public void murmur_128(string text, uint seed, ulong hashA, ulong hashB)
{
ulong a, b;
Murmur3.Hash128(Encoding.ASCII.GetBytes(text), seed, out a, out b);
Assert.Equal(hashA, a);
Assert.Equal(hashB, b);
}
public void identifier_hash_collision_test()
{
var seed = 777u;
var ids = _identifiers.Value;
Console.WriteLine($"Total Identifier Count: {ids.Length}");
Console.WriteLine($"Avg. Identifier Length: {ids.Average(n => n.Length)}");
Console.WriteLine($"Max. Identifier Length: {ids.Max(n => n.Length)}");
Test("Murmur3 32bit", ids, id => Murmur3.Hash32(Encoding.ASCII.GetBytes(id), seed));
Test("Murmur3 16bit", ids, id => To16Bit(Murmur3.Hash32(Encoding.ASCII.GetBytes(id), seed)));
}
UInt64 totalProcessedReferences; //Total processed (met the hashing criteria) references
#endregion Fields
#region Constructors
public SHARDSGhostCache(UInt32 cacheBlockSize, UInt64 maxCacheSizeBytes, bool noisyOutput)
{
Debug.Assert(maxCacheSizeBytes % cacheBlockSize == 0);
UInt64 num_blocks_req = maxCacheSizeBytes / cacheBlockSize;
//if (num_blocks_req > Int32.MaxValue)
//{
// Console.WriteLine("StackDepthGhostCache FAILED to initialize; {0} blocks of size {1} == {2} bytes total is too large",
// num_blocks_req, cacheBlockSize, maxCacheSizeBytes);
// Debug.Assert(0 == 1);
//}
//this.totalAvailCacheBlocks = (Int32)num_blocks_req;
this.totalAvailCacheBlocks = (Int64)num_blocks_req;
//set the sampling parameters
this.modulusP = 16777216; //2^24, as specified in the paper
this.modulusPPower = 24; // power of the modulus (for efficient reuse distance scaling)
this.thresholdT = 167772; // yields sampling rate of 0.01
this.samplingRateR = (double)this.thresholdT / (double)this.modulusP; //just in case we need the sampling rate in a local variable
this.Murmur3HashFunction = new Murmur3();
this.distanceTree = new SortedList<UInt64, GhostCacheElement>(new ReverseComparer());
this.hashTableLookup = new Dictionary<UInt64, GhostCacheElement>();
this.refreshCounter = 0;
this.cacheBlockSize = cacheBlockSize;
this.maxCacheSizeBytes = maxCacheSizeBytes;
this.totalCacheReferences = 0;
this.totalProcessedReferences = 0;
this.reuseAccessHistogram = new UInt32[(Int64)num_blocks_req];
//Initialize counters to 0
for (Int64 i = 0; i < this.totalAvailCacheBlocks; i++)
{
this.reuseAccessHistogram[i] = 0;
}
//Array.Clear(this.reuseAccessHistogram, 0, (Int32)num_blocks_req);
this.noisyOutput = noisyOutput;
}
public static byte[] MurmurHash(this string data)
{
var hasher = new Murmur3();
return(hasher.ComputeHash(Encoding.Unicode.GetBytes(data)));
}
public void murmur_32(string text, uint seed, uint hash)
{
Assert.Equal(hash, Murmur3.Hash32(Encoding.ASCII.GetBytes(text), seed));
}