Cog 678 relational database singleton (#38)

1. Set relational database in cognee to be used as singleton and made
necessary changes to enable this
2. Added SQLite support to dlt pipeline in ingest_data

cognee/infrastructure/databases/relational/get_relational_engine.py

@@ -1,8 +1,10 @@
+from functools import lru_cache
+
 from .config import get_relational_config
 from .create_relational_engine import create_relational_engine
 
-
+@lru_cache
 def get_relational_engine():
     relational_config = get_relational_config()
 
-    return create_relational_engine(**relational_config.to_dict())
+    return create_relational_engine(**relational_config.to_dict())

cognee/infrastructure/databases/relational/sqlalchemy/SqlAlchemyAdapter.py

@@ -6,7 +6,6 @@ from contextlib import asynccontextmanager
 from sqlalchemy import text, select, MetaData, Table
 from sqlalchemy.orm import joinedload
 from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker
-
 from ..ModelBase import Base
 
 class SQLAlchemyAdapter():
@@ -171,6 +170,27 @@ class SQLAlchemyAdapter():
                 results = await connection.execute(query)
             return {result["data_id"]: result["status"] for result in results}
 
+    async def get_all_data_from_table(self, table_name: str, schema: str = "public"):
+        async with self.get_async_session() as session:
+            # Validate inputs to prevent SQL injection
+            if not table_name.isidentifier():
+                raise ValueError("Invalid table name")
+            if schema and not schema.isidentifier():
+                raise ValueError("Invalid schema name")
+
+            if self.engine.dialect.name == "sqlite":
+                table = await self.get_table(table_name)
+            else:
+                table = await self.get_table(table_name, schema)
+
+            # Query all data from the table
+            query = select(table)
+            result = await session.execute(query)
+
+            # Fetch all rows as a list of dictionaries
+            rows = result.mappings().all()
+            return rows
+
     async def execute_query(self, query):
         async with self.engine.begin() as connection:
             result = await connection.execute(text(query))
@@ -205,7 +225,6 @@ class SQLAlchemyAdapter():
                 from cognee.infrastructure.files.storage import LocalStorage
 
                 LocalStorage.remove(self.db_path)
-                self.db_path = None
             else:
                 async with self.engine.begin() as connection:
                     schema_list = await self.get_schema_list()

cognee/infrastructure/databases/vector/pgvector/create_db_and_tables.py

@@ -1,12 +1,12 @@
-from ...relational.ModelBase import Base
 from ..get_vector_engine import get_vector_engine, get_vectordb_config
 from sqlalchemy import text
 
+
 async def create_db_and_tables():
     vector_config = get_vectordb_config()
     vector_engine = get_vector_engine()
 
     if vector_config.vector_db_provider == "pgvector":
-        await vector_engine.create_database()
         async with vector_engine.engine.begin() as connection:
             await connection.execute(text("CREATE EXTENSION IF NOT EXISTS vector;"))
+

cognee/tasks/ingestion/get_dlt_destination.py

@@ -1,9 +1,12 @@
 import os
+from functools import lru_cache
+
 import dlt
 from typing import Union
 
 from cognee.infrastructure.databases.relational import get_relational_config
 
+@lru_cache
 def get_dlt_destination() -> Union[type[dlt.destinations.sqlalchemy], None]:
     """
     Handles propagation of the cognee database configuration to the dlt library

cognee/tasks/ingestion/ingest_data.py

@@ -1,6 +1,7 @@
 import dlt
 import cognee.modules.ingestion as ingestion
 
+from uuid import UUID
 from cognee.shared.utils import send_telemetry
 from cognee.modules.users.models import User
 from cognee.infrastructure.databases.relational import get_relational_engine
@@ -17,25 +18,33 @@ async def ingest_data(file_paths: list[str], dataset_name: str, user: User):
     )
 
     @dlt.resource(standalone = True, merge_key = "id")
-    async def data_resources(file_paths: str, user: User):
+    async def data_resources(file_paths: str):
         for file_path in file_paths:
             with open(file_path.replace("file://", ""), mode = "rb") as file:
                 classified_data = ingestion.classify(file)
-
                 data_id = ingestion.identify(classified_data)
-
                 file_metadata = classified_data.get_metadata()
+                yield {
+                    "id": data_id,
+                    "name": file_metadata["name"],
+                    "file_path": file_metadata["file_path"],
+                    "extension": file_metadata["extension"],
+                    "mime_type": file_metadata["mime_type"],
+                }
 
-                from sqlalchemy import select
-                from cognee.modules.data.models import Data
+    async def data_storing(table_name, dataset_name, user: User):
+        db_engine = get_relational_engine()
 
-                db_engine = get_relational_engine()
-
-                async with db_engine.get_async_session() as session:
+        async with db_engine.get_async_session() as session:
+            # Read metadata stored with dlt
+            files_metadata = await db_engine.get_all_data_from_table(table_name, dataset_name)
+            for file_metadata in files_metadata:
+                    from sqlalchemy import select
+                    from cognee.modules.data.models import Data
                     dataset = await create_dataset(dataset_name, user.id, session)
 
                     data = (await session.execute(
-                        select(Data).filter(Data.id == data_id)
+                        select(Data).filter(Data.id == UUID(file_metadata["id"]))
                     )).scalar_one_or_none()
 
                     if data is not None:
@@ -48,7 +57,7 @@ async def ingest_data(file_paths: list[str], dataset_name: str, user: User):
                         await session.commit()
                     else:
                         data = Data(
-                            id = data_id,
+                            id = UUID(file_metadata["id"]),
                             name = file_metadata["name"],
                             raw_data_location = file_metadata["file_path"],
                             extension = file_metadata["extension"],
@@ -58,25 +67,34 @@ async def ingest_data(file_paths: list[str], dataset_name: str, user: User):
                         dataset.data.append(data)
                         await session.commit()
 
-                yield {
-                    "id": data_id,
-                    "name": file_metadata["name"],
-                    "file_path": file_metadata["file_path"],
-                    "extension": file_metadata["extension"],
-                    "mime_type": file_metadata["mime_type"],
-                }
-
-                await give_permission_on_document(user, data_id, "read")
-                await give_permission_on_document(user, data_id, "write")
+                    await give_permission_on_document(user, UUID(file_metadata["id"]), "read")
+                    await give_permission_on_document(user, UUID(file_metadata["id"]), "write")
 
 
     send_telemetry("cognee.add EXECUTION STARTED", user_id = user.id)
-    run_info = pipeline.run(
-        data_resources(file_paths, user),
-        table_name = "file_metadata",
-        dataset_name = dataset_name,
-        write_disposition = "merge",
-    )
+
+    db_engine = get_relational_engine()
+
+    # Note: DLT pipeline has its own event loop, therefore objects created in another event loop
+    # can't be used inside the pipeline
+    if db_engine.engine.dialect.name == "sqlite":
+        # To use sqlite with dlt dataset_name must be set to "main".
+        # Sqlite doesn't support schemas
+        run_info = pipeline.run(
+            data_resources(file_paths),
+            table_name = "file_metadata",
+            dataset_name = "main",
+            write_disposition = "merge",
+        )
+    else:
+        run_info = pipeline.run(
+            data_resources(file_paths),
+            table_name="file_metadata",
+            dataset_name=dataset_name,
+            write_disposition="merge",
+        )
+
+    await data_storing("file_metadata", dataset_name, user)
     send_telemetry("cognee.add EXECUTION COMPLETED", user_id = user.id)
 
     return run_info