feat: support for in-memory SQLite databases

app/database/db.py

@@ -36,14 +36,39 @@ def _absolutize_sqlite_url(db_url: str) -> str:
     if not u.drivername.startswith("sqlite"):
         return db_url
 
-    # Make path absolute if relative
+    db_path: str = u.database or ""
-    db_path = u.database or ""
+    if isinstance(db_path, str) and db_path.startswith("file:"):
+        return str(u)  # Do not touch SQLite URI databases like: "file:xxx?mode=memory&cache=shared"
     if not os.path.isabs(db_path):
         db_path = os.path.abspath(os.path.join(os.getcwd(), db_path))
         u = u.set(database=db_path)
     return str(u)
 
 
+def _normalize_sqlite_memory_url(db_url: str) -> tuple[str, bool]:
+    """
+    If db_url points at an in-memory SQLite DB (":memory:" or file:... mode=memory),
+    rewrite it to a *named* shared in-memory URI and ensure 'uri=true' is present.
+    Returns: (normalized_url, is_memory)
+    """
+    try:
+        u = make_url(db_url)
+    except Exception:
+        return db_url, False
+    if not u.drivername.startswith("sqlite"):
+        return db_url, False
+
+    db = u.database or ""
+    if db == ":memory:":
+        u = u.set(database=f"file:comfyui_db_{os.getpid()}?mode=memory&cache=shared&uri=true")
+        return str(u), True
+    if isinstance(db, str) and db.startswith("file:") and "mode=memory" in db:
+        if "uri=true" not in db:
+            u = u.set(database=(db + ("&" if "?" in db else "?") + "uri=true"))
+        return str(u), True
+    return str(u), False
+
+
 def _to_sync_driver_url(async_url: str) -> str:
     """Convert an async SQLAlchemy URL to a sync URL for Alembic."""
     u = make_url(async_url)
@@ -70,7 +95,10 @@ def _get_sqlite_file_path(sync_url: str) -> Optional[str]:
 
     if not u.drivername.startswith("sqlite"):
         return None
-    return u.database
+    db_path = u.database
+    if isinstance(db_path, str) and db_path.startswith("file:"):
+        return None  # Not a real file if it is a URI like "file:...?"
+    return db_path
 
 
 def _get_alembic_config(sync_url: str) -> Config:
@@ -96,8 +124,8 @@ async def init_db_engine() -> None:
     if not raw_url:
         raise RuntimeError("Database URL is not configured.")
 
-    # Absolutize SQLite path for async engine
+    db_url, is_mem = _normalize_sqlite_memory_url(raw_url)
-    db_url = _absolutize_sqlite_url(raw_url)
+    db_url = _absolutize_sqlite_url(db_url)
 
     # Prepare async engine
     connect_args = {}
@@ -106,6 +134,8 @@ async def init_db_engine() -> None:
             "check_same_thread": False,
             "timeout": 12,
         }
+        if is_mem:
+            connect_args["uri"] = True
 
     ENGINE = create_async_engine(
         db_url,
@@ -117,18 +147,19 @@ async def init_db_engine() -> None:
     # Enforce SQLite pragmas on the async engine
     if db_url.startswith("sqlite"):
         async with ENGINE.begin() as conn:
-            # WAL for concurrency and durability, Foreign Keys for referential integrity
+            if not is_mem:
-            current_mode = (await conn.execute(text("PRAGMA journal_mode;"))).scalar()
+                # WAL for concurrency and durability, Foreign Keys for referential integrity
-            if str(current_mode).lower() != "wal":
+                current_mode = (await conn.execute(text("PRAGMA journal_mode;"))).scalar()
-                new_mode = (await conn.execute(text("PRAGMA journal_mode=WAL;"))).scalar()
+                if str(current_mode).lower() != "wal":
-                if str(new_mode).lower() != "wal":
+                    new_mode = (await conn.execute(text("PRAGMA journal_mode=WAL;"))).scalar()
-                    raise RuntimeError("Failed to set SQLite journal mode to WAL.")
+                    if str(new_mode).lower() != "wal":
-                LOGGER.info("SQLite journal mode set to WAL.")
+                        raise RuntimeError("Failed to set SQLite journal mode to WAL.")
+                    LOGGER.info("SQLite journal mode set to WAL.")
 
             await conn.execute(text("PRAGMA foreign_keys = ON;"))
             await conn.execute(text("PRAGMA synchronous = NORMAL;"))
 
-    await _run_migrations(raw_url=db_url)
+    await _run_migrations(raw_url=db_url, connect_args=connect_args)
 
     SESSION = async_sessionmaker(
         bind=ENGINE,
@@ -139,7 +170,7 @@ async def init_db_engine() -> None:
     )
 
 
-async def _run_migrations(raw_url: str) -> None:
+async def _run_migrations(raw_url: str, connect_args: dict) -> None:
     """
     Run Alembic migrations up to head.
 
@@ -148,12 +179,11 @@ async def _run_migrations(raw_url: str) -> None:
     """
     # Convert to sync URL and make SQLite URL an absolute one
     sync_url = _to_sync_driver_url(raw_url)
+    sync_url, is_mem = _normalize_sqlite_memory_url(sync_url)
     sync_url = _absolutize_sqlite_url(sync_url)
 
     cfg = _get_alembic_config(sync_url)
-
+    engine = create_engine(sync_url, future=True, connect_args=connect_args)
-    # Inspect current and target heads
-    engine = create_engine(sync_url, future=True)
     with engine.connect() as conn:
         context = MigrationContext.configure(conn)
         current_rev = context.get_current_revision()