Model: Migrate backend detection to a separate function

Seemed out of place in the common load function. In addition, rename
the transformers utils signature which actually takes a directory
instead of a file.

Signed-off-by: kingbri <8082010+kingbri1@users.noreply.github.com>

common/model.py

@@ -57,6 +57,24 @@ def load_progress(module, modules):
     yield module, modules
 
 
+async def detect_backend(model_path: pathlib.Path) -> str:
+    """Determine the appropriate backend based on model files and configuration."""
+
+    try:
+        hf_config = await HuggingFaceConfig.from_directory(model_path)
+        quant_method = hf_config.quant_method()
+
+        if quant_method == "exl3":
+            return "exllamav3"
+        else:
+            return "exllamav2"
+    except Exception as exc:
+        raise ValueError(
+            "Failed to read the model's config.json. "
+            f"Please check your model directory at {model_path}."
+        ) from exc
+
+
 async def apply_inline_overrides(model_dir: pathlib.Path, **kwargs):
     """Sets overrides from a model folder's config yaml."""
 
@@ -124,24 +142,11 @@ async def load_model_gen(model_path: pathlib.Path, **kwargs):
     kwargs = {**config.model_defaults, **kwargs}
     kwargs = await apply_inline_overrides(model_path, **kwargs)
 
-    # Read config.json and detect the quant method
-    hf_config_path = model_path / "config.json"
-    if hf_config_path.exists():
-        try:
-            hf_config = await HuggingFaceConfig.from_file(model_path)
-        except Exception as exc:
-            raise ValueError(
-                "Failed to read the model's config.json. "
-                f"Please check your model directory at {model_path}."
-            ) from exc
-    quant_method = hf_config.quant_method()
-    if quant_method == "exl3":
-        backend_name = "exllamav3"
-    else:
-        backend_name = "exllamav2"
-
     # Create a new container and check if the right dependencies are installed
-    backend_name = unwrap(kwargs.get("backend"), backend_name).lower()
+    backend_name = unwrap(
+        kwargs.get("backend"), await detect_backend(model_path)
+    ).lower()
+    print(backend_name)
     container_class = _BACKEND_REGISTRY.get(backend_name)
 
     if not container_class:

common/transformers_utils.py

@@ -45,7 +45,7 @@ class HuggingFaceConfig(BaseModel):
     quantization_config: Optional[Dict] = None
 
     @classmethod
-    async def from_file(cls, model_directory: pathlib.Path):
+    async def from_directory(cls, model_directory: pathlib.Path):
         """Create an instance from a generation config file."""
 
         hf_config_path = model_directory / "config.json"