chore: Refactor embeddings instantiation to use a singleton pattern

application/vectorstore/base.py

@@ -8,21 +8,21 @@ from langchain_community.embeddings import (
 from langchain_openai import OpenAIEmbeddings
 from application.core.settings import settings
 
-class BaseVectorStore(ABC):
-    def __init__(self):
-        pass
-
-    @abstractmethod
-    def search(self, *args, **kwargs):
-        pass
+class EmbeddingsSingleton:
+    _instances = {}
 
-    def is_azure_configured(self):
-        return settings.OPENAI_API_BASE and settings.OPENAI_API_VERSION and settings.AZURE_DEPLOYMENT_NAME
+    @staticmethod
+    def get_instance(embeddings_name, *args, **kwargs):
+        if embeddings_name not in EmbeddingsSingleton._instances:
+            EmbeddingsSingleton._instances[embeddings_name] = EmbeddingsSingleton._create_instance(embeddings_name, *args, **kwargs)
+        return EmbeddingsSingleton._instances[embeddings_name]
 
-    def _get_embeddings(self, embeddings_name, embeddings_key=None):
+    @staticmethod
+    def _create_instance(embeddings_name, *args, **kwargs):
         embeddings_factory = {
             "openai_text-embedding-ada-002": OpenAIEmbeddings,
             "huggingface_sentence-transformers/all-mpnet-base-v2": HuggingFaceEmbeddings,
+            "huggingface_sentence-transformers-all-mpnet-base-v2": HuggingFaceEmbeddings,
             "huggingface_hkunlp/instructor-large": HuggingFaceInstructEmbeddings,
             "cohere_medium": CohereEmbeddings
         }
@@ -30,32 +30,50 @@ class BaseVectorStore(ABC):
         if embeddings_name not in embeddings_factory:
             raise ValueError(f"Invalid embeddings_name: {embeddings_name}")
 
+        return embeddings_factory[embeddings_name](*args, **kwargs)
+
+class BaseVectorStore(ABC):
+    def __init__(self):
+        pass
+
+    @abstractmethod
+    def search(self, *args, **kwargs):
+        pass
+
+    def is_azure_configured(self):
+        return settings.OPENAI_API_BASE and settings.OPENAI_API_VERSION and settings.AZURE_DEPLOYMENT_NAME
+
+    def _get_embeddings(self, embeddings_name, embeddings_key=None):
         if embeddings_name == "openai_text-embedding-ada-002":
             if self.is_azure_configured():
                 os.environ["OPENAI_API_TYPE"] = "azure"
-                embedding_instance = embeddings_factory[embeddings_name](
+                embedding_instance = EmbeddingsSingleton.get_instance(
+                    embeddings_name,
                     model=settings.AZURE_EMBEDDINGS_DEPLOYMENT_NAME
                 )
             else:
-                embedding_instance = embeddings_factory[embeddings_name](
+                embedding_instance = EmbeddingsSingleton.get_instance(
+                    embeddings_name,
                     openai_api_key=embeddings_key
                 )
         elif embeddings_name == "cohere_medium":
-            embedding_instance = embeddings_factory[embeddings_name](
+            embedding_instance = EmbeddingsSingleton.get_instance(
+                embeddings_name,
                 cohere_api_key=embeddings_key
             )
         elif embeddings_name == "huggingface_sentence-transformers/all-mpnet-base-v2":
             if os.path.exists("./model/all-mpnet-base-v2"):
-                embedding_instance = embeddings_factory[embeddings_name](
+                embedding_instance = EmbeddingsSingleton.get_instance(
+                    embeddings_name,
                     model_name="./model/all-mpnet-base-v2",
-                    model_kwargs={"device": "cpu"},
+                    model_kwargs={"device": "cpu"}
                 )
             else:
-                embedding_instance = embeddings_factory[embeddings_name](
-                    model_kwargs={"device": "cpu"},
+                embedding_instance = EmbeddingsSingleton.get_instance(
+                    embeddings_name,
+                    model_kwargs={"device": "cpu"}
                 )
         else:
-            embedding_instance = embeddings_factory[embeddings_name]()
+            embedding_instance = EmbeddingsSingleton.get_instance(embeddings_name)
 
         return embedding_instance
-