main.go

package main

import (
	"log"
	"math/rand"
	"os"
	"strconv"

	"bazil.org/fuse"
	"bazil.org/fuse/fs"
	"golang.org/x/net/context"
)

func main() {
	client, err := fuse.Mount(
		"mnt",
		fuse.FSName("stupid-rand-example"),
		fuse.Subtype("stupid-rand-example"),
	)

	if err != nil {
		log.Fatal(err)
	}
	defer client.Close()

	fs.Serve(client, FS{})

	<-client.Ready

	if err := client.MountError; err != nil {
		log.Fatal(err)
	}

	log.Println("Bye bye!")
}

type FS struct{}

func (FS) Root() (fs.Node, error) {
	return RandDir{}, nil
}

type RandDir struct{}

func (RandDir) Attr(ctx context.Context, attr *fuse.Attr) error {
	log.Println("RandDir Attr")

	attr.Mode = os.ModeDir | 0555
	return nil
}

func (RandDir) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
	log.Println("RandDir ReadDirAll")

	ret := []fuse.Dirent{}

	for i := 0; i < 10; i += 1 {
		ret = append(ret, fuse.Dirent{Name: strconv.Itoa(i), Type: fuse.DT_Dir})
	}

	return ret, nil
}

func (RandDir) Lookup(ctx context.Context, name string) (fs.Node, error) {
	log.Println("RandDir lookup")

	return RandNumberDir{rand.Int()}, nil
}

type RandNumberDir struct {
	number int
}

func (RandNumberDir) Attr(ctx context.Context, attr *fuse.Attr) error {
	log.Println("RandNumberDir Attr")

	attr.Mode = os.ModeDir | 0555

	return nil
}

func (dir RandNumberDir) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) {
	return []fuse.Dirent{
		{Name: "rand", Type: fuse.DT_File},
	}, nil
}

func (dir RandNumberDir) Lookup(ctx context.Context, name string) (fs.Node, error) {
	log.Println("RandNumberDir Lookup")

	if name == "rand" {
		return StupidFile{strconv.Itoa(dir.number)}, nil
	}

	return nil, fuse.ENOENT
}

type StupidFile struct {
	content string
}

func (file StupidFile) Attr(ctx context.Context, attr *fuse.Attr) error {
	log.Printf("StupidFile (%s) Attr\n", file.content)

	attr.Mode = 0444
	attr.Size = uint64(len(file.content))

	return nil
}

func (file StupidFile) ReadAll(ctx context.Context) ([]byte, error) {
	log.Printf("StupidFile (%s) ReadAll\n", file.content)

	return []byte(file.content), nil
}