deb-python-autobahn/autobahn/websocket/interfaces.py

307 lines
12 KiB
Python

###############################################################################
#
# The MIT License (MIT)
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# Copyright (c) Crossbar.io Technologies GmbH
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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import abc
import six
__all__ = ('IWebSocketChannel',
'IWebSocketChannelFrameApi',
'IWebSocketChannelStreamingApi')
@six.add_metaclass(abc.ABCMeta)
class IWebSocketChannel(object):
"""
A WebSocket channel is a bidirectional, full-duplex, ordered, reliable message channel
over a WebSocket connection as specified in RFC6455.
This interface defines a message-based API to WebSocket plus auxiliary hooks
and methods.
"""
@abc.abstractmethod
def on_connect(self, request_or_response):
"""
Callback fired during WebSocket opening handshake when a client connects (to a server with
request from client) or when server connection established (by a client with response from
server). This method may run asynchronous code.
:param request_or_response: Connection request (for servers) or response (for clients).
:type request_or_response: Instance of :class:`autobahn.websocket.types.ConnectionRequest`
or :class:`autobahn.websocket.types.ConnectionResponse`.
:returns:
When this callback is fired on a WebSocket server, you may return either ``None`` (in
which case the connection is accepted with no specific WebSocket subprotocol) or
an instance of :class:`autobahn.websocket.types.ConnectionAccept`.
When the callback is fired on a WebSocket client, this method must return ``None``.
Do deny a connection, raise an Exception.
You can also return a Deferred/Future that resolves/rejects to the above.
"""
@abc.abstractmethod
def on_open(self):
"""
Callback fired when the initial WebSocket opening handshake was completed.
You now can send and receive WebSocket messages.
"""
@abc.abstractmethod
def send_message(self, message):
"""
Send a WebSocket message over the connection to the peer.
:param message: The WebSocket message to be sent.
:type message: Instance of :class:`autobahn.websocket.types.OutgoingMessage`
"""
@abc.abstractmethod
def on_message(self, message):
"""
Callback fired when a complete WebSocket message was received.
:param message: The WebSocket message received.
:type message: :class:`autobahn.websocket.types.IncomingMessage`
"""
@abc.abstractmethod
def send_close(self, code=None, reason=None):
"""
Starts a WebSocket closing handshake tearing down the WebSocket connection.
:param code: An optional close status code (``1000`` for normal close or ``3000-4999`` for
application specific close).
:type code: int
:param reason: An optional close reason (a string that when present, a status
code MUST also be present).
:type reason: unicode
"""
@abc.abstractmethod
def on_close(self, was_clean, code, reason):
"""
Callback fired when the WebSocket connection has been closed (WebSocket closing
handshake has been finished or the connection was closed uncleanly).
:param wasClean: ``True`` iff the WebSocket connection was closed cleanly.
:type wasClean: bool
:param code: Close status code as sent by the WebSocket peer.
:type code: int or None
:param reason: Close reason as sent by the WebSocket peer.
:type reason: unicode or None
"""
@abc.abstractmethod
def sendPreparedMessage(self, preparedMsg):
"""
Send a message that was previously prepared with :func:`autobahn.websocket.protocol.WebSocketFactory.prepareMessage`.
:param prepareMessage: A previously prepared message.
:type prepareMessage: Instance of :class:`autobahn.websocket.protocol.PreparedMessage`.
"""
@abc.abstractmethod
def send_ping(self, payload=None):
"""
Send a WebSocket ping to the peer.
A peer is expected to pong back the payload a soon as "practical". When more than
one ping is outstanding at a peer, the peer may elect to respond only to the last ping.
:param payload: An (optional) arbitrary payload of length **less than 126** octets.
:type payload: bytes or None
"""
@abc.abstractmethod
def on_ping(self, payload):
"""
Callback fired when a WebSocket ping was received. A default implementation responds
by sending a WebSocket pong.
:param payload: Payload of ping (when there was any). Can be arbitrary, up to `125` octets.
:type payload: bytes
"""
@abc.abstractmethod
def send_pong(self, payload=None):
"""
Send a WebSocket pong to the peer.
A WebSocket pong may be sent unsolicited. This serves as a unidirectional heartbeat.
A response to an unsolicited pong is "not expected".
:param payload: An (optional) arbitrary payload of length < 126 octets.
:type payload: bytes
"""
@abc.abstractmethod
def on_pong(self, payload):
"""
Callback fired when a WebSocket pong was received. A default implementation does nothing.
:param payload: Payload of pong (when there was any). Can be arbitrary, up to 125 octets.
:type payload: bytes
"""
class IWebSocketChannelFrameApi(IWebSocketChannel):
"""
Frame-based API to a WebSocket channel.
"""
@abc.abstractmethod
def onMessageBegin(self, isBinary):
"""
Callback fired when receiving of a new WebSocket message has begun.
:param isBinary: ``True`` if payload is binary, else the payload is UTF-8 encoded text.
:type isBinary: bool
"""
@abc.abstractmethod
def onMessageFrame(self, payload):
"""
Callback fired when a complete WebSocket message frame for a previously begun
WebSocket message has been received.
:param payload: Message frame payload (a list of chunks received).
:type payload: list of bytes
"""
@abc.abstractmethod
def onMessageEnd(self):
"""
Callback fired when a WebSocket message has been completely received (the last
WebSocket frame for that message has been received).
"""
@abc.abstractmethod
def beginMessage(self, isBinary=False, doNotCompress=False):
"""
Begin sending a new WebSocket message.
:param isBinary: ``True`` if payload is binary, else the payload must be UTF-8 encoded text.
:type isBinary: bool
:param doNotCompress: If ``True``, never compress this message. This only applies to
Hybi-Mode and only when WebSocket compression has been negotiated on the WebSocket
connection. Use when you know the payload incompressible (e.g. encrypted or
already compressed).
:type doNotCompress: bool
"""
@abc.abstractmethod
def sendMessageFrame(self, payload, sync=False):
"""
When a message has been previously begun, send a complete message frame in one go.
:param payload: The message frame payload. When sending a text message, the payload must
be UTF-8 encoded already.
:type payload: bytes
:param sync: If ``True``, try to force data onto the wire immediately.
.. warning::
Do NOT use this feature for normal applications.
Performance likely will suffer significantly.
This feature is mainly here for use by Autobahn|Testsuite.
:type sync: bool
"""
@abc.abstractmethod
def endMessage(self):
"""
End a message previously begun message. No more frames may be sent (for that message).
You have to begin a new message before sending again.
"""
class IWebSocketChannelStreamingApi(IWebSocketChannelFrameApi):
"""
Streaming API to a WebSocket channel.
"""
@abc.abstractmethod
def onMessageFrameBegin(self, length):
"""
Callback fired when receiving a new message frame has begun.
A default implementation will prepare to buffer message frame data.
:param length: Payload length of message frame which is subsequently received.
:type length: int
"""
@abc.abstractmethod
def onMessageFrameData(self, payload):
"""
Callback fired when receiving data within a previously begun message frame.
A default implementation will buffer data for frame.
:param payload: Partial payload for message frame.
:type payload: bytes
"""
@abc.abstractmethod
def onMessageFrameEnd(self):
"""
Callback fired when a previously begun message frame has been completely received.
A default implementation will flatten the buffered frame data and
fire `onMessageFrame`.
"""
@abc.abstractmethod
def beginMessageFrame(self, length):
"""
Begin sending a new message frame.
:param length: Length of the frame which is to be started. Must be less or equal **2^63**.
:type length: int
"""
@abc.abstractmethod
def sendMessageFrameData(self, payload, sync=False):
"""
Send out data when within a message frame (message was begun, frame was begun).
Note that the frame is automatically ended when enough data has been sent.
In other words, there is no ``endMessageFrame``, since you have begun the frame
specifying the frame length, which implicitly defined the frame end. This is different
from messages, which you begin *and* end explicitly , since a message can contain
an unlimited number of frames.
:param payload: Frame payload to send.
:type payload: bytes
:param sync: If ``True``, try to force data onto the wire immediately.
.. warning::
Do NOT use this feature for normal applications.
Performance likely will suffer significantly.
This feature is mainly here for use by Autobahn|Testsuite.
:type sync: bool
:returns: When the currently sent message frame is still incomplete, returns octets
remaining to be sent. When the frame is complete, returns **0**. Otherwise the amount
of unconsumed data in payload argument is returned.
:rtype: int
"""