/// <summary>
/// Given a serialized estimator (<paramref name="estimatorStream"/>), determine the size of the difference, create a Bloom filter for the difference and return that Bloom filter
/// </summary>
/// <param name="estimatorStream">The estimator</param>
/// <param name="otherActor"></param>
/// <returns></returns>
public MemoryStream RequestFilter(MemoryStream estimatorStream, PrecalculatedActor <TCount> otherActor)
{
Console.WriteLine($"Estimator size: {estimatorStream.Length} ");
var otherEstimator =
(IHybridEstimatorData <int, TCount>)
_protobufModel.Deserialize(estimatorStream, null, typeof(HybridEstimatorData <int, TCount>));
var estimate = _estimator.Decode(otherEstimator);
if (estimate == null)
{
//additional communication step needed to create a new estimator.
byte failedDecodeCount = 0;
while (estimate == null && failedDecodeCount < 5)
{
var estimator = _hybridEstimatorFactory.Extract(_configuration, _estimator, failedDecodeCount);
using (var stream = new MemoryStream())
{
_protobufModel.Serialize(stream, estimator);
stream.Position = 0;
estimate = otherActor.GetEstimate(stream);
}
failedDecodeCount++;
}
if (estimate == null)
{
throw new NullReferenceException("Did not negotiate a good estimate");
}
}
var result = new MemoryStream();
_protobufModel.Serialize(result, _configuration.DataFactory.Extract(_configuration, _filter, estimate.Value));
result.Position = 0;
Console.WriteLine($"Filter size: {result.Length} ");
return(result);
}
/// <summary>
/// Given the actor, determine the difference.
/// </summary>
/// <param name="actor"></param>
/// <returns></returns>
public Tuple <HashSet <long>, HashSet <long>, HashSet <long> > GetDifference(PrecalculatedActor <TCount> actor)
{
using (var estimatorStream = new MemoryStream())
{
var data = _hybridEstimatorFactory.Extract(_configuration, _estimator);
_protobufModel.Serialize(estimatorStream, data);
estimatorStream.Position = 0;
//send the estimator to the other actor and receive the filter from that actor.
var otherFilterStream = actor.RequestFilter(estimatorStream, this);
var otherFilter = (IInvertibleBloomFilterData <long, int, TCount>)
_protobufModel.Deserialize(otherFilterStream, null,
_configuration.DataFactory.GetDataType <long, int, TCount>());
otherFilterStream.Dispose();
var onlyInThisSet = new HashSet <long>();
var onlyInOtherSet = new HashSet <long>();
var modified = new HashSet <long>();
var succes = _filter.SubtractAndDecode(onlyInThisSet, onlyInOtherSet, modified, otherFilter);
//note: even when not successfully decoded for sure, the sets will contain info.
return(new Tuple <HashSet <long>, HashSet <long>, HashSet <long> >(onlyInThisSet, onlyInOtherSet, modified));
}
}
