From e8cacb57d531137dec3109617e807b30ff5187c9 Mon Sep 17 00:00:00 2001
From: EloquentBrush <147827411+EloquentBrush@users.noreply.github.com>
Date: Mon, 11 May 2026 12:49:19 +0300
Subject: [PATCH] fix(feishu): cap _message_text_cache with LRU eviction to
 prevent unbounded growth

_message_text_cache was a plain dict with no size limit. Every unique
message_id whose text was fetched (for reply-context lookups) stayed in
memory permanently, causing unbounded growth in long-running deployments
with active group chats.

Replace with an OrderedDict and evict the least-recently-used entry
whenever the cache exceeds _FEISHU_MESSAGE_TEXT_CACHE_SIZE (512). Cache
hits call move_to_end() to refresh LRU order. Mirrors the identical
pattern already used by _pending_processing_reactions in the same class.
---
 gateway/platforms/feishu.py | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/gateway/platforms/feishu.py b/gateway/platforms/feishu.py
index 10ddbb17d..2366b65ac 100644
--- a/gateway/platforms/feishu.py
+++ b/gateway/platforms/feishu.py
@@ -240,6 +240,7 @@ _FEISHU_REACTION_FAILURE = "CrossMark"
 # drain on completion; the cap is a safeguard against unbounded growth from
 # delete-failures, not a capacity plan.
 _FEISHU_PROCESSING_REACTION_CACHE_SIZE = 1024
+_FEISHU_MESSAGE_TEXT_CACHE_SIZE = 512       # LRU cap for reply-context message text lookups
 
 # QR onboarding constants
 _ONBOARD_ACCOUNTS_URLS = {
@@ -1452,7 +1453,7 @@ class FeishuAdapter(BasePlatformAdapter):
         self._sent_message_ids_to_chat: Dict[str, str] = {}  # message_id → chat_id (for reaction routing)
         self._sent_message_id_order: List[str] = []  # LRU order for _sent_message_ids_to_chat
         self._chat_info_cache: Dict[str, Dict[str, Any]] = {}
-        self._message_text_cache: Dict[str, Optional[str]] = {}
+        self._message_text_cache: "OrderedDict[str, Optional[str]]" = OrderedDict()
         self._app_lock_identity: Optional[str] = None
         self._text_batch_state = FeishuBatchState()
         self._pending_text_batches = self._text_batch_state.events
@@ -3959,6 +3960,7 @@ class FeishuAdapter(BasePlatformAdapter):
         if not self._client or not message_id:
             return None
         if message_id in self._message_text_cache:
+            self._message_text_cache.move_to_end(message_id)
             return self._message_text_cache[message_id]
         try:
             request = self._build_get_message_request(message_id)
@@ -3980,6 +3982,9 @@ class FeishuAdapter(BasePlatformAdapter):
                 mentions=parent_mentions,
             )
             self._message_text_cache[message_id] = text
+            self._message_text_cache.move_to_end(message_id)
+            while len(self._message_text_cache) > _FEISHU_MESSAGE_TEXT_CACHE_SIZE:
+                self._message_text_cache.popitem(last=False)
             return text
         except Exception:
             logger.warning("[Feishu] Failed to fetch parent message %s", message_id, exc_info=True)