chore: initial commit

Packages/com.kybernetik.animancer/Editor/Serialization/SharedReferenceCache.cs

@@ -0,0 +1,188 @@
+// Animancer // https://kybernetik.com.au/animancer // Copyright 2018-2026 Kybernetik //
+
+#if UNITY_EDITOR
+
+using System.Collections;
+using System.Collections.Generic;
+using UnityEditor;
+using UnityEngine;
+
+namespace Animancer.Editor
+{
+    /// <summary>[Editor-Only]
+    /// A system which gathers information about <see cref="SerializeReference"/> fields to detect when multiple fields
+    /// are referencing the same object.
+    /// </summary>
+    /// https://kybernetik.com.au/animancer/api/Animancer.Editor/SharedReferenceCache
+    public class SharedReferenceCache :
+        IEnumerable<KeyValuePair<object, List<SharedReferenceCache.Field>>>
+    {
+        /************************************************************************************************************************/
+        #region Static Caching
+        /************************************************************************************************************************/
+
+        private static readonly Dictionary<SerializedObject, SharedReferenceCache>
+            SerializedObjectToCache = new();
+
+        /// <summary>Returns a cached <see cref="SharedReferenceCache"/> for the `serializedObject`.</summary>
+        public static SharedReferenceCache Get(SerializedObject serializedObject)
+        {
+            CheckFlush(serializedObject);
+
+            if (!SerializedObjectToCache.TryGetValue(serializedObject, out var cache))
+                SerializedObjectToCache.Add(serializedObject, cache = new(serializedObject));
+
+            return cache;
+        }
+
+        /************************************************************************************************************************/
+
+        private static readonly HashSet<SerializedObject>
+            NotRecentlyUsed = new();
+
+        private const double
+            FlushInterval = 5;
+
+        private static double
+            _LastFlushTime;
+
+        /// <summary>Discards any caches not used during the last <see cref="FlushInterval"/> when it elapses.</summary>
+        private static void CheckFlush(SerializedObject serializedObject)
+        {
+            var currentTime = EditorApplication.timeSinceStartup;
+
+            if (currentTime >= _LastFlushTime + FlushInterval)
+            {
+                _LastFlushTime = currentTime;
+
+                foreach (var unused in NotRecentlyUsed)
+                    SerializedObjectToCache.Remove(unused);
+
+                NotRecentlyUsed.Clear();
+                NotRecentlyUsed.UnionWith(SerializedObjectToCache.Keys);
+            }
+
+            NotRecentlyUsed.Remove(serializedObject);
+        }
+
+        /************************************************************************************************************************/
+
+        /// <summary>The number of editor updates that have occurred since startup.</summary>
+        public static ulong FrameCount { get; private set; }
+
+        static SharedReferenceCache()
+        {
+            EditorApplication.update += () => FrameCount++;
+        }
+
+        /************************************************************************************************************************/
+        #endregion
+        /************************************************************************************************************************/
+
+        /// <summary>Information about a field.</summary>
+        public struct Field
+        {
+            /************************************************************************************************************************/
+
+            /// <summary>The <see cref="Serialization.GetFriendlyPath"/> of the field.</summary>
+            public string path;
+
+            /// <summary>The area where the field was last drawn.</summary>
+            public Rect area;
+
+            /************************************************************************************************************************/
+
+            /// <summary>Creates a new <see cref="Field"/>.</summary>
+            public Field(string path)
+            {
+                this.path = path;
+                area = default;
+            }
+
+            /************************************************************************************************************************/
+        }
+
+        /************************************************************************************************************************/
+
+        private readonly SerializedObject
+            SerializedObject;
+
+        private readonly Dictionary<object, List<Field>>
+            ObjectToReferences = new();
+
+        private ulong
+            _LastGatherFrameCount;
+
+        /************************************************************************************************************************/
+
+        /// <summary>Creates a new <see cref="SharedReferenceCache"/>.</summary>
+        public SharedReferenceCache(SerializedObject serializedObject)
+        {
+            SerializedObject = serializedObject;
+        }
+
+        /************************************************************************************************************************/
+
+        /// <summary>Should <see cref="GatherReferences"/> be called?</summary>
+        public bool ShouldGather
+            => _LastGatherFrameCount != FrameCount;
+
+        /// <summary>Updates the cached reference info.</summary>
+        public void GatherReferences()
+        {
+            _LastGatherFrameCount = FrameCount;
+
+            ObjectToReferences.Clear();
+
+            var property = SerializedObject.GetIterator();
+            while (property.Next(true))
+            {
+                if (property.propertyType != SerializedPropertyType.ManagedReference)
+                    continue;
+
+                var reference = property.managedReferenceValue;
+                if (reference == null)
+                    continue;
+
+                if (!ObjectToReferences.TryGetValue(reference, out var paths))
+                    ObjectToReferences.Add(reference, paths = new());
+
+                paths.Add(new(property.GetFriendlyPath()));
+            }
+        }
+
+        /************************************************************************************************************************/
+
+        /// <summary>Tries to get the info about all fields containing the `reference`.</summary>
+        public bool TryGetInfo(object reference, out List<Field> references)
+        {
+            if (ShouldGather)
+                GatherReferences();
+
+            return ObjectToReferences.TryGetValue(reference, out references);
+        }
+
+        /************************************************************************************************************************/
+
+        /// <summary>Returns an enumerator for all references and their info.</summary>
+        public Dictionary<object, List<Field>>.Enumerator GetEnumerator()
+        {
+            if (ShouldGather)
+                GatherReferences();
+
+            return ObjectToReferences.GetEnumerator();
+        }
+
+        /// <summary>Returns an enumerator for all references and their info.</summary>
+        IEnumerator<KeyValuePair<object, List<Field>>> IEnumerable<KeyValuePair<object, List<Field>>>.GetEnumerator()
+            => GetEnumerator();
+
+        /// <summary>Returns an enumerator for all references and their info.</summary>
+        IEnumerator IEnumerable.GetEnumerator()
+            => GetEnumerator();
+
+        /************************************************************************************************************************/
+    }
+}
+
+#endif