Optimize search algorithms

Quaver.API.Tests/Quaver/Resources/stable-sorting.qua

@@ -0,0 +1,205 @@
+AudioFile: ''
+SongPreviewTime: 0
+BackgroundFile: ''
+MapId: -1
+MapSetId: -1
+Mode: Keys4
+Title: ''
+Artist: ''
+Source: ''
+Tags: ''
+DifficultyName: ''
+EditorLayers: []
+Bookmarks:
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'first'
+- StartTime: 0
+  Note: 'second'
+- StartTime: 0
+  Note: 'third'
+- StartTime: 1000
+  Note: 'fourth'
+- StartTime: 1000
+  Note: 'fifth'
+- StartTime: 1000
+  Note: 'sixth'
+CustomAudioSamples: []
+SoundEffects: []
+TimingPoints:
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 6
+  Signature: 13646
+- StartTime: 0
+  Bpm: 4
+  Signature: 3
+- StartTime: 0
+  Bpm: 12
+  Signature: 4
+- StartTime: 1000
+  Bpm: 27
+  Signature: 246
+- StartTime: 1000
+  Bpm: 1
+  Signature: 12
+- StartTime: 1000
+  Bpm: 136
+  Signature: 3785
+SliderVelocities:
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 1253
+- StartTime: 0
+  Multiplier: 8.4
+- StartTime: 0
+  Multiplier: -1345
+- StartTime: 1000
+  Multiplier: 675
+- StartTime: 1000
+  Multiplier: 0
+- StartTime: 1000
+  Multiplier: -13548
+HitObjects:
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 4
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 3
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 0
+  Lane: 2
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 1000
+  Lane: 7
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 1000
+  Lane: 1
+  KeySounds: []
+  HitSound: Normal
+- StartTime: 1000
+  Lane: 5
+  KeySounds: []
+  HitSound: Normal

Quaver.API.Tests/Quaver/TestCaseQua.cs

@@ -4,10 +4,12 @@
 using System.IO;
 using System.Linq;
 using System.Text;
+using Force.DeepCloner;
 using Quaver.API.Enums;
 using Quaver.API.Maps;
 using Quaver.API.Maps.Structures;
 using Xunit;
+using YamlDotNet.Serialization;
 
 namespace Quaver.API.Tests.Quaver
 {
@@ -249,6 +251,22 @@ public void InvalidKeySoundIndex()
             Assert.False(qua.IsValid());
         }
 
+        [Fact]
+        public void StableSorting()
+        {
+            const string Q = "./Quaver/Resources/stable-sorting.qua";
+            var unsorted = new Deserializer().Deserialize<Qua>(File.ReadAllText(Q));
+            var sorted = unsorted.DeepClone();
+            sorted.Sort();
+
+            Assert.Equal(unsorted.TimingPoints, sorted.TimingPoints, TimingPointInfo.ByValueComparer);
+            Assert.Equal(unsorted.SliderVelocities, sorted.SliderVelocities, SliderVelocityInfo.ByValueComparer);
+            Assert.Equal(unsorted.HitObjects, sorted.HitObjects, HitObjectInfo.ByValueComparer);
+            Assert.Equal(unsorted.CustomAudioSamples, sorted.CustomAudioSamples, CustomAudioSampleInfo.ByValueComparer);
+            Assert.Equal(unsorted.EditorLayers, sorted.EditorLayers, EditorLayerInfo.ByValueComparer);
+            Assert.Equal(unsorted.Bookmarks, sorted.Bookmarks, BookmarkInfo.ByValueComparer);
+        }
+
         [Fact]
         public void SVNormalization()
         {
@@ -282,22 +300,22 @@ public void SVNormalization()
 
                 // Check that the normalization gives the correct result.
                 var quaDenormalizedNormalized = quaDenormalized.WithNormalizedSVs();
-                Assert.True(quaDenormalizedNormalized.EqualByValue(quaNormalized));
+                Assert.True(quaDenormalizedNormalized.EqualByValue(quaNormalized), $"Expected {test} to normalize correctly.");
 
                 // Denormalization can move the first SV (it doesn't matter where to put the InitialScrollVelocity SV).
                 // So check back-and-forth instead of just denormalization.
                 var quaNormalizedDenormalizedNormalized = quaNormalized.WithDenormalizedSVs().WithNormalizedSVs();
-                Assert.True(quaNormalizedDenormalizedNormalized.EqualByValue(quaNormalized));
+                Assert.True(quaNormalizedDenormalizedNormalized.EqualByValue(quaNormalized), $"Expected {test} to remain the same after denormalization and subsequent normalization.");
 
                 // Check that serializing and parsing the result does not change it.
                 var bufferDenormalized = Encoding.UTF8.GetBytes(quaDenormalized.Serialize());
                 var quaDenormalized2 = Qua.Parse(bufferDenormalized, false);
-                Assert.True(quaDenormalized.EqualByValue(quaDenormalized2));
+                Assert.True(quaDenormalized.EqualByValue(quaDenormalized2), $"Expected {test} denormalized to remain the same after serialization and parsing.");
 
                 var bufferNormalized = Encoding.UTF8.GetBytes(quaNormalized.Serialize());
                 var quaNormalized2 = Qua.Parse(bufferNormalized, false);
-                Assert.True(quaNormalized.EqualByValue(quaNormalized2));
+                Assert.True(quaNormalized.EqualByValue(quaNormalized2), $"Expected {test} to normalized to remain the same after serialization and parsing.");
             }
         }
     }
-}
+}

Quaver.API/Helpers/ListHelper.cs

@@ -0,0 +1,50 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ * Copyright (c) 2017-2018 Swan & The Quaver Team <[email protected]>.
+*/
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Reflection.Emit;
+
+namespace Quaver.API.Helpers
+{
+    public static class ListHelper
+    {
+        private static class Cache<T>
+        {
+            public static Converter<List<T>, T[]> Converter { get; } = typeof(List<T>)
+               .GetFields(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic)
+               .FirstOrDefault(x => x.FieldType == typeof(T[])) is { } method
+                ? CreateGetter(method)
+                : x => x.ToArray();
+
+            private static Converter<List<T>, T[]> CreateGetter(FieldInfo field)
+            {
+                var name = $"{field.DeclaringType?.FullName}.get_{field.Name}";
+                var getter = new DynamicMethod(name, typeof(T[]), new[] { typeof(List<T>) }, true);
+                var il = getter.GetILGenerator();
+                il.Emit(OpCodes.Ldarg_0);
+                il.Emit(OpCodes.Ldfld, field);
+                il.Emit(OpCodes.Ret);
+                return (Converter<List<T>, T[]>)getter.CreateDelegate(typeof(Converter<List<T>, T[]>));
+            }
+        }
+
+        /// <summary>
+        ///     Gets the underlying <see cref="Array"/> of the <see cref="List{T}"/>.
+        /// </summary>
+        /// <remarks><para>
+        ///     Be careful when using this method as the <see cref="List{T}"/> cannot safeguard
+        ///     against underlying mutations or out-of-bounds reading within its capacity.
+        /// </para></remarks>
+        /// <param name="list"></param>
+        /// <typeparam name="T"></typeparam>
+        /// <returns></returns>
+        public static T[] GetUnderlyingArray<T>(List<T> list) => Cache<T>.Converter(list);
+    }
+}