Optimize GetOrphans and remove wrong checks from IsNotTransientSlow

src/NHibernate/Async/Collection/AbstractPersistentCollection.cs

@@ -12,6 +12,9 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Data.Common;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
 using NHibernate.Collection.Generic;
 using NHibernate.Engine;
 using NHibernate.Impl;
@@ -22,8 +25,6 @@
 
 namespace NHibernate.Collection
 {
-	using System.Threading.Tasks;
-	using System.Threading;
 	public abstract partial class AbstractPersistentCollection : IPersistentCollection, ILazyInitializedCollection
 	{
 
@@ -91,42 +92,7 @@ public virtual Task ForceInitializationAsync(CancellationToken cancellationToken
 			}
 			return Task.CompletedTask;
 		}
-
-		public Task<ICollection> GetQueuedOrphansAsync(string entityName, CancellationToken cancellationToken)
-		{
-			if (cancellationToken.IsCancellationRequested)
-			{
-				return Task.FromCanceled<ICollection>(cancellationToken);
-			}
-			try
-			{
-				if (HasQueuedOperations)
-				{
-					List<object> additions = new List<object>(operationQueue.Count);
-					List<object> removals = new List<object>(operationQueue.Count);
-					for (int i = 0; i < operationQueue.Count; i++)
-					{
-						IDelayedOperation op = operationQueue[i];
-						if (op.AddedInstance != null)
-						{
-							additions.Add(op.AddedInstance);
-						}
-						if (op.Orphan != null)
-						{
-							removals.Add(op.Orphan);
-						}
-					}
-					return GetOrphansAsync(removals, additions, entityName, session, cancellationToken);
-				}
-
-				return Task.FromResult<ICollection>(CollectionHelper.EmptyCollection);
-			}
-			catch (Exception ex)
-			{
-				return Task.FromException<ICollection>(ex);
-			}
-		}
-
+
 		/// <summary>
 		/// Called before inserting rows, to ensure that any surrogate keys are fully generated
 		/// </summary>
@@ -149,85 +115,12 @@ public virtual Task PreInsertAsync(ICollectionPersister persister, CancellationT
 			}
 		}
 
-		/// <summary>
-		/// Get all "orphaned" elements
-		/// </summary>
-		public abstract Task<ICollection> GetOrphansAsync(object snapshot, string entityName, CancellationToken cancellationToken);
-
-		/// <summary> 
-		/// Given a collection of entity instances that used to
-		/// belong to the collection, and a collection of instances
-		/// that currently belong, return a collection of orphans
-		/// </summary>
-		protected virtual async Task<ICollection> GetOrphansAsync(ICollection oldElements, ICollection currentElements, string entityName, ISessionImplementor session, CancellationToken cancellationToken)
-		{
-			cancellationToken.ThrowIfCancellationRequested();
-			// short-circuit(s)
-			if (currentElements.Count == 0)
-			{
-				// no new elements, the old list contains only Orphans
-				return oldElements;
-			}
-			if (oldElements.Count == 0)
-			{
-				// no old elements, so no Orphans neither
-				return oldElements;
-			}
-
-			IType idType = session.Factory.GetEntityPersister(entityName).IdentifierType;
-
-			// create the collection holding the orphans
-			List<object> res = new List<object>();
-
-			// collect EntityIdentifier(s) of the *current* elements - add them into a HashSet for fast access
-			var currentIds = new HashSet<TypedValue>();
-			foreach (object current in currentElements)
-			{
-				if (current != null && await (ForeignKeys.IsNotTransientSlowAsync(entityName, current, session, cancellationToken)).ConfigureAwait(false))
-				{
-					object currentId = await (ForeignKeys.GetEntityIdentifierIfNotUnsavedAsync(entityName, current, session, cancellationToken)).ConfigureAwait(false);
-					currentIds.Add(new TypedValue(idType, currentId, false));
-				}
-			}
-
-			// iterate over the *old* list
-			foreach (object old in oldElements)
-			{
-				object oldId = await (ForeignKeys.GetEntityIdentifierIfNotUnsavedAsync(entityName, old, session, cancellationToken)).ConfigureAwait(false);
-				if (!currentIds.Contains(new TypedValue(idType, oldId, false)))
-				{
-					res.Add(old);
-				}
-			}
-
-			return res;
-		}
-
 		public async Task IdentityRemoveAsync(IList list, object obj, string entityName, ISessionImplementor session, CancellationToken cancellationToken)
 		{
 			cancellationToken.ThrowIfCancellationRequested();
 			if (obj != null && await (ForeignKeys.IsNotTransientSlowAsync(entityName, obj, session, cancellationToken)).ConfigureAwait(false))
 			{
-				IType idType = session.Factory.GetEntityPersister(entityName).IdentifierType;
-
-				object idOfCurrent = await (ForeignKeys.GetEntityIdentifierIfNotUnsavedAsync(entityName, obj, session, cancellationToken)).ConfigureAwait(false);
-				List<object> toRemove = new List<object>(list.Count);
-				foreach (object current in list)
-				{
-					if (current == null)
-					{
-						continue;
-					}
-					object idOfOld = await (ForeignKeys.GetEntityIdentifierIfNotUnsavedAsync(entityName, current, session, cancellationToken)).ConfigureAwait(false);
-					if (idType.IsEqual(idOfCurrent, idOfOld, session.Factory))
-					{
-						toRemove.Add(current);
-					}
-				}
-				foreach (object ro in toRemove)
-				{
-					list.Remove(ro);
-				}
+				IdentityRemove(list, obj, entityName, session.Factory);
 			}
 		}
 

src/NHibernate/Async/Collection/Generic/PersistentGenericBag.cs

@@ -75,7 +75,9 @@ public override Task<IEnumerable> GetDeletesAsync(ICollectionPersister persister
 				return Task.FromException<IEnumerable>(ex);
 			}
 		}
-
+
+		// Since 5.3
+		[Obsolete("This method has no more usages and will be removed in a future version")]
 		public override Task<ICollection> GetOrphansAsync(object snapshot, string entityName, CancellationToken cancellationToken)
 		{
 			if (cancellationToken.IsCancellationRequested)
@@ -84,8 +86,7 @@ public override Task<ICollection> GetOrphansAsync(object snapshot, string entity
 			}
 			try
 			{
-				var sn = (ICollection) snapshot;
-				return GetOrphansAsync(sn, (ICollection) _gbag, entityName, Session, cancellationToken);
+				return Task.FromResult<ICollection>(GetOrphans(snapshot, entityName));
 			}
 			catch (Exception ex)
 			{

src/NHibernate/Async/Collection/Generic/PersistentGenericIdentifierBag.cs

@@ -155,7 +155,9 @@ public override async Task<object> ReadFromAsync(DbDataReader reader, ICollectio
 			}
 			return element;
 		}
-
+
+		// Since 5.3
+		[Obsolete("This method has no more usages and will be removed in a future version")]
 		public override Task<ICollection> GetOrphansAsync(object snapshot, string entityName, CancellationToken cancellationToken)
 		{
 			if (cancellationToken.IsCancellationRequested)
@@ -164,8 +166,7 @@ public override Task<ICollection> GetOrphansAsync(object snapshot, string entity
 			}
 			try
 			{
-				var sn = (ISet<SnapshotElement>)GetSnapshot();
-				return GetOrphansAsync(sn.ToArray(x => x.Value), (ICollection) _values, entityName, Session, cancellationToken);
+				return Task.FromResult<ICollection>(GetOrphans(snapshot, entityName));
 			}
 			catch (Exception ex)
 			{

src/NHibernate/Async/Collection/Generic/PersistentGenericList.cs

@@ -29,7 +29,9 @@ namespace NHibernate.Collection.Generic
 	using System.Threading;
 	public partial class PersistentGenericList<T> : AbstractPersistentCollection, IList<T>, IList, IQueryable<T>
 	{
-
+
+		// Since 5.3
+		[Obsolete("This method has no more usages and will be removed in a future version")]
 		public override Task<ICollection> GetOrphansAsync(object snapshot, string entityName, CancellationToken cancellationToken)
 		{
 			if (cancellationToken.IsCancellationRequested)
@@ -38,8 +40,7 @@ public override Task<ICollection> GetOrphansAsync(object snapshot, string entity
 			}
 			try
 			{
-				var sn = (IList<T>)snapshot;
-				return GetOrphansAsync((ICollection)sn, (ICollection) WrappedList, entityName, Session, cancellationToken);
+				return Task.FromResult<ICollection>(GetOrphans(snapshot, entityName));
 			}
 			catch (Exception ex)
 			{

src/NHibernate/Async/Collection/Generic/PersistentGenericMap.cs

@@ -29,7 +29,9 @@ namespace NHibernate.Collection.Generic
 	using System.Threading;
 	public partial class PersistentGenericMap<TKey, TValue> : AbstractPersistentCollection, IDictionary<TKey, TValue>, ICollection
 	{
-
+
+		// Since 5.3
+		[Obsolete("This method has no more usages and will be removed in a future version")]
 		public override Task<ICollection> GetOrphansAsync(object snapshot, string entityName, CancellationToken cancellationToken)
 		{
 			if (cancellationToken.IsCancellationRequested)
@@ -38,8 +40,7 @@ public override Task<ICollection> GetOrphansAsync(object snapshot, string entity
 			}
 			try
 			{
-				var sn = (IDictionary<TKey, TValue>) snapshot;
-				return GetOrphansAsync((ICollection)sn.Values, (ICollection)WrappedMap.Values, entityName, Session, cancellationToken);
+				return Task.FromResult<ICollection>(GetOrphans(snapshot, entityName));
 			}
 			catch (Exception ex)
 			{

src/NHibernate/Async/Collection/Generic/PersistentGenericSet.cs

@@ -30,7 +30,9 @@ namespace NHibernate.Collection.Generic
 	using System.Threading;
 	public partial class PersistentGenericSet<T> : AbstractPersistentCollection, ISet<T>, IQueryable<T>
 	{
-
+
+		// Since 5.3
+		[Obsolete("This method has no more usages and will be removed in a future version")]
 		public override Task<ICollection> GetOrphansAsync(object snapshot, string entityName, CancellationToken cancellationToken)
 		{
 			if (cancellationToken.IsCancellationRequested)
@@ -39,12 +41,7 @@ public override Task<ICollection> GetOrphansAsync(object snapshot, string entity
 			}
 			try
 			{
-				var sn = new SetSnapShot<T>((IEnumerable<T>)snapshot);
-
-				// TODO: Avoid duplicating shortcuts and array copy, by making base class GetOrphans() more flexible
-				if (WrappedSet.Count == 0) return Task.FromResult<ICollection>(sn);
-				if (((ICollection)sn).Count == 0) return Task.FromResult<ICollection>(sn);
-				return GetOrphansAsync(sn, WrappedSet.ToArray(), entityName, Session, cancellationToken);
+				return Task.FromResult<ICollection>(GetOrphans(snapshot, entityName));
 			}
 			catch (Exception ex)
 			{

src/NHibernate/Async/Collection/IPersistentCollection.cs

@@ -11,6 +11,8 @@
 using System;
 using System.Collections;
 using System.Data.Common;
+using System.Threading;
+using System.Threading.Tasks;
 using NHibernate.Collection.Generic;
 using NHibernate.Engine;
 using NHibernate.Loader;
@@ -19,8 +21,6 @@
 
 namespace NHibernate.Collection
 {
-	using System.Threading.Tasks;
-	using System.Threading;
 	public partial interface IPersistentCollection
 	{
 
@@ -92,27 +92,11 @@ public partial interface IPersistentCollection
 		/// </summary>
 		Task<IEnumerable> GetDeletesAsync(ICollectionPersister persister, bool indexIsFormula, CancellationToken cancellationToken);
 
-		/// <summary> Get the "queued" orphans</summary>
-		Task<ICollection> GetQueuedOrphansAsync(string entityName, CancellationToken cancellationToken);
-
 		/// <summary>
 		/// Called before inserting rows, to ensure that any surrogate keys are fully generated
 		/// </summary>
 		/// <param name="persister"></param>
 		/// <param name="cancellationToken">A cancellation token that can be used to cancel the work</param>
 		Task PreInsertAsync(ICollectionPersister persister, CancellationToken cancellationToken);
-
-		/// <summary>
-		/// Get all "orphaned" elements
-		/// </summary>
-		/// <param name="snapshot">The snapshot of the collection.</param>
-		/// <param name="entityName">The persistent class whose objects
-		/// the collection is expected to contain.</param>
-		/// <param name="cancellationToken">A cancellation token that can be used to cancel the work</param>
-		/// <returns>
-		/// An <see cref="ICollection"/> that contains all of the elements
-		/// that have been orphaned.
-		/// </returns>
-		Task<ICollection> GetOrphansAsync(object snapshot, string entityName, CancellationToken cancellationToken);
 	}
 }

src/NHibernate/Async/Collection/PersistentArrayHolder.cs

@@ -26,18 +26,23 @@ namespace NHibernate.Collection
 	using System.Threading;
 	public partial class PersistentArrayHolder : AbstractPersistentCollection, ICollection
 	{
-
-		public override async Task<ICollection> GetOrphansAsync(object snapshot, string entityName, CancellationToken cancellationToken)
+
+		// Since 5.3
+		[Obsolete("This method has no more usages and will be removed in a future version")]
+		public override Task<ICollection> GetOrphansAsync(object snapshot, string entityName, CancellationToken cancellationToken)
 		{
-			cancellationToken.ThrowIfCancellationRequested();
-			object[] sn = (object[]) snapshot;
-			object[] arr = (object[]) array;
-			List<object> result = new List<object>(sn);
-			for (int i = 0; i < sn.Length; i++)
+			if (cancellationToken.IsCancellationRequested)
 			{
-				await (IdentityRemoveAsync(result, arr[i], entityName, Session, cancellationToken)).ConfigureAwait(false);
+				return Task.FromCanceled<ICollection>(cancellationToken);
+			}
+			try
+			{
+				return Task.FromResult<ICollection>(GetOrphans(snapshot, entityName));
+			}
+			catch (Exception ex)
+			{
+				return Task.FromException<ICollection>(ex);
 			}
-			return result;
 		}
 
 		public override async Task<bool> EqualsSnapshotAsync(ICollectionPersister persister, CancellationToken cancellationToken)
@@ -147,4 +152,4 @@ public override async Task<bool> NeedsUpdatingAsync(object entry, int i, IType e
 				&& await (elemType.IsDirtyAsync(array.GetValue(i), sn.GetValue(i), Session, cancellationToken)).ConfigureAwait(false);
 		}
 	}
-}
+}

src/NHibernate/Async/Engine/Cascade.cs

@@ -285,11 +285,11 @@ private async Task DeleteOrphansAsync(string entityName, IPersistentCollection p
 			if (pc.WasInitialized)
 			{
 				CollectionEntry ce = eventSource.PersistenceContext.GetCollectionEntry(pc);
-				orphans = ce == null ? CollectionHelper.EmptyCollection : await (ce.GetOrphansAsync(entityName, pc, cancellationToken)).ConfigureAwait(false);
+				orphans = ce == null ? CollectionHelper.EmptyCollection : ce.GetOrphans(entityName, pc);
 			}
 			else
 			{
-				orphans = await (pc.GetQueuedOrphansAsync(entityName, cancellationToken)).ConfigureAwait(false);
+				orphans = pc.GetQueuedOrphans(entityName);
 			}
 
 			foreach (object orphan in orphans)

src/NHibernate/Async/Engine/CollectionEntry.cs

@@ -70,18 +70,5 @@ public async Task PreFlushAsync(IPersistentCollection collection, CancellationTo
 			reached = false;
 			processed = false;
 		}
-
-		public Task<ICollection> GetOrphansAsync(string entityName, IPersistentCollection collection, CancellationToken cancellationToken)
-		{
-			if (snapshot == null)
-			{
-				throw new AssertionFailure("no collection snapshot for orphan delete");
-			}
-			if (cancellationToken.IsCancellationRequested)
-			{
-				return Task.FromCanceled<ICollection>(cancellationToken);
-			}
-			return collection.GetOrphansAsync(snapshot, entityName, cancellationToken);
-		}
 	}
 }