Move all the code to a lib folder

lib/storage/dir.go

@@ -0,0 +1,42 @@
+package storage
+
+import (
+	p "path"
+
+	"os"
+)
+
+const (
+	dir_depth = 2
+	encodeURL = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"
+)
+
+func mkstore(path string) error {
+	return _mkstore(path, dir_depth)
+}
+
+func _mkstore(path string, depth int) error {
+	err := os.MkdirAll(path, os.ModePerm)
+	if err != nil || depth == 0 {
+		return err
+	}
+
+	for _, l := range encodeURL {
+		next_path := p.Join(path, string(l))
+		err = _mkstore(next_path, depth-1)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func idPath(storePath string, id string) string {
+	path := storePath
+	for i := 0; i < dir_depth; i++ {
+		dir := string(id[i])
+		path = p.Join(path, dir)
+	}
+	path = p.Join(path, id)
+	return path
+}