fix: make --load-8bit flag work with weights in safetensors format

Author: xuguodong1999

fastchat/model/compression.py

@@ -168,15 +168,27 @@ def load_compress_model(model_path, device, torch_dtype, use_fast, revision="mai
         base_pattern = os.path.join(model_path, "pytorch_model*.bin")
 
     files = glob.glob(base_pattern)
+    use_safetensors = False
+    if len(files) == 0:
+        base_pattern = os.path.join(model_path, "*.safetensors")
+        files = glob.glob(base_pattern)
+        use_safetensors = True
     if len(files) == 0:
         raise ValueError(
             f"Cannot find any model weight files. "
             f"Please check your (cached) weight path: {model_path}"
         )
 
     compressed_state_dict = {}
+    if use_safetensors:
+        from safetensors.torch import load_file
     for filename in tqdm(files):
-        tmp_state_dict = torch.load(filename, map_location=lambda storage, loc: storage)
+        if use_safetensors:
+            tmp_state_dict = load_file(filename)
+        else:
+            tmp_state_dict = torch.load(
+                filename, map_location=lambda storage, loc: storage
+            )
         for name in tmp_state_dict:
             if name in linear_weights:
                 tensor = tmp_state_dict[name].to(device, dtype=torch_dtype)