Reference blog:
How to Read Source: https://blog.huangz.me/diary/2014/how-to-read-redis-source-code.html
Analytical internal data structures: https://mp.weixin.qq.com/s?__biz=MzA4NTg1MjM0Mg==&mid=2657261203&idx=1&sn=f7ff61ce42e29b874a8026683875bbb1&scene=21#wechat_redirect