ISSUE-44 delete support

server/handlers.go

@@ -297,14 +297,17 @@ type Metadata struct {
 	MaxDownloads int
 	// MaxDate contains the max age of the file
 	MaxDate time.Time
+	// DeletionToken contains the token to match against for deletion
+	DeletionToken string
 }
 
 func MetadataForRequest(contentType string, r *http.Request) Metadata {
 	metadata := Metadata{
-		ContentType:  contentType,
-		MaxDate:      time.Now().Add(time.Hour * 24 * 365 * 10),
-		Downloads:    0,
-		MaxDownloads: 99999999,
+		ContentType:   contentType,
+		MaxDate:       time.Now().Add(time.Hour * 24 * 365 * 10),
+		Downloads:     0,
+		MaxDownloads:  99999999,
+		DeletionToken: Encode(10000000 + int64(rand.Intn(1000000000))) + Encode(10000000 + int64(rand.Intn(1000000000))),
 	}
 
 	if v := r.Header.Get("Max-Downloads"); v == "" {
@@ -411,11 +414,14 @@ func (s *Server) putHandler(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "text/plain")
 
 	relativeURL, _ := url.Parse(path.Join(token, filename))
+	deleteUrl , _ := url.Parse(path.Join(token, filename, metadata.DeletionToken))
 
-	fmt.Fprint(w, escapeFilename(r, relativeURL))
+	w.Header().Set("X-Url-Delete", resolveUrl(r, deleteUrl, true))
+
+	fmt.Fprint(w, resolveUrl(r, relativeURL, false))
 }
 
-func escapeFilename(r *http.Request, u *url.URL) string {
+func resolveUrl(r *http.Request, u *url.URL, absolutePath bool) string {
 	if u.RawQuery != "" {
 		u.Path = fmt.Sprintf("%s?%s", u.Path, url.QueryEscape(u.RawQuery))
 		u.RawQuery = ""
@@ -426,6 +432,10 @@ func escapeFilename(r *http.Request, u *url.URL) string {
 		u.Fragment = ""
 	}
 
+	if absolutePath {
+		r.URL.Path = ""
+	}
+
 	return getURL(r).ResolveReference(u).String()
 }
 
@@ -513,6 +523,54 @@ func (s *Server) CheckMetadata(token, filename string) error {
 	return nil
 }
 
+func (s *Server) CheckDeletionToken(deletionToken, token, filename string) error {
+	s.Lock(token, filename)
+	defer s.Unlock(token, filename)
+
+	var metadata Metadata
+
+	r, _, _, err := s.storage.Get(token, fmt.Sprintf("%s.metadata", filename))
+	if s.storage.IsNotExist(err) {
+		return nil
+	} else if err != nil {
+		return err
+	}
+
+	defer r.Close()
+
+	if err := json.NewDecoder(r).Decode(&metadata); err != nil {
+		return err
+	} else if metadata.DeletionToken != deletionToken {
+		return errors.New("Deletion token doesn't match.")
+	}
+
+	return nil
+}
+
+func (s *Server) deleteHandler(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+
+	token := vars["token"]
+	filename := vars["filename"]
+	deletionToken := vars["deletionToken"]
+
+	if err := s.CheckDeletionToken(deletionToken, token, filename); err != nil {
+		log.Printf("Error metadata: %s", err.Error())
+		http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
+		return
+	}
+
+	err := s.storage.Delete(token, filename)
+	if s.storage.IsNotExist(err) {
+		http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
+		return
+	} else if err != nil {
+		log.Printf("%s", err.Error())
+		http.Error(w, "Could not delete file.", 500)
+		return
+	}
+}
+
 func (s *Server) zipHandler(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
 

server/server.go

@@ -323,6 +323,8 @@ func (s *Server) Run() {
 	r.HandleFunc("/", s.postHandler).Methods("POST")
 	// r.HandleFunc("/{page}", viewHandler).Methods("GET")
 
+	r.HandleFunc("/{token}/{filename}/{deletionToken}", s.deleteHandler).Methods("DELETE")
+
 	r.NotFoundHandler = http.HandlerFunc(s.notFoundHandler)
 
 	mime.AddExtensionType(".md", "text/x-markdown")

server/storage.go

@@ -28,6 +28,7 @@ type Storage interface {
 	Get(token string, filename string) (reader io.ReadCloser, contentType string, contentLength uint64, err error)
 	Head(token string, filename string) (contentType string, contentLength uint64, err error)
 	Put(token string, filename string, reader io.Reader, contentType string, contentLength uint64) error
+	Delete(token string, filename string) error
 	IsNotExist(err error) bool
 
 	Type() string
@@ -81,6 +82,15 @@ func (s *LocalStorage) Get(token string, filename string) (reader io.ReadCloser,
 	return
 }
 
+func (s *LocalStorage) Delete(token string, filename string) (err error) {
+	metadata := filepath.Join(s.basedir, token, fmt.Sprintf("%s.metadata", filename))
+	os.Remove(metadata);
+
+	path := filepath.Join(s.basedir, token, filename)
+	err = os.Remove(path);
+	return
+}
+
 func (s *LocalStorage) IsNotExist(err error) bool {
 	if err == nil {
 		return false
@@ -181,6 +191,16 @@ func (s *S3Storage) Get(token string, filename string) (reader io.ReadCloser, co
 	return
 }
 
+func (s *S3Storage) Delete(token string, filename string) (err error) {
+	metadata := fmt.Sprintf("%s/%s.metadata", token, filename)
+	s.bucket.Del(metadata)
+
+	key := fmt.Sprintf("%s/%s", token, filename)
+	err = s.bucket.Del(key)
+
+	return
+}
+
 func (s *S3Storage) Put(token string, filename string, reader io.Reader, contentType string, contentLength uint64) (err error) {
 	key := fmt.Sprintf("%s/%s", token, filename)
 
@@ -580,6 +600,20 @@ func (s *GDrive) Get(token string, filename string) (reader io.ReadCloser, conte
 	return
 }
 
+func (s *GDrive) Delete(token string, filename string) (err error) {
+	metadata, _ := s.findId(fmt.Sprintf("%s.metadata", filename), token)
+	s.service.Files.Delete(metadata).Do()
+
+	var fileId string
+	fileId, err = s.findId(filename, token)
+	if err != nil {
+		return
+	}
+
+	err = s.service.Files.Delete(fileId).Do()
+	return
+}
+
 func (s *GDrive) IsNotExist(err error) bool {
 	if err == nil {
 		return false