root / ncclient / transport / session.py @ efed7d4c
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1 | d095a59e | Shikhar Bhushan | # Copyright 2009 Shikhar Bhushan
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2 | d095a59e | Shikhar Bhushan | #
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3 | d095a59e | Shikhar Bhushan | # Licensed under the Apache License, Version 2.0 (the "License");
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4 | d095a59e | Shikhar Bhushan | # you may not use this file except in compliance with the License.
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5 | d095a59e | Shikhar Bhushan | # You may obtain a copy of the License at
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6 | d095a59e | Shikhar Bhushan | #
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7 | d095a59e | Shikhar Bhushan | # http://www.apache.org/licenses/LICENSE-2.0
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8 | d095a59e | Shikhar Bhushan | #
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9 | d095a59e | Shikhar Bhushan | # Unless required by applicable law or agreed to in writing, software
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10 | d095a59e | Shikhar Bhushan | # distributed under the License is distributed on an "AS IS" BASIS,
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11 | d095a59e | Shikhar Bhushan | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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12 | d095a59e | Shikhar Bhushan | # See the License for the specific language governing permissions and
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13 | d095a59e | Shikhar Bhushan | # limitations under the License.
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14 | d095a59e | Shikhar Bhushan | |
15 | d095a59e | Shikhar Bhushan | from threading import Thread, Lock, Event |
16 | d095a59e | Shikhar Bhushan | from Queue import Queue |
17 | d095a59e | Shikhar Bhushan | |
18 | d095a59e | Shikhar Bhushan | from . import logger
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19 | 4ba5e843 | Shikhar Bhushan | from ncclient.capabilities import Capabilities, CAPABILITIES |
20 | d095a59e | Shikhar Bhushan | |
21 | d095a59e | Shikhar Bhushan | |
22 | d095a59e | Shikhar Bhushan | class Subject: |
23 | d095a59e | Shikhar Bhushan | |
24 | d095a59e | Shikhar Bhushan | def __init__(self): |
25 | d095a59e | Shikhar Bhushan | self._listeners = set([]) |
26 | d095a59e | Shikhar Bhushan | self._lock = Lock()
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27 | d095a59e | Shikhar Bhushan | |
28 | d095a59e | Shikhar Bhushan | def has_listener(self, listener): |
29 | d095a59e | Shikhar Bhushan | with self._lock: |
30 | d095a59e | Shikhar Bhushan | return (listener in self._listeners) |
31 | d095a59e | Shikhar Bhushan | |
32 | d095a59e | Shikhar Bhushan | def add_listener(self, listener): |
33 | d095a59e | Shikhar Bhushan | with self._lock: |
34 | d095a59e | Shikhar Bhushan | self._listeners.add(listener)
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35 | d095a59e | Shikhar Bhushan | |
36 | d095a59e | Shikhar Bhushan | def remove_listener(self, listener): |
37 | d095a59e | Shikhar Bhushan | with self._lock: |
38 | d095a59e | Shikhar Bhushan | self._listeners.discard(listener)
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39 | d095a59e | Shikhar Bhushan | |
40 | d095a59e | Shikhar Bhushan | def dispatch(self, event, *args, **kwds): |
41 | d095a59e | Shikhar Bhushan | # holding the lock while doing callbacks could lead to a deadlock
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42 | d095a59e | Shikhar Bhushan | # if one of the above methods is called
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43 | d095a59e | Shikhar Bhushan | with self._lock: |
44 | d095a59e | Shikhar Bhushan | listeners = list(self._listeners) |
45 | d095a59e | Shikhar Bhushan | for l in listeners: |
46 | d095a59e | Shikhar Bhushan | try:
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47 | d095a59e | Shikhar Bhushan | logger.debug('dispatching [%s] to [%s]' % (event, l))
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48 | d095a59e | Shikhar Bhushan | getattr(l, event)(*args, **kwds)
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49 | d095a59e | Shikhar Bhushan | except Exception as e: |
50 | d095a59e | Shikhar Bhushan | pass # if a listener doesn't care for some event we don't care |
51 | d095a59e | Shikhar Bhushan | |
52 | d095a59e | Shikhar Bhushan | |
53 | d095a59e | Shikhar Bhushan | class Session(Thread, Subject): |
54 | d095a59e | Shikhar Bhushan | |
55 | d095a59e | Shikhar Bhushan | def __init__(self): |
56 | d095a59e | Shikhar Bhushan | Thread.__init__(self, name='session') |
57 | d095a59e | Shikhar Bhushan | Subject.__init__(self)
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58 | d095a59e | Shikhar Bhushan | self._client_capabilities = CAPABILITIES
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59 | d095a59e | Shikhar Bhushan | self._server_capabilities = None # yet |
60 | d095a59e | Shikhar Bhushan | self._id = None # session-id |
61 | d095a59e | Shikhar Bhushan | self._q = Queue()
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62 | d095a59e | Shikhar Bhushan | self._connected = False # to be set/cleared by subclass implementation |
63 | d095a59e | Shikhar Bhushan | |
64 | d095a59e | Shikhar Bhushan | def _post_connect(self): |
65 | d095a59e | Shikhar Bhushan | from ncclient.content.builders import HelloBuilder |
66 | d095a59e | Shikhar Bhushan | self.send(HelloBuilder.build(self._client_capabilities)) |
67 | d095a59e | Shikhar Bhushan | error = None
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68 | d095a59e | Shikhar Bhushan | init_event = Event() |
69 | 94265508 | Shikhar Bhushan | # callbacks
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70 | d095a59e | Shikhar Bhushan | def ok_cb(id, capabilities): |
71 | 94265508 | Shikhar Bhushan | self._id, self._server_capabilities = id, Capabilities(capabilities) |
72 | d095a59e | Shikhar Bhushan | init_event.set() |
73 | d095a59e | Shikhar Bhushan | def err_cb(err): |
74 | d095a59e | Shikhar Bhushan | error = err |
75 | d095a59e | Shikhar Bhushan | init_event.set() |
76 | d095a59e | Shikhar Bhushan | listener = HelloListener(ok_cb, err_cb) |
77 | d095a59e | Shikhar Bhushan | self.add_listener(listener)
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78 | d095a59e | Shikhar Bhushan | # start the subclass' main loop
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79 | 94265508 | Shikhar Bhushan | self.start()
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80 | d095a59e | Shikhar Bhushan | # we expect server's hello message
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81 | d095a59e | Shikhar Bhushan | init_event.wait() |
82 | d095a59e | Shikhar Bhushan | # received hello message or an error happened
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83 | d095a59e | Shikhar Bhushan | self.remove_listener(listener)
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84 | d095a59e | Shikhar Bhushan | if error:
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85 | d095a59e | Shikhar Bhushan | raise error
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86 | 94265508 | Shikhar Bhushan | logger.info('initialized: session-id=%s | server_capabilities=%s' %
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87 | 94265508 | Shikhar Bhushan | (self.id, self.server_capabilities)) |
88 | d095a59e | Shikhar Bhushan | |
89 | d095a59e | Shikhar Bhushan | def send(self, message): |
90 | d095a59e | Shikhar Bhushan | logger.debug('queueing:%s' % message)
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91 | d095a59e | Shikhar Bhushan | self._q.put(message)
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92 | d095a59e | Shikhar Bhushan | |
93 | d095a59e | Shikhar Bhushan | def connect(self): |
94 | d095a59e | Shikhar Bhushan | raise NotImplementedError |
95 | d095a59e | Shikhar Bhushan | |
96 | d095a59e | Shikhar Bhushan | def run(self): |
97 | d095a59e | Shikhar Bhushan | raise NotImplementedError |
98 | d095a59e | Shikhar Bhushan | |
99 | d095a59e | Shikhar Bhushan | ### Properties
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100 | d095a59e | Shikhar Bhushan | |
101 | d095a59e | Shikhar Bhushan | @property
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102 | d095a59e | Shikhar Bhushan | def client_capabilities(self): |
103 | d095a59e | Shikhar Bhushan | return self._client_capabilities |
104 | d095a59e | Shikhar Bhushan | |
105 | d095a59e | Shikhar Bhushan | @property
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106 | d095a59e | Shikhar Bhushan | def server_capabilities(self): |
107 | d095a59e | Shikhar Bhushan | return self._server_capabilities |
108 | d095a59e | Shikhar Bhushan | |
109 | d095a59e | Shikhar Bhushan | @property
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110 | d095a59e | Shikhar Bhushan | def connected(self): |
111 | d095a59e | Shikhar Bhushan | return self._connected |
112 | d095a59e | Shikhar Bhushan | |
113 | d095a59e | Shikhar Bhushan | @property
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114 | d095a59e | Shikhar Bhushan | def id(self): |
115 | d095a59e | Shikhar Bhushan | return self._id |
116 | d095a59e | Shikhar Bhushan | |
117 | d095a59e | Shikhar Bhushan | |
118 | d095a59e | Shikhar Bhushan | class HelloListener: |
119 | d095a59e | Shikhar Bhushan | |
120 | d095a59e | Shikhar Bhushan | def __init__(self, init_cb, error_cb): |
121 | d095a59e | Shikhar Bhushan | self._init_cb, self._error_cb = init_cb, error_cb |
122 | d095a59e | Shikhar Bhushan | |
123 | d095a59e | Shikhar Bhushan | def __str__(self): |
124 | d095a59e | Shikhar Bhushan | return 'HelloListener' |
125 | d095a59e | Shikhar Bhushan | |
126 | d095a59e | Shikhar Bhushan | ### Events
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127 | d095a59e | Shikhar Bhushan | |
128 | d095a59e | Shikhar Bhushan | def received(self, raw): |
129 | d095a59e | Shikhar Bhushan | logger.debug(raw) |
130 | d095a59e | Shikhar Bhushan | from ncclient.content.parsers import HelloParser |
131 | d095a59e | Shikhar Bhushan | try:
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132 | d095a59e | Shikhar Bhushan | id, capabilities = HelloParser.parse(raw)
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133 | d095a59e | Shikhar Bhushan | except Exception as e: |
134 | d095a59e | Shikhar Bhushan | self._error_cb(e)
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135 | d095a59e | Shikhar Bhushan | else:
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136 | d095a59e | Shikhar Bhushan | self._init_cb(id, capabilities) |
137 | d095a59e | Shikhar Bhushan | |
138 | d095a59e | Shikhar Bhushan | def error(self, err): |
139 | d095a59e | Shikhar Bhushan | self._error_cb(err) |