configurables must contain only settable properties

+ bug fix in TCLRequestHandler (decoding error)
+ cosmetic changes

Change-Id: I824e06f1acf975bb59c3312bb97fdfca23e6c975
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/21826
Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

secop/metaclass.py

@@ -194,10 +194,12 @@ class ModuleMeta(PropertyMeta):
         res = {}
         # collect info about properties
         for pn, pv in cls.properties.items():
+            if pv.settable:
                 res[pn] = pv
         # collect info about parameters and their properties
         for param, pobj in cls.accessibles.items():
             res[param] = {}
             for pn, pv in pobj.getProperties().items():
+                if pv.settable:
                     res[param][pn] = pv
         return res

secop/modules.py

@@ -200,8 +200,7 @@ class Module(HasProperties, metaclass=ModuleMeta):
                 raise
                 # raise ConfigError('Module %s: config parameter %r:\n%r' %
                 #                   (self.name, k, e))
-            # note: this will call write_* methods which will
-            # write to the hardware, if possible!
+            # note: this will NOT call write_* methods!
             if k != 'value':
                 setattr(self, k, v)
             cfgdict.pop(k)

secop/protocol/interface/tcp.py

@@ -122,7 +122,8 @@ class TCPRequestHandler(socketserver.BaseRequestHandler):
                 try:
                     msg = decode_msg(origin)
                 except Exception as err:
-                    msg = origin.split(' ',3)
+                    # we have to decode 'origin' here. utf-8 and ascii may lead to encoding errors
+                    msg = origin.decode('latin-1').split(' ', 3)
                     result = (ERRORPREFIX + msg[0], msg[1], ['InternalError', str(err),
                                                              {'exception': formatException(),
                                                               'traceback': formatExtendedStack()}])