refactor: reduce logging of SQLite pragmas and enhance model provider type safety (#5235)

* feat: add ModelProvidersDict TypedDict and update MODEL_PROVIDERS_DICT type annotation

- Introduced ModelProvidersDict as a TypedDict to define the structure for model provider configurations.
- Updated MODEL_PROVIDERS_DICT to use the new TypedDict for improved type safety and clarity.
- Enhanced code readability and maintainability by specifying input types for model providers.

* fix: prevent duplicate logging of SQLite pragmas in DatabaseService

- Added a flag to track whether SQLite pragmas have been logged to avoid redundant log entries.
- Improved logging efficiency by ensuring that the debug message for setting pragmas is only logged once per session.

src/backend/base/langflow/base/models/model_input_constants.py

@@ -1,3 +1,5 @@
+from typing_extensions import TypedDict
+
 from langflow.base.models.model import LCModelComponent
 from langflow.components.models.amazon_bedrock import AmazonBedrockComponent
 from langflow.components.models.anthropic import AnthropicModelComponent
@@ -5,7 +7,14 @@ from langflow.components.models.azure_openai import AzureChatOpenAIComponent
 from langflow.components.models.groq import GroqModel
 from langflow.components.models.nvidia import NVIDIAModelComponent
 from langflow.components.models.openai import OpenAIModelComponent
-from langflow.inputs.inputs import SecretStrInput
+from langflow.inputs.inputs import InputTypes, SecretStrInput
+
+
+class ModelProvidersDict(TypedDict):
+    fields: dict
+    inputs: list[InputTypes]
+    prefix: str
+    component_class: LCModelComponent
 
 
 def get_filtered_inputs(component_class):
@@ -99,7 +108,7 @@ def _get_amazon_bedrock_inputs_and_fields():
     return amazon_bedrock_inputs, create_input_fields_dict(amazon_bedrock_inputs, "")
 
 
-MODEL_PROVIDERS_DICT = {}
+MODEL_PROVIDERS_DICT: dict[str, ModelProvidersDict] = {}
 
 # Try to add each provider
 try:
@@ -168,5 +177,6 @@ try:
 except ImportError:
     pass
 
+
 MODEL_PROVIDERS = list(MODEL_PROVIDERS_DICT.keys())
 ALL_PROVIDER_FIELDS: list[str] = [field for provider in MODEL_PROVIDERS_DICT.values() for field in provider["fields"]]

src/backend/base/langflow/services/database/service.py

@@ -62,6 +62,7 @@ class DatabaseService(Service):
         else:
             # Construct the path using the langflow directory.
             self.alembic_log_path = Path(langflow_dir) / alembic_log_file
+        self._logged_pragma = False
 
     def reload_engine(self) -> None:
         self._sanitize_database_url()
@@ -122,7 +123,9 @@ class DatabaseService(Service):
             pragmas_list = []
             for key, val in pragmas.items():
                 pragmas_list.append(f"PRAGMA {key} = {val}")
+            if not self._logged_pragma:
                 logger.debug(f"sqlite connection, setting pragmas: {pragmas_list}")
+                self._logged_pragma = True
             if pragmas_list:
                 cursor = dbapi_connection.cursor()
                 try: