private void UpdatePacketFromPlan(PacketPlan plan, Packet <T> packet)
{
foreach (var item in plan.Records)
{
if (this.updateEventHandler != null)
{
var old = packet.Get(item.Key);
if (old != null)
{
/*
* Changing indexed fields is not allowed, because
* that would require an additional read/write pass,
* because then the record belongs to a different
* packet. (It would be inefficient to do a second pass.)
*/
var updatedRecord = updateEventHandler(old, item.Value);
if (updatedRecord == null)
{
/*
* If the event handler returns NULL, then it
* wants to avoid the update.
*/
continue;
}
var newIndexPath = String.Join('\0', table.GetIndexPath(plan.Index, updatedRecord));
if (newIndexPath != plan.IndexPathStr)
{
throw new FatCatException($"An update event handler has changed indexed fields in "
+ $"a record for table '{table.Annotation.Name}'. Changing indexed fields inside OnUpdate functions is not allowed.");
}
/*
* If the unique key has changed,
* then remove the entry under the old key,
* before setting the new.
*/
var newUnique = table.GetUnique(updatedRecord);
if (newUnique != item.Key)
{
packet.Remove(item.Key);
}
packet.Set(newUnique, updatedRecord);
continue;
}
}
packet.Set(item.Key, item.Value);
}
foreach (var key in plan.Removed)
{
packet.Remove(key);
}
}
/// <summary>
/// Removes a record by its unique key.
/// </summary>
public Transaction <T> Remove(T record)
{
foreach (var index in indices)
{
var indexPath = table.GetIndexPath(index, record);
var indexPathStr = String.Join('\0', indexPath);
if (!packetPlans.ContainsKey(indexPathStr))
{
packetPlans[indexPathStr] = new PacketPlan(table, index, indexPath, indexPathStr);
}
packetPlans[indexPathStr].Remove(record);
}
return(this);
}
/// <summary>
/// Entry point for a worker thread
/// </summary>
/// <param name="packetPlan">Payload</param>
private void CommitThread(PacketPlan packetPlan)
{
if (this.exception != null)
{
return;
}
try {
var packet = new Packet <T>(this.table, packetPlan.Index, packetPlan.IndexPath);
using (Locking.GetMutex(packet.FullPath).Lock()) {
packet.Load();
packet.DeserializeDecompress();
this.UpdatePacketFromPlan(packetPlan, packet);
packet.SerializeCompress();
packet.Save();
}
} catch (Exception ex) {
this.exception = ex;
}
}
