L2SS-528: Touched up device & attribute name parsing to have simpler logic and pythonic exceptions.

tangostationcontrol/tangostationcontrol/toolkit/archiver.py

@@ -9,52 +9,51 @@ import json, os
 
 logger = logging.getLogger()
 
-def parse_attribute_name(attribute_name:str):
+def attribute_name_from_url(attribute_name:str):
     """
     For some operations Tango attribute must be transformed from the form 'tango://db:port/domain/family/name/attribute'
     to canonical 'domain/family/name/attribute'
     """
-    chunk_num = len(attribute_name.split('/'))
-    if (chunk_num==7 and attribute_name.split('/')[0]=='tango:'): 
+    if attribute_name.startswith('tango://'):
         return '/'.join(attribute_name.split('/')[3:])
-    else:
-        if (chunk_num!=4):
-            raise AttributeFormatException
-        else:
-            return attribute_name
 
-def parse_device_name(device_name:str, tango_host:str = 'databaseds:10000'):
+    if len(attribute_name.split('/')) != 4:
+        raise ValueError(f"Expected attribute of format 'domain/family/name/attribute', got {attribute_name}")
+
+    return attribute_name
+
+def device_name_url(device_name:str, tango_host:str = 'databaseds:10000'):
     """
     For some operations Tango devices must be transformed from the form 'domain/family/name'
     to 'tango://db:port/domain/family/name'
     """
-    chunk_num = len(device_name.split('/'))
-    if (chunk_num==3):
-        return 'tango://'+tango_host+'/'+device_name
-    elif (chunk_num==6 and device_name.split('/')[0]=='tango:'):
+    if device_name.startswith('tango://'):
         return device_name
-    else:
-        raise ValueError(f'{device_name} is a wrong device name')
+
+    if len(device_name.split('/')) != 3:
+        raise ValueError(f"Expected device name of format 'domain/family/name', got {device_name}")
+
+    return f"tango://{tango_host}/{device_name}"
 
 def split_tango_name(tango_fqname:str, tango_type:str):
     """
     Helper function to split device or attribute Tango full qualified names
     into its components
     """
-    if tango_type.lower()=='device':
+    if tango_type.lower() == 'device':
         try:
             domain, family, member = tango_fqname.split('/')
             return domain, family, member
-        except:
-            raise AttributeFormatException(f"Could not parse device name {tango_fqname}. Please provide FQDN, e.g. STAT/Device/1")
-    elif tango_type.lower()=='attribute':
+        except ValueError as e:
+            raise ValueError(f"Could not parse device name {tango_fqname}. Please provide FQDN, e.g. STAT/Device/1") from e
+    elif tango_type.lower() == 'attribute':
         try:
             domain, family, member, name = tango_fqname.split('/')
             return domain, family, member, name
-        except:
-            raise AttributeFormatException(f"Could not parse attribute name {tango_fqname}. Please provide FQDN, e.g. STAT/Device/1/Attribute")
+        except ValueError as e:
+            raise ValueError(f"Could not parse attribute name {tango_fqname}. Please provide FQDN, e.g. STAT/Device/1/Attribute") from e
     else:
-        raise ValueError(f"Invalid value: {tango_type}. Please set 'device' or 'attribute'")
+        raise ValueError(f"Invalid value: {tango_type}. Please provide 'device' or 'attribute'.")
 
 class Archiver():
     """
@@ -190,7 +189,7 @@ class Archiver():
             es_state = es.state() # ping the device server
             if 'FAULT' in str(es_state):
                 raise Exception(f"{es_name} is in FAULT state")
-            self.cm.ArchiverAdd(parse_device_name(es_name))     
+            self.cm.ArchiverAdd(device_name_url(es_name))
         except Exception as e:
             if 'already_present' in str(e):
                 logger.warning(f"Subscriber {es_name} already present in Configuration Manager")
@@ -204,7 +203,7 @@ class Archiver():
         The ConfigurationManager and EventSubscriber devices must be already up and running.
         The archiving-DBMS must be already properly configured.
         """
-        attribute_name = parse_attribute_name(attribute_name) 
+        attribute_name = attribute_name_from_url(attribute_name)
         try:
             self.cm.write_attribute('SetAttributeName', attribute_name)
             self.cm.write_attribute('SetArchiver', es_name or self.get_next_subscriber())
@@ -250,7 +249,7 @@ class Archiver():
         """
         Stops the data archiving of the attribute passed as input, and remove it from the subscriber's list. 
         """
-        attribute_name = parse_attribute_name(attribute_name)
+        attribute_name = attribute_name_from_url(attribute_name)
         try:
             self.cm.AttributeStop(attribute_name)
             self.cm.AttributeRemove(attribute_name)
@@ -291,7 +290,7 @@ class Archiver():
             exclude_list = [a.lower() for a in exclude]
             attrs_list = [a.lower() for a in list(attributes_nok) if a.lower() not in exclude_list]
             for a in attrs_list:
-                attr_fullname = parse_attribute_name(a)
+                attr_fullname = attribute_name_from_url(a)
                 self.remove_attribute_from_archiver(attr_fullname)
 
     def start_archiving_attribute(self, attribute_name:str):
@@ -299,7 +298,7 @@ class Archiver():
         Starts the archiving of the attribute passed as input.
         The attribute must be already present in the subscriber's list
         """
-        attribute_name = parse_attribute_name(attribute_name)
+        attribute_name = attribute_name_from_url(attribute_name)
         try:
             self.cm.AttributeStart(attribute_name)
         except Exception as e:
@@ -313,7 +312,7 @@ class Archiver():
         Stops the archiving of the attribute passed as input.
         The attribute must be already present in the subscriber's list
         """
-        attribute_name = parse_attribute_name(attribute_name)
+        attribute_name = attribute_name_from_url(attribute_name)
         try:
             self.cm.AttributeStop(attribute_name)
         except Exception as e:
@@ -326,7 +325,7 @@ class Archiver():
         """
         Check if an attribute is in the archiving list
         """
-        attribute_name = parse_attribute_name(attribute_name)
+        attribute_name = attribute_name_from_url(attribute_name)
         attributes = self.cm.AttributeSearch(attribute_name.lower())
         if len(attributes)>1:
             # Handle case same attribute_name r/rw 
@@ -384,7 +383,7 @@ class Archiver():
         """
         Return the error related to the attribute
         """
-        attribute_name = parse_attribute_name(attribute_name)
+        attribute_name = attribute_name_from_url(attribute_name)
         errs_dict = self.get_subscriber_errors()
         for e in errs_dict:
             if attribute_name in e:
@@ -409,7 +408,7 @@ class Archiver():
         """
         Given an attribute name, return the event subscriber associated with it
         """
-        attribute_name = parse_attribute_name(attribute_name)
+        attribute_name = attribute_name_from_url(attribute_name)
         # If the ConfManager manages more than one subscriber
         if len(self.get_subscribers())>1:
             for es_name in self.get_subscribers():
@@ -424,7 +423,7 @@ class Archiver():
         """
         Return the attribute archiving frequency in events/minute 
         """
-        attribute_name = parse_attribute_name(attribute_name)
+        attribute_name = attribute_name_from_url(attribute_name)
         if self.is_attribute_archived(attribute_name):
             es = DeviceProxy(self.get_attribute_subscriber(attribute_name))
             freq_dict = dict((a,r) for a,r in zip(es.AttributeList,es.AttributeRecordFreqList))
@@ -438,7 +437,7 @@ class Archiver():
         """
         Return the attribute failure archiving frequency in events/minute 
         """
-        attribute_name = parse_attribute_name(attribute_name)
+        attribute_name = attribute_name_from_url(attribute_name)
         if self.is_attribute_archived(attribute_name):
             es = DeviceProxy(self.get_attribute_subscriber(attribute_name))
             fail_dict = dict((a,r) for a,r in zip(es.AttributeList,es.AttributeFailureFreqList))