Implement Fast Level Loading

Celeste.Mod.mm/Mod/Core/CoreModuleSettings.cs

@@ -159,6 +159,11 @@ public bool LazyLoading {
         [SettingIgnore]
         public int LogHistoryCountToKeep { get; set; } = 3;
 
+        [SettingNeedsRelaunch]
+        [SettingInGame(false)]
+        [SettingIgnore] // TODO: Show as advanced setting.
+        public bool? FastLevelLoading { get; set; } = null;
+
         [SettingNeedsRelaunch]
         [SettingInGame(false)]
         [SettingIgnore] // TODO: Show as advanced setting.

Celeste.Mod.mm/Patches/AreaData.cs

@@ -2,6 +2,7 @@
 #pragma warning disable CS0649 // Field is never assigned to, and will always have its default value
 
 using Celeste.Mod;
+using Celeste.Mod.Core;
 using Celeste.Mod.Meta;
 using Microsoft.Xna.Framework;
 using Monocle;
@@ -10,6 +11,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text.RegularExpressions;
+using System.Threading.Tasks;
 
 namespace Celeste {
     public class patch_AreaData : AreaData {
@@ -365,7 +367,7 @@ public static patch_AreaData Get(string sid) {
                 }
             }
 
-            for (int i = 0; i < Areas.Count; i++) {
+            static void ProcessMapData(int i) {
                 patch_AreaData area = Areas[i];
                 area.ID = i;
 
@@ -378,7 +380,9 @@ public static patch_AreaData Get(string sid) {
                 }
                 Array.Resize(ref area.Mode, modei);
 
-                Logger.Verbose("AreaData", string.Format("{0}: {1} - {2} sides", i, area.SID, area.Mode.Length));
+                // Do not clutter the log if Fast Level Loading is disabled
+                LogLevel level = (CoreModule.Settings.FastLevelLoading ?? true) ? LogLevel.Info : LogLevel.Verbose;
+                Logger.Log(level, "AreaData", $"{i}: {area.SID} - {area.Mode.Length} sides");
 
                 // Update old MapData areas and load any new areas.
 
@@ -389,7 +393,7 @@ public static patch_AreaData Get(string sid) {
                     area.Mode[0].MapData = new patch_MapData(area.ToKey());
 
                 if (area.IsInterludeUnsafe())
-                    continue;
+                    return;
 
                 // A and (some) B sides have PoemIDs. Can be overridden via empty PoemID.
                 if (area.Mode[0].PoemID == null)
@@ -411,6 +415,15 @@ public static patch_AreaData Get(string sid) {
                 }
             }
 
+            if (CoreModule.Settings.FastLevelLoading ?? true) {
+                Logger.Info("AreaData", $"Loading map data in parallel");
+                Parallel.For(0, Areas.Count, ProcessMapData);
+            } else {
+                for (int i = 0; i < Areas.Count; i++) {
+                    ProcessMapData(i);
+                }
+            }
+
             // Load custom mountains
             // This needs to be done after areas are loaded because it depends on the MapMeta
             MTNExt.LoadMod();

Celeste.Mod.mm/Patches/BinaryPacker.cs

@@ -9,7 +9,7 @@
 
 namespace Celeste {
     static class patch_BinaryPacker {
-        [MonoModIgnore]
+        [ThreadStatic]
         private static string[] stringLookup;
 
         [MonoModIgnore] // We don't want to change anything about the method...

Celeste.Mod.mm/Patches/MapData.cs

@@ -16,6 +16,8 @@
 namespace Celeste {
     public class patch_MapData : MapData {
 
+        private static readonly object locker = new object();
+
         public bool DetectedCassette;
         public int DetectedStrawberriesIncludingUntracked;
         public List<EntityData> DashlessGoldenberries = new List<EntityData>();
@@ -177,7 +179,9 @@ private BinaryPacker.Element Process(BinaryPacker.Element root) {
             if (root.Children.Find(element => element.Name == "meta") is BinaryPacker.Element meta)
                 ProcessMeta(meta);
 
-            new MapDataFixup(this).Process(root);
+            lock (locker) {
+                new MapDataFixup(this).Process(root);
+            }
 
             return root;
         }