C# IEntityPersister.GetVersion方法代码示例

		private static bool IsVersionChanged(object entity, IEventSource source, IEntityPersister persister, object target)
		{
			if (!persister.IsVersioned)
			{
				return false;
			}
			// for merging of versioned entities, we consider the version having
			// been changed only when:
			// 1) the two version values are different;
			//      *AND*
			// 2) The target actually represents database state!
			//
			// This second condition is a special case which allows
			// an entity to be merged during the same transaction
			// (though during a seperate operation) in which it was
			// originally persisted/saved
			bool changed =
				!persister.VersionType.IsSame(persister.GetVersion(target, source.EntityMode),
				                              persister.GetVersion(entity, source.EntityMode), source.EntityMode);

			// TODO : perhaps we should additionally require that the incoming entity
			// version be equivalent to the defined unsaved-value?
			return changed && ExistsInDatabase(target, source, persister);
		}

		protected virtual void PerformUpdate(SaveOrUpdateEvent @event, object entity, IEntityPersister persister)
		{
			if (!persister.IsMutable)
			{
				log.Debug("immutable instance passed to PerformUpdate(), locking");
			}

			if (log.IsDebugEnabled)
			{
				log.Debug("updating " + MessageHelper.InfoString(persister, @event.RequestedId, @event.Session.Factory));
			}

			IEventSource source = @event.Session;

			EntityKey key = new EntityKey(@event.RequestedId, persister, source.EntityMode);

			source.PersistenceContext.CheckUniqueness(key, entity);

			if (InvokeUpdateLifecycle(entity, persister, source))
			{
				Reassociate(@event, @event.Entity, @event.RequestedId, persister);
				return;
			}

			// this is a transient object with existing persistent state not loaded by the session
			new OnUpdateVisitor(source, @event.RequestedId, entity).Process(entity, persister);

			//TODO: put this stuff back in to read snapshot from
			//      the second-level cache (needs some extra work)
			/*Object[] cachedState = null;
			
			if ( persister.hasCache() ) {
			CacheEntry entry = (CacheEntry) persister.getCache()
			.get( event.getRequestedId(), source.getTimestamp() );
			cachedState = entry==null ? 
			null : 
			entry.getState(); //TODO: half-assemble this stuff
			}*/

			source.PersistenceContext.AddEntity(
				entity, 
				persister.IsMutable ? Status.Loaded : Status.ReadOnly,
				null, 
				key,
				persister.GetVersion(entity, source.EntityMode), 
				LockMode.None, 
				true, 
				persister,
				false,
				true);

			//persister.AfterReassociate(entity, source); TODO H3.2 not ported

			if (log.IsDebugEnabled)
			{
				log.Debug("updating " + MessageHelper.InfoString(persister, @event.RequestedId, source.Factory));
			}

			CascadeOnUpdate(@event, persister, entity);
		}