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/api_Img.py

@@ -1,6 +1,6 @@
-from flask import *
-from flask import Blueprint
+from flask import Blueprint, request, abort, make_response
 import db.file , file, gc , app_conf
+from utils.performance_monitor import timing_context
 
 api_Img_bp = Blueprint("api_Img_bp", __name__)
 
@@ -11,21 +11,30 @@ fullSize = conf.getint("img", "fullSize")
 
 @api_Img_bp.route("/api/img/<bookid>/<index>")
 def img(bookid, index):  # 图片接口
-    if request.cookies.get("islogin") is None:
-        return abort(403)
-    if len(db.file.searchByid(bookid)) == 0:
-        return abort(404)
-    # 设置响应类型为图片
-    data, filename = file.raedZip(bookid, index)
-    if isinstance(data, str):
-        abort(404)
-    if request.args.get("mini") == "yes":
-        data = file.thumbnail(data,miniSize,encode=imgencode)
-    else:
-        data = file.thumbnail(data,fullSize,encode=imgencode)
-    response = make_response(data)  # 读取文件
-    del data
-    response.headers.set("Content-Type",f"image/{imgencode}")
-    response.headers.set("Content-Disposition", "inline", filename=filename)
-    gc.collect()
-    return response
+    with timing_context(f"api.img.{bookid}.{index}"):
+        if request.cookies.get("islogin") is None:
+            return abort(403)
+        if len(db.file.searchByid(bookid)) == 0:
+            return abort(404)
+        
+        # 读取图片数据
+        data, filename = file.readZip(bookid, index)
+        if isinstance(data, str):
+            abort(404)
+        
+        # 处理图片尺寸
+        if request.args.get("mini") == "yes":
+            data = file.thumbnail(data, miniSize, encode=imgencode)
+        else:
+            data = file.thumbnail(data, fullSize, encode=imgencode)
+        
+        # 创建响应
+        response = make_response(data)
+        del data  # 及时释放内存
+        
+        response.headers.set("Content-Type", f"image/{imgencode}")
+        response.headers.set("Content-Disposition", "inline", filename=filename)
+        response.headers.set("Cache-Control", "public, max-age=3600")  # 添加缓存头
+        
+        gc.collect()  # 强制垃圾回收
+        return response