#!/usr/bin/env python
##############################################################################
##
# This file is part of Sardana
##
# http://www.sardana-controls.org/
##
# Copyright 2011 CELLS / ALBA Synchrotron, Bellaterra, Spain
##
# Sardana is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
##
# Sardana 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 Lesser General Public License for more details.
##
# You should have received a copy of the GNU Lesser General Public License
# along with Sardana. If not, see <http://www.gnu.org/licenses/>.
##
##############################################################################
"""This module is part of the Python Pool libray. It defines the base classes
for external objects to the pool (like tango objects)"""
__all__ = ["PoolBaseExternalObject", "PoolTangoObject", "PoolExternalObject"]
__docformat__ = "restructuredtext"
import PyTango
from sardana import ElementType
from sardana.pool.poolbaseobject import PoolBaseObject
[docs]
class PoolBaseExternalObject(PoolBaseObject):
"""TODO"""
def __init__(self, **kwargs):
kwargs["elem_type"] = ElementType.External
PoolBaseObject.__init__(self, **kwargs)
[docs]
def get_source(self):
return self.full_name
[docs]
def get_config(self):
raise NotImplementedError
[docs]
class PoolTangoObject(PoolBaseExternalObject):
"""TODO"""
def __init__(self, **kwargs):
kwargs.pop("scheme", "tango")
attribute_name = kwargs.pop("_shortattrname")
host, port = kwargs.pop("host", None), kwargs.pop("port", None)
devalias = kwargs.pop("_devalias", None)
device_name = kwargs.pop("devname", None)
if host is None:
db = PyTango.Database()
host, port = db.get_db_host(), db.get_db_port()
else:
db = PyTango.Database(host, port)
full_name = "<unknown>"
if device_name is None:
if devalias is not None:
try:
device_name = db.get_device_alias(devalias)
full_name = "tango://{0}:{1}/{2}/{3}".format(
host, port, device_name, attribute_name
)
except Exception:
full_name = "{0}/{1}".format(devalias, attribute_name)
else:
full_name = "tango://{0}:{1}/{2}/{3}".format(
host, port, device_name, attribute_name
)
self._device_name = device_name
self._attribute_name = attribute_name
self._config = None
self._device = None
# TODO evaluate to use alias instead of device_name
kwargs["name"] = "{0}/{1}".format(device_name, attribute_name)
kwargs["full_name"] = full_name
PoolBaseExternalObject.__init__(self, **kwargs)
[docs]
def get_device_name(self):
return self._device_name
[docs]
def get_attribute_name(self):
return self._attribute_name
[docs]
def get_device(self):
device = self._device
if device is None:
try:
self._device = device = PyTango.DeviceProxy(self._device_name)
except Exception:
pass
return device
[docs]
def get_config(self):
config = self._config
if config is None:
try:
self._config = config = self._device.get_attribute_config(
self._attribute_name
)
except Exception:
pass
return config
device_name = property(get_device_name)
attribute_name = property(get_attribute_name)
_SCHEME_CLASS = {"tango": PoolTangoObject, None: PoolTangoObject}
[docs]
def PoolExternalObject(**kwargs):
scheme = kwargs.get("scheme", "tango")
klass = _SCHEME_CLASS[scheme]
return klass(**kwargs)