fix: preserve flushed buffers during stop_streaming

pybela/Streamer.py

@@ -273,7 +273,47 @@ async def _async_stop_streaming(self, variables=[]):
             if not _previous_streaming_mode == "PEEK":
                 _print_info(f"Stopped monitoring variables {variables}...")
 
-        self._processed_data_msg_queue = asyncio.Queue()  # clear processed data queue
+        # collect any remaining flushed buffers before clearing the queue
+        # this assures users don't lose final data chunks when stopping streaming
+        try:
+            remaining_messages = []
+            # safely drain the queue without blocking
+            while not self._processed_data_msg_queue.empty():
+                try:
+                    msg = self._processed_data_msg_queue.get_nowait()
+                    remaining_messages.append(msg)
+                    self._processed_data_msg_queue.task_done()
+                except asyncio.QueueEmpty:
+                    # queue became empty during iteration, which is fine
+                    break
+                except Exception:
+                    # any other error, stop processing but don't fail
+                    break
+
+            # process remaining messages by adding them to streaming buffers
+            # this preserves the data for user access via streaming_buffers_queue
+            for msg in remaining_messages:
+                try:
+                    var_name = msg.get("name")
+                    buffer_data = msg.get("buffer")
+                    # only process if we have valid data and the variable exists in our buffers
+                    if (var_name and buffer_data is not None and 
+                        hasattr(self, 'streaming_buffers_queue') and
+                        self.streaming_buffers_queue and 
+                        var_name in self.streaming_buffers_queue):
+                        self.streaming_buffers_queue[var_name].append(buffer_data)
+                except Exception:
+                    # if individual message processing fails, continue with others
+                    # this ensures one bad message doesn't break the entire cleanup
+                    continue
+
+        except Exception:
+            # if the entire buffer collection process fails, don't break stop_streaming
+            # fall back to original behavior (queue clearing without collection)
+            pass
+
+        # always clear the queue, regardless of collection success/failure
+        self._processed_data_msg_queue = asyncio.Queue()
         self._on_buffer_callback_is_active = False
         if self._on_buffer_callback_worker_task:
             self._on_buffer_callback_worker_task.cancel()