StackStorm / st2

st2stream/st2stream/controllers/v1/stream.py

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# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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.
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import six

from st2common import log as logging
from st2common.router import Response
from st2common.util.jsonify import json_encode
from st2common.stream.listener import get_listener

__all__ = [
    'StreamController'
]

LOG = logging.getLogger(__name__)

DEFAULT_EVENTS_WHITELIST = [
    'st2.announcement__*',

    'st2.execution__create',
    'st2.execution__update',
    'st2.execution__delete',

    'st2.liveaction__create',
    'st2.liveaction__update',
    'st2.liveaction__delete',
]


def format(gen):

This seems to re-define the built-in format.

    message = '''event: %s\ndata: %s\n\n'''

    for pack in gen:
        if not pack:
            # Note: gunicorn wsgi handler expect bytes, not unicode
            yield six.binary_type(b'\n')
        else:
            (event, body) = pack
            # Note: gunicorn wsgi handler expect bytes, not unicode
            yield six.binary_type((message % (event, json_encode(body,
                                                                 indent=None))).encode('utf-8'))


class StreamController(object):
    def get_all(self, events=None, action_refs=None, execution_ids=None, requester_user=None):
        events = events if events else DEFAULT_EVENTS_WHITELIST
        action_refs = action_refs if action_refs else None
        execution_ids = execution_ids if execution_ids else None

        def make_response():
            listener = get_listener(name='stream')
            app_iter = format(listener.generator(events=events, action_refs=action_refs,
                                                 execution_ids=execution_ids))
            res = Response(content_type='text/event-stream', app_iter=app_iter)
            return res

        stream = make_response()

        return stream


stream_controller = StreamController()