/// <summary>
/// Intersect Bloom filter data.
/// </summary>
/// <typeparam name="TEntity"></typeparam>
/// <typeparam name="TId"></typeparam>
/// <typeparam name="THash"></typeparam>
/// <typeparam name="TCount"></typeparam>
/// <param name="filterData"></param>
/// <param name="configuration"></param>
/// <param name="otherFilterData"></param>
/// <param name="inPlace"></param>
/// <returns></returns>
internal static InvertibleBloomFilterData <TId, THash, TCount> Intersect <TEntity, TId, THash, TCount>(
this IInvertibleBloomFilterData <TId, THash, TCount> filterData,
IInvertibleBloomFilterConfiguration <TEntity, TId, THash, TCount> configuration,
IInvertibleBloomFilterData <TId, THash, TCount> otherFilterData,
bool inPlace = false
)
where TId : struct
where THash : struct
where TCount : struct
{
if (filterData == null && otherFilterData == null)
{
return(null);
}
if (filterData == null)
{
return(configuration
.DataFactory
.Create(configuration, otherFilterData.Capacity, otherFilterData.BlockSize, otherFilterData.HashFunctionCount));
}
else
{
filterData.SyncCompressionProviders(configuration);
}
if (otherFilterData == null)
{
if (inPlace)
{
filterData.Clear(configuration);
return(filterData.ConvertToBloomFilterData(configuration));
}
return(configuration
.DataFactory
.Create(configuration, filterData.Capacity, filterData.BlockSize, filterData.HashFunctionCount));
}
else
{
otherFilterData.SyncCompressionProviders(configuration);
}
if (!filterData.IsCompatibleWith(otherFilterData, configuration))
{
return(null);
}
var foldFactors = configuration.FoldingStrategy?.GetFoldFactors(filterData.BlockSize, otherFilterData.BlockSize);
var res = inPlace && foldFactors?.Item1 <= 1 ?
filterData.ConvertToBloomFilterData(configuration) :
(foldFactors == null || foldFactors.Item1 <= 1 ?
filterData.CreateDummy(configuration) :
configuration.DataFactory.Create(
configuration,
filterData.Capacity / foldFactors.Item1,
filterData.BlockSize / foldFactors.Item1,
filterData.HashFunctionCount));
foldFactors = foldFactors ?? new Tuple <long, long>(1, 1);
res.IsReverse = filterData.IsReverse;
Parallel.ForEach(
Partitioner.Create(0L, res.BlockSize),
(range, state) =>
{
for (var i = range.Item1; i < range.Item2; i++)
{
var filterDataCount = filterData.Counts.GetFolded(i, foldFactors.Item1, configuration.CountConfiguration.Add);
var otherFilterDataCount = otherFilterData.Counts.GetFolded(i, foldFactors.Item2, configuration.CountConfiguration.Add);
res.Counts[i] = configuration.CountConfiguration.Comparer.Compare(filterDataCount, otherFilterDataCount) < 0 ? filterDataCount : otherFilterDataCount;
res.IdSumProvider[i] = configuration.IdIntersect(
filterData.IdSumProvider.GetFolded(i, filterData.BlockSize, foldFactors.Item1, configuration.IdAdd),
otherFilterData.IdSumProvider.GetFolded(i, otherFilterData.BlockSize, foldFactors.Item2, configuration.IdAdd));
res.HashSumProvider[i] = configuration.HashIntersect(
filterData.HashSumProvider.GetFolded(i, filterData.BlockSize, foldFactors.Item1, configuration.HashAdd),
otherFilterData.HashSumProvider.GetFolded(i, otherFilterData.BlockSize, foldFactors.Item2, configuration.HashAdd));
}
});
res.SubFilter = filterData
.SubFilter
.Intersect(configuration.SubFilterConfiguration, otherFilterData.SubFilter, inPlace)
.ConvertToBloomFilterData(configuration);
res.ItemCount = configuration.CountConfiguration.GetEstimatedCount(res.Counts, res.HashFunctionCount);
return(res);
}
