Remove breaking changes

Author: hazzik

src/NHibernate.Test/NHSpecificTest/SetFixture.cs

@@ -348,8 +348,6 @@ public object NotFoundObject
 			get { throw new NotImplementedException(); }
 		}
 
-		public int BatchSize { get; } = 0;
-
 		public ISessionFactoryImplementor Factory
 		{
 			get { return null; }

src/NHibernate/Collection/AbstractPersistentCollection.cs

@@ -233,7 +233,7 @@ public virtual bool RowUpdatePossible
 		}
 
 		/// <summary></summary>
-		public virtual ISessionImplementor Session
+		protected virtual ISessionImplementor Session
 		{
 			get { return session; }
 		}
@@ -868,5 +868,13 @@ public abstract object ReadFrom(DbDataReader reader, ICollectionPersister role,
 		 */
 
 		#endregion
+
+		/// <summary>
+		/// Get the session associated with the collection.
+		/// </summary>
+		public ISessionImplementor GetCurrentSession()
+		{
+			return session;
+		}
 	}
 }

src/NHibernate/Collection/IPersistentCollection.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections;
 using System.Data.Common;
 using NHibernate.Collection.Generic;
@@ -337,4 +338,21 @@ public partial interface IPersistentCollection
 		/// </returns>
 		ICollection GetOrphans(object snapshot, string entityName);
 	}
+
+	public static class PersistentCollectionExtensions
+	{
+		/// <summary>
+		/// Get the session associated with the collection.
+		/// </summary>
+		//6.0 TODO: Merge into IPersistentCollection interface. Consider converting to a property.
+		public static ISessionImplementor GetCurrentSession(this IPersistentCollection collection)
+		{
+			if (collection is AbstractPersistentCollection apc)
+			{
+				return apc.GetCurrentSession();
+			}
+
+			throw new InvalidOperationException("Only collections of AbstractPersistentCollection are supported.");
+		}
+	}
 }

src/NHibernate/Engine/CollectionEntry.cs

@@ -302,9 +302,9 @@ public void PostInitialize(IPersistentCollection collection)
 		{
 			snapshot = LoadedPersister.IsMutable ? collection.GetSnapshot(LoadedPersister) : null;
 			collection.SetSnapshot(loadedKey, role, snapshot);
-			if (LoadedPersister.BatchSize > 1)
+			if (LoadedPersister.GetBatchSize() > 1)
 			{
-				((AbstractPersistentCollection) collection).Session.PersistenceContext.BatchFetchQueue.RemoveBatchLoadableCollection(this);
+				collection.GetCurrentSession().PersistenceContext.BatchFetchQueue.RemoveBatchLoadableCollection(this);
 			}
 		}
 

src/NHibernate/Engine/StatefulPersistenceContext.cs

@@ -835,7 +835,7 @@ public void AddUninitializedCollection(ICollectionPersister persister, IPersiste
 		{
 			CollectionEntry ce = new CollectionEntry(collection, persister, id, flushing);
 			AddCollection(collection, ce, id);
-			if (persister.BatchSize > 1)
+			if (persister.GetBatchSize() > 1)
 			{
 				batchFetchQueue.AddBatchLoadableCollection(collection, ce);
 			}

src/NHibernate/Event/Default/EvictVisitor.cs

@@ -2,6 +2,7 @@
 using NHibernate.Collection;
 using NHibernate.Engine;
 using NHibernate.Impl;
+using NHibernate.Persister.Collection;
 using NHibernate.Type;
 
 namespace NHibernate.Event.Default
@@ -53,7 +54,7 @@ private void EvictCollection(IPersistentCollection collection)
 			Session.PersistenceContext.CollectionEntries.Remove(collection);
 			if (log.IsDebugEnabled())
 				log.Debug("evicting collection: {0}", MessageHelper.CollectionInfoString(ce.LoadedPersister, collection, ce.LoadedKey, Session));
-			if (ce.LoadedPersister?.BatchSize > 1)
+			if (ce.LoadedPersister?.GetBatchSize() > 1)
 			{
 				Session.PersistenceContext.BatchFetchQueue.RemoveBatchLoadableCollection(ce);
 			}

src/NHibernate/Persister/Collection/AbstractCollectionPersister.cs

@@ -2043,9 +2043,12 @@ public string[] RootTableKeyColumnNames
 			get { return new string[] {IdentifierColumnName}; }
 		}
 
-		public int BatchSize
+		/// <summary>
+		/// Get the batch size of a collection persister.
+		/// </summary>
+		public int GetBatchSize()
 		{
-			get { return batchSize; }
+			return batchSize;
 		}
 
 		public SqlString GetSelectByUniqueKeyString(string propertyName)

src/NHibernate/Persister/Collection/BasicCollectionPersister.cs

@@ -281,7 +281,7 @@ private string ManyToManySelectFragment(IJoinable rhs, string rhsAlias, string l
 		/// </summary>
 		protected override ICollectionInitializer CreateCollectionInitializer(IDictionary<string, IFilter> enabledFilters)
 		{
-			return BatchingCollectionInitializer.CreateBatchingCollectionInitializer(this, BatchSize, Factory, enabledFilters);
+			return BatchingCollectionInitializer.CreateBatchingCollectionInitializer(this, batchSize, Factory, enabledFilters);
 		}
 
 		public override SqlString FromJoinFragment(string alias, bool innerJoin, bool includeSubclasses)
@@ -322,4 +322,4 @@ protected override SqlCommandInfo GenerateIdentityInsertRowString()
 
 		#endregion
 	}
-}
+}

src/NHibernate/Persister/Collection/ICollectionPersister.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.Data.Common;
 using NHibernate.Cache;
@@ -282,7 +283,22 @@ public partial interface ICollectionPersister
 		/// A place-holder to inform that the data-reader was empty.
 		/// </summary>
 		object NotFoundObject { get; }
+	}
+
+	public static class CollectionPersisterExtensions
+	{
+		/// <summary>
+		/// Get the batch size of a collection persister.
+		/// </summary>
+		//6.0 TODO: Merge into ICollectionPersister and convert to a property.
+		public static int GetBatchSize(this ICollectionPersister persister)
+		{
+			if (persister is AbstractCollectionPersister acp)
+			{
+				return acp.GetBatchSize();
+			}
 
-		int BatchSize { get; }
+			throw new InvalidOperationException("Only persisters of AbstractCollectionPersister are supported.");
+		}
 	}
 }

src/NHibernate/Persister/Collection/OneToManyPersister.cs

@@ -343,7 +343,7 @@ protected override SelectFragment GenerateSelectFragment(string alias, string co
 		/// </summary>
 		protected override ICollectionInitializer CreateCollectionInitializer(IDictionary<string, IFilter> enabledFilters)
 		{
-			return BatchingCollectionInitializer.CreateBatchingOneToManyInitializer(this, BatchSize, Factory, enabledFilters);
+			return BatchingCollectionInitializer.CreateBatchingOneToManyInitializer(this, batchSize, Factory, enabledFilters);
 		}
 
 		public override SqlString FromJoinFragment(string alias, bool innerJoin, bool includeSubclasses)
@@ -413,4 +413,4 @@ protected override SqlCommandInfo GenerateIdentityInsertRowString()
 
 		#endregion
 	}
-}
+}