feat(file): 优化文件处理和缓存机制

- 重构文件处理逻辑，提高性能和可维护性
- 增加缓存机制，减少重复读取和处理
- 改进错误处理和日志记录
- 优化缩略图生成算法
- 添加性能监控和测试依赖

router/performance_api.py

@@ -0,0 +1,61 @@
+from flask import Blueprint, render_template, jsonify, request
+from utils.performance_monitor import get_performance_monitor
+from utils.cache_manager import get_cache_manager
+
+performance_bp = Blueprint("performance_bp", __name__)
+
+
+@performance_bp.route("/api/performance/stats")
+def performance_stats():
+    """获取性能统计信息"""
+    if request.cookies.get("islogin") is None:
+        return jsonify({"error": "Unauthorized"}), 403
+    
+    monitor = get_performance_monitor()
+    cache_manager = get_cache_manager()
+    
+    operation_name = request.args.get("operation")
+    
+    stats = {
+        "performance": monitor.get_stats(operation_name),
+        "cache": cache_manager.get_stats(),
+        "recent_errors": monitor.get_recent_errors(5)
+    }
+    
+    return jsonify(stats)
+
+
+@performance_bp.route("/api/performance/clear")
+def clear_performance_data():
+    """清空性能监控数据"""
+    if request.cookies.get("islogin") is None:
+        return jsonify({"error": "Unauthorized"}), 403
+    
+    monitor = get_performance_monitor()
+    monitor.clear_metrics()
+    
+    return jsonify({"message": "Performance data cleared"})
+
+
+@performance_bp.route("/api/cache/clear")
+def clear_cache():
+    """清空缓存"""
+    if request.cookies.get("islogin") is None:
+        return jsonify({"error": "Unauthorized"}), 403
+    
+    cache_manager = get_cache_manager()
+    cache_manager.clear()
+    
+    return jsonify({"message": "Cache cleared"})
+
+
+@performance_bp.route("/api/cache/cleanup")
+def cleanup_cache():
+    """清理过期缓存"""
+    if request.cookies.get("islogin") is None:
+        return jsonify({"error": "Unauthorized"}), 403
+    
+    cache_manager = get_cache_manager()
+    cache_manager.cleanup_expired()
+    
+    return jsonify({"message": "Expired cache cleaned up"})