Source code for bokeh.protocol

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# Copyright (c) 2012 - 2020, Anaconda, Inc., and Bokeh Contributors.
# All rights reserved.
#
# The full license is in the file LICENSE.txt, distributed with this software.
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''' Implement and provide message protocols for communication between Bokeh
Servers and clients.

'''

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# Boilerplate
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import logging # isort:skip
log = logging.getLogger(__name__)

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# Imports
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# External imports
from tornado.escape import json_decode

# Bokeh imports
from . import messages
from .exceptions import ProtocolError
from .messages.ack import ack
from .messages.error import error
from .messages.ok import ok
from .messages.patch_doc import patch_doc
from .messages.pull_doc_reply import pull_doc_reply
from .messages.pull_doc_req import pull_doc_req
from .messages.push_doc import push_doc
from .messages.server_info_reply import server_info_reply
from .messages.server_info_req import server_info_req

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# Globals and constants
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__all__ = (
    'Protocol',
)

SPEC = {
    "ACK": ack,
    "ERROR": error,
    "OK": ok,
    'PATCH-DOC': patch_doc,
    'PULL-DOC-REPLY': pull_doc_reply,
    'PULL-DOC-REQ': pull_doc_req,
    'PUSH-DOC': push_doc,
    'SERVER-INFO-REPLY': server_info_reply,
    'SERVER-INFO-REQ': server_info_req,
}

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# General API
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# Dev API
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[docs]class Protocol: ''' Provide a message factory for the Bokeh Server message protocol. ''' def __init__(self): self._messages = SPEC def __repr__(self): return "Protocol()"
[docs] def create(self, msgtype, *args, **kwargs): ''' Create a new Message instance for the given type. Args: msgtype (str) : ''' if msgtype not in self._messages: raise ProtocolError("Unknown message type %r for Bokeh protocol" % msgtype) return self._messages[msgtype].create(*args, **kwargs)
[docs] def assemble(self, header_json, metadata_json, content_json): ''' Create a Message instance assembled from json fragments. Args: header_json (``JSON``) : metadata_json (``JSON``) : content_json (``JSON``) : Returns: message ''' header = json_decode(header_json) if 'msgtype' not in header: log.error("Bad header with no msgtype was: %r", header) raise ProtocolError("No 'msgtype' in header") return self._messages[header['msgtype']].assemble( header_json, metadata_json, content_json )
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