fix the wrapper of the model.

Signed-off-by: wxywb <xy.wang@zilliz.com>

clip.py

@@ -54,25 +54,20 @@ class Clip(NNOperator):
         self.model_name = model_name
         self.modality = modality
         self.device = device
+        self.checkpoint_path = checkpoint_path
         cfg = self._configs()[model_name]
         try:
             clip_model = CLIPModel.from_pretrained(cfg)
         except Exception as e:
             log.error(f"Fail to load model by name: {self.model_name}")
             raise e
-        if checkpoint_path:
-            try:
-                state_dict = torch.load(checkpoint_path, map_location=self.device)
-                self.model.load_state_dict(state_dict)
-            except Exception as e:
-                log.error(f"Fail to load state dict from {checkpoint_path}: {e}")
+
         if self.modality == 'image':
-            self.model = CLIPModelVision(clip_model)
+            self.model = CLIPModelVision(self._model)
         elif self.modality == 'text':
-            self.model = CLIPModelText(clip_model)
+            self.model = CLIPModelText(self._model)
         else:
             raise ValueError("modality[{}] not implemented.".format(self.modality))
-        self.model.to(self.device)
         self.tokenizer = CLIPTokenizer.from_pretrained(cfg)
         self.processor =  CLIPProcessor.from_pretrained(cfg)
 
@@ -153,7 +148,21 @@ class Clip(NNOperator):
 
     @property
     def _model(self):
-        return self.model
+        cfg = self._configs()[self.model_name]
+        try:
+            hf_clip_model = CLIPModel.from_pretrained(cfg)
+        except Exception as e:
+            log.error(f"Fail to load model by name: {self.model_name}")
+            raise e
+        if self.checkpoint_path:
+            try:
+                state_dict = torch.load(self.checkpoint_path, map_location=self.device)
+                hf_clip_model.load_state_dict(state_dict)
+            except Exception as e:
+                log.error(f"Fail to load state dict from {checkpoint_path}: {e}")
+        hf_clip_model.to(self.device)
+        hf_clip_model.eval()
+        return hf_clip_model
 
     def save_model(self, model_type: str = 'pytorch', output_file: str = 'default'):
         import os