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authorTom Nichols <tmnichols@gmail.com>2010-06-08 10:40:15 -0400
committerTom Nichols <tmnichols@gmail.com>2010-06-08 10:40:15 -0400
commit4fccd77685b73f7cf750fb761ca2714a88caec91 (patch)
treebf856b56b5569de82d2807487130321039b75b4a /sleekxmpp/xmlstream
parent77bff9cce7deff133017c3aa2c36ff121adfd544 (diff)
parent34dc236126d272a16df0915b010dca0e2e38f0d4 (diff)
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Merge branch 'hacks' of git@github.com:tomstrummer/SleekXMPP into hacks
Diffstat (limited to 'sleekxmpp/xmlstream')
-rw-r--r--sleekxmpp/xmlstream/scheduler.py2
-rw-r--r--sleekxmpp/xmlstream/statemachine.py152
-rw-r--r--sleekxmpp/xmlstream/xmlstream.py63
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]