From 11eda44d3451c889469af4e8e30d522b04d2dd15 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Tue, 10 Sep 2019 00:43:30 +0200
Subject: [PATCH] Migrate decoding to line-buffered reader

Migrate all usages of StreamReader in the context of decoding beatmaps,
storyboards or skins to the new LineBufferedReader.
---
 osu.Game.Rulesets.Osu.Tests/StackingTest.cs   |  3 +-
 .../Formats/LegacyBeatmapDecoderTest.cs       | 42 +++++++++----------
 .../Beatmaps/Formats/LegacyDecoderTest.cs     |  4 +-
 .../Formats/LegacyStoryboardDecoderTest.cs    |  6 +--
 .../Beatmaps/Formats/OsuJsonDecoderTest.cs    |  5 ++-
 .../Beatmaps/IO/OszArchiveReaderTest.cs       |  3 +-
 osu.Game.Tests/Skins/LegacySkinDecoderTest.cs |  6 +--
 osu.Game.Tests/WaveformTestBeatmap.cs         |  3 +-
 osu.Game/Beatmaps/BeatmapManager.cs           |  5 ++-
 .../Beatmaps/BeatmapManager_WorkingBeatmap.cs |  8 ++--
 osu.Game/Beatmaps/Formats/Decoder.cs          |  9 ++--
 .../Beatmaps/Formats/JsonBeatmapDecoder.cs    |  7 +---
 .../Beatmaps/Formats/LegacyBeatmapDecoder.cs  |  3 +-
 osu.Game/Beatmaps/Formats/LegacyDecoder.cs    |  4 +-
 .../Formats/LegacyStoryboardDecoder.cs        |  3 +-
 osu.Game/Skinning/LegacySkin.cs               |  3 +-
 .../Tests/Beatmaps/BeatmapConversionTest.cs   |  3 +-
 .../Beatmaps/DifficultyCalculatorTest.cs      |  3 +-
 osu.Game/Tests/Beatmaps/TestBeatmap.cs        |  3 +-
 19 files changed, 64 insertions(+), 59 deletions(-)

diff --git a/osu.Game.Rulesets.Osu.Tests/StackingTest.cs b/osu.Game.Rulesets.Osu.Tests/StackingTest.cs
index e8b99e86f9..871afdb09d 100644
--- a/osu.Game.Rulesets.Osu.Tests/StackingTest.cs
+++ b/osu.Game.Rulesets.Osu.Tests/StackingTest.cs
@@ -7,6 +7,7 @@ using System.Linq;
 using System.Text;
 using NUnit.Framework;
 using osu.Game.Beatmaps;
+using osu.Game.IO;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Osu.Objects;
 using osu.Game.Tests.Beatmaps;
@@ -21,7 +22,7 @@ namespace osu.Game.Rulesets.Osu.Tests
         public void TestStacking()
         {
             using (var stream = new MemoryStream(Encoding.UTF8.GetBytes(beatmap_data)))
-            using (var reader = new StreamReader(stream))
+            using (var reader = new LineBufferedReader(stream))
             {
                 var beatmap = Decoder.GetDecoder<Beatmap>(reader).Decode(reader);
                 var converted = new TestWorkingBeatmap(beatmap).GetPlayableBeatmap(new OsuRuleset().RulesetInfo, Array.Empty<Mod>());
diff --git a/osu.Game.Tests/Beatmaps/Formats/LegacyBeatmapDecoderTest.cs b/osu.Game.Tests/Beatmaps/Formats/LegacyBeatmapDecoderTest.cs
index 535320530d..6a77c6ca96 100644
--- a/osu.Game.Tests/Beatmaps/Formats/LegacyBeatmapDecoderTest.cs
+++ b/osu.Game.Tests/Beatmaps/Formats/LegacyBeatmapDecoderTest.cs
@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using System.IO;
 using NUnit.Framework;
 using osuTK;
 using osuTK.Graphics;
@@ -13,6 +12,7 @@ using osu.Game.Beatmaps;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Beatmaps.Formats;
 using osu.Game.Beatmaps.Timing;
+using osu.Game.IO;
 using osu.Game.Rulesets.Catch.Beatmaps;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Objects;
@@ -30,13 +30,9 @@ namespace osu.Game.Tests.Beatmaps.Formats
         public void TestDecodeBeatmapVersion()
         {
             using (var resStream = TestResources.OpenResource("beatmap-version.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var decoder = Decoder.GetDecoder<Beatmap>(stream);
-
-                stream.BaseStream.Position = 0;
-                stream.DiscardBufferedData();
-
                 var working = new TestWorkingBeatmap(decoder.Decode(stream));
 
                 Assert.AreEqual(6, working.BeatmapInfo.BeatmapVersion);
@@ -51,7 +47,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
 
             using (var resStream = TestResources.OpenResource("Soleily - Renatus (Gamu) [Insane].osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var beatmap = decoder.Decode(stream);
                 var beatmapInfo = beatmap.BeatmapInfo;
@@ -75,7 +71,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder();
 
             using (var resStream = TestResources.OpenResource("Soleily - Renatus (Gamu) [Insane].osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var beatmapInfo = decoder.Decode(stream).BeatmapInfo;
 
@@ -101,7 +97,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder();
 
             using (var resStream = TestResources.OpenResource("Soleily - Renatus (Gamu) [Insane].osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var beatmap = decoder.Decode(stream);
                 var beatmapInfo = beatmap.BeatmapInfo;
@@ -126,7 +122,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder();
 
             using (var resStream = TestResources.OpenResource("Soleily - Renatus (Gamu) [Insane].osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var difficulty = decoder.Decode(stream).BeatmapInfo.BaseDifficulty;
 
@@ -145,7 +141,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
 
             using (var resStream = TestResources.OpenResource("Soleily - Renatus (Gamu) [Insane].osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var beatmap = decoder.Decode(stream);
                 var metadata = beatmap.Metadata;
@@ -164,7 +160,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
 
             using (var resStream = TestResources.OpenResource("Soleily - Renatus (Gamu) [Insane].osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var beatmap = decoder.Decode(stream);
                 var controlPoints = beatmap.ControlPointInfo;
@@ -239,7 +235,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
 
             using (var resStream = TestResources.OpenResource("overlapping-control-points.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var controlPoints = decoder.Decode(stream).ControlPointInfo;
 
@@ -271,7 +267,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacySkinDecoder();
 
             using (var resStream = TestResources.OpenResource("Soleily - Renatus (Gamu) [Insane].osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var comboColors = decoder.Decode(stream).ComboColours;
 
@@ -297,7 +293,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder();
 
             using (var resStream = TestResources.OpenResource("hitobject-combo-offset.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var beatmap = decoder.Decode(stream);
 
@@ -320,7 +316,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder();
 
             using (var resStream = TestResources.OpenResource("hitobject-combo-offset.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var beatmap = decoder.Decode(stream);
 
@@ -343,7 +339,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
 
             using (var resStream = TestResources.OpenResource("Soleily - Renatus (Gamu) [Insane].osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var hitObjects = decoder.Decode(stream).HitObjects;
 
@@ -371,7 +367,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
 
             using (var resStream = TestResources.OpenResource("controlpoint-custom-samplebank.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var hitObjects = decoder.Decode(stream).HitObjects;
 
@@ -393,7 +389,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
 
             using (var resStream = TestResources.OpenResource("hitobject-custom-samplebank.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var hitObjects = decoder.Decode(stream).HitObjects;
 
@@ -411,7 +407,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
 
             using (var resStream = TestResources.OpenResource("hitobject-file-samples.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var hitObjects = decoder.Decode(stream).HitObjects;
 
@@ -431,7 +427,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
 
             using (var resStream = TestResources.OpenResource("slider-samples.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var hitObjects = decoder.Decode(stream).HitObjects;
 
@@ -475,7 +471,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
 
             using (var resStream = TestResources.OpenResource("hitobject-no-addition-bank.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var hitObjects = decoder.Decode(stream).HitObjects;
 
@@ -489,7 +485,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
 
             using (var badResStream = TestResources.OpenResource("invalid-events.osu"))
-            using (var badStream = new StreamReader(badResStream))
+            using (var badStream = new LineBufferedReader(badResStream))
             {
                 Assert.DoesNotThrow(() => decoder.Decode(badStream));
             }
diff --git a/osu.Game.Tests/Beatmaps/Formats/LegacyDecoderTest.cs b/osu.Game.Tests/Beatmaps/Formats/LegacyDecoderTest.cs
index b4d219456c..335a6aeeb0 100644
--- a/osu.Game.Tests/Beatmaps/Formats/LegacyDecoderTest.cs
+++ b/osu.Game.Tests/Beatmaps/Formats/LegacyDecoderTest.cs
@@ -2,9 +2,9 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
-using System.IO;
 using NUnit.Framework;
 using osu.Game.Beatmaps.Formats;
+using osu.Game.IO;
 using osu.Game.Tests.Resources;
 
 namespace osu.Game.Tests.Beatmaps.Formats
@@ -18,7 +18,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LineLoggingDecoder(14);
 
             using (var resStream = TestResources.OpenResource("comments.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 decoder.Decode(stream);
 
diff --git a/osu.Game.Tests/Beatmaps/Formats/LegacyStoryboardDecoderTest.cs b/osu.Game.Tests/Beatmaps/Formats/LegacyStoryboardDecoderTest.cs
index 953763c95d..66d53d7e7b 100644
--- a/osu.Game.Tests/Beatmaps/Formats/LegacyStoryboardDecoderTest.cs
+++ b/osu.Game.Tests/Beatmaps/Formats/LegacyStoryboardDecoderTest.cs
@@ -1,12 +1,12 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using System.IO;
 using System.Linq;
 using NUnit.Framework;
 using osuTK;
 using osu.Framework.Graphics;
 using osu.Game.Beatmaps.Formats;
+using osu.Game.IO;
 using osu.Game.Storyboards;
 using osu.Game.Tests.Resources;
 
@@ -21,7 +21,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyStoryboardDecoder();
 
             using (var resStream = TestResources.OpenResource("Himeringo - Yotsuya-san ni Yoroshiku (RLC) [Winber1's Extreme].osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var storyboard = decoder.Decode(stream);
 
@@ -94,7 +94,7 @@ namespace osu.Game.Tests.Beatmaps.Formats
             var decoder = new LegacyStoryboardDecoder();
 
             using (var resStream = TestResources.OpenResource("variable-with-suffix.osb"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var storyboard = decoder.Decode(stream);
 
diff --git a/osu.Game.Tests/Beatmaps/Formats/OsuJsonDecoderTest.cs b/osu.Game.Tests/Beatmaps/Formats/OsuJsonDecoderTest.cs
index 4859abbb8e..63346b8c9d 100644
--- a/osu.Game.Tests/Beatmaps/Formats/OsuJsonDecoderTest.cs
+++ b/osu.Game.Tests/Beatmaps/Formats/OsuJsonDecoderTest.cs
@@ -8,6 +8,7 @@ using NUnit.Framework;
 using osu.Game.Audio;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.Formats;
+using osu.Game.IO;
 using osu.Game.IO.Serialization;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Scoring;
@@ -148,13 +149,13 @@ namespace osu.Game.Tests.Beatmaps.Formats
         private Beatmap decode(string filename, out Beatmap jsonDecoded)
         {
             using (var stream = TestResources.OpenResource(filename))
-            using (var sr = new StreamReader(stream))
+            using (var sr = new LineBufferedReader(stream))
             {
                 var legacyDecoded = new LegacyBeatmapDecoder { ApplyOffsets = false }.Decode(sr);
 
                 using (var ms = new MemoryStream())
                 using (var sw = new StreamWriter(ms))
-                using (var sr2 = new StreamReader(ms))
+                using (var sr2 = new LineBufferedReader(ms))
                 {
                     sw.Write(legacyDecoded.Serialize());
                     sw.Flush();
diff --git a/osu.Game.Tests/Beatmaps/IO/OszArchiveReaderTest.cs b/osu.Game.Tests/Beatmaps/IO/OszArchiveReaderTest.cs
index 37e0565df0..022b2c1a59 100644
--- a/osu.Game.Tests/Beatmaps/IO/OszArchiveReaderTest.cs
+++ b/osu.Game.Tests/Beatmaps/IO/OszArchiveReaderTest.cs
@@ -7,6 +7,7 @@ using NUnit.Framework;
 using osu.Game.Beatmaps;
 using osu.Game.Tests.Resources;
 using osu.Game.Beatmaps.Formats;
+using osu.Game.IO;
 using osu.Game.IO.Archives;
 
 namespace osu.Game.Tests.Beatmaps.IO
@@ -50,7 +51,7 @@ namespace osu.Game.Tests.Beatmaps.IO
 
                 Beatmap beatmap;
 
-                using (var stream = new StreamReader(reader.GetStream("Soleily - Renatus (Deif) [Platter].osu")))
+                using (var stream = new LineBufferedReader(reader.GetStream("Soleily - Renatus (Deif) [Platter].osu")))
                     beatmap = Decoder.GetDecoder<Beatmap>(stream).Decode(stream);
 
                 var meta = beatmap.Metadata;
diff --git a/osu.Game.Tests/Skins/LegacySkinDecoderTest.cs b/osu.Game.Tests/Skins/LegacySkinDecoderTest.cs
index 8bd846518b..0d96dd08da 100644
--- a/osu.Game.Tests/Skins/LegacySkinDecoderTest.cs
+++ b/osu.Game.Tests/Skins/LegacySkinDecoderTest.cs
@@ -2,8 +2,8 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System.Collections.Generic;
-using System.IO;
 using NUnit.Framework;
+using osu.Game.IO;
 using osu.Game.Skinning;
 using osu.Game.Tests.Resources;
 using osuTK.Graphics;
@@ -20,7 +20,7 @@ namespace osu.Game.Tests.Skins
             var decoder = new LegacySkinDecoder();
 
             using (var resStream = TestResources.OpenResource(hasColours ? "skin.ini" : "skin-empty.ini"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var comboColors = decoder.Decode(stream).ComboColours;
 
@@ -48,7 +48,7 @@ namespace osu.Game.Tests.Skins
             var decoder = new LegacySkinDecoder();
 
             using (var resStream = TestResources.OpenResource("skin.ini"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var config = decoder.Decode(stream);
 
diff --git a/osu.Game.Tests/WaveformTestBeatmap.cs b/osu.Game.Tests/WaveformTestBeatmap.cs
index db9576b5fa..0d16a78f75 100644
--- a/osu.Game.Tests/WaveformTestBeatmap.cs
+++ b/osu.Game.Tests/WaveformTestBeatmap.cs
@@ -9,6 +9,7 @@ using osu.Framework.Graphics.Textures;
 using osu.Framework.Graphics.Video;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.Formats;
+using osu.Game.IO;
 using osu.Game.IO.Archives;
 using osu.Game.Tests.Resources;
 
@@ -56,7 +57,7 @@ namespace osu.Game.Tests
         private Beatmap createTestBeatmap()
         {
             using (var beatmapStream = getBeatmapStream())
-            using (var beatmapReader = new StreamReader(beatmapStream))
+            using (var beatmapReader = new LineBufferedReader(beatmapStream))
                 return Decoder.GetDecoder<Beatmap>(beatmapReader).Decode(beatmapReader);
         }
     }
diff --git a/osu.Game/Beatmaps/BeatmapManager.cs b/osu.Game/Beatmaps/BeatmapManager.cs
index b9ed3664ef..372eec50fd 100644
--- a/osu.Game/Beatmaps/BeatmapManager.cs
+++ b/osu.Game/Beatmaps/BeatmapManager.cs
@@ -20,6 +20,7 @@ using osu.Framework.Platform;
 using osu.Framework.Threading;
 using osu.Game.Beatmaps.Formats;
 using osu.Game.Database;
+using osu.Game.IO;
 using osu.Game.IO.Archives;
 using osu.Game.Online.API;
 using osu.Game.Online.API.Requests;
@@ -264,7 +265,7 @@ namespace osu.Game.Beatmaps
             }
 
             Beatmap beatmap;
-            using (var stream = new StreamReader(reader.GetStream(mapName)))
+            using (var stream = new LineBufferedReader(reader.GetStream(mapName)))
                 beatmap = Decoder.GetDecoder<Beatmap>(stream).Decode(stream);
 
             return new BeatmapSetInfo
@@ -287,7 +288,7 @@ namespace osu.Game.Beatmaps
             {
                 using (var raw = reader.GetStream(name))
                 using (var ms = new MemoryStream()) //we need a memory stream so we can seek
-                using (var sr = new StreamReader(ms))
+                using (var sr = new LineBufferedReader(ms))
                 {
                     raw.CopyTo(ms);
                     ms.Position = 0;
diff --git a/osu.Game/Beatmaps/BeatmapManager_WorkingBeatmap.cs b/osu.Game/Beatmaps/BeatmapManager_WorkingBeatmap.cs
index 1d00c94ef2..b879b92f01 100644
--- a/osu.Game/Beatmaps/BeatmapManager_WorkingBeatmap.cs
+++ b/osu.Game/Beatmaps/BeatmapManager_WorkingBeatmap.cs
@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using System.IO;
 using System.Linq;
 using osu.Framework.Audio;
 using osu.Framework.Audio.Track;
@@ -11,6 +10,7 @@ using osu.Framework.Graphics.Video;
 using osu.Framework.IO.Stores;
 using osu.Framework.Logging;
 using osu.Game.Beatmaps.Formats;
+using osu.Game.IO;
 using osu.Game.Skinning;
 using osu.Game.Storyboards;
 
@@ -33,7 +33,7 @@ namespace osu.Game.Beatmaps
             {
                 try
                 {
-                    using (var stream = new StreamReader(store.GetStream(getPathForFile(BeatmapInfo.Path))))
+                    using (var stream = new LineBufferedReader(store.GetStream(getPathForFile(BeatmapInfo.Path))))
                         return Decoder.GetDecoder<Beatmap>(stream).Decode(stream);
                 }
                 catch
@@ -127,7 +127,7 @@ namespace osu.Game.Beatmaps
 
                 try
                 {
-                    using (var stream = new StreamReader(store.GetStream(getPathForFile(BeatmapInfo.Path))))
+                    using (var stream = new LineBufferedReader(store.GetStream(getPathForFile(BeatmapInfo.Path))))
                     {
                         var decoder = Decoder.GetDecoder<Storyboard>(stream);
 
@@ -136,7 +136,7 @@ namespace osu.Game.Beatmaps
                             storyboard = decoder.Decode(stream);
                         else
                         {
-                            using (var secondaryStream = new StreamReader(store.GetStream(getPathForFile(BeatmapSetInfo.StoryboardFile))))
+                            using (var secondaryStream = new LineBufferedReader(store.GetStream(getPathForFile(BeatmapSetInfo.StoryboardFile))))
                                 storyboard = decoder.Decode(stream, secondaryStream);
                         }
                     }
diff --git a/osu.Game/Beatmaps/Formats/Decoder.cs b/osu.Game/Beatmaps/Formats/Decoder.cs
index 953e50eadc..0f1b617809 100644
--- a/osu.Game/Beatmaps/Formats/Decoder.cs
+++ b/osu.Game/Beatmaps/Formats/Decoder.cs
@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using osu.Game.IO;
 
 namespace osu.Game.Beatmaps.Formats
 {
@@ -13,15 +14,15 @@ namespace osu.Game.Beatmaps.Formats
     {
         protected virtual TOutput CreateTemplateObject() => new TOutput();
 
-        public TOutput Decode(StreamReader primaryStream, params StreamReader[] otherStreams)
+        public TOutput Decode(LineBufferedReader primaryStream, params LineBufferedReader[] otherStreams)
         {
             var output = CreateTemplateObject();
-            foreach (StreamReader stream in otherStreams.Prepend(primaryStream))
+            foreach (LineBufferedReader stream in otherStreams.Prepend(primaryStream))
                 ParseStreamInto(stream, output);
             return output;
         }
 
-        protected abstract void ParseStreamInto(StreamReader stream, TOutput output);
+        protected abstract void ParseStreamInto(LineBufferedReader stream, TOutput output);
     }
 
     public abstract class Decoder
@@ -39,7 +40,7 @@ namespace osu.Game.Beatmaps.Formats
         /// Retrieves a <see cref="Decoder"/> to parse a <see cref="Beatmap"/>.
         /// </summary>
         /// <param name="stream">A stream pointing to the <see cref="Beatmap"/>.</param>
-        public static Decoder<T> GetDecoder<T>(StreamReader stream)
+        public static Decoder<T> GetDecoder<T>(LineBufferedReader stream)
             where T : new()
         {
             if (stream == null)
diff --git a/osu.Game/Beatmaps/Formats/JsonBeatmapDecoder.cs b/osu.Game/Beatmaps/Formats/JsonBeatmapDecoder.cs
index d8482b200f..988968fa42 100644
--- a/osu.Game/Beatmaps/Formats/JsonBeatmapDecoder.cs
+++ b/osu.Game/Beatmaps/Formats/JsonBeatmapDecoder.cs
@@ -1,7 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using System.IO;
+using osu.Game.IO;
 using osu.Game.IO.Serialization;
 
 namespace osu.Game.Beatmaps.Formats
@@ -13,11 +13,8 @@ namespace osu.Game.Beatmaps.Formats
             AddDecoder<Beatmap>("{", m => new JsonBeatmapDecoder());
         }
 
-        protected override void ParseStreamInto(StreamReader stream, Beatmap output)
+        protected override void ParseStreamInto(LineBufferedReader stream, Beatmap output)
         {
-            stream.BaseStream.Position = 0;
-            stream.DiscardBufferedData();
-
             stream.ReadToEnd().DeserializeInto(output);
 
             foreach (var hitObject in output.HitObjects)
diff --git a/osu.Game/Beatmaps/Formats/LegacyBeatmapDecoder.cs b/osu.Game/Beatmaps/Formats/LegacyBeatmapDecoder.cs
index 0532790f0a..6e34fd8e90 100644
--- a/osu.Game/Beatmaps/Formats/LegacyBeatmapDecoder.cs
+++ b/osu.Game/Beatmaps/Formats/LegacyBeatmapDecoder.cs
@@ -8,6 +8,7 @@ using osu.Framework.IO.File;
 using osu.Game.Beatmaps.Timing;
 using osu.Game.Rulesets.Objects.Legacy;
 using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.IO;
 
 namespace osu.Game.Beatmaps.Formats
 {
@@ -41,7 +42,7 @@ namespace osu.Game.Beatmaps.Formats
             offset = FormatVersion < 5 ? 24 : 0;
         }
 
-        protected override void ParseStreamInto(StreamReader stream, Beatmap beatmap)
+        protected override void ParseStreamInto(LineBufferedReader stream, Beatmap beatmap)
         {
             this.beatmap = beatmap;
             this.beatmap.BeatmapInfo.BeatmapVersion = FormatVersion;
diff --git a/osu.Game/Beatmaps/Formats/LegacyDecoder.cs b/osu.Game/Beatmaps/Formats/LegacyDecoder.cs
index 9a8197ad82..83d20da458 100644
--- a/osu.Game/Beatmaps/Formats/LegacyDecoder.cs
+++ b/osu.Game/Beatmaps/Formats/LegacyDecoder.cs
@@ -3,10 +3,10 @@
 
 using System;
 using System.Collections.Generic;
-using System.IO;
 using osu.Framework.Logging;
 using osu.Game.Audio;
 using osu.Game.Beatmaps.ControlPoints;
+using osu.Game.IO;
 using osuTK.Graphics;
 
 namespace osu.Game.Beatmaps.Formats
@@ -21,7 +21,7 @@ namespace osu.Game.Beatmaps.Formats
             FormatVersion = version;
         }
 
-        protected override void ParseStreamInto(StreamReader stream, T output)
+        protected override void ParseStreamInto(LineBufferedReader stream, T output)
         {
             Section section = Section.None;
 
diff --git a/osu.Game/Beatmaps/Formats/LegacyStoryboardDecoder.cs b/osu.Game/Beatmaps/Formats/LegacyStoryboardDecoder.cs
index 14c6ea5c8e..a8f8dbf69d 100644
--- a/osu.Game/Beatmaps/Formats/LegacyStoryboardDecoder.cs
+++ b/osu.Game/Beatmaps/Formats/LegacyStoryboardDecoder.cs
@@ -10,6 +10,7 @@ using osuTK;
 using osuTK.Graphics;
 using osu.Framework.Graphics;
 using osu.Framework.IO.File;
+using osu.Game.IO;
 using osu.Game.Storyboards;
 
 namespace osu.Game.Beatmaps.Formats
@@ -35,7 +36,7 @@ namespace osu.Game.Beatmaps.Formats
             AddDecoder<Storyboard>(@"[Events]", m => new LegacyStoryboardDecoder());
         }
 
-        protected override void ParseStreamInto(StreamReader stream, Storyboard storyboard)
+        protected override void ParseStreamInto(LineBufferedReader stream, Storyboard storyboard)
         {
             this.storyboard = storyboard;
             base.ParseStreamInto(stream, storyboard);
diff --git a/osu.Game/Skinning/LegacySkin.cs b/osu.Game/Skinning/LegacySkin.cs
index 0b1076be01..fea15458e4 100644
--- a/osu.Game/Skinning/LegacySkin.cs
+++ b/osu.Game/Skinning/LegacySkin.cs
@@ -12,6 +12,7 @@ using osu.Framework.Graphics;
 using osu.Framework.Graphics.Textures;
 using osu.Framework.IO.Stores;
 using osu.Game.Audio;
+using osu.Game.IO;
 using osu.Game.Rulesets.Scoring;
 using osuTK.Graphics;
 
@@ -35,7 +36,7 @@ namespace osu.Game.Skinning
         {
             Stream stream = storage?.GetStream(filename);
             if (stream != null)
-                using (StreamReader reader = new StreamReader(stream))
+                using (LineBufferedReader reader = new LineBufferedReader(stream))
                     Configuration = new LegacySkinDecoder().Decode(reader);
             else
                 Configuration = new DefaultSkinConfiguration();
diff --git a/osu.Game/Tests/Beatmaps/BeatmapConversionTest.cs b/osu.Game/Tests/Beatmaps/BeatmapConversionTest.cs
index 3fc9662b17..e99b5fc5fb 100644
--- a/osu.Game/Tests/Beatmaps/BeatmapConversionTest.cs
+++ b/osu.Game/Tests/Beatmaps/BeatmapConversionTest.cs
@@ -13,6 +13,7 @@ using osu.Framework.Graphics.Textures;
 using osu.Framework.Graphics.Video;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.Formats;
+using osu.Game.IO;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Rulesets.Objects;
@@ -142,7 +143,7 @@ namespace osu.Game.Tests.Beatmaps
         private IBeatmap getBeatmap(string name)
         {
             using (var resStream = openResource($"{resource_namespace}.{name}.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var decoder = Decoder.GetDecoder<Beatmap>(stream);
                 ((LegacyBeatmapDecoder)decoder).ApplyOffsets = false;
diff --git a/osu.Game/Tests/Beatmaps/DifficultyCalculatorTest.cs b/osu.Game/Tests/Beatmaps/DifficultyCalculatorTest.cs
index 108fa8ff71..748a52d1c5 100644
--- a/osu.Game/Tests/Beatmaps/DifficultyCalculatorTest.cs
+++ b/osu.Game/Tests/Beatmaps/DifficultyCalculatorTest.cs
@@ -7,6 +7,7 @@ using System.Reflection;
 using NUnit.Framework;
 using osu.Game.Beatmaps;
 using osu.Game.Beatmaps.Formats;
+using osu.Game.IO;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Difficulty;
 using osu.Game.Rulesets.Mods;
@@ -26,7 +27,7 @@ namespace osu.Game.Tests.Beatmaps
         private WorkingBeatmap getBeatmap(string name)
         {
             using (var resStream = openResource($"{resource_namespace}.{name}.osu"))
-            using (var stream = new StreamReader(resStream))
+            using (var stream = new LineBufferedReader(resStream))
             {
                 var decoder = Decoder.GetDecoder<Beatmap>(stream);
                 ((LegacyBeatmapDecoder)decoder).ApplyOffsets = false;
diff --git a/osu.Game/Tests/Beatmaps/TestBeatmap.cs b/osu.Game/Tests/Beatmaps/TestBeatmap.cs
index b77a8508ad..d6f92ba086 100644
--- a/osu.Game/Tests/Beatmaps/TestBeatmap.cs
+++ b/osu.Game/Tests/Beatmaps/TestBeatmap.cs
@@ -5,6 +5,7 @@ using System.Collections.Generic;
 using System.IO;
 using System.Text;
 using osu.Game.Beatmaps;
+using osu.Game.IO;
 using osu.Game.Rulesets;
 using Decoder = osu.Game.Beatmaps.Formats.Decoder;
 
@@ -39,7 +40,7 @@ namespace osu.Game.Tests.Beatmaps
         private static Beatmap createTestBeatmap()
         {
             using (var stream = new MemoryStream(Encoding.UTF8.GetBytes(test_beatmap_data)))
-            using (var reader = new StreamReader(stream))
+            using (var reader = new LineBufferedReader(stream))
                 return Decoder.GetDecoder<Beatmap>(reader).Decode(reader);
         }