public void Handle(CoreProjectionProcessingMessage.CheckpointLoaded message)
{
EnsureState(State.LoadStateRequested);
try {
var checkpointTag = message.CheckpointTag;
var phase = checkpointTag == null ? 0 : checkpointTag.Phase;
var projectionProcessingPhase = _projectionProcessingPhases[phase];
if (checkpointTag == null)
checkpointTag = projectionProcessingPhase.MakeZeroCheckpointTag();
checkpointTag = projectionProcessingPhase.AdjustTag(checkpointTag);
//TODO: initialize projection state here (test it)
//TODO: write test to ensure projection state is correctly loaded from a checkpoint and posted back when enough empty records processed
//TODO: handle errors
_coreProjectionCheckpointWriter.StartFrom(checkpointTag, message.CheckpointEventNumber);
PartitionState rootPartitionState = null;
if (_requiresRootPartition) {
rootPartitionState = PartitionState.Deserialize(message.CheckpointData, checkpointTag);
_partitionStateCache.CacheAndLockPartitionState("", rootPartitionState, null);
}
BeginPhase(projectionProcessingPhase, checkpointTag, rootPartitionState);
GoToState(State.StateLoaded);
if (_startOnLoad) {
if (_slaveProjections != null)
_projectionProcessingPhase.AssignSlaves(_slaveProjections);
_projectionProcessingPhase.Subscribe(checkpointTag, fromCheckpoint: true);
} else
GoToState(State.Stopped);
} catch (Exception ex) {
SetFaulted(ex);
}
}
private void OnLoadPartitionStateReadStreamEventsBackwardCompleted(
ClientMessage.ReadStreamEventsBackwardCompleted message, CheckpointTag requestedStateCheckpointTag,
Action <PartitionState> loadCompleted, string partitionStreamName, string stateEventType)
{
//NOTE: the following remove may do nothing in tests as completed is raised before we return from publish.
_loadStateRequests.Remove(message.CorrelationId);
_readRequestsInProgress--;
if (message.Events.Length == 1)
{
EventRecord @event = message.Events[0].Event;
if (@event.EventType == stateEventType)
{
var parsed = @event.Metadata.ParseCheckpointTagVersionExtraJson(_projectionVersion);
if (parsed.Version.ProjectionId != _projectionVersion.ProjectionId ||
_projectionVersion.Epoch > parsed.Version.Version)
{
var state = new PartitionState("", null, _zeroTag);
loadCompleted(state);
return;
}
else
{
var loadedStateCheckpointTag = parsed.AdjustBy(_positionTagger, _projectionVersion);
// always recovery mode? skip until state before current event
//TODO: skip event processing in case we know i has been already processed
if (loadedStateCheckpointTag < requestedStateCheckpointTag)
{
var state = PartitionState.Deserialize(
Helper.UTF8NoBom.GetString(@event.Data), loadedStateCheckpointTag);
loadCompleted(state);
return;
}
}
}
}
if (message.NextEventNumber == -1)
{
var state = new PartitionState("", null, _zeroTag);
loadCompleted(state);
return;
}
_readRequestsInProgress++;
var corrId = Guid.NewGuid();
var requestId =
_readDispatcher.Publish(
new ClientMessage.ReadStreamEventsBackward(
corrId, corrId, _readDispatcher.Envelope, partitionStreamName, message.NextEventNumber, 1,
resolveLinkTos: false, requireMaster: false, validationStreamVersion: null, user: SystemAccount.Principal),
m =>
OnLoadPartitionStateReadStreamEventsBackwardCompleted(m, requestedStateCheckpointTag, loadCompleted, partitionStreamName, stateEventType));
if (requestId != Guid.Empty)
{
_loadStateRequests.Add(requestId);
}
}
private void OnLoadPartitionStateReadStreamEventsBackwardCompleted(
ClientMessage.ReadStreamEventsBackwardCompleted message, CheckpointTag requestedStateCheckpointTag,
Action <PartitionState> loadCompleted, string partitionStreamName, string stateEventType)
{
//NOTE: the following remove may do nothing in tests as completed is raised before we return from publish.
_loadStateRequests.Remove(message.CorrelationId);
_readRequestsInProgress--;
if (message.Events.Length == 1)
{
EventRecord @event = message.Events[0].Event;
if (@event.EventType == stateEventType)
{
var parsed = @event.Metadata.ParseCheckpointTagVersionExtraJson(_projectionVersion);
if (parsed.Version.ProjectionId != _projectionVersion.ProjectionId ||
_projectionVersion.Epoch > parsed.Version.Version)
{
var state = new PartitionState("", null, _zeroTag);
loadCompleted(state);
return;
}
else
{
var loadedStateCheckpointTag = parsed.AdjustBy(_positionTagger, _projectionVersion);
// always recovery mode? skip until state before current event
//TODO: skip event processing in case we know i has been already processed
if (loadedStateCheckpointTag < requestedStateCheckpointTag)
{
var state = PartitionState.Deserialize(
Helper.UTF8NoBom.GetString(@event.Data), loadedStateCheckpointTag);
loadCompleted(state);
return;
}
}
}
}
if (message.NextEventNumber == -1)
{
var state = new PartitionState("", null, _zeroTag);
loadCompleted(state);
return;
}
ReadPartitionStream(partitionStreamName, message.NextEventNumber, requestedStateCheckpointTag,
loadCompleted, stateEventType);
}
private void OnLoadPartitionStateReadStreamEventsBackwardCompleted(
ClientMessage.ReadStreamEventsBackwardCompleted message, CheckpointTag requestedStateCheckpointTag,
Action <PartitionState> loadCompleted, string partitionStreamName, string stateEventType)
{
_loadStateRequests.Remove(message.CorrelationId);
_readRequestsInProgress--;
if (message.Events.Length == 1)
{
EventRecord @event = message.Events[0].Event;
if (@event.EventType == stateEventType)
{
var parsed = @event.Metadata.ParseCheckpointTagVersionExtraJson(_projectionVersion);
if (parsed.Version.ProjectionId != _projectionVersion.ProjectionId ||
_projectionVersion.Epoch > parsed.Version.Version)
{
var state = new PartitionState("", null, _zeroTag);
loadCompleted(state);
return;
}
else
{
var loadedStateCheckpointTag = parsed.AdjustBy(_positionTagger, _projectionVersion);
var state = PartitionState.Deserialize(
Helper.UTF8NoBom.GetString(@event.Data.Span), loadedStateCheckpointTag);
loadCompleted(state);
return;
}
}
}
if (message.NextEventNumber == -1)
{
var state = new PartitionState("", null, _zeroTag);
loadCompleted(state);
return;
}
ReadPartitionStream(partitionStreamName, message.NextEventNumber, requestedStateCheckpointTag,
loadCompleted, stateEventType);
}