public ConsistentHashRing<string> CreateConsistentHashRingForTenValues()
{
ConsistentHashRing<string> ring = new ConsistentHashRing<string>(
// For testing purposes only, the private key we will use to initialize
// the universal hash function for the hash ring will be the key master from Ghostbusters
"Louis Tully as played by Rick Moranis",
// The ring will contain the words one to ten, capitalized.
_oneToTenAsWords.Select( word => new KeyValuePair<string,string>(word, word) ),
1024);
return ring;
}
public ConsistentHashRing <string> CreateConsistentHashRingForTenValues()
{
ConsistentHashRing <string> ring = new ConsistentHashRing <string>(
// For testing purposes only, the private key we will use to initialize
// the universal hash function for the hash ring will be the key master from Ghostbusters
"Louis Tully as played by Rick Moranis",
// The ring will contain the words one to ten, capitalized.
_oneToTenAsWords.Select(word => new KeyValuePair <string, string>(word, word)),
1024);
return(ring);
}
public void HashRingEvenDistributionTest()
{
Pseudorandom pseudo = new Pseudorandom();
int trials = 10000000;
ConsistentHashRing <string> ring = CreateConsistentHashRingForTenValues();
Dictionary <string, double> ringCoverage = ring.FractionalCoverage;
double expectedFraction = 1d / 10d;
foreach (string word in _oneToTenAsWords)
{
double share = ringCoverage[word];
double bias = (expectedFraction - share) / expectedFraction;
double absBias = Math.Abs(bias);
Assert.True(bias < .15d);
Assert.True(bias < .15d);
}
Dictionary <string, Int64> counts = new Dictionary <string, Int64>();
Dictionary <string, double> frequencies = new Dictionary <string, double>();
foreach (string number in _oneToTenAsWords)
{
counts[number] = 0;
}
for (int i = 0; i < trials; i++)
{
string rand = pseudo.GetString(13);
string word = ring.FindMemberResponsible(rand);
counts[word]++;
}
foreach (string word in _oneToTenAsWords)
{
double freq = frequencies[word] = ((double)counts[word]) / (double)trials;
double error = freq - ringCoverage[word];
Assert.True(Math.Abs(error) < 0.01);
}
}
