// Create adds either a synthetic dir or file, depending on the file
// permissions, if the create is permitted and a file with that name doesn't
// already exist. It also updates mtime, mtime and version for the dir.
func (d *SyntheticDir) Create(user, name string, perms qp.FileMode) (File, error) {
d.Lock()
defer d.Unlock()
owner := d.UID == user
if !PermCheck(owner, false, d.Permissions, qp.OWRITE) {
return nil, ErrPermissionDenied
}
_, ok := d.Tree[name]
if ok {
return nil, ErrFileAlreadyExists
}
var f File
if perms&qp.DMDIR != 0 {
perms = perms & (^qp.FileMode(0777) | (d.Permissions & 0777))
f = NewSyntheticDir(name, perms, d.UID, d.GID)
} else {
perms = perms & (^qp.FileMode(0666) | (d.Permissions & 0666))
f = NewSyntheticFile(name, perms, d.UID, d.GID)
}
d.Tree[name] = f
d.Mtime = time.Now()
d.Atime = d.Mtime
d.Version++
return f, nil
}
func emptyStat() qp.Stat {
return qp.Stat{
Type: ^uint16(0),
Dev: ^uint32(0),
Mode: ^qp.FileMode(0),
Atime: ^uint32(0),
Mtime: ^uint32(0),
Length: ^uint64(0),
}
}
// Create creates either a file or a directory at the specified path. It fails
// if the file already exists, or permissions did not permit it.
func (c *SimpleClient) Create(name string, directory bool) error {
if c.root == nil {
return ErrSimpleClientNotStarted
}
dir := path.Dir(name)
file := path.Base(name)
fid, _, err := c.walkTo(dir)
if err != nil {
return err
}
defer fid.Clunk()
perms := qp.FileMode(0755)
if directory {
perms |= qp.DMDIR
}
_, _, err = fid.Create(file, perms, qp.OREAD)
if err != nil {
return err
}
return nil
}
func setStat(user string, e trees.File, parent trees.Dir, nstat qp.Stat) error {
ostat, err := e.Stat()
if err != nil {
return err
}
length := false
name := false
mode := false
owner := false
if nstat.Type != ^uint16(0) && nstat.Type != ostat.Type {
return errors.New("it is illegal to modify type")
}
if nstat.Dev != ^uint32(0) && nstat.Dev != ostat.Dev {
return errors.New("it is illegal to modify dev")
}
if nstat.MUID != "" && nstat.MUID != ostat.MUID {
return errors.New("it is illegal to modify muid")
}
if nstat.Atime != ^uint32(0) && nstat.Atime != ostat.Atime {
return errors.New("it is illegal to modify atime")
}
if parent == nil && nstat.Name != "" && nstat.Name != ostat.Name {
return errors.New("it is illegal to rename root")
}
if nstat.Length != ^uint64(0) && nstat.Length != ostat.Length {
if ostat.Mode&qp.DMDIR != 0 {
return errors.New("cannot set length of directory")
}
if nstat.Length > ostat.Length {
return errors.New("cannot extend length")
}
length = true
}
if nstat.Name != "" && nstat.Name != ostat.Name {
name = true
}
if (nstat.UID != "" && nstat.UID != ostat.UID) || (nstat.GID != "" && nstat.GID != ostat.GID) {
owner = true
}
if nstat.Mode != ^qp.FileMode(0) && nstat.Mode != ostat.Mode {
mode = true
}
if nstat.Mtime != ^uint32(0) && nstat.Mtime != ostat.Mtime {
// We ignore mtime changes ATM. Only owner can change mtime.
}
if mode {
if err := e.SetMode(user, ostat.Mode&qp.DMDIR | nstat.Mode & ^qp.DMDIR); err != nil {
return err
}
}
if owner {
if err := e.SetOwner(user, nstat.UID, nstat.GID); err != nil {
e.SetMode(user, ostat.Mode)
return err
}
}
if name {
if err := parent.Rename(user, ostat.Name, nstat.Name); err != nil {
e.SetMode(user, ostat.Mode)
e.SetOwner(user, ostat.UID, ostat.GID)
return err
}
}
if length {
if err := e.SetLength(user, nstat.Length); err != nil {
e.SetMode(user, ostat.Mode)
e.SetOwner(user, ostat.UID, ostat.GID)
parent.Rename(user, nstat.Name, ostat.Name)
return err
}
}
return nil
}