go-gemini/fs.go
2020-10-13 20:10:04 -04:00

86 lines
1.8 KiB
Go

package gmi
import (
"io"
"mime"
"os"
"path"
"path/filepath"
)
func init() {
// Add Gemini mime types
mime.AddExtensionType(".gmi", "text/gemini")
mime.AddExtensionType(".gemini", "text/gemini")
}
// FileServer takes a filesystem and returns a Handler which uses that filesystem.
// The returned Handler sanitizes paths before handling them.
func FileServer(fsys FS) Handler {
return fsHandler{fsys}
}
type fsHandler struct {
FS
}
func (fsh fsHandler) Serve(rw *ResponseWriter, req *Request) {
path := path.Clean(req.URL.Path)
f, err := fsh.Open(path)
if err != nil {
NotFound(rw, req)
return
}
// Detect mimetype
ext := filepath.Ext(path)
mimetype := mime.TypeByExtension(ext)
rw.SetMimetype(mimetype)
// Copy file to response writer
io.Copy(rw, f)
}
// TODO: replace with io/fs.FS when available
type FS interface {
Open(name string) (File, error)
}
// TODO: replace with io/fs.File when available
type File interface {
Stat() (os.FileInfo, error)
Read([]byte) (int, error)
Close() error
}
// Dir implements FS using the native filesystem restricted to a specific directory.
type Dir string
// Open tries to open the file with the given name.
// If the file is a directory, it tries to open the index file in that directory.
func (d Dir) Open(name string) (File, error) {
p := path.Join(string(d), name)
f, err := os.OpenFile(p, os.O_RDONLY, 0644)
if err != nil {
return nil, err
}
if stat, err := f.Stat(); err == nil {
if stat.IsDir() {
f, err := os.Open(path.Join(p, "index.gmi"))
if err != nil {
return nil, err
}
stat, err := f.Stat()
if err != nil {
return nil, err
}
if stat.Mode().IsRegular() {
return f, nil
}
return nil, ErrNotAFile
} else if !stat.Mode().IsRegular() {
return nil, ErrNotAFile
}
}
return f, nil
}