itd/fuse/main.go
2023-02-19 16:45:51 +00:00

275 lines
6.0 KiB
Go

package main
import (
"log"
"os"
"context"
"syscall"
"github.com/hanwen/go-fuse/v2/fs"
"github.com/hanwen/go-fuse/v2/fuse"
"strconv"
"strings"
)
func (i *Device) HeartRateBytes() ([]byte, error) {
v, err := i.HeartRate()
return []byte(strconv.Itoa(int(v)) + "\n"), err
}
func (i *Device) BatteryLevelBytes() ([]byte, error) {
v, err := i.BatteryLevel()
return []byte(strconv.Itoa(int(v)) + "\n"), err
}
func (i *Device) StepCountBytes() ([]byte, error) {
v, err := i.StepCount()
return []byte(strconv.Itoa(int(v)) + "\n"), err
}
func (i *Device) MotionBytes() ([]byte, error) {
v, err := i.Motion()
return []byte(strconv.Itoa(int(v.X)) + " " + strconv.Itoa(int(v.Y)) + " " + strconv.Itoa(int(v.Z)) + "\n"), err
}
func (i *Device) AddressBytes() ([]byte, error) {
v := i.Address()
return []byte(v + "\n"), nil
}
func (i *Device) VersionBytes() ([]byte, error) {
v, err := i.Version()
return []byte(v + "\n"), err
}
type ITProperty struct {
name string
Ino uint64
f func() ([]byte, error)
}
type ITNode struct {
fs.Inode
kind int
Ino uint64
lst []DirEntry
path string
}
var properties = []ITProperty {
ITProperty{"heartrate", 2, nil},
ITProperty{"battery", 3, nil},
ITProperty{"motion", 4, nil},
ITProperty{"stepcount", 5, nil},
ITProperty{"version", 6, nil},
ITProperty{"address", 7, nil},
}
var myfs *FS = nil;
var inodemap map[string]uint64 = nil;
var _ = (fs.NodeReaddirer)((*ITNode)(nil))
// Readdir is part of the NodeReaddirer interface
func (n *ITNode) Readdir(ctx context.Context) (fs.DirStream, syscall.Errno) {
switch n.kind {
case 0:
// root folder
r := make([]fuse.DirEntry, 2)
r[0] = fuse.DirEntry{
Name: "device",
Ino: 0,
Mode: fuse.S_IFDIR,
}
r[1] = fuse.DirEntry{
Name: "fs",
Ino: 1,
Mode: fuse.S_IFDIR,
}
return fs.NewListDirStream(r), 0
case 1:
// device folder
r := make([]fuse.DirEntry, 6)
for ind, value := range properties {
r[ind] = fuse.DirEntry{
Name: value.name,
Ino: value.Ino,
Mode: fuse.S_IFREG,
}
}
return fs.NewListDirStream(r), 0
case 2:
// on device
files, _ := myfs.ReadDir(n.path)
r := make([]fuse.DirEntry, len(files))
n.lst = files
for ind, file := range files {
name := file.path[strings.LastIndex(file.path, "/")+1:]
ino := inodemap[file.path]
if ino == 0 {
ino = uint64(len(inodemap)) + 1
inodemap[file.path] = ino
}
if file.flags & 0b1 == 1 {
r[ind] = fuse.DirEntry{
Name: name,
Mode: fuse.S_IFDIR,
Ino : ino + 10,
}
} else {
r[ind] = fuse.DirEntry{
Name: name,
Mode: fuse.S_IFREG,
Ino : ino + 10,
}
}
}
return fs.NewListDirStream(r), 0
}
r := make([]fuse.DirEntry, 0)
return fs.NewListDirStream(r), 0
}
var _ = (fs.NodeLookuper)((*ITNode)(nil))
func (n *ITNode) Lookup(ctx context.Context, name string, out *fuse.EntryOut) (*fs.Inode, syscall.Errno) {
switch n.kind {
case 0:
// root folder
if name == "device" {
stable := fs.StableAttr{
Mode: fuse.S_IFDIR,
Ino: uint64(0),
}
operations := &ITNode{kind: 1, Ino: 0}
child := n.NewInode(ctx, operations, stable)
return child, 0
} else if name == "fs" {
stable := fs.StableAttr{
Mode: fuse.S_IFDIR,
Ino: uint64(1),
}
operations := &ITNode{kind: 2, Ino: 1, path : ""}
child := n.NewInode(ctx, operations, stable)
return child, 0
}
case 1:
// device folder
for _, value := range properties {
if value.name == name {
stable := fs.StableAttr{
Mode: fuse.S_IFREG,
Ino: uint64(value.Ino),
}
operations := &ITNode{kind: 3, Ino: value.Ino}
child := n.NewInode(ctx, operations, stable)
return child, 0
}
}
return nil, syscall.ENOENT
case 2:
// FS object
for _, file := range n.lst {
if file.path != n.path + "/" + name {
continue;
}
log.Println("matched", name)
if file.flags & 0b1 == 1 {
stable := fs.StableAttr{
Mode: fuse.S_IFDIR,
Ino: inodemap[file.path],
}
operations := &ITNode{kind: 2, path: file.path}
child := n.NewInode(ctx, operations, stable)
return child, 0
} else {
stable := fs.StableAttr{
Mode: fuse.S_IFREG,
Ino: inodemap[file.path],
}
operations := &ITNode{kind: 2, path: file.path}
child := n.NewInode(ctx, operations, stable)
return child, 0
}
break;
}
}
return nil, syscall.ENOENT
}
type bytesFileHandle struct {
content []byte
}
var _ = (fs.FileReader)((*bytesFileHandle)(nil))
func (fh *bytesFileHandle) Read(ctx context.Context, dest []byte, off int64) (fuse.ReadResult, syscall.Errno) {
end := off + int64(len(dest))
if end > int64(len(fh.content)) {
end = int64(len(fh.content))
}
return fuse.ReadResultData(fh.content[off:end]), 0
}
var _ = (fs.NodeOpener)((*ITNode)(nil))
func (f *ITNode) Open(ctx context.Context, openFlags uint32) (fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) {
switch f.kind {
case 3:
// Device file
// disallow writes
if fuseFlags&(syscall.O_RDWR|syscall.O_WRONLY) != 0 {
return nil, 0, syscall.EROFS
}
for _, value := range properties {
if value.Ino == f.Ino {
ans, err := value.f()
if err != nil {
return nil, 0, syscall.EROFS
}
fh = &bytesFileHandle{
content: ans,
}
return fh, fuse.FOPEN_DIRECT_IO, 0
}
}
}
return nil, 0, syscall.EROFS
}
func main() {
// This is where we'll mount the FS
mntDir := "/tmp/x"
os.Mkdir(mntDir, 0755)
root := &ITNode{kind: 0}
server, err := fs.Mount(mntDir, root, &fs.Options{
MountOptions: fuse.MountOptions{
// Set to true to see how the file system works.
Debug: false,
},
})
if err != nil {
log.Panic(err)
}
dev := Device{};
properties[0].f = dev.HeartRateBytes;
properties[1].f = dev.BatteryLevelBytes;
properties[2].f = dev.MotionBytes;
properties[3].f = dev.StepCountBytes;
properties[4].f = dev.VersionBytes;
properties[5].f = dev.AddressBytes;
log.Printf("Mounted on %s", mntDir)
log.Printf("Unmount by calling 'fusermount -u %s'", mntDir)
myfs = &FS{};
inodemap = make(map[string]uint64)
// Wait until unmount before exiting
server.Wait()
}