Make UST-related context fields optional

tracetools_analysis/tracetools_analysis/processor/handler.py

@@ -25,18 +25,44 @@ from tracetools_read.utils import get_field
 class EventMetadata():
     """Container for event metadata."""
 
-    def __init__(self, event_name, pid, tid, timestamp, procname, cpu_id) -> None:
+    def __init__(
+        self,
+        event_name,
+        timestamp,
+        cpu_id,
+        procname = None,
+        pid = None,
+        tid = None,
+    ) -> None:
+        """
+        Constructor.
+
+        Parameters with a default value of `None` are not mandatory,
+        since they are not always present.
+        """
         self._event_name = event_name
+        self._timestamp = timestamp
+        self._cpu_id = cpu_id
+        self._procname = procname
         self._pid = pid
         self._tid = tid
-        self._timestamp = timestamp
-        self._procname = procname
-        self._cpu_id = cpu_id
 
     @property
     def event_name(self):
         return self._event_name
 
+    @property
+    def timestamp(self):
+        return self._timestamp
+
+    @property
+    def cpu_id(self):
+        return self._cpu_id
+
+    @property
+    def procname(self):
+        return self._procname
+
     @property
     def pid(self):
         return self._pid
@@ -45,18 +71,6 @@ class EventMetadata():
     def tid(self):
         return self._tid
 
-    @property
-    def timestamp(self):
-        return self._timestamp
-
-    @property
-    def procname(self):
-        return self._procname
-
-    @property
-    def cpu_id(self):
-        return self._cpu_id
-
 
 class EventHandler():
     """Base event handling class."""
@@ -83,24 +97,29 @@ class EventHandler():
         event_name = get_event_name(event)
         handler_function = self._handler_map.get(event_name, None)
         if handler_function is not None:
+            timestamp = get_field(event, '_timestamp')
+            cpu_id = get_field(event, 'cpu_id')
+            # TODO perhaps validate fields depending on the type of event,
+            # i.e. all UST events should have procname, (v)pid and (v)tid
+            # context info, since analyses might not work otherwise
+            procname = get_field(event, 'procname', raise_if_not_found=False)
             pid = get_field(
                 event,
                 'vpid',
                 default=get_field(
                     event,
                     'pid',
-                    raise_if_not_found=False))
+                    raise_if_not_found=False),
+                raise_if_not_found=False)
             tid = get_field(
                 event,
                 'vtid',
                 default=get_field(
                     event,
                     'tid',
-                    raise_if_not_found=False))
-            timestamp = get_field(event, '_timestamp')
-            procname = get_field(event, 'procname')
-            cpu_id = get_field(event, 'cpu_id')
-            metadata = EventMetadata(event_name, pid, tid, timestamp, procname, cpu_id)
+                    raise_if_not_found=False),
+                raise_if_not_found=False)
+            metadata = EventMetadata(event_name, timestamp, cpu_id, procname, pid, tid)
             handler_function(event, metadata)
 
     @classmethod