tailscale/drive/driveimpl/shared/readonlydir.go
Charlotte Brandhorst-Satzkorn 93618a3518
tailscale: update tailfs functions and vars to use drive naming ()
This change updates all tailfs functions and the majority of the tailfs
variables to use the new drive naming.

Updates 

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
2024-04-03 10:09:58 -07:00

112 lines
2.6 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
// Package shared contains types and functions shared by different drive
// packages.
package shared
import (
"errors"
"io"
"io/fs"
"sync"
)
// DirFile implements webdav.File for a virtual directory.
// It mimics the behavior of an os.File that is pointing at a real directory.
type DirFile struct {
// Info provides the fs.FileInfo for this directory
Info fs.FileInfo
// LoadChildren is used to load the fs.FileInfos for this directory's
// children. It is called at most once in order to support listing
// children.
LoadChildren func() ([]fs.FileInfo, error)
// loadChildrenMu guards children and loadedChildren.
loadChildrenMu sync.Mutex
children []fs.FileInfo
loadedChildren bool
}
// Readdir implements interface webdav.File. It lazily loads information about
// children when it is called.
func (d *DirFile) Readdir(count int) ([]fs.FileInfo, error) {
err := d.loadChildrenIfNecessary()
if err != nil {
return nil, err
}
if count <= 0 {
result := d.children
d.children = nil
return result, nil
}
n := len(d.children)
if count < n {
n = count
}
result := d.children[:n]
d.children = d.children[n:]
if len(d.children) == 0 {
err = io.EOF
}
return result, err
}
func (d *DirFile) loadChildrenIfNecessary() error {
d.loadChildrenMu.Lock()
defer d.loadChildrenMu.Unlock()
if !d.loadedChildren {
var err error
d.children, err = d.LoadChildren()
if err != nil {
return err
}
d.loadedChildren = true
}
return nil
}
// Stat implements interface webdav.File.
func (d *DirFile) Stat() (fs.FileInfo, error) {
return d.Info, nil
}
// Close implements interface webdav.File. It does nothing and never returns an
// error.
func (d *DirFile) Close() error {
return nil
}
// Read implements interface webdav.File. As this is a directory, it always
// fails with an fs.PathError.
func (d *DirFile) Read(b []byte) (int, error) {
return 0, &fs.PathError{
Op: "read",
Path: d.Info.Name(),
Err: errors.New("is a directory"),
}
}
// Write implements interface webdav.File. As this is a directory, it always
// fails with an fs.PathError.
func (d *DirFile) Write(b []byte) (int, error) {
return 0, &fs.PathError{
Op: "write",
Path: d.Info.Name(),
Err: errors.New("bad file descriptor"),
}
}
// Seek implements interface webdav.File. As this is a directory, it always
// fails with an fs.PathError.
func (d *DirFile) Seek(offset int64, whence int) (int64, error) {
return 0, &fs.PathError{
Op: "seek",
Path: d.Info.Name(),
Err: errors.New("invalid argument"),
}
}