107 líneas
3,4 KiB
Python
107 líneas
3,4 KiB
Python
"""
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Handlers for the Streaming API:
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https://github.com/tootsuite/mastodon/blob/master/docs/Using-the-API/Streaming-API.md
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"""
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import json
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import logging
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import six
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log = logging.getLogger(__name__)
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class MalformedEventError(Exception):
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"""Raised when the server-sent event stream is malformed."""
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pass
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class StreamListener(object):
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"""Callbacks for the streaming API. Create a subclass, override the on_xxx
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methods for the kinds of events you're interested in, then pass an instance
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of your subclass to Mastodon.user_stream(), Mastodon.public_stream(), or
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Mastodon.hashtag_stream()."""
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def on_update(self, status):
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"""A new status has appeared! 'status' is the parsed JSON dictionary
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describing the status."""
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pass
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def on_notification(self, notification):
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"""A new notification. 'notification' is the parsed JSON dictionary
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describing the notification."""
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pass
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def on_delete(self, status_id):
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"""A status has been deleted. status_id is the status' integer ID."""
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pass
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def handle_heartbeat(self):
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"""The server has sent us a keep-alive message. This callback may be
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useful to carry out periodic housekeeping tasks, or just to confirm
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that the connection is still open."""
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def handle_stream(self, lines):
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"""
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Handles a stream of events from the Mastodon server. When each event
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is received, the corresponding .on_[name]() method is called.
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lines: an iterable of lines of bytes sent by the Mastodon server, as
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returned by requests.Response.iter_lines().
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"""
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event = {}
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for raw_line in lines:
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try:
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line = raw_line.decode('utf-8')
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except UnicodeDecodeError as err:
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six.raise_from(
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MalformedEventError("Malformed UTF-8", line),
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err
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)
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if line.startswith(':'):
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self.handle_heartbeat()
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elif line == '':
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# end of event
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self._despatch(event)
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event = {}
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else:
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key, value = line.split(': ', 1)
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# According to the MDN spec, repeating the 'data' key
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# represents a newline(!)
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if key in event:
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event[key] += '\n' + value
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else:
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event[key] = value
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# end of stream
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if event:
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log.warn("outstanding partial event at end of stream: %s", event)
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def _despatch(self, event):
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try:
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name = event['event']
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data = event['data']
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payload = json.loads(data)
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except KeyError as err:
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six.raise_from(
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MalformedEventError('Missing field', err.args[0], event),
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err
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)
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except ValueError as err:
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# py2: plain ValueError
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# py3: json.JSONDecodeError, a subclass of ValueError
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six.raise_from(
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MalformedEventError('Bad JSON', data),
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err
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)
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handler_name = 'on_' + name
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try:
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handler = getattr(self, handler_name)
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except AttributeError:
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log.warn("Unhandled event '%s'", name)
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else:
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# TODO: allow handlers to return/raise to stop streaming cleanly
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handler(payload)
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