common read/write handlers

introduce CommonReadHandler and CommonWriteHandler for
better handling of the case when several parameters are
read or written in one go.

- ppms: use common handlers
+ ppms: modify error handling when command result is not OK
+ store poll attribute on read_* methods

Change-Id: I9a9d0972e206956bcb5a83c204fe5f92c69716e3
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/27822
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>
This commit is contained in:
2022-02-23 11:22:53 +01:00
parent 99588fc815
commit bf1761bbc4
4 changed files with 333 additions and 103 deletions

View File

@@ -27,17 +27,17 @@ Example 1: combined read/write for multiple parameters
PID_PARAMS = ['p', 'i', 'd']
@ReadHandler(PID_PARAMS)
def read_pid(self, pname):
@CommonReadHandler(PID_PARAMS)
def read_pid(self):
self.p, self.i, self.d = self.get_pid_from_hw()
return Done # Done is indicating that the parameters are already assigned
# no return value
@WriteHandler(PID_PARAMS)
def write_pid(self, pname, value):
pid = self.get_pid_from_hw() # assume this returns a list
pid[PID_PARAMS.index(pname)] = value
self.put_pid_to_hw(pid)
return self.read_pid()
@CommonWriteHandler(PID_PARAMS)
def write_pid(self, values):
# values is a dict[pname] of value, we convert it to a tuple here
self.put_pid_to_hw(values.as_tuple('p', 'i', 'd'')) # or .as_tuple(*PID_PARAMS)
self.read_pid()
# no return value
Example 2: addressable HW parameters
@@ -62,6 +62,8 @@ class Handler:
func = None
method_names = set() # this is shared among all instances of handlers!
wrapped = True # allow to use read_* or write_* as name of the decorated method
prefix = None # 'read_' or 'write_'
poll = None
def __init__(self, keys):
"""initialize the decorator
@@ -86,55 +88,77 @@ class Handler:
return self
return self.func.__get__(obj, owner)
class ReadHandler(Handler):
"""decorator for read methods"""
def __set_name__(self, owner, name):
"""create the wrapped read_* methods"""
"""create the wrapped read_* or write_* methods"""
self.method_names.discard(self.func.__qualname__)
for key in self.keys:
@wraps(self.func)
def wrapped(module, pname=key, func=self.func):
value = func(module, pname)
if value is not Done:
setattr(module, pname, value)
return value
wrapped = self.wrap(key)
method_name = self.prefix + key
wrapped.wrapped = True
method = 'read_' + key
rfunc = getattr(owner, method, None)
if rfunc and not rfunc.wrapped:
raise ProgrammingError('superfluous method %s.%s (overwritten by ReadHandler)'
% (owner.__name__, method))
setattr(owner, method, wrapped)
if self.poll is not None:
# wrapped.poll is False when the nopoll decorator is applied either to self.func or to self
wrapped.poll = getattr(wrapped, 'poll', self.poll)
func = getattr(owner, method_name, None)
if func and not func.wrapped:
raise ProgrammingError('superfluous method %s.%s (overwritten by %s)'
% (owner.__name__, method_name, self.__class__.__name__))
setattr(owner, method_name, wrapped)
def wrap(self, key):
"""create wrapped method from self.func
with name self.prefix + key"""
raise NotImplementedError
class ReadHandler(Handler):
"""decorator for read handler methods"""
prefix = 'read_'
poll = True
def wrap(self, key):
def method(module, pname=key, func=self.func):
value = func(module, pname)
if value is not Done:
setattr(module, pname, value)
return value
return wraps(self.func)(method)
class CommonReadHandler(ReadHandler):
"""decorator for a handler reading several parameters in one go"""
def __init__(self, keys):
"""initialize the decorator
:param keys: parameter names (an iterable)
"""
super().__init__(keys)
self.first_key = next(iter(keys))
def wrap(self, key):
def method(module, func=self.func):
ret = func(module)
if ret not in (None, Done):
raise ProgrammingError('a method wrapped with CommonReadHandler must not return any value')
method = wraps(self.func)(method)
method.poll = self.poll if key == self.first_key else False
return method
class WriteHandler(Handler):
"""decorator for write methods"""
"""decorator for write handler methods"""
prefix = 'write_'
def __set_name__(self, owner, name):
"""create the wrapped write_* methods"""
self.method_names.discard(self.func.__qualname__)
for key in self.keys:
@wraps(self.func)
def wrapped(module, value, pname=key, func=self.func):
value = func(module, pname, value)
if value is not Done:
setattr(module, pname, value)
return value
wrapped.wrapped = True
method = 'write_' + key
wfunc = getattr(owner, method, None)
if wfunc and not wfunc.wrapped:
raise ProgrammingError('superfluous method %s.%s (overwritten by WriteHandler)'
% (owner.__name__, method))
setattr(owner, method, wrapped)
def wrap(self, key):
@wraps(self.func)
def method(module, value, pname=key, func=self.func):
value = func(module, pname, value)
if value is not Done:
setattr(module, pname, value)
return value
return method
class WriteParameters(dict):
@@ -153,33 +177,30 @@ class WriteParameters(dict):
return tuple(self[k] for k in keys)
class MultiWriteHandler(Handler):
class CommonWriteHandler(WriteHandler):
"""decorator for common write handler
calls the wrapped write method function with values as an argument.
- values[pname] returns the to be written value
- values['key'] returns a value taken from writeDict
- or, if not available return obj.key
or, if not available return obj.key
- values.as_tuple() returns a tuple with the items in the same order as keys
"""
def __set_name__(self, owner, name):
"""create the wrapped write_* methods"""
def wrap(self, key):
@wraps(self.func)
def method(module, value, pname=key, func=self.func):
values = WriteParameters(module)
values[pname] = value
ret = func(module, values)
if ret not in (None, Done):
raise ProgrammingError('a method wrapped with CommonWriteHandler must not return any value')
# remove pname from writeDict. this was not removed in WriteParameters, as it was not missing
module.writeDict.pop(pname, None)
return method
self.method_names.discard(self.func.__qualname__)
for key in self.keys:
@wraps(self.func)
def wrapped(module, value, pname=key, func=self.func):
values = WriteParameters(module)
values[pname] = value
func(module, values)
return Done
wrapped.wrapped = True
method = 'write_' + key
wfunc = getattr(owner, method, None)
if wfunc and not wfunc.wrapped:
raise ProgrammingError('superfluous method %s.%s (overwritten by WriteHandler)'
% (owner.__name__, method))
setattr(owner, method, wrapped)
def nopoll(func):
"""decorator to indicate that a read method is not to be polled"""
func.poll = False
return func