JCS-pub/client2/internal/mount/vfs.go

package mount

import (
	"os"
	"syscall"
	"time"

	"github.com/hanwen/go-fuse/v2/fuse"
)

type Config struct {
	GID         uint32        `json:"gid"`
	UID         uint32        `json:"uid"`
	AttrTimeout time.Duration `json:"attrTimeout"`
}

type Vfs struct {
	fs     Fs
	config Config
}

func translateError(err error) syscall.Errno {
	switch err {
	case nil:
		return 0

	case ErrNotExists, os.ErrNotExist:
		return syscall.ENOENT

	case ErrExists, os.ErrExist:
		return syscall.EEXIST

	case ErrPermission, os.ErrPermission:
		return syscall.EACCES

	case ErrNotEmpty:
		return syscall.ENOTEMPTY

	default:
		return syscall.EIO
	}
}

// get the Mode from a vfs Node
func (v *Vfs) getMode(node FsEntry) uint32 {
	Mode := node.Mode().Perm()
	if node.IsDir() {
		Mode |= fuse.S_IFDIR
	} else {
		Mode |= fuse.S_IFREG
	}
	return uint32(Mode)
}

// fill in attr from node
func (v *Vfs) fillAttr(node FsEntry, attr *fuse.Attr) {
	Size := uint64(node.Size())
	const BlockSize = 512
	Blocks := (Size + BlockSize - 1) / BlockSize
	attr.Owner.Gid = v.config.GID
	attr.Owner.Uid = v.config.UID
	attr.Mode = v.getMode(node)
	attr.Size = Size
	attr.Nlink = 1
	attr.Blocks = Blocks
	// attr.Blksize = BlockSize // not supported in freebsd/darwin, defaults to 4k if not set

	createTime := node.CreateTime()
	modTime := node.ModTime()

	attr.Atime = uint64(modTime.Unix())
	attr.Atimensec = uint32(modTime.Nanosecond())

	attr.Mtime = uint64(modTime.Unix())
	attr.Mtimensec = uint32(modTime.Nanosecond())

	attr.Ctime = uint64(createTime.Unix())
	attr.Ctimensec = uint32(createTime.Nanosecond())
}

func (v *Vfs) fillAttrOut(node FsEntry, out *fuse.AttrOut) {
	v.fillAttr(node, &out.Attr)
	out.SetTimeout(v.config.AttrTimeout)
}

func (v *Vfs) fillEntryOut(node FsEntry, out *fuse.EntryOut) {
	v.fillAttr(node, &out.Attr)
	out.SetAttrTimeout(v.config.AttrTimeout)
	out.SetEntryTimeout(v.config.AttrTimeout)
}