perf(db): tune sqlite pool and add maintenance scheduler

db_pool.py

@@ -7,12 +7,28 @@
 
 import sqlite3
 import threading
+import time
 from queue import Empty, Full, Queue
 
+from app_config import get_config
 from app_logger import get_logger
 
 
 logger = get_logger("database")
+config = get_config()
+
+DB_CONNECT_TIMEOUT_SECONDS = max(1, int(getattr(config, "DB_CONNECT_TIMEOUT_SECONDS", 10)))
+DB_BUSY_TIMEOUT_MS = max(1000, int(getattr(config, "DB_BUSY_TIMEOUT_MS", 10000)))
+DB_CACHE_SIZE_KB = max(1024, int(getattr(config, "DB_CACHE_SIZE_KB", 8192)))
+DB_WAL_AUTOCHECKPOINT_PAGES = max(100, int(getattr(config, "DB_WAL_AUTOCHECKPOINT_PAGES", 1000)))
+DB_MMAP_SIZE_MB = max(0, int(getattr(config, "DB_MMAP_SIZE_MB", 256)))
+DB_LOCK_RETRY_COUNT = max(0, int(getattr(config, "DB_LOCK_RETRY_COUNT", 3)))
+DB_LOCK_RETRY_BASE_MS = max(10, int(getattr(config, "DB_LOCK_RETRY_BASE_MS", 50)))
+
+
+def _is_lock_conflict_error(error: sqlite3.OperationalError) -> bool:
+    message = str(error or "").lower()
+    return ("locked" in message) or ("busy" in message)
 
 
 class ConnectionPool:
@@ -46,16 +62,29 @@ class ConnectionPool:
 
     def _create_connection(self):
         """创建新的数据库连接"""
-        conn = sqlite3.connect(self.database, check_same_thread=False)
+        conn = sqlite3.connect(
+            self.database,
+            check_same_thread=False,
+            timeout=DB_CONNECT_TIMEOUT_SECONDS,
+        )
         conn.row_factory = sqlite3.Row
-        # 启用外键约束，确保 ON DELETE CASCADE 等约束生效
-        conn.execute("PRAGMA foreign_keys=ON")
-        # 设置WAL模式提高并发性能
-        conn.execute("PRAGMA journal_mode=WAL")
-        # 在WAL模式下使用NORMAL同步，兼顾性能与可靠性
-        conn.execute("PRAGMA synchronous=NORMAL")
-        # 设置合理的超时时间
-        conn.execute("PRAGMA busy_timeout=5000")
+        pragma_statements = [
+            "PRAGMA foreign_keys=ON",
+            "PRAGMA journal_mode=WAL",
+            "PRAGMA synchronous=NORMAL",
+            f"PRAGMA busy_timeout={DB_BUSY_TIMEOUT_MS}",
+            "PRAGMA temp_store=MEMORY",
+            f"PRAGMA cache_size={-DB_CACHE_SIZE_KB}",
+            f"PRAGMA wal_autocheckpoint={DB_WAL_AUTOCHECKPOINT_PAGES}",
+        ]
+        if DB_MMAP_SIZE_MB > 0:
+            pragma_statements.append(f"PRAGMA mmap_size={DB_MMAP_SIZE_MB * 1024 * 1024}")
+
+        for statement in pragma_statements:
+            try:
+                conn.execute(statement)
+            except sqlite3.DatabaseError as e:
+                logger.warning(f"设置数据库参数失败 ({statement}): {e}")
         return conn
 
     def _close_connection(self, conn) -> None:
@@ -198,7 +227,20 @@ class PooledConnection:
 
     def commit(self):
         """提交事务"""
-        self._conn.commit()
+        for attempt in range(DB_LOCK_RETRY_COUNT + 1):
+            try:
+                self._conn.commit()
+                return
+            except sqlite3.OperationalError as e:
+                if (not _is_lock_conflict_error(e)) or attempt >= DB_LOCK_RETRY_COUNT:
+                    raise
+
+                sleep_seconds = (DB_LOCK_RETRY_BASE_MS * (2**attempt)) / 1000.0
+                logger.warning(
+                    f"数据库提交遇到锁冲突，{sleep_seconds:.3f}s 后重试 "
+                    f"({attempt + 1}/{DB_LOCK_RETRY_COUNT})"
+                )
+                time.sleep(sleep_seconds)
 
     def rollback(self):
         """回滚事务"""