PHP 正则 preg_match 匹配长度限制
https://learnku.com/articles/7193/php-regular-preg-match-matching-length-limit
深悉正则(pcre)最大回溯/递归限制
http://www.laruence.com/2010/06/08/1579.html
Redis 的内存优化
https://cachecloud.github.io/2017/02/16/Redis内存优化
Content-Disposition 的 filename 与 filename 区别*
https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Headers/Content-Disposition
Redis Scan 命令原理
https://segmentfault.com/a/1190000018218584
Redis 字典的遍历 dictScan 算法
http://www.langdebuqing.com/redis%20notebook/redis源码解读：字典的遍历dictScan.html