public override int SaveChanges()
{
var count = 0;
var relation = Table.Relation;
var addedEntities = AddedEntities.ToArray();
var changes = Changes.Values.ToArray();
AddedEntities.Clear();
Changes.Clear();
Local.Clear();
foreach (var entity in addedEntities)
{
AddToRelation(entity);
count++;
}
foreach (var change in changes)
{
switch (change.ChangeType)
{
case ChangeType.Add:
AddToRelation(change.Entity);
count++;
break;
case ChangeType.Remove:
if (!relation.Remove(change.Id))
{
ThrowRemovingNonexistingKeyException();
}
count++;
break;
case ChangeType.Update:
var values = EntityOperation.NonkeyValues(change.Entity);
if (!values.SequenceEqual(change.Original))
{
// Throws if the key not found.
relation[change.Id] = change.Entity;
count++;
}
break;
default:
throw new Exception("changeType = " + change.ChangeType);
}
}
return(count);
}
IEnumerable <TEntity> Enumerate()
{
foreach (var entity in AddedEntities.ToArray())
{
yield return(entity);
}
var ids =
Changes.Values.Select(ch => ch.Id)
.Concat(Table.Relation.Keys)
.ToArray()
.Distinct();
foreach (var id in ids)
{
var entity = Find(id);
if (entity != null)
{
yield return(entity);
}
}
}