Revert "Merge pull request #441 from tacchinotacchi/archive-reader"

This reverts commit 6f20473e65, reversing
changes made to c76a495d3d.

osu.Game/Beatmaps/IO/ArchiveReader.cs

@@ -0,0 +1,75 @@
+// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using osu.Framework.IO.Stores;
+using osu.Framework.Platform;
+using osu.Game.Database;
+
+namespace osu.Game.Beatmaps.IO
+{
+    public abstract class ArchiveReader : IDisposable, IResourceStore<byte[]>
+    {
+        private class Reader
+        {
+            public Func<Storage, string, bool> Test { get; set; }
+            public Type Type { get; set; }
+        }
+
+        private static List<Reader> readers { get; } = new List<Reader>();
+
+        public static ArchiveReader GetReader(Storage storage, string path)
+        {
+            foreach (var reader in readers)
+            {
+                if (reader.Test(storage, path))
+                    return (ArchiveReader)Activator.CreateInstance(reader.Type, storage.GetStream(path));
+            }
+            throw new IOException(@"Unknown file format");
+        }
+
+        protected static void AddReader<T>(Func<Storage, string, bool> test) where T : ArchiveReader
+        {
+            readers.Add(new Reader { Test = test, Type = typeof(T) });
+        }
+
+        /// <summary>
+        /// Reads the beatmap metadata from this archive.
+        /// </summary>
+        public abstract BeatmapMetadata ReadMetadata();
+
+        /// <summary>
+        /// Gets a list of beatmap file names.
+        /// </summary>
+        public string[] BeatmapFilenames { get; protected set; }
+
+        /// <summary>
+        /// The storyboard filename. Null if no storyboard is present.
+        /// </summary>
+        public string StoryboardFilename { get; protected set; }
+
+        /// <summary>
+        /// Opens a stream for reading a specific file from this archive.
+        /// </summary>
+        public abstract Stream GetStream(string name);
+
+        public abstract void Dispose();
+
+        public virtual byte[] Get(string name)
+        {
+            using (Stream input = GetStream(name))
+            {
+                if (input == null)
+                    return null;
+
+                using (MemoryStream ms = new MemoryStream())
+                {
+                    input.CopyTo(ms);
+                    return ms.ToArray();
+                }
+            }
+        }
+    }
+}