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//go:build plan9
// +build plan9
package osfs
import (
"io"
"os"
"path/filepath"
"syscall"
)
func (f *file) Lock() error {
// Plan 9 uses a mode bit instead of explicit lock/unlock syscalls.
//
// Per http://man.cat-v.org/plan_9/5/stat: “Exclusive use files may be open
// for I/O by only one fid at a time across all clients of the server. If a
// second open is attempted, it draws an error.”
//
// There is no obvious way to implement this function using the exclusive use bit.
// See https://golang.org/src/cmd/go/internal/lockedfile/lockedfile_plan9.go
// for how file locking is done by the go tool on Plan 9.
return nil
}
func (f *file) Unlock() error {
return nil
}
func rename(from, to string) error {
// If from and to are in different directories, copy the file
// since Plan 9 does not support cross-directory rename.
if filepath.Dir(from) != filepath.Dir(to) {
fi, err := os.Stat(from)
if err != nil {
return &os.LinkError{"rename", from, to, err}
}
if fi.Mode().IsDir() {
return &os.LinkError{"rename", from, to, syscall.EISDIR}
}
fromFile, err := os.Open(from)
if err != nil {
return &os.LinkError{"rename", from, to, err}
}
toFile, err := os.OpenFile(to, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, fi.Mode())
if err != nil {
return &os.LinkError{"rename", from, to, err}
}
_, err = io.Copy(toFile, fromFile)
if err != nil {
return &os.LinkError{"rename", from, to, err}
}
// Copy mtime and mode from original file.
// We need only one syscall if we avoid os.Chmod and os.Chtimes.
dir := fi.Sys().(*syscall.Dir)
var d syscall.Dir
d.Null()
d.Mtime = dir.Mtime
d.Mode = dir.Mode
if err = dirwstat(to, &d); err != nil {
return &os.LinkError{"rename", from, to, err}
}
// Remove original file.
err = os.Remove(from)
if err != nil {
return &os.LinkError{"rename", from, to, err}
}
return nil
}
return os.Rename(from, to)
}
func dirwstat(name string, d *syscall.Dir) error {
var buf [syscall.STATFIXLEN]byte
n, err := d.Marshal(buf[:])
if err != nil {
return &os.PathError{"dirwstat", name, err}
}
if err = syscall.Wstat(name, buf[:n]); err != nil {
return &os.PathError{"dirwstat", name, err}
}
return nil
}
func umask(new int) func() {
return func() {
}
}
|
