Move cache check from AbstractEntityPersister.IsTransient to ForeignKeys.IsTransientSlow

Author: bahusoid

src/NHibernate/Engine/ForeignKeys.cs

@@ -1,4 +1,7 @@
 
+using System;
+using System.Threading;
+using System.Threading.Tasks;
 using NHibernate.Id;
 using NHibernate.Persister.Entity;
 using NHibernate.Proxy;
@@ -211,25 +214,37 @@ public static bool IsNotTransientSlow(string entityName, object entity, ISession
 		/// </remarks>
 		public static bool IsTransientSlow(string entityName, object entity, ISessionImplementor session)
 		{
-			return IsTransientFast(entityName, entity, session) ??
-			       HasDbSnapshot(entityName, entity, session);
+			bool? isTransient = IsTransientFast(entityName, entity, session);
+			if (isTransient.HasValue)
+				return isTransient.Value;
+
+			var persister = session.GetEntityPersister(entityName, entity);
+			var id = persister.GetIdentifier(entity);
+
+			// check to see if it is in the second-level cache
+			if (persister.HasCache && session.CacheMode.HasFlag(CacheMode.Get))
+			{
+				var ck = session.GenerateCacheKey(id, persister.IdentifierType, persister.RootEntityName);
+				if (persister.Cache.Get(ck, session.Timestamp) != null)
+					return false;
+			}
+
+			return HasDbSnapshot(persister, id, session);
 		}
 
-		static bool HasDbSnapshot(string entityName, object entity, ISessionImplementor session)
+		static bool HasDbSnapshot(IEntityPersister persister, object identifier, ISessionImplementor session)
 		{
-			IEntityPersister persister = session.GetEntityPersister(entityName, entity);
 			if (persister.IdentifierGenerator is Assigned)
 			{
 				// When using assigned identifiers we cannot tell if an entity
 				// is transient or detached without querying the database.
 				// This could potentially cause Select N+1 in cascaded saves, so warn the user.
 				log.Warn("Unable to determine if {0} with assigned identifier {1} is transient or detached; querying the database. Use explicit Save() or Update() in session to prevent this.", 
-					entity, persister.GetIdentifier(entity));
+					persister.EntityName, identifier);
 			}
 
 			// hit the database, after checking the session cache for a snapshot
-			System.Object[] snapshot =
-				session.PersistenceContext.GetDatabaseSnapshot(persister.GetIdentifier(entity), persister);
+			System.Object[] snapshot = session.PersistenceContext.GetDatabaseSnapshot(identifier, persister);
 			return snapshot == null;
 		}
 

src/NHibernate/Persister/Entity/AbstractEntityPersister.cs

@@ -4230,14 +4230,7 @@ public virtual void AfterReassociate(object entity, ISessionImplementor session)
 				}
 			}
 
-			// check to see if it is in the second-level cache
-			if (HasCache && session.CacheMode.HasFlag(CacheMode.Get))
-			{
-				CacheKey ck = session.GenerateCacheKey(id, IdentifierType, RootEntityName);
-				if (Cache.Get(ck, session.Timestamp) != null)
-					return false;
-			}
-
+			//Note: second level cache check is moved to ForeignKeys.IsTransientSlow as a potentially slow operation
 			return null;
 		}