/// <summary>
/// Ukoliko klijent prestane da bude zainteresovan na neki DMS tip ili uopsteno na promene NMS modela onda radi Unsubscribed
/// </summary>
/// <param name="topics">Lista DMS tipova sa kojih se odjavljuje</param>
/// <returns></returns>
public void Unsubscribed(List <DMSType> topics)
{
OperationContext context = OperationContext.Current;
ITwoPhaseCommit client = context.GetCallbackChannel <ITwoPhaseCommit>();
if (!subscribers.ContainsKey(client))
{
return;
}
foreach (DMSType topic in topics)
{
if (!subscribers[client].Contains(topic))
{
continue;
}
subscribers[client].Remove(topic);
}
if (subscribers[client].Count != 0)
{
return;
}
subscribers.Remove(client);
}
public virtual void TestNullTPCs()
{
int numObjects = Random.Next(4) + 3; // between [3, 6]
ITwoPhaseCommit[] tpcs = new ITwoPhaseCommit[numObjects];
bool setNull = false;
for (int i = 0; i < tpcs.Length; i++)
{
bool isNull = Random.NextDouble() < 0.3;
if (isNull)
{
setNull = true;
tpcs[i] = null;
}
else
{
tpcs[i] = new TwoPhaseCommitImpl(false, false, false);
}
}
if (!setNull)
{
// none of the TPCs were picked to be null, pick one at random
int idx = Random.Next(numObjects);
tpcs[idx] = null;
}
// following call would fail if TPCTool won't handle null TPCs properly
TwoPhaseCommitTool.Execute(tpcs);
}
/// <summary>
/// Executes a 2-phase commit algorithm by first
/// <see cref="ITwoPhaseCommit.PrepareCommit()"/> all objects and only if all succeed,
/// it proceeds with <see cref="ITwoPhaseCommit.Commit()"/>. If any of the objects
/// fail on either the preparation or actual commit, it terminates and
/// <see cref="ITwoPhaseCommit.Rollback()"/> all of them.
/// <para/>
/// <b>NOTE:</b> It may happen that an object fails to commit, after few have
/// already successfully committed. This tool will still issue a rollback
/// instruction on them as well, but depending on the implementation, it may
/// not have any effect.
/// <para/>
/// <b>NOTE:</b> if any of the objects are <c>null</c>, this method simply
/// skips over them.
/// </summary>
/// <exception cref="PrepareCommitFailException">
/// if any of the objects fail to
/// <see cref="ITwoPhaseCommit.PrepareCommit()"/> </exception>
/// <exception cref="CommitFailException">
/// if any of the objects fail to <see cref="ITwoPhaseCommit.Commit()"/> </exception>
public static void Execute(params ITwoPhaseCommit[] objects)
{
ITwoPhaseCommit tpc = null;
try
{
// first, all should successfully prepareCommit()
for (int i = 0; i < objects.Length; i++)
{
tpc = objects[i];
if (tpc != null)
{
tpc.PrepareCommit();
}
}
}
catch (Exception t)
{
// first object that fails results in rollback all of them and
// throwing an exception.
Rollback(objects);
throw new PrepareCommitFailException(t, tpc);
}
// If all successfully prepareCommit(), attempt the actual commit()
try
{
for (int i = 0; i < objects.Length; i++)
{
tpc = objects[i];
if (tpc != null)
{
tpc.Commit();
}
}
}
catch (Exception t)
{
// first object that fails results in rollback all of them and
// throwing an exception.
Rollback(objects);
throw new CommitFailException(t, tpc);
}
}
/// <summary>
/// Svi zainteresovani za promene statickog modela se prijavljuju na dogadjaje preko ove metode
/// </summary>
/// <param name="topics">List DMS tipova na koje se klijent prijavljuje</param>
public void Subscribed(List <DMSType> topics)
{
OperationContext context = OperationContext.Current;
ITwoPhaseCommit client = context.GetCallbackChannel <ITwoPhaseCommit>();
if (!subscribers.ContainsKey(client))
{
subscribers.Add(client, topics);
}
foreach (DMSType topic in topics)
{
if (subscribers[client].Contains(topic))
{
continue;
}
subscribers[client].Add(topic);
}
}
/// <summary>
/// Sole constructor. </summary>
public CommitFailException(Exception cause, ITwoPhaseCommit obj)
: base("commit() failed on " + obj, cause)
{
}
