mega refactoring, now EntityView and EntityStructs use almost exactly the same code

introduced EntityViewStruct
cut a lot of code not needed anymore
breaking change engines add and remove callback now accept only ref params
breaking change QueryEntityViewsAsArray renamed in to QueryEntityViewsCacheFriendly

Svelto.Common

@@ -1 +1 @@
-Subproject commit 460c00846a3b547c4567aec8bdfff82a9861869c
+Subproject commit 3c1360fcb86cdb70dcb00149a26d2064ec6fbe63

Svelto.ECS.csproj

@@ -1,7 +1,8 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
     <AssemblyName>Svelto.ECS</AssemblyName>
+    <LangVersion>6</LangVersion>
+    <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="System.Reflection" Version="4.3.0" />

Svelto.ECS/DataStructures/TypeSafeDictionary.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using Svelto.DataStructures;
 
@@ -13,20 +13,31 @@ namespace Svelto.ECS.Internal
     /// </summary>
     public interface ITypeSafeDictionary
     {
-        void        FillWithIndexedEntityViews(ITypeSafeList entityViews);
-        bool        Remove(EGID entityId);
-        IEntityData GetIndexedEntityView(EGID entityID);
+        void RemoveEntityFromDicAndEngines(EGID entityGid,
+                                           Dictionary<Type, FasterList<IHandleEntityViewEngineAbstracted>>
+                                               entityViewEnginesDB);
+        void RemoveEntityViewsFromEngines(
+            Dictionary<Type, FasterList<IHandleEntityViewEngineAbstracted>> entityViewEngines);
+        void AddCapacity(int size);
+        bool Remove(long idGid);
+        ITypeSafeDictionary Create();
+        int Count { get; }
+        void FillWithIndexedEntityViews(ITypeSafeDictionary entityViews);
+        void AddEntityViewsToEngines(FasterList<IHandleEntityViewEngineAbstracted> enginesForEntityView);
     }
 
-    class TypeSafeDictionaryForClass<TValue> : Dictionary<long, TValue>, ITypeSafeDictionary where TValue : IEntityData
+    class TypeSafeDictionary<TValue> : FasterDictionary<long, TValue>, ITypeSafeDictionary where TValue : IEntityData
     {
-        internal static readonly ReadOnlyDictionary<long, TValue> Default =
-            new ReadOnlyDictionary<long, TValue>(new Dictionary<long, TValue>());
+        public TypeSafeDictionary(int size):base(size)
+        {}
 
-        public void FillWithIndexedEntityViews(ITypeSafeList entityViews)
+        public TypeSafeDictionary()
+        {}
+
+        public void FillWithIndexedEntityViews(ITypeSafeDictionary entityViews)
         {
             int count;
-            var buffer = FasterList<TValue>.NoVirt.ToArrayFast((FasterList<TValue>) entityViews, out count);
+            var buffer = (entityViews as TypeSafeDictionary<TValue>).GetFasterValuesBuffer(out count);
 
             try
             {
@@ -43,16 +54,53 @@ namespace Svelto.ECS.Internal
             }
         }
 
-        public bool Remove(EGID entityId)
+        public void AddEntityViewsToEngines(FasterList<IHandleEntityViewEngineAbstracted> enginesForEntityView)
+        {
+            throw new NotImplementedException();
+        }
+
+        public void RemoveEntityFromDicAndEngines(EGID entityGid,
+                                                  Dictionary<Type, FasterList<IHandleEntityViewEngineAbstracted>>
+                                                      entityViewEnginesDB)
+        {
+            
+            
+            TValue entity = this[entityGid.GID];
+
+            RemoveEntityViewsFromEngines(entityViewEnginesDB, ref entity);
+
+            Remove(entityGid.GID);
+        }
+
+        public void RemoveEntityViewsFromEngines(Dictionary<Type, FasterList<IHandleEntityViewEngineAbstracted>> entityViewEnginesDB, ref TValue entity)
         {
-            base.Remove(entityId.GID);
+            FasterList<IHandleEntityViewEngineAbstracted> entityViewsEngines;
+            if (entityViewEnginesDB.TryGetValue(typeof(TValue), out entityViewsEngines))
+                for (int i = 0; i < entityViewEnginesDB.Count; i++)
+                    (entityViewsEngines[i] as IHandleEntityStructEngine<TValue>).Remove(ref entity);
+        }
+        
+        public void RemoveEntityViewsFromEngines(Dictionary<Type, FasterList<IHandleEntityViewEngineAbstracted>> entityViewEnginesDB)
+        {
+            int count;
+            TValue[] values = this.GetFasterValuesBuffer(out count);
+
+            for (int i = 0; i < count; i++)
+            {
+                TValue entity = values[i];
 
-            return Count > 0;
+                RemoveEntityViewsFromEngines(entityViewEnginesDB, ref entity);
+            }
+        }
+
+        public void AddCapacity(int size)
+        {
+            throw new NotImplementedException();
         }
 
-        public IEntityData GetIndexedEntityView(EGID entityID)
+        public ITypeSafeDictionary Create()
         {
-            return this[entityID.GID];
+            return new TypeSafeDictionary<TValue>();
         }
     }
 }

Svelto.ECS/DataStructures/TypeSafeFasterListForECS.cs

@@ -1,225 +0,0 @@
-using System;
-using System.Collections;
-using System.Collections.Generic;
-using DBC;
-using Svelto.DataStructures;
-
-namespace Svelto.ECS.Internal
-{
-    public interface ITypeSafeList : IEnumerable
-    {
-        bool isQueryiableEntityView { get; }
-        void AddRange(ITypeSafeList entityViewListValue);
-
-        ITypeSafeList       Create();
-        bool                MappedRemove(EGID entityID);
-        ITypeSafeDictionary CreateIndexedDictionary();
-        EGIDEnumerator      EntityIDS();
-        void                AddCapacity(int capacity);
-
-        void Fill(FasterList<IHandleEntityViewEngineAbstracted> enginesForEntityView);
-    }
-
-    public struct EGIDEnumerator:IEnumerable, IEnumerator
-    {
-        Dictionary<long, int>.Enumerator _keysEnumerator;
-
-        public EGIDEnumerator(Dictionary<long, int> mappedIndices)
-        {
-            _keysEnumerator = mappedIndices.GetEnumerator();
-        }
-
-        public bool MoveNext()
-        {
-            return _keysEnumerator.MoveNext();
-        }
-
-        public void Reset()
-        {
-            throw new NotImplementedException();
-        }
-
-        public object Current { get { return new EGID(_keysEnumerator.Current.Key);} }
-        public IEnumerator GetEnumerator()
-        {
-            return this;
-        }
-    }
-
-    class TypeSafeFasterListForECS<T> : FasterList<T> where T : IEntityData
-    {
-        protected TypeSafeFasterListForECS()
-        {
-            _mappedIndices = new Dictionary<long, int>();
-        }
-
-        protected TypeSafeFasterListForECS(int size) : base(size)
-        {
-            _mappedIndices = new Dictionary<long, int>();
-        }
-
-        public bool MappedRemove(EGID entityID)
-        {
-            var index = _mappedIndices[entityID.GID];
-
-            Check.Assert(entityID.GID == this[index].ID.GID,
-                         "Something went wrong with the Svelto.ECS code, please contact the author");
-
-            _mappedIndices.Remove(entityID.GID);
-
-            if (UnorderedRemoveAt(index))
-            {
-                _mappedIndices[this[index].ID.GID] = index;
-            }
-
-            return Count > 0;
-        }
-
-        public void AddRange(ITypeSafeList entityViewListValue)
-        {
-            var index = Count;
-
-            base.AddRange(entityViewListValue as FasterList<T>);
-
-            for (var i = index; i < Count; ++i)
-            {
-                try
-                {
-                    _mappedIndices.Add(this[i].ID.GID, i);
-                }
-                catch (Exception e)
-                {
-                    throw new TypeSafeFasterListForECSException(e);
-                }
-            }
-        }
-
-        public new void Add(T entityView)
-        {
-            var index = Count;
-
-            base.Add(entityView);
-
-            try
-            {
-                _mappedIndices.Add(entityView.ID.GID, index);
-            }
-            catch (Exception e)
-            {
-                throw new TypeSafeFasterListForECSException(e);
-            }
-        }
-
-        public void AddCapacity(int capacity)
-        {
-            if (ToArrayFast().Length < Count + capacity)
-                Resize(Count + capacity);
-        }
-
-        public int GetIndexFromID(EGID entityID)
-        {
-            return _mappedIndices[entityID.GID];
-        }
-        
-        public EGIDEnumerator EntityIDS()
-        {
-            return new EGIDEnumerator(_mappedIndices);
-        }
-
-        readonly Dictionary<long, int> _mappedIndices;
-    }
-
-    class TypeSafeFasterListForECSForStructs<T> : TypeSafeFasterListForECS<T>, ITypeSafeList where T:struct, IEntityData
-    {
-        public TypeSafeFasterListForECSForStructs(int size) : base(size)
-        {}
-
-        public TypeSafeFasterListForECSForStructs()
-        {}
-
-        public ITypeSafeList Create()
-        {
-            return new TypeSafeFasterListForECSForStructs<T>();
-        }
-
-        public bool isQueryiableEntityView
-        {
-            get { return false; }
-        }
-
-        public ITypeSafeDictionary CreateIndexedDictionary()
-        {
-            throw new NotImplementedException();
-        }
-
-        public void Fill(FasterList<IHandleEntityViewEngineAbstracted> enginesForEntityView)
-        {
-            var thisfastList = NoVirt.ToArrayFast(this);
-            for (int i = 0; i < Count; i++)
-            {
-                int count;
-                var fastList = FasterList<IHandleEntityViewEngineAbstracted>.NoVirt.ToArrayFast(enginesForEntityView, out count);
-                for (int j = 0; j < count; j++)
-                {
-#if ENGINE_PROFILER_ENABLED
-                    EngineProfiler.MonitorAddDuration<T>(fastList[j], entityView);
-#else
-                    (fastList[j] as IHandleEntityStructEngine<T>).Add(ref thisfastList[j]);
-#endif
-                }
-            }
-        }
-
-        public ITypeSafeList Create(int size)
-        {
-            return new TypeSafeFasterListForECSForStructs<T>(size);
-        }
-    }
-    
-    class TypeSafeFasterListForECSForClasses<T> : TypeSafeFasterListForECS<T>, ITypeSafeList where T:IEntityData, new()
-    {
-        public TypeSafeFasterListForECSForClasses(int size) : base(size)
-        {}
-
-        public TypeSafeFasterListForECSForClasses()
-        {}
-
-        public ITypeSafeList Create()
-        {
-            return new TypeSafeFasterListForECSForClasses<T>();
-        }
-
-        public bool isQueryiableEntityView
-        {
-            get { return true; }
-        }
-
-        public ITypeSafeDictionary CreateIndexedDictionary()
-        {
-            return new TypeSafeDictionaryForClass<T>();
-        }
-
-        public void Fill(FasterList<IHandleEntityViewEngineAbstracted> enginesForEntityView)
-        {
-            var thisfastList = NoVirt.ToArrayFast(this);
-            for (int i = 0; i < Count; i++)
-            {
-                int count;
-                var fastList = FasterList<IHandleEntityViewEngineAbstracted>.NoVirt.ToArrayFast(enginesForEntityView, out count);
-                for (int j = 0; j < count; j++)
-                {
-#if ENGINE_PROFILER_ENABLED
-                    EngineProfiler.MonitorAddDuration(fastList[j], entityView);
-#else
-                    (fastList[j] as IHandleEntityStructEngine<T>).Add(ref thisfastList[j]);
-#endif
-                }
-            }
-        }
-
-        public ITypeSafeList Create(int size)
-        {
-            return new TypeSafeFasterListForECSForClasses<T>(size);
-        }
-    }
-}

Svelto.ECS/DataStructures/TypeSafeFasterListForECSException.cs

@@ -1,10 +0,0 @@
-using System;
-
-namespace Svelto.ECS
-{
-    public class TypeSafeFasterListForECSException : Exception
-    {
-        public TypeSafeFasterListForECSException(Exception exception):base("Trying to add an Entity View with the same ID more than once", exception)
-        {}
-    }
-}

Svelto.ECS/EGID.cs

@@ -11,18 +11,19 @@ namespace Svelto.ECS
             get { return _GID; }
         }
         
-        public int ID
+        public int entityID
         {
             get { return (int) (_GID & 0xFFFFFFFF); }
         }
         
-        public int group
+        public int groupID
         {
             get { return (int) (_GID >> 32); }
         }
 
         public EGID(int entityID, int groupID) : this()
         {
+            DBC.Check.Require(groupID != ExclusiveGroups.StandardEntity, "can't use an exclusive group ID");
             _GID = MAKE_GLOBAL_ID(entityID, groupID);
         }
         
@@ -31,19 +32,9 @@ namespace Svelto.ECS
             _GID = MAKE_GLOBAL_ID(entityID, ExclusiveGroups.StandardEntity);
         }
 
-        internal EGID(long otherID)
-        {
-            _GID = otherID;
-        }
-
         static long MAKE_GLOBAL_ID(int entityId, int groupId)
         {
             return (long)groupId << 32 | (uint)entityId;
         }
-
-        public bool IsEqualTo(EGID otherGID)
-        {
-            return otherGID._GID == _GID;
-        }
     }
 }

Svelto.ECS/EnginesRoot.GenericEntityFactory.cs

@@ -19,24 +19,24 @@ namespace Svelto.ECS
 
             public void BuildEntity<T>(int entityID, object[] implementors) where T : IEntityDescriptor, new()
             {
-                _weakEngine.Target.BuildEntity<T>(entityID, implementors);
+                _weakEngine.Target.BuildEntity<T>(new EGID(entityID), implementors);
             }
 
             public void BuildEntity(int entityID, EntityDescriptorInfo entityDescriptor, object[] implementors = null)
             {
-                _weakEngine.Target.BuildEntity(entityID, entityDescriptor, implementors);
+                _weakEngine.Target.BuildEntity(new EGID(entityID), entityDescriptor, implementors);
             }
 
             public void BuildEntity<T>(int entityID, int groupID, object[] implementors)
                 where T : IEntityDescriptor, new()
             {
-                _weakEngine.Target.BuildEntity<T>(entityID, groupID, implementors);
+                _weakEngine.Target.BuildEntity<T>(new EGID(entityID, groupID), implementors);
             }
 
             public void BuildEntity(int entityID, int groupID, EntityDescriptorInfo entityDescriptor,
                                            object[] implementors)
             {
-                _weakEngine.Target.BuildEntity(entityID, groupID, entityDescriptor, implementors);
+                _weakEngine.Target.BuildEntity(new EGID(entityID, groupID), entityDescriptor, implementors);
             }
 
             public void PreallocateEntitySpace<T>(int size) where T : IEntityDescriptor, new()

Svelto.ECS/EnginesRoot.GenericEntityFunctions.cs

@@ -19,12 +19,12 @@ namespace Svelto.ECS
 
             public void RemoveEntity(int entityID)
             {
-                _weakReference.Target.RemoveEntity(entityID, ExclusiveGroups.StandardEntity);
+                _weakReference.Target.RemoveEntity(new EGID(entityID));
             }
             
             public void RemoveEntity(int entityID, int groupID)
             {
-                _weakReference.Target.RemoveEntity(entityID, groupID);
+                _weakReference.Target.RemoveEntity(new EGID(entityID, groupID));
             }
 
             public void RemoveEntity(EGID entityEGID)

Svelto.ECS/EnginesRootEngines.cs

@@ -37,15 +37,12 @@ namespace Svelto.ECS
             _entityViewEngines = new Dictionary<Type, FasterList<IHandleEntityViewEngineAbstracted>>();
             _otherEngines = new FasterList<IEngine>();
 
-            _groupEntityViewsDB = new Dictionary<int, Dictionary<Type, ITypeSafeList>>();
-            _groupEntityViewsDB[ExclusiveGroups.StandardEntity] = new Dictionary<Type, ITypeSafeList>();
-            _globalEntityViewsDBDic = new Dictionary<Type, ITypeSafeDictionary>();
+            _groupEntityViewsDB = new Dictionary<int, Dictionary<Type, ITypeSafeDictionary>>();
+            _groupEntityViewsDB[ExclusiveGroups.StandardEntity] = new Dictionary<Type, ITypeSafeDictionary>();
             
-            _entityInfos = new Dictionary<long, IEntityViewBuilder[]>();
-            
-            _groupedEntityViewsToAdd = new DoubleBufferedEntityViews<Dictionary<int, Dictionary<Type, ITypeSafeList>>>();
+            _groupedEntityViewsToAdd = new DoubleBufferedEntityViews<Dictionary<int, Dictionary<Type, ITypeSafeDictionary>>>();
 
-            _DB = new EntityViewsDB(_globalEntityViewsDBDic, _groupEntityViewsDB);
+            _DB = new EntityViewsDB(_groupEntityViewsDB);
 
             _scheduler = entityViewScheduler;
             _scheduler.Schedule(new WeakAction(SubmitEntityViews));
@@ -119,7 +116,7 @@ namespace Svelto.ECS
         }
 
         readonly Dictionary<Type, FasterList<IHandleEntityViewEngineAbstracted>> _entityViewEngines;    
-        readonly FasterList<IEngine> _otherEngines;
+        readonly FasterList<IEngine>                                             _otherEngines;
         
         static readonly Type _entityViewType= typeof(IEntityData);
         static readonly Type _objectType = typeof(object);

Svelto.ECS/EnginesRootEntities.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using DBC;
-using Svelto.DataStructures;
 using Svelto.ECS.Internal;
 
 #if ENGINE_PROFILER_ENABLED && UNITY_EDITOR
@@ -15,10 +14,8 @@ namespace Svelto.ECS
         public void Dispose()
         {
             foreach (var groups in _groupEntityViewsDB)
-                foreach (var entity in groups.Value)
-                    if (entity.Value.isQueryiableEntityView == true)
-                        foreach (var entityView in entity.Value)
-                            RemoveEntityViewFromEngines(_entityViewEngines, entityView as IEntityData, entity.Key);
+                foreach (var entityList in groups.Value)
+                    entityList.Value.RemoveEntityViewsFromEngines(_entityViewEngines);
         }
 
         ///--------------------------------------------
@@ -35,18 +32,6 @@ namespace Svelto.ECS
 
         ///--------------------------------------------
 
-        void BuildEntity<T>(int entityID, object[] implementors = null) where T : IEntityDescriptor, new()
-        {
-            BuildEntity<T>
-                (entityID, ExclusiveGroups.StandardEntity, implementors);
-        }
-
-        void BuildEntity(int entityID, EntityDescriptorInfo entityDescriptor, object[] implementors)
-        {
-            BuildEntity
-                (entityID, ExclusiveGroups.StandardEntity, entityDescriptor, implementors);
-        }
-
         /// <summary>
         /// Build the entity using the entityID, inside the group with Id groupID, using the
         /// implementors (if necessary). The entityViews generated will be stored to be
@@ -54,25 +39,22 @@ namespace Svelto.ECS
         /// </summary>
         /// <typeparam name="T"></typeparam>
         /// <param name="entityID"></param>
-        /// <param name="groupID"></param>
         /// <param name="implementors"></param>
-        void BuildEntity<T>(int entityID, int groupID, object[] implementors = null)
+        void BuildEntity<T>(EGID entityID, object[] implementors = null)
             where T : IEntityDescriptor, new()
         {
-            EntityFactory.BuildGroupedEntityViews(entityID, groupID,
+            EntityFactory.BuildGroupedEntityViews(entityID,
                                                   _groupedEntityViewsToAdd.current,
                                                   EntityDescriptorTemplate<T>.Default,
-                                                  _entityInfos,
                                                   implementors);
         }
 
-        void BuildEntity(int entityID, int groupID, EntityDescriptorInfo entityDescriptor,
+        void BuildEntity(EGID entityID, EntityDescriptorInfo entityDescriptor,
                                 object[] implementors = null)
         {
-            EntityFactory.BuildGroupedEntityViews(entityID, groupID,
+            EntityFactory.BuildGroupedEntityViews(entityID,
                                                   _groupedEntityViewsToAdd.current,
                                                   entityDescriptor,
-                                                  _entityInfos,
                                                    implementors);
         }
 
@@ -95,12 +77,12 @@ namespace Svelto.ECS
                 var entityViewType    = entityViewBuilder.GetEntityViewType();
 
                 //reserve space for the global pool
-                ITypeSafeList dbList;
+                ITypeSafeDictionary dbList;
 
                 //reserve space for the single group
-                Dictionary<Type, ITypeSafeList> @group;
+                Dictionary<Type, ITypeSafeDictionary> @group;
                 if (_groupEntityViewsDB.TryGetValue(groupID, out group) == false)
-                    group = _groupEntityViewsDB[groupID] = new Dictionary<Type, ITypeSafeList>();
+                    group = _groupEntityViewsDB[groupID] = new Dictionary<Type, ITypeSafeDictionary>();
                 
                 if (group.TryGetValue(entityViewType, out dbList) == false)
                     group[entityViewType] = entityViewBuilder.Preallocate(ref dbList, size);
@@ -108,7 +90,7 @@ namespace Svelto.ECS
                     dbList.AddCapacity(size);
                 
                 if (_groupedEntityViewsToAdd.current.TryGetValue(groupID, out group) == false)
-                    group = _groupEntityViewsDB[groupID] = new Dictionary<Type, ITypeSafeList>();
+                    group = _groupEntityViewsDB[groupID] = new Dictionary<Type, ITypeSafeDictionary>();
                 
                 //reserve space to the temporary buffer
                 if (group.TryGetValue(entityViewType, out dbList) == false)
@@ -120,102 +102,40 @@ namespace Svelto.ECS
         
         ///--------------------------------------------
         /// 
-        void RemoveEntity(int entityID, int groupID)
-        {
-            RemoveEntity(new EGID(entityID, groupID));
-        }
-
         void RemoveEntity(EGID entityGID)
         {
-            var entityViewBuilders = _entityInfos[entityGID.GID];
+            var typeSafeDictionary = _groupEntityViewsDB[entityGID.groupID][typeof(EntityInfoView)] as TypeSafeDictionary<EntityInfoView>;
+            var entityInfoView = typeSafeDictionary[entityGID.GID];
+            var entityViewBuilders = entityInfoView.entityViewsToBuild;
             var entityViewBuildersCount = entityViewBuilders.Length;
             
             //for each entity view generated by the entity descriptor
             for (var i = 0; i < entityViewBuildersCount; i++)
             {
                 var entityViewType = entityViewBuilders[i].GetEntityViewType();
-
-                if (entityViewBuilders[i].isQueryiableEntityView)
-                {
-                    var group = _groupEntityViewsDB[entityGID.group];
-                    InternalRemoveEntityViewFromDBDicAndEngines(entityViewType, entityGID);
-                    RemoveEntityViewFromDB(@group, entityViewType, entityGID);
-                }
+                var group = _groupEntityViewsDB[entityGID.groupID];
+                
+                _groupEntityViewsDB[entityGID.groupID][entityViewType].RemoveEntityFromDicAndEngines(entityGID, _entityViewEngines);
+                RemoveEntityViewFromGroup(group, entityViewType, entityGID);
             }
-
-            _entityInfos.Remove(entityGID.GID);
         }
 
-        static void RemoveEntityViewFromDB(Dictionary<Type, ITypeSafeList> @group, Type entityViewType, EGID id)
+        static void RemoveEntityViewFromGroup(Dictionary<Type, ITypeSafeDictionary> @group, Type entityViewType, EGID id)
         {
             //remove it from entity views group DB
             var typeSafeList = @group[entityViewType];
-            if (typeSafeList.MappedRemove(id) == false) //clean up
+            if (typeSafeList.Remove(id.GID) == false) //clean up
                 @group.Remove(entityViewType);
         }
 
         void RemoveGroupAndEntitiesFromDB(int groupID)
         {
-            foreach (var group in _groupEntityViewsDB[groupID])
-            {
-                var entityViewType = group.Key;
-
-                var entities = group.Value.EntityIDS();
-
-                foreach (EGID entityID in entities)
-                {
-                    if (group.Value.isQueryiableEntityView)
-                        InternalRemoveEntityViewFromDBDicAndEngines(entityViewType, entityID);
-                }
-            }
+            foreach (var entiTypeSafeList in _groupEntityViewsDB[groupID])
+                entiTypeSafeList.Value.RemoveEntityViewsFromEngines(_entityViewEngines);
 
             _groupEntityViewsDB.Remove(groupID);
         }
 
-        void InternalRemoveEntityViewFromDBDicAndEngines(Type entityViewType, EGID id)
-        {
-            var typeSafeDictionary = _globalEntityViewsDBDic[entityViewType];
-            {
-                var entityView = typeSafeDictionary.GetIndexedEntityView(id);
-
-                //the reason why this for exists is because in the past hierarchical entity views
-                //where supported :(
-                //Only EntityView can be removed from engines (won't work for IEntityData or IEntityData)
-                for (var current = entityViewType; current != _entityViewType; current = current.BaseType)
-                {
-#if DEBUG && !PROFILER                    
-                    if (current != entityViewType)
-                        Utility.Console.LogWarning("Hierarchical Entity Views are design mistakes, ECS is not OOD!!");
-#endif                        
-                        
-                    RemoveEntityViewFromEngines(_entityViewEngines, entityView, current);
-                }
-            }
-            typeSafeDictionary.Remove(id);
-        }
-        
-        static void RemoveEntityViewFromEngines(Dictionary<Type, FasterList<IHandleEntityViewEngineAbstracted>> entityViewEngines,
-                                                IEntityData entityView, Type entityViewType)
-        {
-            FasterList<IHandleEntityViewEngineAbstracted> enginesForEntityView;
-
-            if (entityViewEngines.TryGetValue(entityViewType, out enginesForEntityView))
-            {
-                int count;
-                var fastList = FasterList<IHandleEntityViewEngineAbstracted>.NoVirt.ToArrayFast(enginesForEntityView, out count);
-
-                for (var j = 0; j < count; j++)
-                {
-#if ENGINE_PROFILER_ENABLED && UNITY_EDITOR
-                    EngineProfiler.MonitorRemoveDuration(fastList[j], entityView);
-#else
-                    var handleMixedEntityViewEngine = (fastList[j] as IHandleEntityViewEngine);
-                    handleMixedEntityViewEngine.Remove(entityView);
-#endif
-                }
-            }
-        }
-        
         ///--------------------------------------------
 
         void SwapEntityGroup(int entityID, int fromGroupID, int toGroupID)
@@ -224,15 +144,17 @@ namespace Svelto.ECS
                           "can't move an entity to the same group where it already belongs to");
 
             var entityegid = new EGID(entityID, fromGroupID);
-            var entityViewBuilders = _entityInfos[entityegid.GID];
+            var entityViewBuilders =
+                ((TypeSafeDictionary<EntityInfoView>) _groupEntityViewsDB[fromGroupID][typeof(EntityInfoView)])
+                [entityegid.GID].entityViewsToBuild;
             var entityViewBuildersCount = entityViewBuilders.Length;
 
             var groupedEntities = _groupEntityViewsDB[fromGroupID];
 
-            Dictionary<Type, ITypeSafeList> groupedEntityViewsTyped;
+            Dictionary<Type, ITypeSafeDictionary> groupedEntityViewsTyped;
             if (_groupEntityViewsDB.TryGetValue(toGroupID, out groupedEntityViewsTyped) == false)
             {
-                groupedEntityViewsTyped = new Dictionary<Type, ITypeSafeList>();
+                groupedEntityViewsTyped = new Dictionary<Type, ITypeSafeDictionary>();
 
                 _groupEntityViewsDB.Add(toGroupID, groupedEntityViewsTyped);
             }
@@ -243,30 +165,19 @@ namespace Svelto.ECS
                 var entityViewType    = entityViewBuilder.GetEntityViewType();
 
                 var           fromSafeList = groupedEntities[entityViewType];
-                ITypeSafeList toSafeList;
+                ITypeSafeDictionary toSafeList;
 
                 if (groupedEntityViewsTyped.TryGetValue(entityViewType, out toSafeList) == false)
                     groupedEntityViewsTyped[entityViewType] = toSafeList = fromSafeList.Create();
 
                 entityViewBuilder.MoveEntityView(entityegid, fromSafeList, toSafeList);
-                fromSafeList.MappedRemove(entityegid);
+                fromSafeList.Remove(entityegid.GID);
             }
-
-            _entityInfos.Remove(entityegid.GID);
-            _entityInfos.Add(new EGID(entityID, toGroupID).GID, entityViewBuilders);
         }
 
         readonly EntityViewsDB _DB;
         
         //grouped set of entity views, this is the standard way to handle entity views
-        readonly Dictionary<int, Dictionary<Type, ITypeSafeList>>         _groupEntityViewsDB;
-        
-        
-        //TODO: Use faster dictionary and merge these two?
-        
-        //indexable entity views when the entity ID is known. Usually useful to handle
-        //event based logic.
-        readonly Dictionary<Type, ITypeSafeDictionary>  _globalEntityViewsDBDic;
-        readonly Dictionary<long, IEntityViewBuilder[]> _entityInfos;
+        readonly Dictionary<int, Dictionary<Type, ITypeSafeDictionary>>         _groupEntityViewsDB;
     }
 }

Svelto.ECS/EnginesRootSubmission.cs

@@ -40,85 +40,56 @@ namespace Svelto.ECS
             }
         }
         //todo: can I make the entity creation less complicated?
-        void AddEntityViewsToTheDBAndSuitableEngines(Dictionary<int, Dictionary<Type, ITypeSafeList>> groupsToSubmit)
+        void AddEntityViewsToTheDBAndSuitableEngines(Dictionary<int, Dictionary<Type, ITypeSafeDictionary>> groupsToSubmit)
         {
             //for each groups there is a dictionary of built lists of EntityView grouped by type
             foreach (var groupToSubmit in groupsToSubmit)
             {
-                Dictionary<Type, ITypeSafeList> groupDB;
+                Dictionary<Type, ITypeSafeDictionary> groupDB;
                 int groupID = groupToSubmit.Key;
 
                 //if the group doesn't exist in the current DB let's create it frst
                 if (_groupEntityViewsDB.TryGetValue(groupID, out groupDB) == false)
-                    groupDB = _groupEntityViewsDB[groupID] = new Dictionary<Type, ITypeSafeList>();
+                    groupDB = _groupEntityViewsDB[groupID] = new Dictionary<Type, ITypeSafeDictionary>();
 
-                foreach (var entityViewsPerType in groupToSubmit.Value)
+                foreach (var entityViewList in groupToSubmit.Value)
                 {
                     //add the entity View in the group
-                    if (entityViewsPerType.Value.isQueryiableEntityView == true)
-                        AddEntityViewToDB(groupDB, entityViewsPerType);
-                    //and it's not a struct, add in the indexable DB too
-                    AddEntityViewToEntityViewsDictionary(_globalEntityViewsDBDic, entityViewsPerType.Value, entityViewsPerType.Key);
+                    ITypeSafeDictionary dbList;
+                    if (groupDB.TryGetValue(entityViewList.Key, out dbList) == false)
+                        dbList = groupDB[entityViewList.Key] = entityViewList.Value.Create();
+
+                    dbList.FillWithIndexedEntityViews(entityViewList.Value);
                 }
             }
 
             //then submit everything in the engines, so that the DB is up to date
             //with all the entity views and struct created by the entity built
             foreach (var groupToSubmit in groupsToSubmit)
-            {
+            {    
                 foreach (var entityViewsPerType in groupToSubmit.Value)
                 {
                     var type = entityViewsPerType.Key;
                     for (var current = type;
                          current != _entityViewType && current != _objectType && current != _valueType;
                          current = current.BaseType)
-                        AddEntityViewToTheSuitableEngines(_entityViewEngines, entityViewsPerType.Value,
+                        AddEntityViewsToTheSuitableEngines(_entityViewEngines, entityViewsPerType.Value,
                                                           current);
                 }
             }
         }
 
-        static void AddEntityViewToDB(  Dictionary<Type, ITypeSafeList> entityViewsDB, 
-                                        KeyValuePair<Type, ITypeSafeList> entityViewList)
-        {
-            
-            {
-                ITypeSafeList dbList;
-
-                if (entityViewsDB.TryGetValue(entityViewList.Key, out dbList) == false)
-                    dbList = entityViewsDB[entityViewList.Key] = entityViewList.Value.Create();
-
-                dbList.AddRange(entityViewList.Value);
-            }
-        }
-
-        static void AddEntityViewToEntityViewsDictionary(Dictionary<Type, ITypeSafeDictionary> entityViewsDBdic,
-                                                        ITypeSafeList entityViews, Type entityViewType)
-        {
-            if (entityViews.isQueryiableEntityView == true)
-            {
-                ITypeSafeDictionary entityViewsDic;
-    
-                if (entityViewsDBdic.TryGetValue(entityViewType, out entityViewsDic) == false)
-                    entityViewsDic = entityViewsDBdic[entityViewType] = entityViews.CreateIndexedDictionary();
-    
-                entityViewsDic.FillWithIndexedEntityViews(entityViews);
-            }
-        }
-
-        static void AddEntityViewToTheSuitableEngines(Dictionary<Type, FasterList<IHandleEntityViewEngineAbstracted>> entityViewEngines, 
-        ITypeSafeList entityViewsList, 
-        Type entityViewType)
+        static void AddEntityViewsToTheSuitableEngines( Dictionary<Type, FasterList<IHandleEntityViewEngineAbstracted>> entityViewEngines, 
+                                                        ITypeSafeDictionary entityViewsList, 
+                                                        Type entityViewType)
         {
             FasterList<IHandleEntityViewEngineAbstracted> enginesForEntityView;
 
             if (entityViewEngines.TryGetValue(entityViewType, out enginesForEntityView))
-            {
-                entityViewsList.Fill(enginesForEntityView);
-            }
+                entityViewsList.AddEntityViewsToEngines(enginesForEntityView);
         }
         
-        readonly DoubleBufferedEntityViews<Dictionary<int, Dictionary<Type, ITypeSafeList>>> _groupedEntityViewsToAdd;
+        readonly DoubleBufferedEntityViews<Dictionary<int, Dictionary<Type, ITypeSafeDictionary>>> _groupedEntityViewsToAdd;
         readonly EntitySubmissionScheduler _scheduler;
     }
 }

Svelto.ECS/EntityFactory.cs

@@ -5,26 +5,23 @@ namespace Svelto.ECS.Internal
 {
     static class EntityFactory
     {
-        internal static void BuildGroupedEntityViews(int entityID, int groupID,
-                                                     Dictionary<int, Dictionary<Type, ITypeSafeList>> groupEntityViewsByType,
+        internal static void BuildGroupedEntityViews(EGID egid,
+                                                     Dictionary<int, Dictionary<Type, ITypeSafeDictionary>> groupEntityViewsByType,
                                                      EntityDescriptorInfo entityViewsToBuildDescriptor,
-                                                     Dictionary<long, IEntityViewBuilder[]> entityInfos,
                                                      object[] implementors)
         {
-            var @group = FetchGroup(groupID, groupEntityViewsByType);
+            var @group = FetchGroup(egid.groupID, groupEntityViewsByType);
 
-            BuildEntityViewsAndAddToGroup(new EGID(entityID, groupID), group, entityViewsToBuildDescriptor, implementors);
-            
-            entityInfos.Add(new EGID(entityID, groupID).GID, entityViewsToBuildDescriptor.entityViewsToBuild);
+            BuildEntityViewsAndAddToGroup(egid, group, entityViewsToBuildDescriptor, implementors);
         }
 
-        static Dictionary<Type, ITypeSafeList> FetchGroup(int groupID, Dictionary<int, Dictionary<Type, ITypeSafeList>> groupEntityViewsByType)
+        static Dictionary<Type, ITypeSafeDictionary> FetchGroup(int groupID, Dictionary<int, Dictionary<Type, ITypeSafeDictionary>> groupEntityViewsByType)
         {
-            Dictionary<Type, ITypeSafeList> group;
+            Dictionary<Type, ITypeSafeDictionary> group;
 
             if (groupEntityViewsByType.TryGetValue(groupID, out @group) == false)
             {
-                @group = new Dictionary<Type, ITypeSafeList>();
+                @group = new Dictionary<Type, ITypeSafeDictionary>();
                 groupEntityViewsByType.Add(groupID, @group);
             }
 
@@ -32,37 +29,43 @@ namespace Svelto.ECS.Internal
         }
 
         static void BuildEntityViewsAndAddToGroup(EGID entityID,
-            Dictionary<Type, ITypeSafeList> entityViewsByType,
+            Dictionary<Type, ITypeSafeDictionary> entityViewsByType,
             EntityDescriptorInfo entityViewsToBuildDescriptor,
             object[] implementors)
         {
             var entityViewsToBuild           = entityViewsToBuildDescriptor.entityViewsToBuild;
             var count                        = entityViewsToBuild.Length;
 
-            for (var index = 0; index < count; index++)
+            for (var index = 0; index < count; ++index)
             {
                 var entityViewBuilder = entityViewsToBuild[index];
                 var entityViewType    = entityViewBuilder.GetEntityViewType();
 
                 BuildEntityView(entityID, entityViewsByType, entityViewType, entityViewBuilder, implementors);
             }
+
+            _viewBuilder._initializer = new EntityInfoView() {entityViewsToBuild = entityViewsToBuild};
+            BuildEntityView(entityID, entityViewsByType, _viewType, _viewBuilder, null);
         }
 
-        static void BuildEntityView(EGID  entityID,       Dictionary<Type, ITypeSafeList> entityViewsByType,
-                                           Type entityViewType, IEntityViewBuilder entityViewBuilder, object[] implementors)
+        static void BuildEntityView(EGID  entityID, Dictionary<Type, ITypeSafeDictionary> entityViewsByType,
+                                    Type entityViewType, IEntityViewBuilder entityViewBuilder, object[] implementors)
         {
-            ITypeSafeList entityViewsList;
+            ITypeSafeDictionary safeDictionary;
 
             var entityViewsPoolWillBeCreated =
-                entityViewsByType.TryGetValue(entityViewType, out entityViewsList) == false;
+                entityViewsByType.TryGetValue(entityViewType, out safeDictionary) == false;
 
             //passing the undefined entityViewsByType inside the entityViewBuilder will allow
             //it to be created with the correct type and casted back to the undefined list.
             //that's how the list will be eventually of the target type.
-            entityViewBuilder.BuildEntityViewAndAddToList(ref entityViewsList, entityID, implementors);
+            entityViewBuilder.BuildEntityViewAndAddToList(ref safeDictionary, entityID, implementors);
 
             if (entityViewsPoolWillBeCreated)
-                entityViewsByType.Add(entityViewType, entityViewsList);
+                entityViewsByType.Add(entityViewType, safeDictionary);
         }
+        
+        static readonly EntityViewBuilder<EntityInfoView> _viewBuilder = new EntityViewBuilder<EntityInfoView>();
+        static readonly Type                              _viewType = typeof(EntityInfoView);
     }
 }

Svelto.ECS/EntityViewBuilder.cs

@@ -8,29 +8,48 @@ namespace Svelto.ECS
 {
     public class EntityViewBuilder<EntityViewType> : IEntityViewBuilder where EntityViewType : IEntityData, new()
     {
-        public void BuildEntityViewAndAddToList(ref ITypeSafeList list, EGID entityID, object[] implementors)
+        public EntityViewBuilder(ref EntityViewType initializer)
+        {
+            _initializer = initializer;
+        }
+        
+        public EntityViewBuilder()
+        {}
+        
+        public void BuildEntityViewAndAddToList(ref ITypeSafeDictionary list, EGID entityID, object[] implementors)
         {
             if (list == null)
-                list = new TypeSafeFasterListForECSForClasses<EntityViewType>();
-
-            var castedList = list as TypeSafeFasterListForECSForClasses<EntityViewType>;
+                list = new TypeSafeDictionary<EntityViewType>();
 
-            var lentityView = EntityView<EntityViewType>.BuildEntityView(entityID);
+            var castedList = list as TypeSafeDictionary<EntityViewType>;
 
-            castedList.Add(lentityView);
+            if (implementors != null)
+            {
+                EntityViewType lentityView; 
+                    
+                EntityView<EntityViewType>.BuildEntityView(entityID, out lentityView);
 
-            var entityView = lentityView;
-
-            this.FillEntityView(ref entityView
-                                             , entityViewBlazingFastReflection
-                                               , implementors
-                                               , DESCRIPTOR_NAME);
+                this.FillEntityView(ref lentityView
+                                  , entityViewBlazingFastReflection
+                                  , implementors
+                                  , DESCRIPTOR_NAME);
+                
+                castedList.Add(entityID.GID, ref lentityView);
+            }
+            else
+            {
+                DBC.Check.Require(_initializer != null, "Implementors not found on a EntityView instance");
+                   
+                _initializer.ID = entityID;
+                
+                castedList.Add(entityID.GID, ref _initializer);
+            }
         }
 
-        public ITypeSafeList Preallocate(ref ITypeSafeList list, int size)
+        public ITypeSafeDictionary Preallocate(ref ITypeSafeDictionary list, int size)
         {
             if (list == null)
-                list = new TypeSafeFasterListForECSForClasses<EntityViewType>(size);
+                list = new TypeSafeDictionary<EntityViewType>(size);
             else
                 list.AddCapacity(size);
 
@@ -42,24 +61,22 @@ namespace Svelto.ECS
             return ENTITY_VIEW_TYPE;
         }
 
-        public void MoveEntityView(EGID entityID, ITypeSafeList fromSafeList, ITypeSafeList toSafeList)
+        public void MoveEntityView(EGID entityID, ITypeSafeDictionary fromSafeList, ITypeSafeDictionary toSafeList)
         {
-            var fromCastedList = fromSafeList as TypeSafeFasterListForECSForClasses<EntityViewType>;
-            var toCastedList = toSafeList as TypeSafeFasterListForECSForClasses<EntityViewType>;
+            var fromCastedList = fromSafeList as TypeSafeDictionary<EntityViewType>;
+            var toCastedList = toSafeList as TypeSafeDictionary<EntityViewType>;
 
-            toCastedList.Add(fromCastedList[fromCastedList.GetIndexFromID(entityID)]);
-        }
-
-        public bool isQueryiableEntityView
-        {
-            get { return true; }
+            toCastedList.Add(entityID.GID, fromCastedList[entityID.GID]);
+            fromCastedList.Remove(entityID.GID);
         }
 
         FasterList<KeyValuePair<Type, CastedAction<EntityViewType>>> entityViewBlazingFastReflection
         {
-            get { return EntityView<EntityViewType>.FieldCache<EntityViewType>.list; }
+            get { return EntityView<EntityViewType>.FieldCache.list; }
         }
-
+        
+        internal EntityViewType _initializer;
+        
         static readonly Type ENTITY_VIEW_TYPE = typeof(EntityViewType);
         static string DESCRIPTOR_NAME = ENTITY_VIEW_TYPE.ToString();
     }

Svelto.ECS/EntityViewStructBuilder.cs

@@ -1,56 +0,0 @@
-using System;
-using Svelto.ECS.Internal;
-
-namespace Svelto.ECS
-{
-    public class EntityViewStructBuilder<EntityViewType> : IEntityViewBuilder where EntityViewType : struct, IEntityData
-    {
-        public EntityViewStructBuilder(ref EntityViewType initializer)
-        {
-            _initializer = initializer;
-        }
-        
-        public void BuildEntityViewAndAddToList(ref ITypeSafeList list, EGID entityID, object[] implementors = null)
-        {
-            _initializer.ID = entityID;
-            
-            if (list == null)
-                list = new TypeSafeFasterListForECSForStructs<EntityViewType>();
-
-            var castedList = list as TypeSafeFasterListForECSForStructs<EntityViewType>;
-            
-            castedList.Add(_initializer);
-        }
-
-        public ITypeSafeList Preallocate(ref ITypeSafeList list, int size)
-        {
-            if (list == null)
-                list = new TypeSafeFasterListForECSForStructs<EntityViewType>(size);
-            else
-                list.AddCapacity(size);
-
-            return list;
-        }
-
-        public Type GetEntityViewType()
-        {
-            return ENTITY_VIEW_TYPE;
-        }
-
-        public void MoveEntityView(EGID entityID, ITypeSafeList fromSafeList, ITypeSafeList toSafeList)
-        {
-            var fromCastedList = fromSafeList as TypeSafeFasterListForECSForStructs<EntityViewType>;
-            var toCastedList = toSafeList as TypeSafeFasterListForECSForStructs<EntityViewType>;
-
-            toCastedList.Add(fromCastedList[fromCastedList.GetIndexFromID(entityID)]);
-        }
-
-        public bool isQueryiableEntityView
-        {
-            get { return false; }
-        }
-
-        static readonly Type ENTITY_VIEW_TYPE = typeof(EntityViewType);
-        EntityViewType _initializer;
-   }    
-}

Svelto.ECS/FillEntityView.cs → Svelto.ECS/EntityViewUtility.cs

@@ -5,13 +5,13 @@ using Svelto.ECS;
 using Svelto.Utilities;
 using Console = Utility.Console;
 
-static class FillEntityViewASD
+static class EntityViewUtility
 {
-    public static void FillEntityView<T>(this IEntityViewBuilder entityViewBuilder, 
-                                         ref T entityView, 
-                                         FasterList<KeyValuePair<Type, CastedAction<T>>> entityViewBlazingFastReflection , 
-                                         object[]           implementors
-                                         , string             entityDescriptorName)
+    public static void FillEntityView<T>(this IEntityViewBuilder entityViewBuilder
+                                       , ref T entityView
+                                       , FasterList<KeyValuePair<Type, CastedAction<T>>> entityViewBlazingFastReflection 
+                                       , object[] implementors
+                                       , string entityDescriptorName)
     {
         int count;
 
@@ -19,9 +19,10 @@ static class FillEntityViewASD
         var setters =
             FasterList<KeyValuePair<Type, CastedAction<T>>>
                .NoVirt.ToArrayFast(entityViewBlazingFastReflection, out count);
-
-        if (count == 0) return;
-
+#if DEBUG && !PROFILER
+        if (count == 0) 
+            throw new Exception(NO_COMPONENTS_EXCEPTION.FastConcat("Type ", entityDescriptorName, " entityView ", entityViewBuilder.GetEntityViewType().ToString()));
+#endif
         for (var index = 0; index < implementors.Length; index++)
         {
             var implementor = implementors[index];
@@ -45,7 +46,7 @@ static class FillEntityViewASD
                     else
                         implementorsByType[componentType] = new Tuple<object, int>(implementor, 1);
 #else
-                        implementorsByType[componentType] = implementor;
+                    implementorsByType[componentType] = implementor;
 #endif
                 }
             }
@@ -65,7 +66,7 @@ static class FillEntityViewASD
 #if DEBUG && !PROFILER
             Tuple<object, int> component;
 #else
-                    object component;
+            object component;
 #endif
 
             if (implementorsByType.TryGetValue(fieldType, out component) == false)
@@ -88,7 +89,7 @@ static class FillEntityViewASD
 #if DEBUG && !PROFILER
             fieldSetter.Value.Call(ref entityView, component.implementorType);
 #else
-                fieldSetter.Value.Call(entityView, component);
+            fieldSetter.Value.Call(ref entityView, component);
 #endif
         }
 
@@ -118,7 +119,9 @@ static class FillEntityViewASD
     }
 #endif
     static readonly Dictionary<Type, Type[]> _cachedTypes = new Dictionary<Type, Type[]>();
-        
+    const string NO_COMPONENTS_EXCEPTION =
+        "<color=orange>Svelto.ECS</color> An entity view without component interfaces has been found, if you are using an entity view struct or an entity struct, do not pass implementors";
+
     const string DUPLICATE_IMPLEMENTOR_ERROR =
         "<color=orange>Svelto.ECS</color> the same component is implemented with more than one implementor. This is considered an error and MUST be fixed. ";
 

Svelto.ECS/EntityViewsDB.cs

@@ -6,70 +6,54 @@ namespace Svelto.ECS.Internal
 {
     class EntityViewsDB : IEntityViewsDB
     {
-        internal EntityViewsDB(  Dictionary<Type, ITypeSafeDictionary> entityViewsDBdic,
-                                Dictionary<int, Dictionary<Type, ITypeSafeList>>  groupEntityViewsDB)
+        internal EntityViewsDB(Dictionary<int, Dictionary<Type, ITypeSafeDictionary>>  groupEntityViewsDB)
         {
-            _groupedEntityViewsDBDic = entityViewsDBdic;
             _groupEntityViewsDB = groupEntityViewsDB;
         }
 
-        public FasterReadOnlyList<T> QueryEntityViews<T>() where T:IEntityData
+        public ReadOnlyCollectionStruct<T> QueryEntityViews<T>() where T:IEntityData
         {
-            var type = typeof(T);
-
-            ITypeSafeList entityViews;
-
-            if (_groupEntityViewsDB[ExclusiveGroups.StandardEntity].TryGetValue(type, out entityViews) == false)
-                return RetrieveEmptyEntityViewList<T>();
-
-            return new FasterReadOnlyList<T>((FasterList<T>)entityViews);
+            return QueryEntityViews<T>(ExclusiveGroups.StandardEntity);
         }
 
-        public FasterReadOnlyList<T> QueryGroupedEntityViews<T>(int @group) where T:IEntityData
+        public ReadOnlyCollectionStruct<T> QueryEntityViews<T>(int @group) where T:IEntityData
         {
-            Dictionary<Type, ITypeSafeList> entitiesInGroupPerType;
+            Dictionary<Type, ITypeSafeDictionary> entitiesInGroupPerType;
 
             if (_groupEntityViewsDB.TryGetValue(group, out entitiesInGroupPerType) == false)
                 return RetrieveEmptyEntityViewList<T>();
 
-            ITypeSafeList outList;
+            ITypeSafeDictionary outList;
             if (entitiesInGroupPerType.TryGetValue(typeof(T), out outList) == false)
                 return RetrieveEmptyEntityViewList<T>();
-            
-            return new FasterReadOnlyList<T>((FasterList<T>) outList);
+
+            return (outList as TypeSafeDictionary<T>).FasterValues;
         }
 
-        public T[] QueryEntityViewsAsArray<T>(out int count) where T : IEntityData
+        public T[] QueryEntityViewsCacheFriendly<T>(out int count) where T : IEntityData
         {
-            var type = typeof(T);
-            count = 0;
-            
-            ITypeSafeList entityViews;
-
-            if (_groupEntityViewsDB[ExclusiveGroups.StandardEntity].TryGetValue(type, out entityViews) == false)
-                return RetrieveEmptyEntityViewArray<T>();
-            
-            return FasterList<T>.NoVirt.ToArrayFast((FasterList<T>)entityViews, out count);
+            return QueryEntityViewsCacheFriendly<T>(ExclusiveGroups.StandardEntity, out count);
         }
         
-        public T[] QueryGroupedEntityViewsAsArray<T>(int @group, out int count) where T : IEntityData
+        public T[] QueryEntityViewsCacheFriendly<T>(int @group, out int count) where T : IEntityData
         {
             var type = typeof(T);
             count = 0;
             
-            Dictionary<Type, ITypeSafeList> entitiesInGroupPerType;
+            Dictionary<Type, ITypeSafeDictionary> entitiesInGroupPerType;
             
             if (_groupEntityViewsDB.TryGetValue(group, out entitiesInGroupPerType) == false)
                 return RetrieveEmptyEntityViewArray<T>();
             
-            ITypeSafeList outList;
+            ITypeSafeDictionary outList;
             if (entitiesInGroupPerType.TryGetValue(typeof(T), out outList) == false)
                 return RetrieveEmptyEntityViewArray<T>();
-                       
-            return FasterList<T>.NoVirt.ToArrayFast((FasterList<T>)entitiesInGroupPerType[type], out count);
+
+            var typeSafeDictionary = entitiesInGroupPerType[type];
+            return ((TypeSafeDictionary<T>) typeSafeDictionary).GetFasterValuesBuffer(out count);
         }
 
-        public T QueryEntityView<T>(EGID entityGID) where T : IEntityData
+        public T QueryEntityView<T>(EGID entityGID) where T : class, IEntityData
         {
             T entityView;
 
@@ -88,11 +72,17 @@ namespace Svelto.ECS.Internal
             var type = typeof(T);
 
             T internalEntityView;
-
             ITypeSafeDictionary entityViews;
+            
+            Dictionary<Type, ITypeSafeDictionary> entitiesInGroupPerType;
+            if (_groupEntityViewsDB.TryGetValue(entityGID.groupID, out entitiesInGroupPerType) == false)
+            {
+                entityView = default(T);
+                return false;
+            }
 
-            _groupedEntityViewsDBDic.TryGetValue(type, out entityViews);
-            var casted = entityViews as TypeSafeDictionaryForClass<T>;
+            entitiesInGroupPerType.TryGetValue(type, out entityViews);
+            var casted = entityViews as TypeSafeDictionary<T>;
 
             if (casted != null &&
                 casted.TryGetValue(entityGID.GID, out internalEntityView))
@@ -107,21 +97,17 @@ namespace Svelto.ECS.Internal
             return false;
         }
 
-        static FasterReadOnlyList<T> RetrieveEmptyEntityViewList<T>()
+        static ReadOnlyCollectionStruct<T> RetrieveEmptyEntityViewList<T>()
         {
-            return FasterReadOnlyList<T>.DefaultList;
+            return ReadOnlyCollectionStruct<T>.DefaultList;
         }
 
         static T[] RetrieveEmptyEntityViewArray<T>()
         {
             return FasterList<T>.DefaultList.ToArrayFast();
         }
-        
      
         //grouped set of entity views, this is the standard way to handle entity views
-        readonly Dictionary<int, Dictionary<Type, ITypeSafeList>> _groupEntityViewsDB;
-        //indexable entity views when the entity ID is known. Usually useful to handle
-        //event based logic.
-        readonly Dictionary<Type, ITypeSafeDictionary> _groupedEntityViewsDBDic;
+        readonly Dictionary<int, Dictionary<Type, ITypeSafeDictionary>> _groupEntityViewsDB;
     }
 }

Svelto.ECS/ExclusiveGroups.cs

@@ -2,6 +2,6 @@
 {
     static class ExclusiveGroups
     {
-        internal const int StandardEntity = 0xFF;
+        internal const int StandardEntity = int.MaxValue;
     }
 }

Svelto.ECS/IEngine.cs

@@ -4,11 +4,6 @@ namespace Svelto.ECS.Internal
 {
     public interface IHandleEntityViewEngineAbstracted : IEngine
     {}
-    
-    public interface IHandleEntityViewEngine : IHandleEntityViewEngineAbstracted
-    {
-        void Remove(IEntityData entityView);
-    }
 }
 
 namespace Svelto.ECS
@@ -19,5 +14,6 @@ namespace Svelto.ECS
     public interface IHandleEntityStructEngine<T> : IHandleEntityViewEngineAbstracted
     {
         void Add(ref T entityView);
+        void Remove(ref T entityView);
     }
 }

Svelto.ECS/IEntityView.cs

@@ -22,36 +22,43 @@ namespace Svelto.ECS
 
         EGID _ID;
     }
-    
-    static class EntityView<T> where T: IEntityData, new()
+
+    public struct EntityInfoView : IEntityData
     {
-        internal static T BuildEntityView(EGID ID) 
+        public EGID ID { get; set; }
+        
+        public IEntityViewBuilder[] entityViewsToBuild;
+    }
+
+    public static class EntityView<T> where T: IEntityData, new()
+    {
+        internal static void BuildEntityView(EGID ID, out T entityView) 
         {
-            if (FieldCache<T>.list.Count == 0)
+            if (FieldCache.list == null)
             {
+                FieldCache.list = new FasterList<KeyValuePair<Type, CastedAction<T>>>();
+                
                 var type = typeof(T);
 
                 var fields = type.GetFields(BindingFlags.Public |
                                             BindingFlags.Instance);
-
+    
                 for (int i = fields.Length - 1; i >= 0; --i)
                 {
                     var field = fields[i];
 
                     CastedAction<T> setter = FastInvoke<T>.MakeSetter(field);
                     
-                    FieldCache<T>.list.Add(new KeyValuePair<Type, CastedAction<T>>(field.FieldType, setter));
+                    FieldCache.list.Add(new KeyValuePair<Type, CastedAction<T>>(field.FieldType, setter));
                 }
             }
 
-            return new T { ID = ID };
+            entityView = new T { ID = ID };
         }
 
-        //check if I can remove W
-        internal static class FieldCache<W>
+        public static class FieldCache
         {
-            internal static readonly FasterList<KeyValuePair<Type, CastedAction<T>>> list
-                = new FasterList<KeyValuePair<Type, CastedAction<T>>>();
+            public static FasterList<KeyValuePair<Type, CastedAction<T>>> list;
         }
     }
 }

Svelto.ECS/IEntityViewBuilder.cs

@@ -5,12 +5,10 @@ namespace Svelto.ECS
 {
     public interface IEntityViewBuilder
     {
-        void          BuildEntityViewAndAddToList(ref ITypeSafeList list, EGID entityID, object[] implementors);
-        ITypeSafeList Preallocate(ref                 ITypeSafeList list, int  size);
+        void BuildEntityViewAndAddToList(ref ITypeSafeDictionary list, EGID entityID, object[] implementors);
+        ITypeSafeDictionary Preallocate(ref ITypeSafeDictionary list, int size);
 
         Type GetEntityViewType();
-        void MoveEntityView(EGID entityID, ITypeSafeList fromSafeList, ITypeSafeList toSafeList);
-
-        bool isQueryiableEntityView { get; }
+        void MoveEntityView(EGID entityID, ITypeSafeDictionary fromSafeList, ITypeSafeDictionary toSafeList);
     }
 }

Svelto.ECS/IEntityViewsDB.cs

@@ -4,13 +4,13 @@ namespace Svelto.ECS
 {
     public interface IEntityViewsDB
     {
-        FasterReadOnlyList<T> QueryEntityViews<T>() where T : IEntityData;
-        FasterReadOnlyList<T> QueryGroupedEntityViews<T>(int group) where T : IEntityData;
+        ReadOnlyCollectionStruct<T> QueryEntityViews<T>() where T : IEntityData;
+        ReadOnlyCollectionStruct<T> QueryEntityViews<T>(int group) where T : IEntityData;
 
-        T[] QueryEntityViewsAsArray<T>(out int    count) where T : IEntityData;
-        T[] QueryGroupedEntityViewsAsArray<T>(int group, out int count) where T : IEntityData;
+        T[] QueryEntityViewsCacheFriendly<T>(out int    count) where T : IEntityData;
+        T[] QueryEntityViewsCacheFriendly<T>(int group, out int count) where T : IEntityData;
 
         bool TryQueryEntityView<T>(EGID ID, out T entityView) where T : IEntityData;
-        T    QueryEntityView<T>(EGID entityGID) where T : IEntityData;
+        T    QueryEntityView<T>(EGID entityGID) where T : class, IEntityData;
     }
 }

Svelto.ECS/MixedEntityDescriptor.cs

@@ -1,107 +0,0 @@
-namespace Svelto.ECS
-{
-    public abstract class MixedEntityDescriptor<T>:IEntityDescriptor where T : class, IEntityViewBuilder, new()
-    {
-        static MixedEntityDescriptor()
-        {
-            _entityViewsToBuild = new IEntityViewBuilder[] {new T()};
-        }
-        
-        public IEntityViewBuilder[] entityViewsToBuild
-        {
-            get { return _entityViewsToBuild; }
-        }
-        
-        static readonly IEntityViewBuilder[] _entityViewsToBuild;
-    }
-
-    public abstract class MixedEntityDescriptor<T, U> : IEntityDescriptor where T : class, IEntityViewBuilder, new() 
-                                                                       where U : class, IEntityViewBuilder, new()
-    {
-        static MixedEntityDescriptor()
-        {
-            _entityViewsToBuild = new IEntityViewBuilder[] {new T(), new U()};
-        }
-
-        public IEntityViewBuilder[] entityViewsToBuild
-        {
-            get { return _entityViewsToBuild; }
-        }
-        
-        static readonly IEntityViewBuilder[] _entityViewsToBuild;
-    }
-
-    public abstract class MixedEntityDescriptor<T, U, V> : IEntityDescriptor where T : class, IEntityViewBuilder, new()
-                                                                          where U : class, IEntityViewBuilder, new()
-                                                                          where V : class, IEntityViewBuilder, new()
-    {
-        static MixedEntityDescriptor()
-        {
-            _entityViewsToBuild = new IEntityViewBuilder[] {new T(), new U(), new V()};
-        }
-
-        public IEntityViewBuilder[] entityViewsToBuild
-        {
-            get { return _entityViewsToBuild; }
-        }
-        
-        static readonly IEntityViewBuilder[] _entityViewsToBuild;
-    }
-
-    public abstract class MixedEntityDescriptor<T, U, V, W> : IEntityDescriptor where T : class, IEntityViewBuilder, new()
-                                                                             where U : class, IEntityViewBuilder, new()
-                                                                             where V : class, IEntityViewBuilder, new()
-                                                                             where W : class, IEntityViewBuilder, new()
-    {
-        static MixedEntityDescriptor()
-        {
-            _entityViewsToBuild = new IEntityViewBuilder[] {new T(), new U(), new V(), new W()};
-        }
-
-        public IEntityViewBuilder[] entityViewsToBuild
-        {
-            get { return _entityViewsToBuild; }
-        }
-        
-        static readonly IEntityViewBuilder[] _entityViewsToBuild;
-    }
-
-    public abstract class MixedEntityDescriptor<T, U, V, W, X> : IEntityDescriptor where T : class, IEntityViewBuilder, new()
-                                                                                where U : class, IEntityViewBuilder, new()
-                                                                                where V : class, IEntityViewBuilder, new()
-                                                                                where W : class, IEntityViewBuilder, new()
-                                                                                where X : class, IEntityViewBuilder, new()
-    {
-        static MixedEntityDescriptor()
-        {
-            _entityViewsToBuild = new IEntityViewBuilder[] {new T(), new U(), new V(), new W(), new X()};
-        }
-
-        public IEntityViewBuilder[] entityViewsToBuild
-        {
-            get { return _entityViewsToBuild; }
-        }
-        
-        static readonly IEntityViewBuilder[] _entityViewsToBuild;
-    }
-
-    public abstract class MixedEntityDescriptor<T, U, V, W, X, Y> : IEntityDescriptor where T : class, IEntityViewBuilder, new()
-                                                                                   where U : class, IEntityViewBuilder, new()
-                                                                                   where V : class, IEntityViewBuilder, new()
-                                                                                   where W : class, IEntityViewBuilder, new()
-                                                                                   where X : class, IEntityViewBuilder, new()
-                                                                                   where Y : class, IEntityViewBuilder, new()
-    {
-        static MixedEntityDescriptor()
-        {
-            _entityViewsToBuild = new IEntityViewBuilder[] {new T(), new U(), new V(), new W(), new X(), new Y()};
-        }
-
-        public IEntityViewBuilder[] entityViewsToBuild
-        {
-            get { return _entityViewsToBuild; }
-        }       
-        
-        static readonly IEntityViewBuilder[] _entityViewsToBuild;
-    }
-}

Svelto.ECS/MultiEntityViewsEngine.cs

@@ -1,65 +1,17 @@
-using Svelto.ECS.Internal;
-
-namespace Svelto.ECS.Internal
-{
-    public abstract class MultiEntityViewsEngine<T>:IHandleEntityStructEngine<T>, 
-                                                    IHandleEntityViewEngine where T:IEntityData
-    {
-        public void Add(ref T entityView)
-        {
-            Add(entityView);
-        }
-
-        public virtual void Remove(IEntityData entityView)
-        {
-            Remove((T) entityView);
-        }
-
-        protected abstract void Add(T entityView);
-        protected abstract void Remove(T entityView);
-    }
-}
-
 namespace Svelto.ECS
 {
-    public abstract class MultiEntityViewsEngine<T, U> : MultiEntityViewsEngine<T>, IHandleEntityStructEngine<U>
+    public abstract class MultiEntityViewsEngine<T, U> : SingleEntityViewEngine<T>, IHandleEntityStructEngine<U>
         where U : IEntityData where T : IEntityData
     {
-        protected abstract void Add(U    entityView);
-        protected abstract void Remove(U entityView);
-
-        public override void Remove(IEntityData entityView)
-        {
-            if (entityView is U)
-                Remove((U) entityView);
-            else
-                base.Remove(entityView);
-        }
-
-        public void Add(ref U entityView)
-        {
-            Add(entityView);
-        }
+        public abstract void Add(ref    U entityView);
+        public abstract void Remove(ref U entityView);
     }
 
     public abstract class MultiEntityViewsEngine<T, U, V> : MultiEntityViewsEngine<T, U>, IHandleEntityStructEngine<V>
         where V :  IEntityData where U :  IEntityData where T :  IEntityData
     {
-        protected abstract void Add(V    entityView);
-        protected abstract void Remove(V entityView);
-
-        public override void Remove(IEntityData entityView)
-        {
-            if (entityView is V)
-                Remove((V) entityView);
-            else
-                base.Remove(entityView);
-        }
-
-        public void Add(ref V entityView)
-        {
-            Add(entityView);
-        }
+        public abstract void Add(ref    V entityView);
+        public abstract void Remove(ref V entityView);
     }
 
     /// <summary>
@@ -70,20 +22,7 @@ namespace Svelto.ECS
     public abstract class MultiEntityViewsEngine<T, U, V, W> : MultiEntityViewsEngine<T, U, V>, IHandleEntityStructEngine<W>
         where W :  IEntityData where V :  IEntityData where U :  IEntityData where T : IEntityData
     {
-        protected abstract void Add(W    entityView);
-        protected abstract void Remove(W entityView);
-
-        public override void Remove(IEntityData entityView)
-        {
-            if (entityView is W)
-                Remove((W) entityView);
-            else
-                base.Remove(entityView);
-        }
-
-        public void Add(ref W entityView)
-        {
-            Add(entityView);
-        }
+        public abstract void Add(ref    W entityView);
+        public abstract void Remove(ref W entityView);
     }
 }

Svelto.ECS/Profiler/EngineProfiler.cs

@@ -12,7 +12,7 @@ namespace Svelto.ECS.Profiler
     {
         static readonly Stopwatch _stopwatch = new Stopwatch();
 
-        public static void MonitorAddDuration<T>(IHandleEntityViewEngineAbstracted engine, T entityView)
+        public static void MonitorAddDuration<T>(IHandleEntityViewEngineAbstracted engine, ref T entityView)
         {
             EngineInfo info;
             if (engineInfos.TryGetValue(engine.GetType(), out info))
@@ -25,13 +25,13 @@ namespace Svelto.ECS.Profiler
             }
         }
 
-        public static void MonitorRemoveDuration<T>(IHandleEntityViewEngineAbstracted engine, IEntityData entityView)
+        public static void MonitorRemoveDuration<T>(IHandleEntityViewEngineAbstracted engine, ref T entityView)
         {
             EngineInfo info;
             if (engineInfos.TryGetValue(engine.GetType(), out info))
             {
                 _stopwatch.Start();
-                (engine as IHandleEntityViewEngine).Remove(entityView);
+                (engine as IHandleEntityStructEngine<T>).Remove(ref entityView);
                 _stopwatch.Stop();
 
                 info.AddRemoveDuration(_stopwatch.Elapsed.TotalMilliseconds);

Svelto.ECS/SingleEntityViewEngine.cs

@@ -1,20 +1,8 @@
-using Svelto.ECS.Internal;
-
 namespace Svelto.ECS
 {
-    public abstract class SingleEntityViewEngine<T> : IHandleEntityViewEngine where T : class, IEntityData
+    public abstract class SingleEntityViewEngine<T> : IHandleEntityStructEngine<T> where T : IEntityData
     {
-        public void Add(IEntityData entityView)
-        {
-            Add((T) entityView);
-        }
-
-        public void Remove(IEntityData entityView)
-        {
-            Remove((T) entityView);
-        }
-
-        protected abstract void Add(T    entityView);
-        protected abstract void Remove(T entityView);
+        public abstract void Add(ref T    entityView);
+        public abstract void Remove(ref T entityView);
     }
 }