make return value 'Done' unneccessary

'Done' was introduced in order to suppress unneccessary
duplicate updates. However, since super calls on access methods are
allowed, it is not nice when such a method returns Done, as this
is not automagically replaced by the current parameter value.
As a consequence:

- using Done is discouraged, but not (yet) removed in all code
- the 'omit_unchanged_within' property is moved from Module to an
  internal Parameter property 'update_unchanged'
- its default is moved from a SEC node property to generalConfig
- the 'update_unchanged' parameter property may be set to
  'never' for parameters where duplicate updates make no sense
- this property might be set to 'always', for measurements, where
  even unchanged values taken from HW should be transmitted

Change-Id: I2847c983ca09c2c4098e402edd08d0c96c3913f4
Reviewed-on: https://forge.frm2.tum.de/review/c/secop/frappy/+/30672
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

test/test_handler.py

@@ -23,7 +23,8 @@
 
 from frappy.rwhandler import ReadHandler, WriteHandler, \
     CommonReadHandler, CommonWriteHandler, nopoll
-from frappy.core import Module, Parameter, FloatRange, Done
+from frappy.core import Module, Parameter, FloatRange
+from frappy.lib import generalConfig
 
 
 class DispatcherStub:
@@ -31,9 +32,9 @@ class DispatcherStub:
     # initial value from the timestamp. However, in the test below
     # the second update happens after the updates dict is cleared
     # -> we have to inhibit the 'omit unchanged update' feature
-    omit_unchanged_within = 0
 
     def __init__(self, updates):
+        generalConfig.testinit(omit_unchanged_within=0)
         self.updates = updates
 
     def announce_update(self, modulename, pname, pobj):
@@ -104,7 +105,7 @@ def test_handler():
     assert m.b == 7
     assert data.pop() == 'b'
 
-    data.append(Done)
+    data.append(m.b)
     assert m.read_b() == 7
     assert data.pop() == 'b'
 

test/test_modules.py

@@ -31,6 +31,7 @@ from frappy.errors import ProgrammingError, ConfigError
 from frappy.modules import Communicator, Drivable, Readable, Module
 from frappy.params import Command, Parameter
 from frappy.rwhandler import ReadHandler, WriteHandler, nopoll
+from frappy.lib import generalConfig
 
 
 class DispatcherStub:
@@ -38,9 +39,9 @@ class DispatcherStub:
     # initial value from the timestamp. However, in the test below
     # the second update happens after the updates dict is cleared
     # -> we have to inhibit the 'omit unchanged update' feature
-    omit_unchanged_within = 0
 
     def __init__(self, updates):
+        generalConfig.testinit(omit_unchanged_within=0)
         self.updates = updates
 
     def announce_update(self, modulename, pname, pobj):
@@ -239,12 +240,12 @@ def test_ModuleMagic():
         'export', 'group', 'description', 'features',
         'meaning', 'visibility', 'implementation', 'interface_classes', 'target', 'stop',
         'status', 'param1', 'param2', 'cmd', 'a2', 'pollinterval', 'slowinterval', 'b2',
-        'cmd2', 'value', 'a1'}
+        'cmd2', 'value', 'a1', 'omit_unchanged_within'}
     assert set(cfg['value'].keys()) == {
         'group', 'export', 'relative_resolution',
         'visibility', 'unit', 'default', 'value', 'datatype', 'fmtstr',
         'absolute_resolution', 'max', 'min', 'readonly', 'constant',
-        'description', 'needscfg'}
+        'description', 'needscfg', 'update_unchanged'}
 
     # check on the level of classes
     # this checks Newclass1 too, as it is inherited by Newclass2
@@ -739,3 +740,46 @@ def test_write_method_returns_none():
     mod = Mod('mod', LoggerStub(), {'description': ''}, ServerStub({}))
     mod.write_a(1.5)
     assert mod.a == 1.5
+
+
+@pytest.mark.parametrize('arg, value', [
+    ('always', 0),
+    (0, 0),
+    ('never', 999999999),
+    (999999999, 999999999),
+    ('default', 0.25),
+    (1, 1),
+])
+def test_update_unchanged_ok(arg, value):
+    srv = ServerStub({})
+    generalConfig.testinit(omit_unchanged_within=0.25)  # override value from DispatcherStub
+
+    class Mod1(Module):
+        a = Parameter('', FloatRange(), default=0, update_unchanged=arg)
+
+    mod1 = Mod1('mod1', LoggerStub(), {'description': ''}, srv)
+    par = mod1.parameters['a']
+    assert par.omit_unchanged_within == value
+    assert Mod1.a.omit_unchanged_within == 0
+
+    class Mod2(Module):
+        a = Parameter('', FloatRange(), default=0)
+
+    mod2 = Mod2('mod2', LoggerStub(), {'description': '', 'a': {'update_unchanged': arg}}, srv)
+    par = mod2.parameters['a']
+    assert par.omit_unchanged_within == value
+    assert Mod2.a.omit_unchanged_within == 0
+
+
+def test_omit_unchanged_within():
+    srv = ServerStub({})
+    generalConfig.testinit(omit_unchanged_within=0.25)  # override call from DispatcherStub
+
+    class Mod(Module):
+        a = Parameter('', FloatRange())
+
+    mod1 = Mod('mod1', LoggerStub(), {'description': ''}, srv)
+    assert mod1.parameters['a'].omit_unchanged_within == 0.25
+
+    mod2 = Mod('mod2', LoggerStub(), {'description': '', 'omit_unchanged_within': 0.125}, srv)
+    assert mod2.parameters['a'].omit_unchanged_within == 0.125

test/test_params.py

@@ -109,3 +109,21 @@ def test_Export():
     class Mod(HasAccessibles):
         param = Parameter('description1', datatype=BoolType, default=False)
     assert Mod.param.export == '_param'
+
+
+@pytest.mark.parametrize('arg, value', [
+    ('always', 0),
+    (0, 0),
+    ('never', 999999999),
+    (999999999, 999999999),
+    (1, 1),
+])
+def test_update_unchanged_ok(arg, value):
+    par = Parameter('', datatype=FloatRange(), default=0, update_unchanged=arg)
+    assert par.update_unchanged == value
+
+
+@pytest.mark.parametrize('arg', ['alws', '', -2, -0.1, None])
+def test_update_unchanged_fail(arg):
+    with pytest.raises(ProgrammingError):
+        Parameter('', datatype=FloatRange(), default=0, update_unchanged=arg)

test/test_poller.py

@@ -31,6 +31,7 @@ import pytest
 
 from frappy.core import Module, Parameter, FloatRange, Readable, ReadHandler, nopoll
 from frappy.lib.multievent import MultiEvent
+from frappy.lib import generalConfig
 
 
 class Time:
@@ -66,13 +67,14 @@ class DispatcherStub:
 
 class ServerStub:
     def __init__(self):
+        generalConfig.testinit()
         self.dispatcher = DispatcherStub()
 
 
 class Base(Module):
     def __init__(self):
         srv = ServerStub()
-        super().__init__('mod', logging.getLogger('dummy'), dict(description=''), srv)
+        super().__init__('mod', logging.getLogger('dummy'), {'description': ''}, srv)
         self.dispatcher = srv.dispatcher
 
     def run(self, maxcycles):

test/test_statemachine.py

@@ -24,6 +24,7 @@
 from frappy.core import Drivable, Parameter
 from frappy.datatypes import StatusType, Enum
 from frappy.states import StateMachine, Stop, Retry, Finish, Start, HasStates, status_code
+from frappy.lib import generalConfig
 
 
 class LoggerStub:
@@ -189,9 +190,9 @@ class DispatcherStub:
     # initial value from the timestamp. However, in the test below
     # the second update happens after the updates dict is cleared
     # -> we have to inhibit the 'omit unchanged update' feature
-    omit_unchanged_within = 0
 
     def __init__(self, updates):
+        generalConfig.testinit(omit_unchanged_within=0)
         self.updates = updates
 
     def announce_update(self, modulename, pname, pobj):