/// <summary>
/// Create a <seealso cref="ReplayMerge"/> to manage the merging of a replayed stream and switching over to live stream as
/// appropriate.
/// </summary>
/// <param name="subscription"> to use for the replay and live stream. Must be a multi-destination subscription. </param>
/// <param name="archive"> to use for the replay. </param>
/// <param name="replayChannel"> to use for the replay. </param>
/// <param name="replayDestination"> to send the replay to and the destination added by the <seealso cref="Subscription"/>. </param>
/// <param name="liveDestination"> for the live stream and the destination added by the <seealso cref="Subscription"/>. </param>
/// <param name="recordingId"> for the replay. </param>
/// <param name="startPosition"> for the replay. </param>
/// <param name="epochClock"> to use for progress checks. </param>
/// <param name="mergeProgressTimeoutMs"> to use for progress checks. </param>
public ReplayMerge(Subscription subscription, AeronArchive archive, string replayChannel, string replayDestination,
string liveDestination, long recordingId, long startPosition, IEpochClock epochClock,
long mergeProgressTimeoutMs)
{
if (subscription.Channel.StartsWith(IPC_CHANNEL) || replayChannel.StartsWith(IPC_CHANNEL) ||
replayDestination.StartsWith(IPC_CHANNEL) || liveDestination.StartsWith(IPC_CHANNEL))
{
throw new System.ArgumentException("IPC merging is not supported");
}
ChannelUri subscriptionChannelUri = ChannelUri.Parse(subscription.Channel);
if (!MDC_CONTROL_MODE_MANUAL.Equals(subscriptionChannelUri.Get(MDC_CONTROL_MODE_PARAM_NAME)))
{
throw new ArgumentException("Subscription must have manual control-mode: control-mode=" +
subscriptionChannelUri.Get(MDC_CONTROL_MODE_PARAM_NAME));
}
ChannelUri replayChannelUri = ChannelUri.Parse(replayChannel);
replayChannelUri.Put(LINGER_PARAM_NAME, "0");
replayChannelUri.Put(EOS_PARAM_NAME, "false");
this.archive = archive;
this.subscription = subscription;
this.epochClock = epochClock;
this.replayDestination = replayDestination;
this.replayChannel = replayChannelUri.ToString();
this.liveDestination = liveDestination;
this.recordingId = recordingId;
this.startPosition = startPosition;
this.timeOfLastProgressMs = epochClock.Time();
this.mergeProgressTimeoutMs = mergeProgressTimeoutMs;
subscription.AsyncAddDestination(replayDestination);
}
private int AttemptLiveJoin(long nowMs)
{
int workCount = 0;
if (Aeron.NULL_VALUE == activeCorrelationId)
{
long correlationId = archive.Ctx().AeronClient().NextCorrelationId();
if (archive.Proxy().GetRecordingPosition(recordingId, correlationId, archive.ControlSessionId()))
{
activeCorrelationId = correlationId;
timeOfLastProgressMs = nowMs;
workCount += 1;
}
}
else if (PollForResponse(archive, activeCorrelationId))
{
nextTargetPosition = PolledRelevantId(archive);
activeCorrelationId = Aeron.NULL_VALUE;
if (AeronArchive.NULL_POSITION == nextTargetPosition)
{
long correlationId = archive.Ctx().AeronClient().NextCorrelationId();
if (archive.Proxy().GetRecordingPosition(recordingId, correlationId, archive.ControlSessionId()))
{
activeCorrelationId = correlationId;
timeOfLastProgressMs = nowMs;
}
}
else
{
State nextState = State.CATCHUP;
if (null != image)
{
long position = image.Position;
if (ShouldAddLiveDestination(position))
{
subscription.AsyncAddDestination(liveDestination);
timeOfLastProgressMs = nowMs;
isLiveAdded = true;
}
else if (ShouldStopAndRemoveReplay(position))
{
subscription.AsyncRemoveDestination(replayDestination);
StopReplay();
timeOfLastProgressMs = nowMs;
nextState = State.MERGED;
}
}
SetState(nextState);
}
workCount += 1;
}
return(workCount);
}