ncclient:NETCONF Python client

# Copyright 2009 Shikhar Bhushan

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#    http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

from threading import Event, Lock

from uuid import uuid1

from weakref import WeakValueDictionary

from ncclient.content import XMLConverter

from ncclient.content import qualify as _

from ncclient.content import unqualify as __

from ncclient.glue import Listener

from listener import RPCReplyListener

from reply import RPCReply

import logging

logger = logging.getLogger('ncclient.rpc')

class RPC(object):

    DEPENDS = []

    REPLY_CLS = RPCReply

    def __init__(self, session, async=False, timeout=None):

        if not session.can_pipeline:

            raise UserWarning('Asynchronous mode not supported for this device/session')

        self._session = session

        try:

            for cap in self.DEPENDS:

                self._assert(cap)

        except AttributeError:

            pass        

        self._async = async

        self._timeout = timeout

        self._id = uuid1().urn

        self._listener = RPCReplyListener(session)

        self._listener.register(self._id, self)

        self._reply = None

        self._reply_event = Event()

    def _build(self, opspec, encoding='utf-8'):

        "TODO: docstring"

        spec = {

            'tag': _('rpc'),

            'attributes': {'message-id': self._id},

            'subtree': opspec

            }

        return XMLConverter(spec).to_string(encoding)

    def _request(self, op):

        req = self._build(op)

        self._session.send(req)

        if self._async:

            return self._reply_event

        else:

            self._reply_event.wait(self._timeout)

            if self._reply_event.isSet():

                self._reply.parse()

                return self._reply

            else:

                raise ReplyTimeoutError

    def request(self):

        return self._request(self.SPEC)

    def _delivery_hook(self):

        'For subclasses'

        pass

    def _assert(self, capability):

        if capability not in self._session.server_capabilities:

            raise MissingCapabilityError('Server does not support [%s]' % cap)

    def deliver(self, raw):

        self._reply = self.REPLY_CLS(raw)

        self._delivery_hook()

        self._reply_event.set()

    @property

    def has_reply(self):

        return self._reply_event.isSet()

    @property

    def reply(self):

        return self._reply

    @property

    def id(self):

        return self._id

    @property

    def session(self):

        return self._session

    @property

    def reply_event(self):

        return self._reply_event

    def set_async(self, bool): self._async = bool

    async = property(fget=lambda self: self._async, fset=set_async)

    def set_timeout(self, timeout): self._timeout = timeout

    timeout = property(fget=lambda self: self._timeout, fset=set_timeout)