frappy/secop/params.py
Markus Zolliker f9a2152883 enhance documentation
- flatten hierarchy (some links do not work when using folders)
- add a tutorial for programming a simple driver
- clean description using inspect.cleandoc
+ fix a bug with 'unit' pseudo property in a Parameter used as override

Change-Id: I31ddba5d516d1ee5e785e28fbd79fca44ed23f5e
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/25000
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>
2021-02-26 17:27:13 +01:00

421 lines
18 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>
# Markus Zolliker <markus.zolliker@psi.ch>
#
# *****************************************************************************
"""Define classes for Parameters/Commands and Overriding them"""
import inspect
import itertools
from collections import OrderedDict
from secop.datatypes import CommandType, DataType, StringType, BoolType, EnumType, DataTypeType, ValueType, OrType, \
NoneOr, TextType, IntRange, TupleOf
from secop.errors import ProgrammingError, BadValueError
from secop.properties import HasProperties, Property
object_counter = itertools.count(1)
class Accessible(HasProperties):
"""base class for Parameter and Command"""
properties = {}
kwds = None # is a dict if it might be used as Override
def __init__(self, ctr, **kwds):
self.ctr = ctr or next(object_counter)
super(Accessible, self).__init__()
# do not use self.properties.update here, as no invalid values should be
# assigned to properties, even not before checkProperties
for k,v in kwds.items():
self.setProperty(k, v)
def __repr__(self):
props = []
for k, prop in sorted(self.__class__.properties.items()):
v = self.properties.get(k, prop.default)
if v != prop.default:
props.append('%s=%r' % (k, v))
return '%s(%s, ctr=%d)' % (self.__class__.__name__, ', '.join(props), self.ctr)
def as_dict(self):
return self.properties
def override(self, from_object=None, **kwds):
"""return a copy of ourselfs, modified by <other>"""
props = dict(self.properties, ctr=self.ctr)
if from_object:
props.update(from_object.kwds)
props.update(kwds)
props['datatype'] = props['datatype'].copy()
return type(self)(inherit=False, internally_called=True, **props)
def copy(self):
"""return a copy of ourselfs"""
props = dict(self.properties, ctr=self.ctr)
# deep copy, as datatype might be altered from config
props['datatype'] = props['datatype'].copy()
return type(self)(inherit=False, internally_called=True, **props)
def for_export(self):
"""prepare for serialisation"""
return self.exportProperties()
class Parameter(Accessible):
"""defines a parameter
:param description: description
:param datatype: the datatype
:param inherit: whether properties not given should be inherited.
defaults to True when datatype or description is missing, else to False
:param reorder: when True, put this parameter after all inherited items in the accessible list
:param kwds: optional properties
:param ctr: (for internal use only)
:param internally_used: (for internal use only)
"""
# storage for Parameter settings + value + qualifiers
properties = {
'description': Property('mandatory description of the parameter', TextType(),
extname='description', mandatory=True),
'datatype': Property('datatype of the Parameter (SECoP datainfo)', DataTypeType(),
extname='datainfo', mandatory=True),
'readonly': Property('not changeable via SECoP (default True)', BoolType(),
extname='readonly', default=True),
'group': Property('optional parameter group this parameter belongs to', StringType(),
extname='group', default=''),
'visibility': Property('optional visibility hint', EnumType('visibility', user=1, advanced=2, expert=3),
extname='visibility', default=1),
'constant': Property('optional constant value for constant parameters', ValueType(),
extname='constant', default=None, mandatory=False),
'default': Property('[internal] default (startup) value of this parameter '
'if it can not be read from the hardware',
ValueType(), export=False, default=None, mandatory=False),
'export': Property('''
[internal] export settings
* False: not accessible via SECoP.
* True: exported, name automatic.
* a string: exported with custom name''',
OrType(BoolType(), StringType()), export=False, default=True),
'poll': Property('''
[internal] polling indicator
may be:
* None (omitted): will be converted to True/False if handler is/is not None
* False or 0 (never poll this parameter)
* True or 1 (AUTO), converted to SLOW (readonly=False)
DYNAMIC (*status* and *value*) or REGULAR (else)
* 2 (SLOW), polled with lower priority and a multiple of pollinterval
* 3 (REGULAR), polled with pollperiod
* 4 (DYNAMIC), if BUSY, with a fraction of pollinterval,
else polled with pollperiod
''',
NoneOr(IntRange()), export=False, default=None),
'needscfg': Property('[internal] needs value in config', NoneOr(BoolType()), export=False, default=None),
'optional': Property('[internal] is this parameter optional?', BoolType(), export=False,
settable=False, default=False),
'handler': Property('[internal] overload the standard read and write functions',
ValueType(), export=False, default=None, mandatory=False, settable=False),
'initwrite': Property('[internal] write this parameter on initialization'
' (default None: write if given in config)',
NoneOr(BoolType()), export=False, default=None, mandatory=False, settable=False),
}
def __init__(self, description=None, datatype=None, inherit=True, *,
reorder=False, ctr=None, internally_called=False, **kwds):
if datatype is not None:
if not isinstance(datatype, DataType):
if isinstance(datatype, type) and issubclass(datatype, DataType):
# goodie: make an instance from a class (forgotten ()???)
datatype = datatype()
else:
raise ProgrammingError(
'datatype MUST be derived from class DataType!')
kwds['datatype'] = datatype
if description is not None:
if not internally_called:
description = inspect.cleandoc(description)
kwds['description'] = description
unit = kwds.pop('unit', None)
if unit is not None and datatype: # for legacy code only
datatype.setProperty('unit', unit)
constant = kwds.get('constant')
if constant is not None:
constant = datatype(constant)
# The value of the `constant` property should be the
# serialised version of the constant, or unset
kwds['constant'] = datatype.export_value(constant)
kwds['readonly'] = True
if internally_called: # fixes in case datatype has changed
default = kwds.get('default')
if default is not None:
try:
datatype(default)
except BadValueError:
# clear default, if it does not match datatype
kwds['default'] = None
super().__init__(ctr, **kwds)
if inherit:
if reorder:
kwds['ctr'] = next(object_counter)
if unit is not None:
kwds['unit'] = unit
self.kwds = kwds # contains only the items which must be overwritten
# internal caching: value and timestamp of last change...
self.value = self.default
self.timestamp = 0
self.readerror = None # if not None, indicates that last read was not successful
def export_value(self):
return self.datatype.export_value(self.value)
def getProperties(self):
"""get also properties of datatype"""
superProp = super().getProperties().copy()
superProp.update(self.datatype.getProperties())
return superProp
def setProperty(self, key, value):
"""set also properties of datatype"""
if key in self.__class__.properties:
super().setProperty(key, value)
else:
self.datatype.setProperty(key, value)
def checkProperties(self):
super().checkProperties()
self.datatype.checkProperties()
def for_export(self):
"""prepare for serialisation
readonly is mandatory for serialisation, but not for declaration in classes
"""
r = super().for_export()
if 'readonly' not in r:
r['readonly'] = self.__class__.properties['readonly'].default
return r
class UnusedClass:
# do not derive anything from this!
pass
class Parameters(OrderedDict):
"""class storage for Parameters"""
def __init__(self, *args, **kwds):
self.exported = {} # only for lookups!
super(Parameters, self).__init__(*args, **kwds)
def __setitem__(self, key, value):
if value.export:
if isinstance(value, PREDEFINED_ACCESSIBLES.get(key, UnusedClass)):
value.properties['export'] = key
else:
value.properties['export'] = '_' + key
self.exported[value.export] = key
super(Parameters, self).__setitem__(key, value)
def __getitem__(self, item):
return super(Parameters, self).__getitem__(self.exported.get(item, item))
class Commands(Parameters):
"""class storage for Commands"""
class Override:
"""Stores the overrides to be applied to a Parameter
note: overrides are applied by the metaclass during class creating
reorder=True: use position of Override instead of inherited for the order
"""
def __init__(self, description="", datatype=None, *, reorder=False, **kwds):
self.kwds = kwds
# allow to override description and datatype without keyword
if description:
self.kwds['description'] = description
if datatype is not None:
self.kwds['datatype'] = datatype
if reorder: # result from apply must use new ctr from Override
self.kwds['ctr'] = next(object_counter)
def __repr__(self):
return '%s(%s)' % (self.__class__.__name__, ', '.join(
['%s=%r' % (k, v) for k, v in sorted(self.kwds.items())]))
def apply(self, obj):
return obj.override(self)
class Command(Accessible):
# to be merged with usercommand
properties = {
'description': Property('description of the Command', TextType(),
extname='description', export=True, mandatory=True),
'group': Property('optional command group of the command.', StringType(),
extname='group', export=True, default=''),
'visibility': Property('optional visibility hint', EnumType('visibility', user=1, advanced=2, expert=3),
extname='visibility', export=True, default=1),
'export': Property('''
[internal] export settings
* False: not accessible via SECoP.
* True: exported, name automatic.
* a string: exported with custom name''',
OrType(BoolType(), StringType()), export=False, default=True),
'optional': Property('[internal] is the command optional to implement? (vs. mandatory)',
BoolType(), export=False, default=False, settable=False),
'datatype': Property('[internal] datatype of the command, auto generated from \'argument\' and \'result\'',
DataTypeType(), extname='datainfo', mandatory=True),
'argument': Property('datatype of the argument to the command, or None',
NoneOr(DataTypeType()), export=False, mandatory=True),
'result': Property('datatype of the result from the command, or None',
NoneOr(DataTypeType()), export=False, mandatory=True),
}
def __init__(self, description=None, *, reorder=False, inherit=True,
internally_called=False, ctr=None, **kwds):
if internally_called:
inherit = False
# make sure either all or no datatype info is in kwds
if 'argument' in kwds or 'result' in kwds:
datatype = CommandType(kwds.get('argument'), kwds.get('result'))
else:
datatype = kwds.get('datatype')
datainfo = {}
datainfo['datatype'] = datatype or CommandType()
datainfo['argument'] = datainfo['datatype'].argument
datainfo['result'] = datainfo['datatype'].result
if datatype:
kwds.update(datainfo)
if description is not None:
kwds['description'] = description
if datatype:
datainfo = {}
super(Command, self).__init__(ctr, **datainfo, **kwds)
if inherit:
if reorder:
kwds['ctr'] = next(object_counter)
self.kwds = kwds
@property
def argument(self):
return self.datatype.argument
@property
def result(self):
return self.datatype.result
class usercommand(Command):
"""decorator to turn a method into a command
:param argument: the datatype of the argument or None
:param result: the datatype of the result or None
:param inherit: whether properties not given should be inherited.
defaults to True when datatype or description is missing, else to False
:param reorder: when True, put this command after all inherited items in the accessible list
:param kwds: optional properties
{all properties}
"""
func = None
def __init__(self, argument=False, result=None, inherit=True, **kwds):
if result or kwds or isinstance(argument, DataType) or not callable(argument):
# normal case
self.func = None
if argument is False and result:
argument = None
if argument is not False:
if isinstance(argument, (tuple, list)):
# goodie: allow declaring multiple arguments as a tuple
# TODO: check that calling works properly
argument = TupleOf(*argument)
kwds['argument'] = argument
kwds['result'] = result
self.kwds = kwds
else:
# goodie: allow @usercommand instead of @usercommand()
self.func = argument # this is the wrapped method!
if argument.__doc__ is not None:
kwds['description'] = argument.__doc__
self.name = self.func.__name__
super().__init__(kwds.pop('description', ''), inherit=inherit, **kwds)
def override(self, from_object=None, **kwds):
result = super().override(from_object, **kwds)
func = kwds.pop('func', from_object.func if from_object else None)
if func:
result(func) # pylint: disable=not-callable
return result
def __set_name__(self, owner, name):
self.name = name
def __get__(self, obj, owner=None):
if obj is None:
return self
if not self.func:
raise ProgrammingError('usercommand %s not properly configured' % self.name)
return self.func.__get__(obj, owner)
def __call__(self, fun):
description = self.kwds.get('description') or fun.__doc__
self.properties['description'] = self.kwds['description'] = description
self.name = fun.__name__
self.func = fun
return self
# list of predefined accessibles with their type
PREDEFINED_ACCESSIBLES = dict(
value = Parameter,
status = Parameter,
target = Parameter,
pollinterval = Parameter,
ramp = Parameter,
user_ramp = Parameter,
setpoint = Parameter,
time_to_target = Parameter,
unit = Parameter, # reserved name
loglevel = Parameter, # reserved name
mode = Parameter, # reserved name
stop = Command,
reset = Command,
go = Command,
abort = Command,
shutdown = Command,
communicate = Command,
)