it works

vfs/vfs.go

@@ -0,0 +1,26 @@
+package vfs
+
+// VFS is the interface that wraps the basic methods of a virtual file system.
+type VFS interface {
+	// Name returns the name of the file system.
+	Name() string
+
+	// Size returns the total size of all files in the file system.
+	Size() int64
+
+	// Set sets the value of key as src.
+	// Setting the same key multiple times, the last set call takes effect.
+	Set(key string, src []byte) error
+
+	// Delete deletes the value of key.
+	Delete(key string) error
+
+	// Get gets the value of key to dst, and returns dst no matter whether or not there is an error.
+	Get(key string) ([]byte, error)
+
+	// Stat returns the FileInfo of key.
+	Stat(key string) (*FileInfo, error)
+
+	// StatAll returns the FileInfo of all keys.
+	StatAll() []*FileInfo
+}