public virtual async Task OnReplicateAsync(ReplicateEvent @event, CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
IEventSource source = @event.Session;
if (source.PersistenceContext.ReassociateIfUninitializedProxy(@event.Entity))
{
log.Debug("uninitialized proxy passed to replicate()");
return;
}
object entity = await(source.PersistenceContext.UnproxyAndReassociateAsync(@event.Entity, cancellationToken)).ConfigureAwait(false);
if (source.PersistenceContext.IsEntryFor(entity))
{
log.Debug("ignoring persistent instance passed to replicate()");
//hum ... should we cascade anyway? throw an exception? fine like it is?
return;
}
IEntityPersister persister = source.GetEntityPersister(@event.EntityName, entity);
// get the id from the object
/*if ( persister.isUnsaved(entity, source) ) {
* throw new TransientObjectException("transient instance passed to replicate()");
* }*/
object id = persister.GetIdentifier(entity);
if (id == null)
{
throw new TransientObjectException("instance with null id passed to replicate()");
}
ReplicationMode replicationMode = @event.ReplicationMode;
object oldVersion;
if (replicationMode == ReplicationMode.Exception)
{
//always do an INSERT, and let it fail by constraint violation
oldVersion = null;
}
else
{
//what is the version on the database?
oldVersion = await(persister.GetCurrentVersionAsync(id, source, cancellationToken)).ConfigureAwait(false);
}
if (oldVersion != null)
{
if (log.IsDebugEnabled())
{
log.Debug("found existing row for {0}", MessageHelper.InfoString(persister, id, source.Factory));
}
// HHH-2378
object realOldVersion = persister.IsVersioned ? oldVersion : null;
bool canReplicate =
replicationMode.ShouldOverwriteCurrentVersion(entity, realOldVersion,
persister.GetVersion(entity),
persister.VersionType);
if (canReplicate)
{
//will result in a SQL UPDATE:
await(PerformReplicationAsync(entity, id, realOldVersion, persister, replicationMode, source, cancellationToken)).ConfigureAwait(false);
}
else
{
//else do nothing (don't even reassociate object!)
log.Debug("no need to replicate");
}
//TODO: would it be better to do a refresh from db?
}
else
{
// no existing row - do an insert
if (log.IsDebugEnabled())
{
log.Debug("no existing row, replicating new instance {0}", MessageHelper.InfoString(persister, id, source.Factory));
}
bool regenerate = persister.IsIdentifierAssignedByInsert; // prefer re-generation of identity!
EntityKey key = regenerate ? null : source.GenerateEntityKey(id, persister);
await(PerformSaveOrReplicateAsync(entity, key, persister, regenerate, replicationMode, source, true, cancellationToken)).ConfigureAwait(false);
}
}
