frappy/secop/protocol/dispatcher.py
Enrico Faulhaber 9a402857f3 Only send async updates for exported params
Change-Id: I466d99bf0234529ed58fa8045af83a0da44f96f7
2017-09-11 15:22:13 +02:00

434 lines
17 KiB
Python

# -*- coding: utf-8 -*-
# *****************************************************************************
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# Module authors:
# Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
#
# *****************************************************************************
"""Dispatcher for SECoP Messages
Interface to the service offering part:
- 'handle_request(connectionobj, data)' handles incoming request
will call 'queue_request(data)' on connectionobj before returning
- 'add_connection(connectionobj)' registers new connection
- 'remove_connection(connectionobj)' removes now longer functional connection
- may at any time call 'queue_async_request(connobj, data)' on the connobj
Interface to the modules:
- add_module(modulename, moduleobj, export=True) registers a new module under the
given name, may also register it for exporting (making accessible)
- get_module(modulename) returns the requested module or None
- remove_module(modulename_or_obj): removes the module (during shutdown)
"""
import time
import threading
from messages import *
from errors import *
from secop.lib.parsing import format_time
from secop.lib import formatExtendedStack, formatException
class Dispatcher(object):
def __init__(self, logger, options):
self.equipment_id = options.pop('equipment_id')
self.log = logger
# map ALL modulename -> moduleobj
self._modules = {}
# list of EXPORTED modules
self._export = []
# list all connections
self._connections = []
# active (i.e. broadcast-receiving) connections
self._active_connections = set()
# map eventname -> list of subscribed connections
self._subscriptions = {}
self._lock = threading.RLock()
def handle_request(self, conn, msg):
"""handles incoming request
will call 'queue.request(data)' on conn to send reply before returning
"""
self.log.debug('Dispatcher: handling msg: %r' % msg)
# play thread safe !
with self._lock:
reply = None
# generate reply (coded and framed)
msgname = msg.__class__.__name__
if msgname.endswith('Request'):
msgname = msgname[:-len('Request')]
if msgname.endswith('Message'):
msgname = msgname[:-len('Message')]
self.log.debug('Looking for handle_%s' % msgname)
handler = getattr(self, 'handle_%s' % msgname, None)
if handler:
try:
reply = handler(conn, msg)
except SECOPError as err:
self.log.exception(err)
reply = msg.get_error(
errorclass=err.__class__.__name__,
errorinfo=[repr(err), str(msg)])
except (ValueError, TypeError) as err:
self.log.exception(err)
reply = msg.get_error(
errorclass='BadValue',
errorinfo=[repr(err), str(msg)])
except Exception as err:
self.log.exception(err)
reply = msg.get_error(
errorclass='InternalError', errorinfo=[
formatException(), str(msg), formatExtendedStack()])
else:
self.log.debug('Can not handle msg %r' % msg)
reply = self.unhandled(conn, msg)
if reply:
conn.queue_reply(reply)
def broadcast_event(self, msg, reallyall=False):
"""broadcasts a msg to all active connections"""
if reallyall:
listeners = self._connections
else:
if getattr(msg, 'command', None) is None:
eventname = '%s:%s' % (msg.module, msg.parameter
if msg.parameter else 'value')
else:
eventname = '%s:%s()' % (msg.module, msg.command)
listeners = self._subscriptions.get(eventname, [])
listeners += list(self._active_connections)
for conn in listeners:
conn.queue_async_reply(msg)
def announce_update(self, moduleobj, pname, pobj):
"""called by modules param setters to notify subscribers of new values
"""
msg = Value(
moduleobj.name,
parameter=pname,
value=pobj.export_value,
t=pobj.timestamp)
self.broadcast_event(msg)
def subscribe(self, conn, modulename, pname='value'):
eventname = '%s:%s' % (modulename, pname)
self._subscriptions.setdefault(eventname, set()).add(conn)
def unsubscribe(self, conn, modulename, pname='value'):
eventname = '%s:%s' % (modulename, pname)
if eventname in self._subscriptions:
self._subscriptions.remove(conn)
def add_connection(self, conn):
"""registers new connection"""
self._connections.append(conn)
def remove_connection(self, conn):
"""removes now longer functional connection"""
if conn in self._connections:
self._connections.remove(conn)
for _evt, conns in self._subscriptions.items():
conns.discard(conn)
def activate_connection(self, conn):
self._active_connections.add(conn)
def deactivate_connection(self, conn):
self._active_connections.discard(conn)
def register_module(self, moduleobj, modulename, export=True):
self.log.debug('registering module %r as %s (export=%r)' %
(moduleobj, modulename, export))
self._modules[modulename] = moduleobj
if export:
self._export.append(modulename)
def get_module(self, modulename):
if modulename in self._modules:
return self._modules[modulename]
elif modulename in self._modules.values():
return modulename
raise NoSuchModuleError(module=str(modulename))
def remove_module(self, modulename_or_obj):
moduleobj = self.get_module(modulename_or_obj) or modulename_or_obj
modulename = moduleobj.name
if modulename in self._export:
self._export.remove(modulename)
self._modules.pop(modulename)
# XXX: also clean _subscriptions
def list_module_names(self):
# return a copy of our list
return self._export[:]
def list_module_params(self, modulename, only_static=False):
self.log.debug('list_module_params(%r)' % modulename)
if modulename in self._export:
# omit export=False params!
res = {}
for paramname, param in self.get_module(modulename).PARAMS.items():
if param.export:
res[paramname] = param.as_dict(only_static)
self.log.debug('list params for module %s -> %r' %
(modulename, res))
return res
self.log.debug('-> module is not to be exported!')
return {}
def list_module_cmds(self, modulename):
self.log.debug('list_module_cmds(%r)' % modulename)
if modulename in self._export:
# omit export=False params!
res = {}
for cmdname, cmdobj in self.get_module(modulename).CMDS.items():
res[cmdname] = cmdobj.as_dict()
self.log.debug('list cmds for module %s -> %r' % (modulename, res))
return res
self.log.debug('-> module is not to be exported!')
return {}
def get_descriptive_data(self):
"""returns a python object which upon serialisation results in the descriptive data"""
# XXX: be lazy and cache this?
# format: {[{[{[, specific entries first
result = {'modules': []}
for modulename in self._export:
module = self.get_module(modulename)
# some of these need rework !
mod_desc = {'parameters': [], 'commands': []}
for pname, param in self.list_module_params(
modulename, only_static=True).items():
mod_desc['parameters'].extend([pname, param])
for cname, cmd in self.list_module_cmds(modulename).items():
mod_desc['commands'].extend([cname, cmd])
for propname, prop in module.PROPERTIES.items():
mod_desc[propname] = prop
result['modules'].extend([modulename, mod_desc])
result['equipment_id'] = self.equipment_id
result['firmware'] = 'The SECoP playground'
result['version'] = "2017.07"
# XXX: what else?
return result
def get_descriptive_data_old(self):
# XXX: be lazy and cache this?
result = {'modules': {}}
for modulename in self._export:
module = self.get_module(modulename)
# some of these need rework !
dd = {
'parameters': self.list_module_params(
modulename,
only_static=True),
'commands': self.list_module_cmds(modulename),
'properties': module.PROPERTIES,
}
result['modules'][modulename] = dd
result['equipment_id'] = self.equipment_id
result['firmware'] = 'The SECoP playground'
result['version'] = "2017.01"
# XXX: what else?
return result
def _execute_command(self, modulename, command, arguments=None):
if arguments is None:
arguments = []
moduleobj = self.get_module(modulename)
if moduleobj is None:
raise NoSuchModuleError(module=modulename)
cmdspec = moduleobj.CMDS.get(command, None)
if cmdspec is None:
raise NoSuchCommandError(module=modulename, command=command)
if len(cmdspec.arguments) != len(arguments):
raise BadValueError(
module=modulename,
command=command,
reason='Wrong number of arguments!')
# now call func and wrap result as value
# note: exceptions are handled in handle_request, not here!
func = getattr(moduleobj, 'do_' + command)
res = func(*arguments)
res = CommandReply(
module=modulename,
command=command,
result=res,
qualifiers=dict(t=time.time()))
# res = Value(modulename, command=command, value=func(*arguments), t=time.time())
return res
def _setParamValue(self, modulename, pname, value):
moduleobj = self.get_module(modulename)
if moduleobj is None:
raise NoSuchModuleError(module=modulename)
pobj = moduleobj.PARAMS.get(pname, None)
if pobj is None:
raise NoSuchParamError(module=modulename, parameter=pname)
if pobj.readonly:
raise ReadonlyError(module=modulename, parameter=pname)
writefunc = getattr(moduleobj, 'write_%s' % pname, None)
# note: exceptions are handled in handle_request, not here!
if writefunc:
value = writefunc(value)
else:
setattr(moduleobj, pname, value)
if pobj.timestamp:
return WriteReply(
module=modulename,
parameter=pname,
value=[pobj.value, dict(t=format_time(pobj.timestamp))])
return WriteReply(
module=modulename, parameter=pname, value=[pobj.value, {}])
def _getParamValue(self, modulename, pname):
moduleobj = self.get_module(modulename)
if moduleobj is None:
raise NoSuchModuleError(module=modulename)
pobj = moduleobj.PARAMS.get(pname, None)
if pobj is None:
raise NoSuchParamError(module=modulename, parameter=pname)
readfunc = getattr(moduleobj, 'read_%s' % pname, None)
if readfunc:
# should also update the pobj (via the setter from the metaclass)
# note: exceptions are handled in handle_request, not here!
readfunc()
if pobj.timestamp:
res = Value(
modulename,
parameter=pname,
value=pobj.export_value,
t=pobj.timestamp)
else:
res = Value(modulename, parameter=pname, value=pobj.export_value)
return res
# now the (defined) handlers for the different requests
def handle_Help(self, conn, msg):
return HelpMessage()
def handle_Identify(self, conn, msg):
return IdentifyReply(version_string='currently,is,ignored,here')
def handle_Describe(self, conn, msg):
# XXX:collect descriptive data
return DescribeReply(
equipment_id=self.equipment_id,
description=self.get_descriptive_data())
def handle_Poll(self, conn, msg):
# XXX: trigger polling and force sending event
res = self._getParamValue(msg.module, msg.parameter or 'value')
# self.broadcast_event(res)
if conn in self._active_connections:
return None # already send to myself
return res # send reply to inactive conns
def handle_Write(self, conn, msg):
# notify all by sending WriteReply
#msg1 = WriteReply(**msg.as_dict())
# self.broadcast_event(msg1)
# try to actually write XXX: should this be done asyncron? we could
# just return the reply in that case
if msg.parameter:
res = self._setParamValue(msg.module, msg.parameter, msg.value)
else:
# first check if module has a target
if 'target' not in self.get_module(msg.module).PARAMS:
raise ReadonlyError(module=msg.module, parameter=None)
res = self._setParamValue(msg.module, 'target', msg.value)
res.parameter = 'target'
# self.broadcast_event(res)
# if conn in self._active_connections:
# return None # already send to myself
return res
def handle_Command(self, conn, msg):
# notify all by sending CommandReply
#msg1 = CommandReply(**msg.as_dict())
# self.broadcast_event(msg1)
# XXX: should this be done asyncron? we could just return the reply in
# that case
# try to actually execute command
res = self._execute_command(msg.module, msg.command, msg.arguments)
# self.broadcast_event(res)
# if conn in self._active_connections:
# return None # already send to myself
return res # send reply to inactive conns
def handle_Heartbeat(self, conn, msg):
return HeartbeatReply(**msg.as_dict())
def handle_Activate(self, conn, msg):
self.activate_connection(conn)
# easy approach: poll all values...
for modulename, moduleobj in self._modules.items():
for pname, pobj in moduleobj.PARAMS.items():
if not pobj.export:
continue
# WARNING: THIS READS ALL PARAMS FROM HW!
# XXX: should we send the cached values instead? (pbj.value)
# also: ignore errors here.
try:
res = self._getParamValue(modulename, pname)
except SECOPError as e:
self.log.error('decide what to do here!')
self.log.exception(e)
res = Value(
module=modulename,
parameter=pname,
value=pobj.export_value,
t=pobj.timestamp,
unit=pobj.unit)
if res.value != Ellipsis: # means we do not have a value at all so skip this
self.broadcast_event(res)
else:
self.log.error(
'activate: got no value for %s:%s!' %
modulename, pname)
conn.queue_async_reply(ActivateReply(**msg.as_dict()))
return None
def handle_Deactivate(self, conn, msg):
self.deactivate_connection(conn)
conn.queue_async_reply(DeactivateReply(**msg.as_dict()))
return None
def handle_Error(self, conn, msg):
return msg
def unhandled(self, conn, msg):
"""handler for unhandled Messages
(no handle_<messagename> method was defined)
"""
self.log.error('IGN: got unhandled request %s' % msg)
return msg.get_error(
errorclass="InternalError", errorinfo="Unhandled Request")