如何在php中定义应用程序静态变量（您可以将其称为内存中的全局共享缓存）？

Question

I am coming from asp.net world and I need to rewrite a small library from .net to php. My library needs to download a file from somewhere and use that information for all page requests (I do not want to have dependency on files or database). In asp.net you can use static variables and those variables are shared between all page requests but as far as I know in php statics are behaving differently and are not shared between user requests. What is the way to implement this library t in php?