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deb-python-autobahn/autobahn/twisted/wamp.py

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###############################################################################
#
# The MIT License (MIT)
#
# Copyright (c) Crossbar.io Technologies GmbH
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#
###############################################################################
from __future__ import absolute_import
import six
import inspect
import txaio
txaio.use_twisted() # noqa
from twisted.internet.defer import inlineCallbacks
from autobahn.websocket.util import parse_url as parse_ws_url
from autobahn.rawsocket.util import parse_url as parse_rs_url
from autobahn.twisted.websocket import WampWebSocketClientFactory
from autobahn.twisted.rawsocket import WampRawSocketClientFactory
from autobahn.websocket.compress import PerMessageDeflateOffer, \
PerMessageDeflateResponse, PerMessageDeflateResponseAccept
from autobahn.wamp import protocol
from autobahn.wamp.types import ComponentConfig
__all__ = [
'ApplicationSession',
'ApplicationSessionFactory',
'ApplicationRunner',
'Application',
'Service',
# new API
'Session'
]
try:
from twisted.application import service
except (ImportError, SyntaxError):
# Not on PY3 yet
service = None
__all__.pop(__all__.index('Service'))
class ApplicationSession(protocol.ApplicationSession):
"""
WAMP application session for Twisted-based applications.
"""
class ApplicationSessionFactory(protocol.ApplicationSessionFactory):
"""
WAMP application session factory for Twisted-based applications.
"""
session = ApplicationSession
"""
The application session class this application session factory will use. Defaults to :class:`autobahn.twisted.wamp.ApplicationSession`.
"""
class ApplicationRunner(object):
"""
This class is a convenience tool mainly for development and quick hosting
of WAMP application components.
It can host a WAMP application component in a WAMP-over-WebSocket client
connecting to a WAMP router.
"""
log = txaio.make_logger()
def __init__(self, url, realm, extra=None, serializers=None, ssl=None, proxy=None, headers=None):
"""
:param url: The WebSocket URL of the WAMP router to connect to (e.g. `ws://somehost.com:8090/somepath`)
:type url: unicode
:param realm: The WAMP realm to join the application session to.
:type realm: unicode
:param extra: Optional extra configuration to forward to the application component.
:type extra: dict
:param serializers: A list of WAMP serializers to use (or None for default serializers).
Serializers must implement :class:`autobahn.wamp.interfaces.ISerializer`.
:type serializers: list
:param ssl: (Optional). If specified this should be an
instance suitable to pass as ``sslContextFactory`` to
:class:`twisted.internet.endpoints.SSL4ClientEndpoint`` such
as :class:`twisted.internet.ssl.CertificateOptions`. Leaving
it as ``None`` will use the result of calling Twisted's
:meth:`twisted.internet.ssl.platformTrust` which tries to use
your distribution's CA certificates.
:type ssl: :class:`twisted.internet.ssl.CertificateOptions`
:param proxy: Explicit proxy server to use; a dict with ``host`` and ``port`` keys
:type proxy: dict or None
"""
assert(type(url) == six.text_type)
assert(realm is None or type(realm) == six.text_type)
assert(extra is None or type(extra) == dict)
assert(proxy is None or type(proxy) == dict)
self.url = url
self.realm = realm
self.extra = extra or dict()
self.serializers = serializers
self.ssl = ssl
self.proxy = proxy
self.headers = headers
def run(self, make, start_reactor=True, auto_reconnect=False, log_level='info'):
"""
Run the application component.
:param make: A factory that produces instances of :class:`autobahn.asyncio.wamp.ApplicationSession`
when called with an instance of :class:`autobahn.wamp.types.ComponentConfig`.
:type make: callable
:param start_reactor: if True (the default) this method starts
the Twisted reactor and doesn't return until the reactor
stops. If there are any problems starting the reactor or
connect()-ing, we stop the reactor and raise the exception
back to the caller.
:returns: None is returned, unless you specify
``start_reactor=False`` in which case the Deferred that
connect() returns is returned; this will callback() with
an IProtocol instance, which will actually be an instance
of :class:`WampWebSocketClientProtocol`
"""
if start_reactor:
# only select framework, set loop and start logging when we are asked
# start the reactor - otherwise we are running in a program that likely
# already tool care of all this.
from twisted.internet import reactor
txaio.use_twisted()
txaio.config.loop = reactor
txaio.start_logging(level=log_level)
if callable(make):
# factory for use ApplicationSession
def create():
cfg = ComponentConfig(self.realm, self.extra)
try:
session = make(cfg)
except Exception:
self.log.failure('ApplicationSession could not be instantiated: {log_failure.value}')
if start_reactor and reactor.running:
reactor.stop()
raise
else:
return session
else:
create = make
if self.url.startswith(u'rs'):
# try to parse RawSocket URL ..
isSecure, host, port = parse_rs_url(self.url)
# create a WAMP-over-RawSocket transport client factory
transport_factory = WampRawSocketClientFactory(create)
else:
# try to parse WebSocket URL ..
isSecure, host, port, resource, path, params = parse_ws_url(self.url)
# create a WAMP-over-WebSocket transport client factory
transport_factory = WampWebSocketClientFactory(create, url=self.url, serializers=self.serializers, proxy=self.proxy, headers=self.headers)
# client WebSocket settings - similar to:
# - http://crossbar.io/docs/WebSocket-Compression/#production-settings
# - http://crossbar.io/docs/WebSocket-Options/#production-settings
# The permessage-deflate extensions offered to the server ..
offers = [PerMessageDeflateOffer()]
# Function to accept permessage_delate responses from the server ..
def accept(response):
if isinstance(response, PerMessageDeflateResponse):
return PerMessageDeflateResponseAccept(response)
# set WebSocket options for all client connections
transport_factory.setProtocolOptions(maxFramePayloadSize=1048576,
maxMessagePayloadSize=1048576,
autoFragmentSize=65536,
failByDrop=False,
openHandshakeTimeout=2.5,
closeHandshakeTimeout=1.,
tcpNoDelay=True,
autoPingInterval=10.,
autoPingTimeout=5.,
autoPingSize=4,
perMessageCompressionOffers=offers,
perMessageCompressionAccept=accept)
# supress pointless log noise
transport_factory.noisy = False
# if user passed ssl= but isn't using isSecure, we'll never
# use the ssl argument which makes no sense.
context_factory = None
if self.ssl is not None:
if not isSecure:
raise RuntimeError(
'ssl= argument value passed to %s conflicts with the "ws:" '
'prefix of the url argument. Did you mean to use "wss:"?' %
self.__class__.__name__)
context_factory = self.ssl
elif isSecure:
from twisted.internet.ssl import optionsForClientTLS
context_factory = optionsForClientTLS(host)
from twisted.internet import reactor
if self.proxy is not None:
from twisted.internet.endpoints import TCP4ClientEndpoint
client = TCP4ClientEndpoint(reactor, self.proxy['host'], self.proxy['port'])
transport_factory.contextFactory = context_factory
elif isSecure:
from twisted.internet.endpoints import SSL4ClientEndpoint
assert context_factory is not None
client = SSL4ClientEndpoint(reactor, host, port, context_factory)
else:
from twisted.internet.endpoints import TCP4ClientEndpoint
client = TCP4ClientEndpoint(reactor, host, port)
# as the reactor shuts down, we wish to wait until we've sent
# out our "Goodbye" message; leave() returns a Deferred that
# fires when the transport gets to STATE_CLOSED
def cleanup(proto):
if hasattr(proto, '_session') and proto._session is not None:
if proto._session.is_attached():
return proto._session.leave()
elif proto._session.is_connected():
return proto._session.disconnect()
# when our proto was created and connected, make sure it's cleaned
# up properly later on when the reactor shuts down for whatever reason
def init_proto(proto):
reactor.addSystemEventTrigger('before', 'shutdown', cleanup, proto)
return proto
use_service = False
if auto_reconnect:
try:
# since Twisted 16.1.0
from twisted.application.internet import ClientService
use_service = True
except ImportError:
use_service = False
if use_service:
self.log.debug('using t.a.i.ClientService')
# this is automatically reconnecting
service = ClientService(client, transport_factory)
service.startService()
d = service.whenConnected()
else:
# this is only connecting once!
self.log.debug('using t.i.e.connect()')
d = client.connect(transport_factory)
# if we connect successfully, the arg is a WampWebSocketClientProtocol
d.addCallback(init_proto)
# if the user didn't ask us to start the reactor, then they
# get to deal with any connect errors themselves.
if start_reactor:
# if an error happens in the connect(), we save the underlying
# exception so that after the event-loop exits we can re-raise
# it to the caller.
class ErrorCollector(object):
exception = None
def __call__(self, failure):
self.exception = failure.value
reactor.stop()
connect_error = ErrorCollector()
d.addErrback(connect_error)
# now enter the Twisted reactor loop
reactor.run()
# if we exited due to a connection error, raise that to the
# caller
if connect_error.exception:
raise connect_error.exception
else:
# let the caller handle any errors
return d
class _ApplicationSession(ApplicationSession):
"""
WAMP application session class used internally with :class:`autobahn.twisted.app.Application`.
"""
def __init__(self, config, app):
"""
:param config: The component configuration.
:type config: Instance of :class:`autobahn.wamp.types.ComponentConfig`
:param app: The application this session is for.
:type app: Instance of :class:`autobahn.twisted.wamp.Application`.
"""
# noinspection PyArgumentList
ApplicationSession.__init__(self, config)
self.app = app
@inlineCallbacks
def onConnect(self):
"""
Implements :func:`autobahn.wamp.interfaces.ISession.onConnect`
"""
yield self.app._fire_signal('onconnect')
self.join(self.config.realm)
@inlineCallbacks
def onJoin(self, details):
"""
Implements :func:`autobahn.wamp.interfaces.ISession.onJoin`
"""
for uri, proc in self.app._procs:
yield self.register(proc, uri)
for uri, handler in self.app._handlers:
yield self.subscribe(handler, uri)
yield self.app._fire_signal('onjoined')
@inlineCallbacks
def onLeave(self, details):
"""
Implements :func:`autobahn.wamp.interfaces.ISession.onLeave`
"""
yield self.app._fire_signal('onleave')
self.disconnect()
@inlineCallbacks
def onDisconnect(self):
"""
Implements :func:`autobahn.wamp.interfaces.ISession.onDisconnect`
"""
yield self.app._fire_signal('ondisconnect')
class Application(object):
"""
A WAMP application. The application object provides a simple way of
creating, debugging and running WAMP application components.
"""
log = txaio.make_logger()
def __init__(self, prefix=None):
"""
:param prefix: The application URI prefix to use for procedures and topics,
e.g. ``"com.example.myapp"``.
:type prefix: unicode
"""
self._prefix = prefix
# procedures to be registered once the app session has joined the router/realm
self._procs = []
# event handler to be subscribed once the app session has joined the router/realm
self._handlers = []
# app lifecycle signal handlers
self._signals = {}
# once an app session is connected, this will be here
self.session = None
def __call__(self, config):
"""
Factory creating a WAMP application session for the application.
:param config: Component configuration.
:type config: Instance of :class:`autobahn.wamp.types.ComponentConfig`
:returns: obj -- An object that derives of
:class:`autobahn.twisted.wamp.ApplicationSession`
"""
assert(self.session is None)
self.session = _ApplicationSession(config, self)
return self.session
def run(self, url=u"ws://localhost:8080/ws", realm=u"realm1", start_reactor=True):
"""
Run the application.
:param url: The URL of the WAMP router to connect to.
:type url: unicode
:param realm: The realm on the WAMP router to join.
:type realm: unicode
"""
runner = ApplicationRunner(url, realm)
return runner.run(self.__call__, start_reactor)
def register(self, uri=None):
"""
Decorator exposing a function as a remote callable procedure.
The first argument of the decorator should be the URI of the procedure
to register under.
:Example:
.. code-block:: python
@app.register('com.myapp.add2')
def add2(a, b):
return a + b
Above function can then be called remotely over WAMP using the URI `com.myapp.add2`
the function was registered under.
If no URI is given, the URI is constructed from the application URI prefix
and the Python function name.
:Example:
.. code-block:: python
app = Application('com.myapp')
# implicit URI will be 'com.myapp.add2'
@app.register()
def add2(a, b):
return a + b
If the function `yields` (is a co-routine), the `@inlineCallbacks` decorator
will be applied automatically to it. In that case, if you wish to return something,
you should use `returnValue`:
:Example:
.. code-block:: python
from twisted.internet.defer import returnValue
@app.register('com.myapp.add2')
def add2(a, b):
res = yield stuff(a, b)
returnValue(res)
:param uri: The URI of the procedure to register under.
:type uri: unicode
"""
def decorator(func):
if uri:
_uri = uri
else:
assert(self._prefix is not None)
_uri = "{0}.{1}".format(self._prefix, func.__name__)
if inspect.isgeneratorfunction(func):
func = inlineCallbacks(func)
self._procs.append((_uri, func))
return func
return decorator
def subscribe(self, uri=None):
"""
Decorator attaching a function as an event handler.
The first argument of the decorator should be the URI of the topic
to subscribe to. If no URI is given, the URI is constructed from
the application URI prefix and the Python function name.
If the function yield, it will be assumed that it's an asynchronous
process and inlineCallbacks will be applied to it.
:Example:
.. code-block:: python
@app.subscribe('com.myapp.topic1')
def onevent1(x, y):
print("got event on topic1", x, y)
:param uri: The URI of the topic to subscribe to.
:type uri: unicode
"""
def decorator(func):
if uri:
_uri = uri
else:
assert(self._prefix is not None)
_uri = "{0}.{1}".format(self._prefix, func.__name__)
if inspect.isgeneratorfunction(func):
func = inlineCallbacks(func)
self._handlers.append((_uri, func))
return func
return decorator
def signal(self, name):
"""
Decorator attaching a function as handler for application signals.
Signals are local events triggered internally and exposed to the
developer to be able to react to the application lifecycle.
If the function yield, it will be assumed that it's an asynchronous
coroutine and inlineCallbacks will be applied to it.
Current signals :
- `onjoined`: Triggered after the application session has joined the
realm on the router and registered/subscribed all procedures
and event handlers that were setup via decorators.
- `onleave`: Triggered when the application session leaves the realm.
.. code-block:: python
@app.signal('onjoined')
def _():
# do after the app has join a realm
:param name: The name of the signal to watch.
:type name: unicode
"""
def decorator(func):
if inspect.isgeneratorfunction(func):
func = inlineCallbacks(func)
self._signals.setdefault(name, []).append(func)
return func
return decorator
@inlineCallbacks
def _fire_signal(self, name, *args, **kwargs):
"""
Utility method to call all signal handlers for a given signal.
:param name: The signal name.
:type name: str
"""
for handler in self._signals.get(name, []):
try:
# FIXME: what if the signal handler is not a coroutine?
# Why run signal handlers synchronously?
yield handler(*args, **kwargs)
except Exception as e:
# FIXME
self.log.info("Warning: exception in signal handler swallowed: {err}", err=e)
if service:
# Don't define it if Twisted's service support isn't here
class Service(service.MultiService):
"""
A WAMP application as a twisted service.
The application object provides a simple way of creating, debugging and running WAMP application
components inside a traditional twisted application
This manages application lifecycle of the wamp connection using startService and stopService
Using services also allows to create integration tests that properly terminates their connections
It can host a WAMP application component in a WAMP-over-WebSocket client
connecting to a WAMP router.
"""
factory = WampWebSocketClientFactory
def __init__(self, url, realm, make, extra=None, context_factory=None):
"""
:param url: The WebSocket URL of the WAMP router to connect to (e.g. `ws://somehost.com:8090/somepath`)
:type url: unicode
:param realm: The WAMP realm to join the application session to.
:type realm: unicode
:param make: A factory that produces instances of :class:`autobahn.asyncio.wamp.ApplicationSession`
when called with an instance of :class:`autobahn.wamp.types.ComponentConfig`.
:type make: callable
:param extra: Optional extra configuration to forward to the application component.
:type extra: dict
:param context_factory: optional, only for secure connections. Passed as contextFactory to
the ``listenSSL()`` call; see https://twistedmatrix.com/documents/current/api/twisted.internet.interfaces.IReactorSSL.connectSSL.html
:type context_factory: twisted.internet.ssl.ClientContextFactory or None
You can replace the attribute factory in order to change connectionLost or connectionFailed behaviour.
The factory attribute must return a WampWebSocketClientFactory object
"""
self.url = url
self.realm = realm
self.extra = extra or dict()
self.make = make
self.context_factory = context_factory
service.MultiService.__init__(self)
self.setupService()
def setupService(self):
"""
Setup the application component.
"""
is_secure, host, port, resource, path, params = parse_ws_url(self.url)
# factory for use ApplicationSession
def create():
cfg = ComponentConfig(self.realm, self.extra)
session = self.make(cfg)
return session
# create a WAMP-over-WebSocket transport client factory
transport_factory = self.factory(create, url=self.url)
# setup the client from a Twisted endpoint
if is_secure:
from twisted.application.internet import SSLClient
ctx = self.context_factory
if ctx is None:
from twisted.internet.ssl import optionsForClientTLS
ctx = optionsForClientTLS(host)
client = SSLClient(host, port, transport_factory, contextFactory=ctx)
else:
if self.context_factory is not None:
raise Exception("context_factory specified on non-secure URI")
from twisted.application.internet import TCPClient
client = TCPClient(host, port, transport_factory)
client.setServiceParent(self)
# new API
class Session(ApplicationSession):
# shim that lets us present pep8 API for user-classes to override,
# but also backwards-compatible for existing code using
# ApplicationSession "directly".
# XXX note to self: if we release this as "the" API, then we can
# change all internal Autobahn calls to .on_join() etc, and make
# ApplicationSession a subclass of Session -- and it can then be
# separate deprecated and removed, ultimately, if desired.
def onJoin(self, details):
return self.on_join(details)
# XXX def onChallenge(self, )
# XXX def onOpen ??
def onLeave(self, details):
return self.on_leave(details)
def onDisconnect(self):
return self.on_disconnect()
def on_join(self, details):
pass
def on_leave(self, details):
self.disconnect()
def on_disconnect(self):
pass
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