Initialize collections on demand

Author: hazzik

src/NHibernate/Action/BulkOperationCleanupAction.cs

@@ -20,8 +20,8 @@ public partial class BulkOperationCleanupAction :
 		ICacheableExecutable
 	{
 		private readonly ISessionFactoryImplementor _factory;
-		private readonly HashSet<string> _affectedEntityNames = new HashSet<string>();
-		private readonly HashSet<string> _affectedCollectionRoles = new HashSet<string>();
+		private readonly HashSet<string> _affectedEntityNames;
+		private readonly HashSet<string> _affectedCollectionRoles;
 		private readonly string[] _spaces;
 		private readonly bool _hasCache;
 
@@ -34,12 +34,22 @@ public BulkOperationCleanupAction(ISessionImplementor session, IQueryable[] affe
 				if (queryables.HasCache)
 				{
 					_hasCache = true;
+					if (_affectedEntityNames == null)
+					{
+						_affectedEntityNames = new HashSet<string>();
+					}
+
 					_affectedEntityNames.Add(queryables.EntityName);
 				}
 
 				var roles = _factory.GetCollectionRolesByEntityParticipant(queryables.EntityName);
 				if (roles != null)
 				{
+					if (_affectedCollectionRoles == null)
+					{
+						_affectedCollectionRoles = new HashSet<string>();
+					}
+
 					_affectedCollectionRoles.UnionWith(roles);
 				}
 
@@ -56,6 +66,8 @@ public BulkOperationCleanupAction(ISessionImplementor session, ISet<string> quer
 		{
 			//from H3.2 TODO: cache the autodetected information and pass it in instead.
 			_factory = session.Factory;
+			_affectedEntityNames = new HashSet<string>();
+			_affectedCollectionRoles = new HashSet<string>();
 
 			var tmpSpaces = new HashSet<string>(querySpaces);
 			var acmd = _factory.GetAllClassMetadata();
@@ -70,12 +82,22 @@ public BulkOperationCleanupAction(ISessionImplementor session, ISet<string> quer
 					if (persister.HasCache)
 					{
 						_hasCache = true;
+						if (_affectedEntityNames == null)
+						{
+							_affectedEntityNames = new HashSet<string>();
+						}
+
 						_affectedEntityNames.Add(persister.EntityName);
 					}
 
 					var roles = session.Factory.GetCollectionRolesByEntityParticipant(persister.EntityName);
 					if (roles != null)
 					{
+						if (_affectedCollectionRoles == null)
+						{
+							_affectedCollectionRoles = new HashSet<string>();
+						}
+
 						_affectedCollectionRoles.UnionWith(roles);
 					}