itd/fuse/main.go

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package main
import (
"log"
"os"
"context"
"syscall"
"github.com/hanwen/go-fuse/v2/fs"
"github.com/hanwen/go-fuse/v2/fuse"
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"strconv"
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"strings"
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)
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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
}
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type ITProperty struct {
name string
Ino uint64
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f func() ([]byte, error)
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}
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type ITNode struct {
fs.Inode
kind int
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Ino uint64
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lst []DirEntry
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self DirEntry
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path string
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}
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var properties = []ITProperty {
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ITProperty{"heartrate", 2, nil},
ITProperty{"battery", 3, nil},
ITProperty{"motion", 4, nil},
ITProperty{"stepcount", 5, nil},
ITProperty{"version", 6, nil},
ITProperty{"address", 7, nil},
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}
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var myfs *FS = nil;
var inodemap map[string]uint64 = nil;
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var _ = (fs.NodeReaddirer)((*ITNode)(nil))
// Readdir is part of the NodeReaddirer interface
func (n *ITNode) Readdir(ctx context.Context) (fs.DirStream, syscall.Errno) {
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switch n.kind {
case 0:
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// 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
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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
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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
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}
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) {
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switch n.kind {
case 0:
// root folder
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if name == "device" {
stable := fs.StableAttr{
Mode: fuse.S_IFDIR,
Ino: uint64(0),
}
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operations := &ITNode{kind: 1, Ino: 0}
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child := n.NewInode(ctx, operations, stable)
return child, 0
} else if name == "fs" {
stable := fs.StableAttr{
Mode: fuse.S_IFDIR,
Ino: uint64(1),
}
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operations := &ITNode{kind: 2, Ino: 1, path : ""}
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child := n.NewInode(ctx, operations, stable)
return child, 0
}
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case 1:
// device folder
for _, value := range properties {
if value.name == name {
stable := fs.StableAttr{
Mode: fuse.S_IFREG,
Ino: uint64(value.Ino),
}
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operations := &ITNode{kind: 3, Ino: value.Ino}
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child := n.NewInode(ctx, operations, stable)
return child, 0
}
}
return nil, syscall.ENOENT
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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],
}
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operations := &ITNode{
kind: 2, path: file.path,
self: file,
}
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child := n.NewInode(ctx, operations, stable)
return child, 0
}
break;
}
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}
return nil, syscall.ENOENT
}
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type bytesFileReadHandle struct {
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content []byte
}
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var _ = (fs.FileReader)((*bytesFileReadHandle)(nil))
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func (fh *bytesFileReadHandle) Read(ctx context.Context, dest []byte, off int64) (fuse.ReadResult, syscall.Errno) {
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end := off + int64(len(dest))
if end > int64(len(fh.content)) {
end = int64(len(fh.content))
}
return fuse.ReadResultData(fh.content[off:end]), 0
}
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type bytesFileWriteHandle struct {
content []byte
path string
}
var _ = (fs.FileWriter)((*bytesFileWriteHandle)(nil))
func (fh *bytesFileWriteHandle) Write(ctx context.Context, data []byte, off int64) (written uint32, errno syscall.Errno) {
if off != int64(len(fh.content)) {
}
fh.content = append(fh.content[:], data[:]...)
return uint32(len(data)), 0
}
var _ = (fs.FileFlusher)((*bytesFileWriteHandle)(nil))
func (fh *bytesFileWriteHandle) Flush(ctx context.Context) (errno syscall.Errno) {
fp, err := myfs.Create(fh.path, uint32(len(fh.content)))
if err != nil {
return syscall.EROFS
}
nread, err := fp.Write(fh.content)
if err != nil || nread != len(fh.content) {
return syscall.EROFS
}
return 0
}
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var _ = (fs.NodeGetattrer)((*ITNode)(nil))
func (bn *ITNode) Getattr(ctx context.Context, f fs.FileHandle, out *fuse.AttrOut) syscall.Errno {
out.Ino = bn.Ino
out.Mtime = bn.self.modtime
out.Ctime = bn.self.modtime
out.Atime = bn.self.modtime
out.Size = uint64(bn.self.size)
return 0
}
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var _ = (fs.NodeSetattrer)((*ITNode)(nil))
func (bn *ITNode) Setattr(ctx context.Context, fh fs.FileHandle, in *fuse.SetAttrIn, out *fuse.AttrOut) syscall.Errno {
out.Size = 0;
out.Mtime = 0;
return 0
}
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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 {
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case 2:
// FS file
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if openFlags&syscall.O_RDWR != 0 {
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return nil, 0, syscall.EROFS
}
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if openFlags & syscall.O_WRONLY != 0 {
fh = &bytesFileWriteHandle{
path : f.path,
content : make([]byte, 0),
}
return fh, fuse.FOPEN_DIRECT_IO, 0
} else {
fp, err := myfs.Open(f.path)
if err != nil {
return nil, 0, syscall.EROFS
}
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buf := make([]byte, f.self.size);
nread, err := fp.Read(buf)
if err != nil || nread != int(f.self.size) {
return nil, 0, syscall.EROFS
}
fh = &bytesFileReadHandle{
content: buf,
}
return fh, fuse.FOPEN_DIRECT_IO, 0
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}
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case 3:
// Device file
// disallow writes
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if openFlags&(syscall.O_RDWR|syscall.O_WRONLY) != 0 {
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return nil, 0, syscall.EROFS
}
for _, value := range properties {
if value.Ino == f.Ino {
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ans, err := value.f()
if err != nil {
return nil, 0, syscall.EROFS
}
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fh = &bytesFileReadHandle{
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content: ans,
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}
return fh, fuse.FOPEN_DIRECT_IO, 0
}
}
}
return nil, 0, syscall.EROFS
}
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var _ = (fs.NodeCreater)((*ITNode)(nil))
func (f *ITNode) Create(ctx context.Context, name string, flags uint32, mode uint32, out *fuse.EntryOut) (node *fs.Inode, fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) {
if f.kind != 2 {
return nil, nil, 0, syscall.EROFS
}
path := f.path + "/" + name
ino := uint64(len(inodemap)) + 11
inodemap[path] = ino
stable := fs.StableAttr{
Mode: fuse.S_IFREG,
Ino: ino,
}
operations := &ITNode{
kind: 2, Ino: ino,
path : path,
}
node = f.NewInode(ctx, operations, stable)
fh = &bytesFileWriteHandle{
path : path,
content : make([]byte, 0),
}
errno = 0
return node, fh, fuseFlags, 0
}
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var _ = (fs.NodeMkdirer)((*ITNode)(nil))
func (f *ITNode) Mkdir(ctx context.Context, name string, mode uint32, out *fuse.EntryOut) (*fs.Inode, syscall.Errno) {
if f.kind != 2 {
return nil, syscall.EROFS
}
path := f.path + "/" + name
err := myfs.Mkdir(path)
if err != nil {
return nil, syscall.EROFS
}
ino := uint64(len(inodemap)) + 11
inodemap[path] = ino
stable := fs.StableAttr{
Mode: fuse.S_IFDIR,
Ino: ino,
}
operations := &ITNode{
kind: 2, Ino: ino,
path : path,
}
node := f.NewInode(ctx, operations, stable)
return node, 0
}
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var _ = (fs.NodeRenamer)((*ITNode)(nil))
func (f *ITNode) Rename(ctx context.Context, name string, newParent fs.InodeEmbedder, newName string, flags uint32) syscall.Errno {
p1 := f.path + "/" + name
p2 := newParent.EmbeddedInode().Path(nil)[2:] + "/" + newName
err := myfs.Rename(p1, p2)
if err != nil {
return syscall.EROFS
}
ino := inodemap[p1]
delete(inodemap, p1)
inodemap[p2] = ino
return 0
}
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var _ = (fs.NodeUnlinker)((*ITNode)(nil))
func (f *ITNode) Unlink(ctx context.Context, name string) syscall.Errno {
delete(inodemap, f.path + "/" + name)
err := myfs.Remove(f.path + "/" + name)
if err != nil {
return syscall.EROFS
}
return 0
}
var _ = (fs.NodeRmdirer)((*ITNode)(nil))
func (f *ITNode) Rmdir(ctx context.Context, name string) syscall.Errno {
return f.Unlink(ctx, name)
}
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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)
}
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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;
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log.Printf("Mounted on %s", mntDir)
log.Printf("Unmount by calling 'fusermount -u %s'", mntDir)
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myfs = &FS{};
inodemap = make(map[string]uint64)
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// Wait until unmount before exiting
server.Wait()
}