fix: Handle SQLite URLs in SqliteSessionService

The SqliteSessionService now accepts database paths in the form of SQLite URLs (e.g., "sqlite:///./sessions.db", "sqlite+aiosqlite:////absolute.db")

Close #4077

Co-authored-by: George Weale <[email protected]>
PiperOrigin-RevId: 853922433

Author: GWeale

src/google/adk/sessions/sqlite_session_service.py

@@ -22,6 +22,8 @@
 import time
 from typing import Any
 from typing import Optional
+from urllib.parse import unquote
+from urllib.parse import urlparse
 import uuid
 
 import aiosqlite
@@ -91,6 +93,42 @@
 ])
 
 
+def _parse_db_path(db_path: str) -> tuple[str, str, bool]:
+  """Normalizes a SQLite db path from a URL or filesystem path.
+
+  Returns:
+    A tuple of:
+      - filesystem path (for `os.path.exists` and user-facing messages)
+      - value to pass to sqlite/aiosqlite connect
+      - whether to pass `uri=True` to sqlite/aiosqlite connect
+
+  Notes:
+    When a SQLAlchemy-style SQLite URL is provided, this follows SQLAlchemy's
+    conventions:
+      - `sqlite:///relative.db` is a path relative to the current working dir.
+      - `sqlite:////absolute.db` is an absolute filesystem path.
+  """
+  if not db_path.startswith(("sqlite:", "sqlite+aiosqlite:")):
+    return db_path, db_path, False
+
+  parsed = urlparse(db_path)
+  raw_path = unquote(parsed.path)
+  if not raw_path:
+    return db_path, db_path, False
+
+  normalized_path = raw_path
+  if normalized_path.startswith("//"):
+    normalized_path = normalized_path[1:]
+  elif normalized_path.startswith("/"):
+    normalized_path = normalized_path[1:]
+
+  if parsed.query:
+    # sqlite3 only treats the filename as a URI when it starts with `file:`.
+    return normalized_path, f"file:{normalized_path}?{parsed.query}", True
+
+  return normalized_path, normalized_path, False
+
+
 class SqliteSessionService(BaseSessionService):
   """A session service that uses an SQLite database for storage via aiosqlite.
 
@@ -100,17 +138,19 @@ class SqliteSessionService(BaseSessionService):
 
   def __init__(self, db_path: str):
     """Initializes the SQLite session service with a database path."""
-    self._db_path = db_path
+    self._db_path, self._db_connect_path, self._db_connect_uri = _parse_db_path(
+        db_path
+    )
 
     if self._is_migration_needed():
       raise RuntimeError(
-          f"Database {db_path} seems to use an old schema."
+          f"Database {self._db_path} seems to use an old schema."
           " Please run the migration command to"
           " migrate it to the new schema. Example: `python -m"
           " google.adk.sessions.migration.migrate_from_sqlalchemy_sqlite"
-          f" --source_db_path {db_path} --dest_db_path"
-          f" {db_path}.new` then backup {db_path} and rename"
-          f" {db_path}.new to {db_path}."
+          f" --source_db_path {self._db_path} --dest_db_path"
+          f" {self._db_path}.new` then backup {self._db_path} and rename"
+          f" {self._db_path}.new to {self._db_path}."
       )
 
   @override
@@ -415,7 +455,9 @@ async def append_event(self, session: Session, event: Event) -> Event:
   @asynccontextmanager
   async def _get_db_connection(self):
     """Connects to the db and performs initial setup."""
-    async with aiosqlite.connect(self._db_path) as db:
+    async with aiosqlite.connect(
+        self._db_connect_path, uri=self._db_connect_uri
+    ) as db:
       db.row_factory = aiosqlite.Row
       await db.execute(PRAGMA_FOREIGN_KEYS)
       await db.executescript(CREATE_SCHEMA_SQL)
@@ -514,7 +556,9 @@ def _is_migration_needed(self) -> bool:
     if not os.path.exists(self._db_path):
       return False
     try:
-      with sqlite3.connect(self._db_path) as conn:
+      with sqlite3.connect(
+          self._db_connect_path, uri=self._db_connect_uri
+      ) as conn:
         cursor = conn.cursor()
         # Check if events table exists
         cursor.execute(

tests/unittests/sessions/test_session_service.py

@@ -15,6 +15,7 @@
 from datetime import datetime
 from datetime import timezone
 import enum
+import sqlite3
 
 from google.adk.errors.already_exists_error import AlreadyExistsError
 from google.adk.events.event import Event
@@ -60,6 +61,46 @@ async def session_service(request, tmp_path):
     await service.close()
 
 
+@pytest.mark.asyncio
+async def test_sqlite_session_service_accepts_sqlite_urls(
+    tmp_path, monkeypatch
+):
+  monkeypatch.chdir(tmp_path)
+
+  service = SqliteSessionService('sqlite+aiosqlite:///./sessions.db')
+  await service.create_session(app_name='app', user_id='user')
+  assert (tmp_path / 'sessions.db').exists()
+
+  service = SqliteSessionService('sqlite:///./sessions2.db')
+  await service.create_session(app_name='app', user_id='user')
+  assert (tmp_path / 'sessions2.db').exists()
+
+
+@pytest.mark.asyncio
+async def test_sqlite_session_service_preserves_uri_query_parameters(
+    tmp_path, monkeypatch
+):
+  monkeypatch.chdir(tmp_path)
+  db_path = tmp_path / 'readonly.db'
+  with sqlite3.connect(db_path) as conn:
+    conn.execute('CREATE TABLE IF NOT EXISTS t (id INTEGER)')
+    conn.commit()
+
+  service = SqliteSessionService(f'sqlite+aiosqlite:///{db_path}?mode=ro')
+  # `mode=ro` opens the DB read-only; schema creation should fail.
+  with pytest.raises(sqlite3.OperationalError, match=r'readonly'):
+    await service.create_session(app_name='app', user_id='user')
+
+
+@pytest.mark.asyncio
+async def test_sqlite_session_service_accepts_absolute_sqlite_urls(tmp_path):
+  abs_db_path = tmp_path / 'absolute.db'
+  abs_url = 'sqlite+aiosqlite:////' + str(abs_db_path).lstrip('/')
+  service = SqliteSessionService(abs_url)
+  await service.create_session(app_name='app', user_id='user')
+  assert abs_db_path.exists()
+
+
 @pytest.mark.asyncio
 async def test_get_empty_session(session_service):
   assert not await session_service.get_session(