200 lines
7.4 KiB
Python
200 lines
7.4 KiB
Python
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import logging
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import time
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from coapthon import defines
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__author__ = 'Giacomo Tanganelli'
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logger = logging.getLogger(__name__)
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class ObserveItem(object):
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def __init__(self, timestamp, non_counter, allowed, transaction):
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"""
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Data structure for the Observe option
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:param timestamp: the timestamop of last message sent
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:param non_counter: the number of NON notification sent
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:param allowed: if the client is allowed as observer
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:param transaction: the transaction
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"""
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self.timestamp = timestamp
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self.non_counter = non_counter
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self.allowed = allowed
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self.transaction = transaction
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class ObserveLayer(object):
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"""
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Manage the observing feature. It store observing relationships.
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"""
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def __init__(self):
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self._relations = {}
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def send_request(self, request):
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"""
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Add itself to the observing list
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:param request: the request
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:return: the request unmodified
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"""
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if request.observe == 0:
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# Observe request
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host, port = request.destination
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key_token = hash(str(host) + str(port) + str(request.token))
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self._relations[key_token] = ObserveItem(time.time(), None, True, None)
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return request
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def receive_response(self, transaction):
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"""
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Sets notification's parameters.
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:type transaction: Transaction
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:param transaction: the transaction
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:rtype : Transaction
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:return: the modified transaction
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"""
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host, port = transaction.response.source
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key_token = hash(str(host) + str(port) + str(transaction.response.token))
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if key_token in self._relations and transaction.response.type == defines.Types["CON"]:
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transaction.notification = True
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return transaction
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def send_empty(self, message):
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"""
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Eventually remove from the observer list in case of a RST message.
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:type message: Message
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:param message: the message
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:return: the message unmodified
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"""
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host, port = message.destination
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key_token = hash(str(host) + str(port) + str(message.token))
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if key_token in self._relations and message.type == defines.Types["RST"]:
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del self._relations[key_token]
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return message
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def receive_request(self, transaction):
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"""
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Manage the observe option in the request end eventually initialize the client for adding to
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the list of observers or remove from the list.
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:type transaction: Transaction
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:param transaction: the transaction that owns the request
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:rtype : Transaction
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:return: the modified transaction
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"""
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if transaction.request.observe == 0:
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# Observe request
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host, port = transaction.request.source
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key_token = hash(str(host) + str(port) + str(transaction.request.token))
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non_counter = 0
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if key_token in self._relations:
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# Renew registration
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allowed = True
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else:
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allowed = False
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self._relations[key_token] = ObserveItem(time.time(), non_counter, allowed, transaction)
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elif transaction.request.observe == 1:
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host, port = transaction.request.source
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key_token = hash(str(host) + str(port) + str(transaction.request.token))
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logger.info("Remove Subscriber")
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try:
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del self._relations[key_token]
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except KeyError:
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pass
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return transaction
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def receive_empty(self, empty, transaction):
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"""
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Manage the observe feature to remove a client in case of a RST message receveide in reply to a notification.
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:type empty: Message
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:param empty: the received message
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:type transaction: Transaction
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:param transaction: the transaction that owns the notification message
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:rtype : Transaction
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:return: the modified transaction
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"""
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if empty.type == defines.Types["RST"]:
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host, port = transaction.request.source
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key_token = hash(str(host) + str(port) + str(transaction.request.token))
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logger.info("Remove Subscriber")
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try:
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del self._relations[key_token]
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except KeyError:
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pass
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transaction.completed = True
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return transaction
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def send_response(self, transaction):
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"""
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Finalize to add the client to the list of observer.
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:type transaction: Transaction
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:param transaction: the transaction that owns the response
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:return: the transaction unmodified
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"""
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host, port = transaction.request.source
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key_token = hash(str(host) + str(port) + str(transaction.request.token))
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if key_token in self._relations:
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if transaction.response.code == defines.Codes.CONTENT.number:
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if transaction.resource is not None and transaction.resource.observable:
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transaction.response.observe = transaction.resource.observe_count
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self._relations[key_token].allowed = True
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self._relations[key_token].transaction = transaction
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self._relations[key_token].timestamp = time.time()
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else:
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del self._relations[key_token]
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elif transaction.response.code >= defines.Codes.ERROR_LOWER_BOUND:
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del self._relations[key_token]
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return transaction
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def notify(self, resource, root=None):
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"""
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Prepare notification for the resource to all interested observers.
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:rtype: list
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:param resource: the resource for which send a new notification
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:param root: deprecated
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:return: the list of transactions to be notified
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"""
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ret = []
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if root is not None:
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resource_list = root.with_prefix_resource(resource.path)
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else:
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resource_list = [resource]
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for key in self._relations.keys():
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if self._relations[key].transaction.resource in resource_list:
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if self._relations[key].non_counter > defines.MAX_NON_NOTIFICATIONS \
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or self._relations[key].transaction.request.type == defines.Types["CON"]:
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self._relations[key].transaction.response.type = defines.Types["CON"]
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self._relations[key].non_counter = 0
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elif self._relations[key].transaction.request.type == defines.Types["NON"]:
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self._relations[key].non_counter += 1
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self._relations[key].transaction.response.type = defines.Types["NON"]
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self._relations[key].transaction.resource = resource
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del self._relations[key].transaction.response.mid
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del self._relations[key].transaction.response.token
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ret.append(self._relations[key].transaction)
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return ret
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def remove_subscriber(self, message):
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"""
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Remove a subscriber based on token.
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:param message: the message
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"""
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logger.debug("Remove Subcriber")
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host, port = message.destination
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key_token = hash(str(host) + str(port) + str(message.token))
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try:
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self._relations[key_token].transaction.completed = True
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del self._relations[key_token]
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except KeyError:
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logger.warning("No Subscriber")
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