Optimize data directory, hash one level

This brings REST backend up to date with local backend.  Repository
format is now identical between them.  You can now access REST
repository locally, and vice versa.  This is a nice feature!

handlers.go

@@ -32,6 +32,7 @@ func AuthHandler(f *HtpasswdFile, h http.Handler) http.HandlerFunc {
 			http.Error(w, "401 unauthorized", 401)
 			return
 		}
+
 		h.ServeHTTP(w, r)
 	}
 }
@@ -45,6 +46,7 @@ func CheckConfig(c *Context) http.HandlerFunc {
 			http.Error(w, "404 not found", 404)
 			return
 		}
+
 		w.Header().Add("Content-Length", fmt.Sprint(st.Size()))
 	}
 }
@@ -58,6 +60,7 @@ func GetConfig(c *Context) http.HandlerFunc {
 			http.Error(w, "404 not found", 404)
 			return
 		}
+
 		w.Write(bytes)
 	}
 }
@@ -76,6 +79,7 @@ func SaveConfig(c *Context) http.HandlerFunc {
 			http.Error(w, "500 internal server error", 500)
 			return
 		}
+
 		w.Write([]byte("200 ok"))
 	}
 }
@@ -86,20 +90,36 @@ func ListBlobs(c *Context) http.HandlerFunc {
 		vars := strings.Split(r.RequestURI, "/")
 		dir := vars[1]
 		path := filepath.Join(c.path, dir)
-		files, err := ioutil.ReadDir(path)
+
+		items, err := ioutil.ReadDir(path)
 		if err != nil {
 			http.Error(w, "404 not found", 404)
 			return
 		}
-		names := make([]string, len(files))
-		for i, f := range files {
-			names[i] = f.Name()
+
+		var names []string
+		for _, i := range items {
+			if dir == "data" {
+				subpath := filepath.Join(path, i.Name())
+				subitems, err := ioutil.ReadDir(subpath)
+				if err != nil {
+					http.Error(w, "404 not found", 404)
+					return
+				}
+				for _, f := range subitems {
+					names = append(names, f.Name())
+				}
+			} else {
+				names = append(names, i.Name())
+			}
 		}
+
 		data, err := json.Marshal(names)
 		if err != nil {
 			http.Error(w, "500 internal server error", 500)
 			return
 		}
+
 		w.Write(data)
 	}
 }
@@ -110,12 +130,18 @@ func CheckBlob(c *Context) http.HandlerFunc {
 		vars := strings.Split(r.RequestURI, "/")
 		dir := vars[1]
 		name := vars[2]
+
+		if dir == "data" {
+			name = filepath.Join(name[:2], name)
+		}
 		path := filepath.Join(c.path, dir, name)
+
 		st, err := os.Stat(path)
 		if err != nil {
 			http.Error(w, "404 not found", 404)
 			return
 		}
+
 		w.Header().Add("Content-Length", fmt.Sprint(st.Size()))
 	}
 }
@@ -126,13 +152,19 @@ func GetBlob(c *Context) http.HandlerFunc {
 		vars := strings.Split(r.RequestURI, "/")
 		dir := vars[1]
 		name := vars[2]
+
+		if dir == "data" {
+			name = filepath.Join(name[:2], name)
+		}
 		path := filepath.Join(c.path, dir, name)
+
 		file, err := fs.Open(path)
 		if err != nil {
 			http.Error(w, "404 not found", 404)
 			return
 		}
 		defer file.Close()
+
 		http.ServeContent(w, r, "", time.Unix(0, 0), file)
 	}
 }
@@ -143,8 +175,14 @@ func SaveBlob(c *Context) http.HandlerFunc {
 		vars := strings.Split(r.RequestURI, "/")
 		dir := vars[1]
 		name := vars[2]
+
+		if dir == "data" {
+			os.MkdirAll(filepath.Join(c.path, dir, name[:2]), 0700)
+			name = filepath.Join(name[:2], name)
+		}
 		path := filepath.Join(c.path, dir, name)
-		tmp := path + "_tmp"
+
+		tmp := path + ".tmp"
 		tf, err := fs.OpenFile(tmp, os.O_CREATE|os.O_WRONLY, 0600)
 		if err != nil {
 			http.Error(w, "500 internal server error", 500)
@@ -163,6 +201,7 @@ func SaveBlob(c *Context) http.HandlerFunc {
 			http.Error(w, "500 internal server error", 500)
 			return
 		}
+
 		w.Write([]byte("200 ok"))
 	}
 }
@@ -173,12 +212,18 @@ func DeleteBlob(c *Context) http.HandlerFunc {
 		vars := strings.Split(r.RequestURI, "/")
 		dir := vars[1]
 		name := vars[2]
+
+		if dir == "data" {
+			name = filepath.Join(name[:2], name)
+		}
 		path := filepath.Join(c.path, dir, name)
+
 		err := os.Remove(path)
 		if err != nil {
 			http.Error(w, "500 internal server error", 500)
 			return
 		}
+
 		w.Write([]byte("200 ok"))
 	}
 }