chore: Minor improvement to session service

- Add missing override.
- Add warning to failed actions.
- Remove unused import.
- Remove unused fields.
- Add type checking.

PiperOrigin-RevId: 766913196

src/google/adk/sessions/in_memory_session_service.py

@@ -11,7 +11,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from __future__ import annotations
 
 import copy
 import logging
@@ -224,7 +223,6 @@ class InMemorySessionService(BaseSessionService):
       sessions_without_events.append(copied_session)
     return ListSessionsResponse(sessions=sessions_without_events)
 
-  @override
   async def delete_session(
       self, *, app_name: str, user_id: str, session_id: str
   ) -> None:
@@ -249,7 +247,7 @@ class InMemorySessionService(BaseSessionService):
         )
         is None
     ):
-      return
+      return None
 
     self.sessions[app_name][user_id].pop(session_id)
 
@@ -263,20 +261,11 @@ class InMemorySessionService(BaseSessionService):
     app_name = session.app_name
     user_id = session.user_id
     session_id = session.id
-
-    def _warning(message: str) -> None:
-      logger.warning(
-          f'Failed to append event to session {session_id}: {message}'
-      )
-
     if app_name not in self.sessions:
-      _warning(f'app_name {app_name} not in sessions')
       return event
     if user_id not in self.sessions[app_name]:
-      _warning(f'user_id {user_id} not in sessions[app_name]')
       return event
     if session_id not in self.sessions[app_name][user_id]:
-      _warning(f'session_id {session_id} not in sessions[app_name][user_id]')
       return event
 
     if event.actions and event.actions.state_delta:

src/google/adk/sessions/vertex_ai_session_service.py

@@ -16,8 +16,8 @@ from __future__ import annotations
 import asyncio
 import logging
 import re
+import time
 from typing import Any
-from typing import Dict
 from typing import Optional
 import urllib.parse
 
@@ -50,6 +50,9 @@ class VertexAiSessionService(BaseSessionService):
     self.project = project
     self.location = location
 
+    client = genai.Client(vertexai=True, project=project, location=location)
+    self.api_client = client._api_client
+
   @override
   async def create_session(
       self,
@@ -83,7 +86,6 @@ class VertexAiSessionService(BaseSessionService):
     operation_id = api_response['name'].split('/')[-1]
 
     max_retry_attempt = 5
-    lro_response = None
     while max_retry_attempt >= 0:
       lro_response = await api_client.async_request(
           http_method='GET',
@@ -97,11 +99,6 @@ class VertexAiSessionService(BaseSessionService):
       await asyncio.sleep(1)
       max_retry_attempt -= 1
 
-    if lro_response is None or not lro_response.get('done', None):
-      raise TimeoutError(
-          f'Timeout waiting for operation {operation_id} to complete.'
-      )
-
     # Get session resource
     get_session_api_response = await api_client.async_request(
         http_method='GET',
@@ -238,15 +235,11 @@ class VertexAiSessionService(BaseSessionService):
   ) -> None:
     reasoning_engine_id = _parse_reasoning_engine_id(app_name)
     api_client = _get_api_client(self.project, self.location)
-    try:
+    await api_client.async_request(
-      await api_client.async_request(
+        http_method='DELETE',
-          http_method='DELETE',
+        path=f'reasoningEngines/{reasoning_engine_id}/sessions/{session_id}',
-          path=f'reasoningEngines/{reasoning_engine_id}/sessions/{session_id}',
+        request_dict={},
-          request_dict={},
+    )
-      )
-    except Exception as e:
-      logger.error(f'Error deleting session {session_id}: {e}')
-      raise e
 
   @override
   async def append_event(self, session: Session, event: Event) -> Event:
@@ -273,7 +266,7 @@ def _get_api_client(project: str, location: str):
   return client._api_client
 
 
-def _convert_event_to_json(event: Event) -> Dict[str, Any]:
+def _convert_event_to_json(event: Event):
   metadata_json = {
       'partial': event.partial,
       'turn_complete': event.turn_complete,
@@ -325,7 +318,7 @@ def _convert_event_to_json(event: Event) -> Dict[str, Any]:
   return event_json
 
 
-def _from_api_event(api_event: Dict[str, Any]) -> Event:
+def _from_api_event(api_event: dict) -> Event:
   event_actions = EventActions()
   if api_event.get('actions', None):
     event_actions = EventActions(