There are 2 repositories under filesystem-cache topic.
filesystem pool library for the Go programming language
File System backend for Dogpile Cache
Filesystem-based cache system for PHP 7.
PippoProxy is a 100% pure Java HTTP proxy designed/implemented for Apache Tomcat
filesystem cache pruning tool for maintaining LRU caches.
A configurable two-level cache (for caching Objects). Level 1 is memory, level 2 is filesystem. One can specify cache strategies and max sizes of both levels 1 and 2. Three cache replacement policies have been set: Least Frequently Used, Least Recently Used, Most Recently Used.