From 44c9070d0927035f5b6cd49eef02925895312278 Mon Sep 17 00:00:00 2001
From: zhenghaoz <zhangzhenghao@hotmail.com>
Date: Wed, 29 Apr 2026 12:28:01 +0800
Subject: [PATCH 1/2] Fix MySQL kv cache value length limitation

---
 utils.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/utils.py b/utils.py
index 6a35c26..6b58d14 100644
--- a/utils.py
+++ b/utils.py
@@ -4,6 +4,7 @@
 import os
 import re
 import sys
+from threading import Lock
 from typing import List, Optional, Tuple, Dict, Any
 
 import pytz
@@ -18,6 +19,25 @@
 from pydantic import BaseModel
 
 MAX_COMMENT_LENGTH = 512
+_kv_cache_schema_checked = False
+_kv_cache_schema_lock = Lock()
+
+
+def ensure_kv_cache_schema(engine) -> None:
+    """Ensure kv_cache.v can store large payloads in MySQL."""
+    global _kv_cache_schema_checked
+    if _kv_cache_schema_checked:
+        return
+
+    with _kv_cache_schema_lock:
+        if _kv_cache_schema_checked:
+            return
+        if engine.dialect.name == "mysql":
+            with engine.begin() as conn:
+                conn.exec_driver_sql(
+                    "ALTER TABLE kv_cache MODIFY COLUMN v LONGTEXT NOT NULL"
+                )
+        _kv_cache_schema_checked = True
 
 
 openai_client = OpenAI(
@@ -99,6 +119,7 @@ def get_cached(k: str) -> Optional[Any]:
     from sqlalchemy.orm import sessionmaker
 
     engine = create_engine(os.getenv("SQLALCHEMY_DATABASE_URI"))
+    ensure_kv_cache_schema(engine)
     Session = sessionmaker()
     Session.configure(bind=engine)
     session = Session()
@@ -118,6 +139,7 @@ def save_cache(k: str, v: Any, expiry_hours: int = KvCache.DEFAULT_EXPIRY_HOURS)
     from sqlalchemy.orm import sessionmaker
 
     engine = create_engine(os.getenv("SQLALCHEMY_DATABASE_URI"))
+    ensure_kv_cache_schema(engine)
     Session = sessionmaker()
     Session.configure(bind=engine)
     session = Session()

From 872954047a97d2253b5bb02d7fc15b9d66d96f71 Mon Sep 17 00:00:00 2001
From: zhenghaoz <zhangzhenghao@hotmail.com>
Date: Wed, 29 Apr 2026 12:48:06 +0800
Subject: [PATCH 2/2] Define kv_cache.v as LONGTEXT at DDL for MySQL

---
 utils.py | 25 ++-----------------------
 1 file changed, 2 insertions(+), 23 deletions(-)

diff --git a/utils.py b/utils.py
index 6b58d14..0abc4c3 100644
--- a/utils.py
+++ b/utils.py
@@ -4,7 +4,6 @@
 import os
 import re
 import sys
-from threading import Lock
 from typing import List, Optional, Tuple, Dict, Any
 
 import pytz
@@ -14,30 +13,12 @@
 from github.GithubException import *
 from gorse import Gorse, GorseException
 from sqlalchemy import Column, String, Integer, DateTime, JSON, Text
+from sqlalchemy.dialects.mysql import LONGTEXT
 from sqlalchemy.orm import declarative_base
 from openai import OpenAI
 from pydantic import BaseModel
 
 MAX_COMMENT_LENGTH = 512
-_kv_cache_schema_checked = False
-_kv_cache_schema_lock = Lock()
-
-
-def ensure_kv_cache_schema(engine) -> None:
-    """Ensure kv_cache.v can store large payloads in MySQL."""
-    global _kv_cache_schema_checked
-    if _kv_cache_schema_checked:
-        return
-
-    with _kv_cache_schema_lock:
-        if _kv_cache_schema_checked:
-            return
-        if engine.dialect.name == "mysql":
-            with engine.begin() as conn:
-                conn.exec_driver_sql(
-                    "ALTER TABLE kv_cache MODIFY COLUMN v LONGTEXT NOT NULL"
-                )
-        _kv_cache_schema_checked = True
 
 
 openai_client = OpenAI(
@@ -103,7 +84,7 @@ class KvCache(Base):
     __tablename__ = 'kv_cache'
 
     k = Column(String(256), primary_key=True)
-    v = Column(Text, nullable=False)
+    v = Column(Text().with_variant(LONGTEXT, "mysql"), nullable=False)
     expire = Column(DateTime, nullable=False)
 
     DEFAULT_EXPIRY_HOURS = 24
@@ -119,7 +100,6 @@ def get_cached(k: str) -> Optional[Any]:
     from sqlalchemy.orm import sessionmaker
 
     engine = create_engine(os.getenv("SQLALCHEMY_DATABASE_URI"))
-    ensure_kv_cache_schema(engine)
     Session = sessionmaker()
     Session.configure(bind=engine)
     session = Session()
@@ -139,7 +119,6 @@ def save_cache(k: str, v: Any, expiry_hours: int = KvCache.DEFAULT_EXPIRY_HOURS)
     from sqlalchemy.orm import sessionmaker
 
     engine = create_engine(os.getenv("SQLALCHEMY_DATABASE_URI"))
-    ensure_kv_cache_schema(engine)
     Session = sessionmaker()
     Session.configure(bind=engine)
     session = Session()