code.grnet.gr Git - ncclient/blob - ncclient/session.py

   1 # Copyright 2009 Shikhar Bhushan
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #    http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 import logging
  16 from threading import Thread, Event
  17 from Queue import Queue
  18
  19 import content
  20 from capabilities import Capabilities, CAPABILITIES
  21 from error import ClientError
  22 from subject import Subject
  23
  24 logger = logging.getLogger('ncclient.session')
  25
  26 class SessionError(ClientError): pass
  27
  28 class Session(Thread, Subject):
  29
  30     def __init__(self):
  31         Thread.__init__(self, name='session')
  32         Subject.__init__(self, listeners=[HelloListener(self)])
  33         self._client_capabilities = CAPABILITIES
  34         self._server_capabilities = None # yet
  35         self._id = None # session-id
  36         self._error = None
  37         self._init_event = Event()
  38         self._q = Queue()
  39         self._connected = False # to be set/cleared by subclass
  40
  41     def _post_connect(self):
  42         # start the subclass' main loop
  43         self.start()
  44         # queue client's hello message for sending
  45         self.send(content.Hello.build(self._client_capabilities))
  46         # we expect server's hello message, wait for _init_event to be set by HelloListener
  47         self._init_event.wait()
  48         # there may have been an error
  49         if self._error:
  50             self._close()
  51             raise self._error
  52
  53     def initialize(self, id, capabilities):
  54         self._id, self._capabilities = id, Capabilities(capabilities)
  55         self._init_event.set()
  56
  57     def initialize_error(self, err):
  58         self._error = err
  59         self._init_event.set()
  60
  61     def send(self, message):
  62         logger.debug('queueing message: \n%s' % message)
  63         self._q.put(message)
  64
  65     def connect(self):
  66         raise NotImplementedError
  67
  68     def run(self):
  69         raise NotImplementedError
  70
  71     def capabilities(self, whose='client'):
  72         if whose == 'client':
  73             return self._client_capabilities
  74         elif whose == 'server':
  75             return self._server_capabilities
  76
  77     ### Properties
  78
  79     @property
  80     def client_capabilities(self):
  81         return self._client_capabilities
  82
  83     @property
  84     def server_capabilities(self):
  85         return self._server_capabilities
  86
  87     @property
  88     def connected(self):
  89         return self._connected
  90
  91     @property
  92     def id(self):
  93         return self._id