Store cache in $XDG_CACHE_HOM or ~/.cache

On linux, /tmp is most of the time an in memory filesystem, wipe out after a reboot.

So for a long term cache, this does not work, unless you can specify a custom location.
I can't find out how to specify a said custom location. Where is the doc? How do you use FileSystem() or LocalFileSystem() (not really user friendly API)

You should be able to choose where the cache is stored, and a default location better be $XDG_CACHE_HOME if set or else $HOME/.cache on linux.

/tmp is for temporary file not cache

首先跟踪 issue 中提到的 FileSystem() 和 LocalFileSystem() API，并了解 Linux 上如何选择缓存目录。完成的实现应包括可配置的缓存位置，并在适当情况下默认使用 $XDG_CACHE_HOME 或 $HOME/.cache，同时提供说明如何选择自定义位置的文档。

由索引模型根据 Issue 内容生成。