public KafkaBackedDb(IChangeTrackingDataStore dataStore, KafkaConsumer <TValue> kafkaConsumer)
{
_dataStore = dataStore;
_dataStore.GetChanges <Offset>().Subscribe(offset => Console.WriteLine(offset));
var offsetKey = $"{typeof(TValue).Name}.offset";
var currentOffset = _dataStore.Get <long>(offsetKey).Result;
kafkaConsumer.SeekToOffset(currentOffset);
kafkaConsumer.Start();
kafkaConsumer.Subscription
.ObserveOn(TaskPoolScheduler.Default)
.SubscribeOn(TaskPoolScheduler.Default)
.Subscribe(async message =>
{
var value = message.Value;
var currentValue = await _dataStore.Get <TValue>(message.Key);
if (!(currentValue is null))
{
value.UpdateObject(currentValue);
}
await _dataStore.Set(value, message.Key);
await _dataStore.Set(message.Offset.Value, offsetKey);
});
}
public LayeredDataStore(IChangeTrackingDataStore fast, IChangeTrackingDataStore slow)
{
_fast = fast;
_slow = slow;
}