Fix memory empty issue (#15411)

Fix memory empty issue

memory/services/messages.py

@@ -13,6 +13,7 @@
 #  See the License for the specific language governing permissions and
 #  limitations under the License.
 #
+import os
 import sys
 from typing import List
 
@@ -20,8 +21,12 @@ from common import settings
 from common.constants import MemoryType
 from common.doc_store.doc_store_base import OrderByExpr, MatchExpr
 
+def _es_index_prefix() -> str:
+    return os.environ.get("ES_INDEX_PREFIX", "").strip()
 
-def index_name(uid: str): return f"memory_{uid}"
+def index_name(uid: str):
+    prefix = _es_index_prefix()
+    return f"memory_{prefix}_{uid}" if prefix else f"memory_{uid}"
 
 
 class MessageService:
@@ -179,7 +184,13 @@ class MessageService:
 
     @staticmethod
     def calculate_message_size(message: dict):
-        return sys.getsizeof(message["content"]) + sys.getsizeof(message["content_embed"][0]) * len(message["content_embed"])
+        content_embed = message.get("content_embed")
+        embed_size = (
+            sys.getsizeof(content_embed[0]) * len(content_embed)
+            if content_embed is not None and len(content_embed) > 0
+            else 0
+        )
+        return sys.getsizeof(message.get("content", "")) + embed_size
 
     @classmethod
     def calculate_memory_size(cls, memory_ids: List[str], uid_list: List[str]):