import github.com/AndrusGerman/vfs

// Create a vfs accessing the filesystem of the underlying OS
var osfs vfs.Filesystem = vfs.OS()
osfs.Mkdir("/tmp", 0777)

// Make the filesystem read-only:
osfs = vfs.ReadOnly(osfs) // Simply wrap filesystems to change its behaviour

// os.O_CREATE will fail and return vfs.ErrReadOnly
// os.O_RDWR is supported but Write(..) on the file is disabled
f, _ := osfs.OpenFile("/tmp/example.txt", os.O_RDWR, 0)

// Return vfs.ErrReadOnly
_, err := f.Write([]byte("Write on readonly fs?"))
if err != nil {
    fmt.Errorf("Filesystem is read only!\n")
}

// Create a fully writable filesystem in memory
mfs := memfs.Create()
mfs.Mkdir("/root", 0777)

// Create a vfs supporting mounts
// The root fs is accessing the filesystem of the underlying OS
fs := mountfs.Create(osfs)

// Mount a memfs inside /memfs
// /memfs may not exist
fs.Mount(mfs, "/memfs")

// This will create /testdir inside the memfs
fs.Mkdir("/memfs/testdir", 0777)

// This would create /tmp/testdir inside your OS fs
// But the rootfs `osfs` is read-only
fs.Mkdir("/tmp/testdir", 0777)

// Create multiple fully writable filesystem in memory
inMemoryA := memfs.Create()
inMemoryB := memfs.Create()

// Join and replication events vfs
replivfs := replicationfs.NewReplication(inMemoryA, inMemoryB)

// Create a vfs accessing the filesystem of the underlying OS
primaryDisk := prefixfs.Create(vfs.OS(), "/myosfolder")
// Sync primaryDisk to => replivfs
err := replicationfs.Sync(nil, primaryDisk, replivfs)
if err != nil {
	panic(err)
}

// Save Data
// Create a vfs accessing the filesystem of the underlying OS
primaryDisk := prefixfs.Create(vfs.OS(), "/myosfolder")
file, err := os.Create("mybackup.vfs")
if err != nil {
	panic(err)
}
// Save data vfs
err = dumpfs.NewDumpfs(primaryDisk, file) // save data in file
if err != nil {
	panic(err)
}
file.Close()

// Read save Data
// Create a fully writable filesystem in memory
mvfs := memfs.Create()
file, err = os.Open("mybackup.vfs")
if err != nil {
	panic(err)
}
err = dumpfs.GetDumpfs(file, mvfs)// Set save data in new fs
if err != nil {
	panic(err)
}