lib: make discarded events/packets support and clock snapshots optional

[babeltrace.git] / bindings / python / bt2 / bt2 / message_iterator.py

diff --git a/bindings/python/bt2/bt2/message_iterator.py b/bindings/python/bt2/bt2/message_iterator.py
index 7ac98f3dfcf64c35792972ae675c9a7695c757c6..fad4c4d608f8a00853dcdc9b1f2aaff2b74901ea 100644 (file)
--- a/bindings/python/bt2/bt2/message_iterator.py
+++ b/bindings/python/bt2/bt2/message_iterator.py
@@ -276,15 +276,23 @@ class _UserMessageIterator(_MessageIterator):
                                          end_clock_snapshot=None):
         utils._check_type(stream, bt2.stream._Stream)
 
-        if beg_clock_snapshot is None and end_clock_snapshot is None:
-            ptr = native_bt.message_discarded_events_create(self._ptr, stream._ptr)
-        elif beg_clock_snapshot is not None and end_clock_snapshot is not None:
+        if not stream.stream_class.supports_discarded_events:
+            raise ValueError('stream class does not support discarded events')
+
+        if stream.stream_class.discarded_events_have_default_clock_snapshots:
+            if beg_clock_snapshot is None or end_clock_snapshot is None:
+                raise ValueError('discarded events have default clock snapshots for this stream class')
+
             utils._check_uint64(beg_clock_snapshot)
             utils._check_uint64(end_clock_snapshot)
             ptr = native_bt.message_discarded_events_create_with_default_clock_snapshots(
                 self._ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot)
         else:
-            raise ValueError('begin and end clock snapshots must be both provided or both omitted')
+            if beg_clock_snapshot is not None or end_clock_snapshot is not None:
+                raise ValueError('discarded events have no default clock snapshots for this stream class')
+
+            ptr = native_bt.message_discarded_events_create(
+                self._ptr, stream._ptr)
 
         if ptr is None:
             raise bt2.CreationError('cannot discarded events message object')
@@ -299,15 +307,23 @@ class _UserMessageIterator(_MessageIterator):
     def _create_discarded_packets_message(self, stream, count=None, beg_clock_snapshot=None, end_clock_snapshot=None):
         utils._check_type(stream, bt2.stream._Stream)
 
-        if beg_clock_snapshot is None and end_clock_snapshot is None:
-            ptr = native_bt.message_discarded_packets_create(self._ptr, stream._ptr)
-        elif beg_clock_snapshot is not None and end_clock_snapshot is not None:
+        if not stream.stream_class.supports_discarded_packets:
+            raise ValueError('stream class does not support discarded packets')
+
+        if stream.stream_class.discarded_packets_have_default_clock_snapshots:
+            if beg_clock_snapshot is None or end_clock_snapshot is None:
+                raise ValueError('discarded packets have default clock snapshots for this stream class')
+
             utils._check_uint64(beg_clock_snapshot)
             utils._check_uint64(end_clock_snapshot)
             ptr = native_bt.message_discarded_packets_create_with_default_clock_snapshots(
                 self._ptr, stream._ptr, beg_clock_snapshot, end_clock_snapshot)
         else:
-            raise ValueError('begin and end clock snapshots must be both provided or both omitted')
+            if beg_clock_snapshot is not None or end_clock_snapshot is not None:
+                raise ValueError('discarded packets have no default clock snapshots for this stream class')
+
+            ptr = native_bt.message_discarded_packets_create(
+                self._ptr, stream._ptr)
 
         if ptr is None:
             raise bt2.CreationError('cannot discarded packets message object')