go-gemini/fs.go
2021-02-08 12:50:52 -05:00

116 lines
2.4 KiB
Go

package gemini
import (
"io"
"mime"
"os"
"path"
)
func init() {
// Add Gemini mime types
mime.AddExtensionType(".gmi", "text/gemini")
mime.AddExtensionType(".gemini", "text/gemini")
}
// FileServer returns a handler that serves Gemini requests with the contents
// of the file system rooted at root.
// The returned handler cleans paths before handling them.
//
// TODO: Use io/fs.FS when available.
func FileServer(fsys FS) Handler {
return fsHandler{fsys}
}
type fsHandler struct {
FS
}
func (fsh fsHandler) ServeGemini(w *ResponseWriter, r *Request) {
p := path.Clean(r.URL.Path)
f, err := fsh.Open(p)
if err != nil {
w.Status(StatusNotFound)
return
}
// Detect mimetype
ext := path.Ext(p)
mimetype := mime.TypeByExtension(ext)
w.Meta(mimetype)
// Copy file to response writer
_, _ = io.Copy(w, f)
}
// FS represents a filesystem.
//
// TODO: Replace with io/fs.FS when available.
type FS interface {
Open(name string) (File, error)
}
// File represents a file.
//
// 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.
//
// TODO: replace with os.DirFS when available.
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)
return openFile(p)
}
// ServeFile responds to the request with the contents of the named file
// or directory.
//
// TODO: Use io/fs.FS when available.
func ServeFile(w *ResponseWriter, fs FS, name string) {
f, err := fs.Open(name)
if err != nil {
w.Status(StatusNotFound)
return
}
// Detect mimetype
ext := path.Ext(name)
mimetype := mime.TypeByExtension(ext)
w.Meta(mimetype)
// Copy file to response writer
_, _ = io.Copy(w, f)
}
func openFile(p string) (File, error) {
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, os.ErrNotExist
} else if !stat.Mode().IsRegular() {
return nil, os.ErrNotExist
}
}
return f, nil
}