73 lines
3.1 KiB
Python
73 lines
3.1 KiB
Python
# Copyright 2017, David Wilson
|
|
#
|
|
# Redistribution and use in source and binary forms, with or without
|
|
# modification, are permitted provided that the following conditions are met:
|
|
#
|
|
# 1. Redistributions of source code must retain the above copyright notice,
|
|
# this list of conditions and the following disclaimer.
|
|
#
|
|
# 2. Redistributions in binary form must reproduce the above copyright notice,
|
|
# this list of conditions and the following disclaimer in the documentation
|
|
# and/or other materials provided with the distribution.
|
|
#
|
|
# 3. Neither the name of the copyright holder nor the names of its contributors
|
|
# may be used to endorse or promote products derived from this software without
|
|
# specific prior written permission.
|
|
#
|
|
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
|
|
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
# POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
from __future__ import absolute_import
|
|
import mitogen.service
|
|
|
|
|
|
class ContextService(mitogen.service.Service):
|
|
"""
|
|
Used by worker processes connecting back into the top-level process to
|
|
fetch the single Context instance corresponding to the supplied connection
|
|
configuration, creating a matching connection if it does not exist.
|
|
|
|
For connection methods and their parameters, refer to:
|
|
https://mitogen.readthedocs.io/en/latest/api.html#context-factories
|
|
|
|
This concentrates all SSH connections in the top-level process, which may
|
|
become a bottleneck. There are multiple ways to fix that:
|
|
* creating one .local() child context per CPU and sharding connections
|
|
between them, using the master process to route messages, or
|
|
* as above, but having each child create a unique UNIX listener and
|
|
having workers connect in directly.
|
|
|
|
:param dict dct:
|
|
Parameters passed to mitogen.master.Router.[method](). One key,
|
|
"method", is popped from the dictionary and used to look up the method.
|
|
|
|
:returns mitogen.master.Context:
|
|
Corresponding Context instance.
|
|
"""
|
|
handle = 500
|
|
max_message_size = 1000
|
|
|
|
def __init__(self, router):
|
|
super(ContextService, self).__init__(router)
|
|
self._context_by_key = {}
|
|
|
|
def validate_args(self, args):
|
|
return isinstance(args, dict)
|
|
|
|
def dispatch(self, dct, msg):
|
|
key = repr(sorted(dct.items()))
|
|
if key not in self._context_by_key:
|
|
method = getattr(self.router, dct.pop('method'))
|
|
self._context_by_key[key] = method(**dct)
|
|
return self._context_by_key[key]
|
|
|