %s." % to_state ) + if not (isinstance(from_states,tuple) or isinstance(from_states,list)): + raise ValueError( "from_states should be a list or tuple" ) + + for state in from_states: + if not state in self.__states: + raise ValueError( "StateMachine does not contain from_state %s." % state ) + if not to_state in self.__states: + raise ValueError( "StateMachine does not contain to_state %s." % to_state ) + with self.lock: start = time.time() while not self.__current_state in from_states: # detect timeout: @@ -73,32 +86,78 @@ class StateMachine(object): self.lock.wait(wait) if self.__current_state in from_states: # should always be True due to lock + + return_val = True + # Note that func might throw an exception, but that's OK, it aborts the transition + if func is not None: return_val = func(*args,**kwargs) + + # some 'false' value returned from func, + # indicating that transition should not occur: + if not return_val: return return_val + logging.debug(' ==== TRANSITION %s -> %s', self.__current_state, to_state) self.__current_state = to_state self.lock.notifyAll() - return True + return return_val # some 'true' value returned by func or True if func was None else: logging.error( "StateMachine bug!! The lock should ensure this doesn't happen!" ) return False + def transition_ctx(self, from_state, to_state, wait=0.0): + ''' + Use the state machine as a context manager. The transition occurs on /exit/ from + the `with` context, so long as no exception is thrown. For example: + + :: + + with state_machine.transition_ctx('one','two', wait=5) as locked: + if locked: + # the state machine is currently locked in state 'one', and will + # transition to 'two' when the 'with' statement ends, so long as + # no exception is thrown. + print 'Currently locked in state one: %s' % state_machine['one'] + + else: + # The 'wait' timed out, and no lock has been acquired + print 'Timed out before entering state "one"' + + print 'Since no exception was thrown, we are now in state "two": %s' % state_machine['two'] + + + The other main difference between this method and `transition()` is that the + state machine is locked for the duration of the `with` statement (normally, + after a `transition() occurs, the state machine is immediately unlocked and + available to another thread to call `transition()` again. + ''' + + if not from_state in self.__states: + raise ValueError( "StateMachine does not contain from_state %s." % state ) + if not to_state in self.__states: + raise ValueError( "StateMachine does not contain to_state %s." % to_state ) + + return _StateCtx(self, from_state, to_state, wait) + + def ensure(self, state, wait=0.0): ''' Ensure the state machine is currently in `state`, or wait until it enters `state`. ''' return self.ensure_any( (state,), wait=wait ) + def ensure_any(self, states, wait=0.0): ''' Ensure we are currently in one of the given `states` ''' - with self.lock: - for state in states: - if isinstance(state,tuple) or isinstance(state,list): - raise ValueError( "State %s should be a string. Did you mean to call 'StateMachine.transition_any()?" % str(state) ) - if not state in self.__states: - raise ValueError( "StateMachine does not contain state %s." % state ) + if not (isinstance(states,tuple) or isinstance(states,list)): + raise ValueError('states arg should be a tuple or list') + for state in states: + if not state in self.__states: + raise ValueError( "StateMachine does not contain state '%s'" % state ) + + with self.lock: start = time.time() while not self.__current_state in states: # detect timeout: @@ -110,7 +169,19 @@ class StateMachine(object): def reset(self): # TODO need to lock before calling this? self.transition(self.__current_state, self._default_state) - + + + def _set_state(self, state): #unsynchronized, only call internally after lock is acquired + self.__current_state = state + return state + + + def current_state(self): + ''' + Return the current state name. + ''' + return self.__current_state + def __getitem__(self, state): ''' @@ -118,13 +189,46 @@ class StateMachine(object): Use `StateMachine.ensure(state)` to wait until the machine enters a certain state. ''' return self.__current_state == state + + def __str__(self): + return "".join(( "StateMachine(", ','.join(self.__states), "): ", self.__current_state )) + + +class _StateCtx: + + def __init__( self, state_machine, from_state, to_state, wait ): + self.state_machine = state_machine + self.from_state = from_state + self.to_state = to_state + self.wait = wait + self._timeout = False + def __enter__(self): - self.lock.acquire() - return self + self.state_machine.lock.acquire() + start = time.time() + while not self.state_machine[ self.from_state ]: + # detect timeout: + if time.time() >= start + self.wait: + logging.debug('StateMachine timeout while waiting for state: %s', self.from_state ) + self._timeout = True # to indicate we should not transition + return False + self.state_machine.lock.wait(self.wait) + + logging.debug('StateMachine entered context in state: %s', + self.state_machine.current_state() ) + return True def __exit__(self, exc_type, exc_val, exc_tb): - self.lock.nofityAll() - self.lock.release() + if exc_val is not None: + logging.exception( "StateMachine exception in context, remaining in state: %s\n%s:%s", + self.state_machine.current_state(), exc_type.__name__, exc_val ) + elif not self._timeout: + logging.debug(' ==== TRANSITION %s -> %s', + self.state_machine.current_state(), self.to_state) + self.state_machine._set_state( self.to_state ) + + self.state_machine.lock.notifyAll() + self.state_machine.lock.release() return False # re-raise any exception diff --git a/sleekxmpp/xmlstream/xmlstream.py b/sleekxmpp/xmlstream/xmlstream.py index 3bcb3412..6dbe7b30 100644 --- a/sleekxmpp/xmlstream/xmlstream.py +++ b/sleekxmpp/xmlstream/xmlstream.py @@ -16,6 +16,7 @@ from . stanzabase import StanzaBase from xml.etree import cElementTree from xml.parsers import expat import logging +import random import socket import threading import time @@ -46,6 +47,10 @@ class CloseStream(Exception): stanza_extensions = {} +RECONNECT_MAX_DELAY = 3600 +RECONNECT_QUIESCE_FACTOR = 1.6180339887498948 # Phi +RECONNECT_QUIESCE_JITTER = 0.11962656472 # molar Planck constant times c, joule meter/mole + class XMLStream(object): "A connection manager with XML events." @@ -95,13 +100,29 @@ class XMLStream(object): self.filesocket = filesocket def connect(self, host='', port=0, use_ssl=None, use_tls=None): - "Link to connectTCP" - if self.state.transition('disconnected', 'connecting'): - return self.connectTCP(host, port, use_ssl, use_tls) + "Establish a socket connection to the given XMPP server." + + if not self.state.transition('disconnected','connected', + func=self.connectTCP, args=[host, port, use_ssl, use_tls] ): + + if self.state['connected']: logging.debug('Already connected') + else: logging.warning("Connection failed" ) + return False + + logging.debug('Connection complete.') + return True + + # TODO currently a caller can't distinguish between "connection failed" and + # "we're already trying to connect from another thread" def connectTCP(self, host='', port=0, use_ssl=None, use_tls=None, reattempt=True): "Connect and create socket" - while reattempt and not self.state['connected']: # the self.state part is redundant. + + # Note that this is thread-safe by merit of being called solely from connect() which + # holds the state lock. + + delay = 1.0 # reconnection delay + while self.run: logging.debug('connecting....') try: if host and port: @@ -109,27 +130,39 @@ class XMLStream(object): if use_ssl is not None: self.use_ssl = use_ssl if use_tls is not None: + # TODO this variable doesn't seem to be used for anything! self.use_tls = use_tls if sys.version_info < (3, 0): self.socket = filesocket.Socket26(socket.AF_INET, socket.SOCK_STREAM) else: self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) self.socket.settimeout(None) #10) + if self.use_ssl and self.ssl_support: logging.debug("Socket Wrapped for SSL") self.socket = ssl.wrap_socket(self.socket,ca_certs=self.ca_certs) - except: - logging.exception("Connection error") - try: + self.socket.connect(self.address) self.filesocket = self.socket.makefile('rb', 0) - if not self.state.transition('connecting','connected'): - logging.error( "State transition error!!!! Shouldn't have happened" ) - logging.debug('connect complete.') + return True + except socket.error as serr: - logging.error("Could not connect. Socket Error #%s: %s" % (serr.errno, serr.strerror)) - time.sleep(1) # TODO proper quiesce if connection attempt fails + logging.exception("Socket Error #%s: %s", serr.errno, serr.strerror) + if not reattempt: return False + except: + logging.exception("Connection error") + if not reattempt: return False + + # quiesce if rconnection fails: + # This algorithm based loosely on Twisted internet.protocol + # http://twistedmatrix.com/trac/browser/trunk/twisted/internet/protocol.py#L310 + delay = min(delay * RECONNECT_QUIESCE_FACTOR, RECONNECT_MAX_DELAY) + delay = random.normalvariate(delay, delay * RECONNECT_QUIESCE_JITTER) + logging.debug('Waiting %fs until next reconnect attempt...', delay) + time.sleep(delay) + + def connectUnix(self, filepath): "Connect to Unix file and create socket" @@ -244,11 +277,12 @@ class XMLStream(object): data = None try: - data = self.sendqueue.get(True,10) + data = self.sendqueue.get(True,5) logging.debug("SEND: %s" % data) self.socket.sendall(data.encode('utf-8')) except queue.Empty: - logging.debug('nothing on send queue') +# logging.debug('Nothing on send queue') + pass except socket.timeout: # this is to prevent a thread blocked indefinitely logging.debug('timeout sending packet data') @@ -335,6 +369,7 @@ class XMLStream(object): try: event = self.eventqueue.get(True, timeout=5) except queue.Empty: +# logging.debug('Nothing on event queue') event = None if event is not None: etype = event[0] |