dgstreams: implemented protection against double connection

DeGirum · Nov 11, 2024 · 5ec112c · 5ec112c
1 parent b6836b8
commit 5ec112c
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Showing 2 changed files with 11 additions and 3 deletions.
diff --git a/degirum_tools/streams_base.py b/degirum_tools/streams_base.py
@@ -244,9 +244,9 @@ def connect_to(self, other_gizmo, inp: Union[int, Stream] = 0):
 
         Returns self
         """
-        other_gizmo._output_refs.append(
-            self.get_input(inp) if isinstance(inp, int) else inp
-        )
+        inp_stream = self.get_input(inp) if isinstance(inp, int) else inp
+        if not inp_stream in other_gizmo._output_refs:
+            other_gizmo._output_refs.append(inp_stream)
         self._connected_gizmos.add(other_gizmo)
         other_gizmo._connected_gizmos.add(self)
         return self

diff --git a/test/test_streams.py b/test/test_streams.py
@@ -57,7 +57,15 @@ def test_streams_connection(short_video):
     source = streams.VideoSourceGizmo(short_video)
     sink = VideoSink()
     c = streams.Composition(source >> sink)
+    assert source._connected_gizmos == {sink}
+    assert sink._connected_gizmos == {source}
+    assert set(c._gizmos) == {source, sink}
 
+    # double connection: should be the same as single connection
+    source = streams.VideoSourceGizmo(short_video)
+    sink = VideoSink()
+    c = streams.Composition(source >> sink, source >> sink)
+    assert len(source._output_refs) == 1 and source._output_refs[0] is sink.get_input(0)
     assert source._connected_gizmos == {sink}
     assert sink._connected_gizmos == {source}
     assert set(c._gizmos) == {source, sink}