cache metadata files

ImageViewer/ViewController.swift

@@ -102,6 +102,7 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
 
     var imageView = UIImageView()
     var mode = PageTurnMode.leftToRight
+    var metadataList: [String: Metadata] = [:]
     var metadata: Metadata!
     var currentPage: Int!
     var progress = ProgressIndices(v: 0, c: 0, i: 0)
@@ -241,6 +242,7 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
                             .path
                         ).utf8)
                 )
+                metadataList[dir] = metadata
                 loadLocalState()
                 comics.append(
                     Comic(
@@ -583,7 +585,7 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
         if let path = getPathFromComicName(name: name) {
             currentPath = path
 
-            metadata = getMetadata(path: path)!
+            metadata = metadataList[path]
 
             globalState.comicName = metadata.title
             saveGlobalState()