root / ncclient / transport / session.py @ 65c6a607
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# Copyright 2009 Shikhar Bhushan
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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from threading import Event |
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from Queue import Queue |
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from ncclient.capabilities import Capabilities |
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from ncclient.glue import Subject |
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from hello import HelloHandler |
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import logging |
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logger = logging.getLogger('ncclient.transport.session')
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class Session(Thread): |
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"TODO: docstring"
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def __init__(self, capabilities): |
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"Subclass constructor should call this"
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Thread.__init__(self)
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self.setDaemon(True) |
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self._listeners = set() # TODO(?) weakref |
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self._lock = Lock()
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self.setName('session') |
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self._q = Queue()
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self._client_capabilities = capabilities
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self._server_capabilities = None # yet |
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self._id = None # session-id |
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self._connected = False # to be set/cleared by subclass implementation |
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logger.debug('%r created: client_capabilities=%r' %
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(self, self._client_capabilities)) |
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def _dispatch_message(self, raw): |
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"TODO: docstring"
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try:
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root = parse_root(raw) |
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except Exception as e: |
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logger.error('error parsing dispatch message: %s' % e)
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return
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with self._lock: |
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listeners = list(self._listeners) |
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for l in listeners: |
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logger.debug('dispatching message to %r' % l)
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try:
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l.callback(root, raw) |
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except Exception as e: |
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logger.warning('[error] %r' % e)
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def _dispatch_error(self, err): |
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"TODO: docstring"
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with self._lock: |
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listeners = list(self._listeners) |
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for l in listeners: |
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logger.debug('dispatching error to %r' % l)
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try:
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l.errback(err) |
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except Exception as e: |
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logger.warning('error %r' % e)
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def _post_connect(self): |
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"Greeting stuff"
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init_event = Event() |
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error = [None] # so that err_cb can bind error[0]. just how it is. |
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# callbacks
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def ok_cb(id, capabilities): |
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self._id = id |
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self._server_capabilities = Capabilities(capabilities)
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init_event.set() |
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def err_cb(err): |
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error[0] = err
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init_event.set() |
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listener = HelloHandler(ok_cb, err_cb) |
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self.add_listener(listener)
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self.send(HelloHandler.build(self._client_capabilities)) |
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logger.debug('starting main loop')
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self.start()
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# we expect server's hello message
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init_event.wait() |
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# received hello message or an error happened
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self.remove_listener(listener)
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if error[0]: |
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raise error[0] |
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logger.info('initialized: session-id=%s | server_capabilities=%s' %
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(self._id, self._server_capabilities)) |
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def add_listener(self, listener): |
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"TODO: docstring"
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logger.debug('installing listener %r' % listener)
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with self._lock: |
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self._listeners.add(listener)
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def remove_listener(self, listener): |
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"TODO: docstring"
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logger.debug('discarding listener %r' % listener)
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with self._lock: |
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self._listeners.discard(listener)
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def get_listener_instance(self, cls): |
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'''This is useful when we want to maintain one listener of a particular
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type per subject i.e. a multiton.
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'''
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with self._lock: |
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for listener in self._listeners: |
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if isinstance(listener, cls): |
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return listener
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def connect(self, *args, **kwds): |
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"Subclass implements"
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raise NotImplementedError |
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def run(self): |
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"Subclass implements"
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raise NotImplementedError |
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def send(self, message): |
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"TODO: docstring"
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logger.debug('queueing %s' % message)
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self._q.put(message)
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### Properties
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@property
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def client_capabilities(self): |
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return self._client_capabilities |
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@property
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def server_capabilities(self): |
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return self._server_capabilities |
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@property
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def connected(self): |
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return self._connected |
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@property
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def id(self): |
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return self._id |
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@property
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def can_pipeline(self): |
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return True |