remove asdict() which involves object deep copy.

Signed-off-by: Staszek Pasko <[email protected]>

Author: p88h

vllm/v1/serial_utils.py

@@ -91,8 +91,12 @@ def enc_hook(self, obj: Any) -> Any:
             ret = []
             for elem in obj.values():
                 # Encode as plain dictionary + special handling for .field
-                ret.append(
-                    asdict(elem) | {"field": self._encode_field(elem.field)})
+                ret.append({
+                    "modality": elem.modality,
+                    "key": elem.key,
+                    "data": self._encode_nested_tensors(elem.data),
+                    "field": self._encode_field(elem.field),
+                })
             return ret
 
         if isinstance(obj, FunctionType):
@@ -126,6 +130,11 @@ def _encode_ndarray(
         # backing buffers that we've stashed in `aux_buffers`.
         return obj.dtype.str, obj.shape, data
 
+    def _encode_nested_tensors(self, obj: Any) -> NestedTensors:
+        if isinstance(obj, torch.Tensor):
+            return self._encode_ndarray(obj.numpy())
+        return [self._encode_nested_tensors(x) for x in obj]
+
     def _encode_field(self, field: BaseMultiModalField):
         # Encode the field as a dictionary + special handling for .field
         d = asdict(field)