vfs: Add go-billy dependency and make sure vfs.Handle implements billy.File

billy defines a common file system interface that is used in multiple go packages.
vfs.Handle implements billy.File mostly, only two methods needed to be added to
make it compliant.

An interface check is added as well.

This is a preliminary work for adding serve nfs command.

go.mod

@@ -26,6 +26,7 @@ require (
 	github.com/gabriel-vasile/mimetype v1.4.2
 	github.com/gdamore/tcell/v2 v2.6.0
 	github.com/go-chi/chi/v5 v5.0.10
+	github.com/go-git/go-billy/v5 v5.4.1
 	github.com/google/uuid v1.3.1
 	github.com/hanwen/go-fuse/v2 v2.3.0
 	github.com/henrybear327/Proton-API-Bridge v0.0.0-20230908065933-5bfa15b567db

go.sum

@@ -187,6 +187,8 @@ github.com/glycerine/go-unsnap-stream v0.0.0-20180323001048-9f0cb55181dd/go.mod
 github.com/glycerine/goconvey v0.0.0-20180728074245-46e3a41ad493/go.mod h1:Ogl1Tioa0aV7gstGFO7KhffUsb9M4ydbEbbxpcEDc24=
 github.com/go-chi/chi/v5 v5.0.10 h1:rLz5avzKpjqxrYwXNfmjkrYYXOyLJd37pz53UFHC6vk=
 github.com/go-chi/chi/v5 v5.0.10/go.mod h1:DslCQbL2OYiznFReuXYUmQ2hGd1aDpCnlMNITLSKoi8=
+github.com/go-git/go-billy/v5 v5.4.1 h1:Uwp5tDRkPr+l/TnbHOQzp+tmJfLceOlbVucgpTz8ix4=
+github.com/go-git/go-billy/v5 v5.4.1/go.mod h1:vjbugF6Fz7JIflbVpl1hJsGjSHNltrSw45YK/ukIvQg=
 github.com/go-gl/glfw v0.0.0-20190409004039-e6da0acd62b1/go.mod h1:vR7hzQXu2zJy9AVAgeJqvqgH9Q5CA+iKCZ2gyEVpxRU=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20191125211704-12ad95a8df72/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20200222043503-6f7a984d4dc4/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=

vfs/read_write.go

@@ -30,6 +30,16 @@ type RWFileHandle struct {
 	writeCalled bool // if any Write() methods have been called
 }
 
+// Lock performs Unix locking, not supported
+func (fh *RWFileHandle) Lock() error {
+	return os.ErrInvalid
+}
+
+// Unlock performs Unix unlocking, not supported
+func (fh *RWFileHandle) Unlock() error {
+	return os.ErrInvalid
+}
+
 func newRWFileHandle(d *Dir, f *File, flags int) (fh *RWFileHandle, err error) {
 	defer log.Trace(f.Path(), "")("err=%v", &err)
 	// get an item to represent this from the cache

vfs/vfs.go

@@ -32,6 +32,7 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/go-git/go-billy/v5"
 	"github.com/rclone/rclone/fs"
 	"github.com/rclone/rclone/fs/cache"
 	"github.com/rclone/rclone/fs/log"
@@ -119,6 +120,8 @@ type Handle interface {
 	Release() error
 	Node() Node
 	//	Size() int64
+	Lock() error
+	Unlock() error
 }
 
 // baseHandle implements all the missing methods
@@ -144,6 +147,8 @@ func (h baseHandle) WriteString(s string) (n int, err error)              { retu
 func (h baseHandle) Flush() (err error)                                   { return ENOSYS }
 func (h baseHandle) Release() (err error)                                 { return ENOSYS }
 func (h baseHandle) Node() Node                                           { return nil }
+func (h baseHandle) Unlock() error                                        { return os.ErrInvalid }
+func (h baseHandle) Lock() error                                          { return os.ErrInvalid }
 
 //func (h baseHandle) Size() int64                                          { return 0 }
 
@@ -154,6 +159,7 @@ var (
 	_ Handle     = (*ReadFileHandle)(nil)
 	_ Handle     = (*WriteFileHandle)(nil)
 	_ Handle     = (*DirHandle)(nil)
+	_ billy.File = (Handle)(nil)
 )
 
 // VFS represents the top level filing system

vfs/vfstest/os.go

@@ -48,6 +48,14 @@ func (f realOsFile) Node() vfs.Node {
 	return nil
 }
 
+func (f realOsFile) Lock() error {
+	return os.ErrInvalid
+}
+
+func (f realOsFile) Unlock() error {
+	return os.ErrInvalid
+}
+
 // Chtimes
 func (r realOs) Chtimes(name string, atime time.Time, mtime time.Time) error {
 	return os.Chtimes(name, atime, mtime)