94 lines
2.1 KiB
Go
94 lines
2.1 KiB
Go
package fsx
|
|
|
|
import (
|
|
"io/fs"
|
|
"path/filepath"
|
|
|
|
"github.com/tkw1536/goprogram/lib/collection"
|
|
)
|
|
|
|
// Censor returns a new filesystem censors files for which the censor function returns true.
|
|
//
|
|
// A censored file cannot be opened by the filesystem and return [fs.ErrNotExist].
|
|
// Hard and Soft Links pointing to the file might still read it.
|
|
func Censor(fsys fs.FS, censor func(name string) bool) fs.FS {
|
|
return &censorFS{
|
|
fsys: fsys,
|
|
censor: censor,
|
|
}
|
|
}
|
|
|
|
type censorFS struct {
|
|
censor func(path string) bool
|
|
fsys fs.FS
|
|
}
|
|
|
|
func (cf *censorFS) Sub(path string) (fs.FS, error) {
|
|
sub, err := fs.Sub(cf.fsys, path)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &censorFS{
|
|
censor: func(name string) bool {
|
|
return cf.censor(filepath.Join(path, name))
|
|
},
|
|
fsys: sub,
|
|
}, nil
|
|
}
|
|
|
|
func (ef *censorFS) Open(name string) (fs.File, error) {
|
|
if ef.censor(name) {
|
|
return nil, fs.ErrNotExist
|
|
}
|
|
|
|
file, err := ef.fsys.Open(name)
|
|
|
|
// we need to also censor the ReadDir function of the returned file
|
|
// this is to prevent the file from appearing in directory listings.
|
|
if rdf, ok := file.(fs.ReadDirFile); ok {
|
|
return &censorFSFile{
|
|
ReadDirFile: rdf,
|
|
|
|
name: name,
|
|
censor: ef,
|
|
}, err
|
|
}
|
|
return file, err
|
|
}
|
|
|
|
type censorFSFile struct {
|
|
fs.ReadDirFile
|
|
|
|
name string
|
|
censor *censorFS
|
|
}
|
|
|
|
func (f *censorFSFile) ReadDir(n int) ([]fs.DirEntry, error) {
|
|
entries, err := f.ReadDirFile.ReadDir(n)
|
|
return f.censor.handleReadDir(f.name, entries, err)
|
|
}
|
|
|
|
func (ef *censorFS) ReadDir(name string) ([]fs.DirEntry, error) {
|
|
if ef.censor(name) {
|
|
return nil, fs.ErrNotExist
|
|
}
|
|
|
|
// censor ReadDir() entries too
|
|
entries, err := fs.ReadDir(ef.fsys, name)
|
|
return ef.handleReadDir(name, entries, err)
|
|
}
|
|
|
|
// handleReadDir censors a ReadDir call
|
|
func (ef *censorFS) handleReadDir(base string, entries []fs.DirEntry, err error) ([]fs.DirEntry, error) {
|
|
entries = collection.Filter(entries, func(entry fs.DirEntry) bool {
|
|
return !ef.censor(filepath.Join(base, entry.Name()))
|
|
})
|
|
return entries, err
|
|
}
|
|
|
|
func (ef *censorFS) ReadFile(name string) ([]byte, error) {
|
|
if ef.censor(name) {
|
|
return nil, fs.ErrNotExist
|
|
}
|
|
return fs.ReadFile(ef.fsys, name)
|
|
}
|