feat: add configurations for memory only, disk only, and memory & disk modes

vfs/cache/cache.go

@@ -21,23 +21,24 @@ type CacheFS struct {
 type CacheHandler func(*vfs.FileInfo, cachestate.CacheState) bool
 
 // New creates a new CacheFS. fast is used for caching, and slow is used for storage. fast should obviously be faster than slow.
-func New(fast, slow vfs.VFS, cacheHandler CacheHandler) *CacheFS {
-	if slow == nil {
-		panic("slow is nil")
-	}
-
-	if fast == slow {
-		panic("fast and slow are the same")
-	}
-
+func New(cacheHandler CacheHandler) *CacheFS {
 	return &CacheFS{
-		fast: fast,
-		slow: slow,
-
 		cacheHandler: cacheHandler,
 	}
 }
 
+func (c *CacheFS) SetSlow(vfs vfs.VFS) {
+	if vfs == nil {
+		panic("vfs is nil") // panic if the vfs is nil
+	}
+
+	c.slow = vfs
+}
+
+func (c *CacheFS) SetFast(vfs vfs.VFS) {
+	c.fast = vfs
+}
+
 // cacheState returns the state of the file at key.
 func (c *CacheFS) cacheState(key string) cachestate.CacheState {
 	if c.fast != nil {