Added missing file

server/lorax_server/adapters/utils.py

@@ -0,0 +1,31 @@
+from typing import Optional
+
+from huggingface_hub import HfApi
+
+from lorax_server.utils.sources import HUB, PBASE, S3, get_model_source, map_pbase_model_id_to_s3
+from lorax_server.utils.weights import download_weights
+
+
+def download_adapter(
+    adapter_id: str,
+    adapter_source: str,
+    api_token: Optional[str] = None,
+) -> int:
+    if adapter_source == PBASE:
+        adapter_id = map_pbase_model_id_to_s3(adapter_id, api_token)
+        adapter_source = S3
+
+    if adapter_source == HUB:
+        # Quick auth check on the repo against the token
+        HfApi(token=api_token).model_info(adapter_id, revision=None)
+
+    # fail fast if ID is not an adapter (i.e. it is a full model)
+    source = get_model_source(adapter_source, adapter_id, extension=".safetensors", api_token=api_token)
+    source.load_config()
+
+    download_weights(
+        adapter_id, source=adapter_source, api_token=api_token
+    )
+
+    # Calculate size of adapter to be loaded
+    return source.get_weight_bytes()