feat: add non-component-based hook execution deduplication (#142)

This is in preparation for coordination with VRCF:
https://discord.com/channels/1001423276553285653/1001424777401077830/1201398914574712842

CHANGELOG.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [unreleased]
 
 ### Added
+- Added a non-component-based check for double execution of hooks (#142)
 
 ### Fixed
 

Editor/VRChat/BuildFrameworkPreprocessHook.cs

@@ -27,8 +27,13 @@ internal class BuildFrameworkPreprocessHook : IVRCSDKPreprocessAvatarCallback
 
         public bool OnPreprocessAvatar(GameObject avatarGameObject)
         {
+            // Legacy: For VRCF
             if (avatarGameObject.GetComponent<AlreadyProcessedTag>()?.processingCompleted == true) return true;
 
+            var state = HookDedup.RecordAvatar(avatarGameObject);
+            if (state.ranEarlyHook) return true;
+            state.ranEarlyHook = true;
+
             try
             {
                 var holder = avatarGameObject.AddComponent<ContextHolder>();
@@ -53,7 +58,11 @@ internal class BuildFrameworkOptimizeHook : IVRCSDKPreprocessAvatarCallback
         public bool OnPreprocessAvatar(GameObject avatarGameObject)
         {
             if (avatarGameObject.GetComponent<AlreadyProcessedTag>()?.processingCompleted == true) return true;
-
+
+            var state = HookDedup.RecordAvatar(avatarGameObject);
+            if (state.ranOptimization) return true;
+            state.ranOptimization = true;
+
             var holder = avatarGameObject.GetComponent<ContextHolder>();
             if (holder == null) return true;
 

Editor/VRChat/HookDedup.cs

@@ -0,0 +1,43 @@
+#if NDMF_VRCSDK3_AVATARS
+
+using System.Runtime.CompilerServices;
+using UnityEngine;
+
+namespace nadena.dev.ndmf.VRChat
+{
+    /// <summary>
+    /// Ensures that we don't run hooks more than once. This is in preparation for coordinating with VRCFury to have all
+    /// nondestructive utilities independently execute hooks as part of Apply on Play, while deduplicating to ensure that
+    /// we don't rerun hooks on the same avatar.
+    /// </summary>
+    internal static class HookDedup
+    {
+        internal class State
+        {
+            internal bool ranEarlyHook;
+            internal bool ranOptimization;
+        }
+
+        private static ConditionalWeakTable<GameObject, State> _avatars = new ConditionalWeakTable<GameObject, State>();
+
+        public static State RecordAvatar(GameObject root)
+        {
+            if (_avatars.TryGetValue(root, out var state))
+            {
+                return state;
+            }
+
+            state = new State();
+            _avatars.Add(root, state);
+
+            return state;
+        }
+
+        public static bool HasAvatar(GameObject root)
+        {
+            return _avatars.TryGetValue(root, out _);
+        }
+    }
+}
+
+#endif