Ejemplo n.º 1
0
        /// <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">The other party involved</param>
        /// <returns></returns>
        public MemoryStream RequestFilter(MemoryStream estimatorStream, Actor <TCount> otherActor)
        {
            Console.WriteLine($"Estimator size: {estimatorStream.Length} ");
            var otherEstimator =
                (IHybridEstimatorData <int, TCount>)
                _protobufModel.Deserialize(estimatorStream, null, typeof(HybridEstimatorData <int, TCount>));
            var estimator = _hybridEstimatorFactory.CreateMatchingEstimator(otherEstimator, _configuration,
                                                                            _dataSet.LongCount());

            foreach (var item in _dataSet)
            {
                estimator.Add(item);
            }
            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)
                {
                    estimator = _hybridEstimatorFactory.Create(_configuration, _dataSet.Count(), ++failedDecodeCount);
                    foreach (var item in _dataSet)
                    {
                        estimator.Add(item);
                    }
                    using (var stream = new MemoryStream())
                    {
                        _protobufModel.Serialize(stream, estimator.Extract());
                        stream.Position = 0;
                        estimate        = otherActor.GetEstimate(stream);
                    }
                }
                if (estimate == null)
                {
                    throw new NullReferenceException("Did not negotiate a good estimate");
                }
            }
            var filter = _bloomFilterFactory.Create(_configuration, estimate.Value, 0.001F, true);

            foreach (var item in _dataSet)
            {
                filter.Add(item);
            }
            var result = new MemoryStream();

            _protobufModel.Serialize(result, filter.Extract());
            result.Position = 0;
            Console.WriteLine($"Filter size: {result.Length} ");
            return(result);
        }
Ejemplo n.º 2
0
 /// <summary>
 /// Constructor
 /// </summary>
 /// <param name="dataSet">The data set for this actor</param>
 /// <param name="hybridEstimatorFactory">Factory for creating estimators</param>
 /// <param name="bloomFilterFactory">Factory for creating Bloom filters</param>
 /// <param name="configuration">Bloom filter configuration to use</param>
 public PrecalculatedActor(IList <TestEntity> dataSet,
                           IHybridEstimatorFactory hybridEstimatorFactory,
                           IInvertibleBloomFilterFactory bloomFilterFactory,
                           IInvertibleBloomFilterConfiguration <TestEntity, long, int, TCount> configuration)
 {
     _protobufModel = TypeModel.Create();
     _protobufModel.UseImplicitZeroDefaults = true;
     _hybridEstimatorFactory = hybridEstimatorFactory;
     _configuration          = configuration;
     //terribly over size the estimator.
     _estimator = _hybridEstimatorFactory.Create(_configuration, 100000);
     foreach (var itm in dataSet)
     {
         _estimator.Add(itm);
     }
     //sized to number of differences it can handle, not to the size of the data.
     _filter = bloomFilterFactory.Create(_configuration, 5000, 0.001F, true);
     foreach (var item in dataSet)
     {
         _filter.Add(item);
     }
 }