Improve documentation

gateway/gateway.go

@@ -415,18 +415,25 @@ func (gw *Gateway) modifyMessage(msg *config.Message) {
 	}
 }
 
+// handleFiles uploads or places all files on the given msg to the MediaServer and
+// adds the new URL of the file on the MediaServer onto the given msg.
 func (gw *Gateway) handleFiles(msg *config.Message) {
 	reg := regexp.MustCompile("[^a-zA-Z0-9]+")
-	// if we don't have a attachfield or we don't have a mediaserver configured return
+
+	// If we don't have a attachfield or we don't have a mediaserver configured return
 	if msg.Extra == nil || (gw.Config.General.MediaServerUpload == "" && gw.Config.General.MediaServerPath == "") {
 		return
 	}
 
-	// if we actually have files, start uploading them to the mediaserver
+	// If we don't have files, nothing to upload.
-	if len(msg.Extra["file"]) > 0 {
+	if len(msg.Extra["file"]) == 0 {
+		return
+	}
+
 	client := &http.Client{
 		Timeout: time.Second * 5,
 	}
+
 	for i, f := range msg.Extra["file"] {
 		fi := f.(config.FileInfo)
 		ext := filepath.Ext(fi.Name)
@@ -435,8 +442,9 @@ func (gw *Gateway) handleFiles(msg *config.Message) {
 		fi.Name = fi.Name + ext
 		sha1sum := fmt.Sprintf("%x", sha1.Sum(*fi.Data))
 
-			durl := gw.Config.General.MediaServerDownload + "/" + sha1sum + "/" + fi.Name
 		if gw.Config.General.MediaServerUpload != "" {
+			// Use MediaServerUpload. Upload using a PUT HTTP request and basicauth.
+
 			url := gw.Config.General.MediaServerUpload + "/" + sha1sum + "/" + fi.Name
 
 			req, err := http.NewRequest("PUT", url, bytes.NewReader(*fi.Data))
@@ -454,6 +462,8 @@ func (gw *Gateway) handleFiles(msg *config.Message) {
 				continue
 			}
 		} else {
+			// Use MediaServerPath. Place the file on the current filesystem.
+
 			dir := gw.Config.General.MediaServerPath + "/" + sha1sum
 			err := os.Mkdir(dir, os.ModePerm)
 			if err != nil && !os.IsExist(err) {
@@ -471,14 +481,16 @@ func (gw *Gateway) handleFiles(msg *config.Message) {
 			}
 		}
 
+		// Download URL.
+		durl := gw.Config.General.MediaServerDownload + "/" + sha1sum + "/" + fi.Name
+
+		flog.Debugf("mediaserver download URL = %s", durl)
+
 		// We uploaded/placed the file successfully. Add the SHA and URL.
 		extra := msg.Extra["file"][i].(config.FileInfo)
 		extra.URL = durl
 		extra.SHA = sha1sum
 		msg.Extra["file"][i] = extra
-
-			flog.Debugf("mediaserver download URL = %s", durl)
-		}
 	}
 }