async Task <SAFENetworkContext> RequireContextAsync(RootName root, string apiKey = null)
{
if (root == null)
{
throw new ArgumentNullException(nameof(root));
}
if (!_contextCache.TryGetValue(root, out SAFENetworkContext result))
{
var(stream, store) = await DbFactory.GetDriveDbsAsync(root, apiKey, _secretKey);
_sequenceNr = new SequenceNr();
var localState = new Memory.MemoryGateway();
var driveCache = new Memory.SAFENetworkDriveCache(store, localState);
var network = new SAFENetworkEventService(stream, store, _secretKey);
var materializer = new DriveMaterializer(root, localState, _sequenceNr);
var conflictHandler = new VersionConflictHandler(network, materializer);
var driveWriter = new DriveWriter(root, driveCache, _sequenceNr);
var dbName = Utils.Scrambler.Obfuscate(root.Value, _secretKey);
var transactor = new EventTransactor(driveWriter,
new DiskWALTransactor(dbName, conflictHandler.Upload), _secretKey);
_contextCache.Add(root, result = new SAFENetworkContext(transactor, new DriveReader(driveCache)));
var _ = driveCache.GetDrive(root, apiKey, _parameters); // needs to be loaded
// We need to wait for all events in local WAL to have been persisted to network
// before we materialize new events from network.
transactor.Start(_cancellation); // start uploading to network
while (DiskWALTransactor.AnyInQueue(dbName)) // wait until queue is empty
{
await Task.Delay(500); // beware, this will - currently - spin eternally if there is an unresolved version conflict
}
// (todo: should load snapshot + all events since)
var allEvents = network.LoadAsync(fromVersion: 0); // load all events from network (since we don't store it locally)
var isMaterialized = await materializer.Materialize(allEvents); // recreate the filesystem locally in memory
if (!isMaterialized)
{
throw new InvalidDataException("Could not materialize network filesystem!");
}
}
return(result);
}
public VersionConflictHandler(SAFENetworkEventService service, DriveMaterializer materializer)
{
_service = service;
_materializer = materializer;
}