/// <summary>
/// Initializes a new instance of <see cref="FilterLoadPayload"/> with the given parameters.
/// </summary>
/// <exception cref="ArgumentException"/>
/// <exception cref="ArgumentNullException"/>
/// <exception cref="ArgumentOutOfRangeException"/>
/// <param name="filter">Filter to use</param>
/// <param name="hashCount">Number of hash functions to use</param>
/// <param name="tweak">The tweak</param>
/// <param name="flags">Bloom filter flags</param>
public FilterLoadPayload(byte[] filter, uint hashCount, uint tweak, BloomFlags flags)
{
Filter = filter;
HashFuncCount = hashCount;
Tweak = tweak;
Flags = flags;
}
public BloomFilter CreateBloomFilter(double fp, BloomFlags flags = BloomFlags.UPDATE_ALL)
{
var toTrack = GetDataToTrack().ToArray();
var scriptCount = _TrackedScripts.Count(s => !s.Value.IsInternal);
var filter = new BloomFilter(scriptCount == 0 ? 1 : scriptCount, fp, _Tweak, flags);
foreach (var data in toTrack)
{
filter.Insert(data);
}
return(filter);
}
public BloomFilter(int nElements, double nFPRate, uint nTweakIn, BloomFlags nFlagsIn = BloomFlags.UPDATE_ALL)
{
// The ideal size for a bloom filter with a given number of elements and false positive rate is:
// - nElements * log(fp rate) / ln(2)^2
// We ignore filter parameters which will create a bloom filter larger than the protocol limits
vData = new byte[Math.Min((uint)(-1 / LN2SQUARED * nElements * (decimal)Math.Log(nFPRate)), MAX_BLOOM_FILTER_SIZE) / 8];
//vData(min((unsigned int)(-1 / LN2SQUARED * nElements * log(nFPRate)), MAX_BLOOM_FILTER_SIZE * 8) / 8),
// The ideal number of hash functions is filter size * ln(2) / number of elements
// Again, we ignore filter parameters which will create a bloom filter with more hash functions than the protocol limits
// See http://en.wikipedia.org/wiki/Bloom_filter for an explanation of these formulas
this.nHashFuncs = Math.Min((uint)(vData.Length * 8 / nElements * LN2), MAX_HASH_FUNCS);
this.nTweak = nTweakIn;
this.nFlags = (byte)nFlagsIn;
}
public BloomFilter(uint nElements, double nFPRate, uint nTweakIn, BloomFlags nFlagsIn = BloomFlags.UPDATE_ALL)
{
// The ideal size for a bloom filter with a given number of elements and false positive rate is:
// - nElements * log(fp rate) / ln(2)^2
// We ignore filter parameters which will create a bloom filter larger than the protocol limits
vData = new byte[Math.Min((uint)(-1 / LN2SQUARED * nElements * (decimal)Math.Log(nFPRate)), MAX_BLOOM_FILTER_SIZE) / 8];
//vData(min((unsigned int)(-1 / LN2SQUARED * nElements * log(nFPRate)), MAX_BLOOM_FILTER_SIZE * 8) / 8),
// The ideal number of hash functions is filter size * ln(2) / number of elements
// Again, we ignore filter parameters which will create a bloom filter with more hash functions than the protocol limits
// See http://en.wikipedia.org/wiki/Bloom_filter for an explanation of these formulas
this.nHashFuncs = Math.Min((uint)(vData.Length * 8 / nElements * LN2), MAX_HASH_FUNCS);
this.nTweak = nTweakIn;
this.nFlags = (byte)nFlagsIn;
}
public BloomFilter(int nElements, double nFPRate, BloomFlags nFlagsIn = BloomFlags.UPDATE_ALL)
: this(nElements, nFPRate, RandomUtils.GetUInt32(), nFlagsIn)
{
}
public BloomFilter CreateBloomFilter(double fp, BloomFlags flags = BloomFlags.UPDATE_ALL)
{
var toTrack = GetDataToTrack().ToArray();
var scriptCount = _TrackedScripts.Count(s => !s.Value.IsInternal);
var filter = new BloomFilter(scriptCount, fp, _Tweak, flags);
foreach(var data in toTrack)
filter.Insert(data);
return filter;
}
public BloomFilter(int nElements, double nFPRate, BloomFlags nFlagsIn = BloomFlags.UPDATE_ALL)
: this(nElements, nFPRate, RandomUtils.GetUInt32(), nFlagsIn)
{
}
