d079bf38e7
__metaclass__ can't be used with python 3 as metaclass syntax has been changed in python 3. Signed-off-by: Fumihiko Kakuma <kakuma@valinux.co.jp> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
89 lines
2.7 KiB
Python
89 lines
2.7 KiB
Python
# Copyright (C) 2014 Nippon Telegraph and Telephone Corporation.
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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
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# 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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"""
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Module defines protocol based classes and utils.
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"""
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from abc import ABCMeta
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from abc import abstractmethod
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import six
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@six.add_metaclass(ABCMeta)
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class Protocol(object):
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"""Interface for various protocols.
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Protocol usually encloses a transport/connection/socket to
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peer/client/server and encodes and decodes communication/messages. Protocol
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can also maintain any related state machine, protocol message encoding or
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decoding utilities. This interface identifies minimum methods to support to
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facilitate or provide hooks to sub-classes to override behavior as
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appropriate.
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"""
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@abstractmethod
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def data_received(self, data):
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"""Handler for date received over connection/transport.
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Here *data* is in raw bytes. This *data* should further be converted to
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protocol specific messages and as appropriate transition to new state
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machine state or send appropriate response.
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"""
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pass
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@abstractmethod
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def connection_made(self):
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"""Called when connection has been established according to protocol.
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This is the right place to do some initialization or sending initial
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hello messages.
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"""
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pass
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@abstractmethod
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def connection_lost(self, reason):
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"""Handler called when connection to peer/remote according to protocol
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has been lost.
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Here we can do any clean-up related to connection/transport/timers/etc.
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"""
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pass
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@six.add_metaclass(ABCMeta)
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class Factory(object):
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"""This is a factory which produces protocols.
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Can also act as context for protocols.
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"""
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# Put a subclass of Protocol here:
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protocol = None
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@abstractmethod
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def build_protocol(self, socket):
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"""Create an instance of a subclass of Protocol.
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Override this method to alter how Protocol instances get created.
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"""
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raise NotImplementedError()
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@abstractmethod
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def start_protocol(self, socket):
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"""Launch protocol instance to handle input on an incoming connection.
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"""
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raise NotImplementedError()
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