Speed up load of embedding models and hence app start when no internet

- Set `local_files_only=True' when not connected to internet.
- This variable is passed through sentence_transformers library to huggingface_hub.
- Huggingface_hub directly looks for model on disk rather than trying to
  retrieve it from huggingface when `local_files_only=True'.
- This speeds up model load time on app start.

See https://github.com/UKPLab/sentence-transformers/pull/2603 for
details

pyproject.toml

@@ -52,7 +52,7 @@ dependencies = [
     "pyyaml ~= 6.0",
     "rich >= 13.3.1",
     "schedule == 1.1.0",
-    "sentence-transformers == 2.5.1",
+    "sentence-transformers == 3.0.0",
     "transformers >= 4.28.0",
     "torch == 2.2.2",
     "uvicorn == 0.17.6",

src/khoj/processor/embeddings.py

@@ -13,7 +13,7 @@ from tenacity import (
 )
 from torch import nn
 
-from khoj.utils.helpers import get_device, merge_dicts
+from khoj.utils.helpers import get_device, is_internet_connected, merge_dicts
 from khoj.utils.rawconfig import SearchResponse
 
 logger = logging.getLogger(__name__)
@@ -31,9 +31,10 @@ class EmbeddingsModel:
     ):
         default_query_encode_kwargs = {"show_progress_bar": False, "normalize_embeddings": True}
         default_docs_encode_kwargs = {"show_progress_bar": True, "normalize_embeddings": True}
+        default_model_kwargs = {"device": get_device(), "local_files_only": not is_internet_connected(timeout=5)}
         self.query_encode_kwargs = merge_dicts(query_encode_kwargs, default_query_encode_kwargs)
         self.docs_encode_kwargs = merge_dicts(docs_encode_kwargs, default_docs_encode_kwargs)
-        self.model_kwargs = merge_dicts(model_kwargs, {"device": get_device()})
+        self.model_kwargs = merge_dicts(model_kwargs, default_model_kwargs)
         self.model_name = model_name
         self.inference_endpoint = embeddings_inference_endpoint
         self.api_key = embeddings_inference_endpoint_api_key
@@ -97,7 +98,9 @@ class CrossEncoderModel:
         cross_encoder_inference_endpoint_api_key: str = None,
     ):
         self.model_name = model_name
-        self.cross_encoder_model = CrossEncoder(model_name=self.model_name, device=get_device())
+        self.cross_encoder_model = CrossEncoder(
+            model_name=self.model_name, device=get_device(), local_files_only=not is_internet_connected(timeout=5)
+        )
         self.inference_endpoint = cross_encoder_inference_endpoint
         self.api_key = cross_encoder_inference_endpoint_api_key
 

src/khoj/utils/helpers.py

@@ -404,9 +404,9 @@ def is_valid_url(url: str) -> bool:
         return False
 
 
-def is_internet_connected():
+def is_internet_connected(timeout=None):
     try:
-        response = requests.head("https://www.google.com")
+        response = requests.head("https://www.google.com", timeout=timeout)
         return response.status_code == 200
     except:
         return False