public K GetWeightedRandom(ConcurrentBag <K> exclude)
{
lock ( Wheel )
{
var pos = 0.0;
var subset = Wheel;
if (exclude != null && exclude.Any())
{
subset = Wheel.Where(one => !exclude.Contains(one.Id));
}
var subsetsum = subset.Sum(one => one.Space);
var target = BufUtils.RandomDouble(subsetsum);
foreach (var one in subset)
{
pos += one.Space;
if (pos >= target)
{
Logging.LogDebugData($"Roulette: {one.Id}");
return(one.Id);
}
}
if (subset.Any())
{
return(subset.Random().Id);
}
return(Wheel.Random().Id);
}
}
public static uint RandomUintNZ()
{
uint result;
do
{
result = BufUtils.RandomUint();
} while (result == 0);
return(result);
}
public static BufLen Decrypt(BufLen data, I2PPrivateKey pkey, bool zeropad)
{
if (data == null || (zeropad && data.Length != 514))
{
throw new ArgumentException("ElGamal padded data to decrypt must be exactly 514 bytes!");
}
if (!zeropad && data.Length != 512)
{
throw new ArgumentException("ElGamal data to decrypt must be exactly 512 bytes!");
}
var x = I2PConstants.ElGamalP.Subtract(pkey.ToBigInteger()).Subtract(BigInteger.One);
BigInteger a, b;
var reader = new BufRefLen(data);
if (zeropad)
{
reader.Seek(1);
a = reader.ReadBigInteger(256);
reader.Seek(1);
b = reader.ReadBigInteger(256);
}
else
{
a = reader.ReadBigInteger(256);
b = reader.ReadBigInteger(256);
}
var m2 = b.Multiply(a.ModPow(x, I2PConstants.ElGamalP));
var m1 = m2.Mod(I2PConstants.ElGamalP);
var m = m1.ToByteArray(255);
var hash = I2PHashSHA256.GetHash(m, 33, 222);
if (!BufUtils.Equal(m, 1, hash, 0, 32))
{
throw new HashCheckFailException();
}
return(new BufLen(m, 33, 222));
}
public K GetWeightedRandom()
{
lock ( Wheel )
{
var pos = 0f;
var target = BufUtils.RandomFloat(TotalSpaceSum);
foreach (var one in Wheel)
{
pos += one.Space;
if (pos >= target)
{
RandomFitEMA = (49 * RandomFitEMA + one.Space + MinFit - 1) / 50f;
DebugUtils.LogDebug(() => "Roulette: " + one.Id.ToString());
return(one.Id);
}
}
return(Wheel[BufUtils.RandomInt(Wheel.Count)].Id);
}
}
public static BufLen Decrypt(BufLen data, I2PPrivateKey pkey, bool zeropad)
{
if (data == null || zeropad && data.Length != EncryptedPaddedLength)
{
throw new ArgumentException($"ElGamal padded data to decrypt must be exactly {EncryptedPaddedLength} bytes!");
}
if (!zeropad && data.Length != EncryptedShortLength)
{
throw new ArgumentException($"ElGamal data to decrypt must be exactly {EncryptedShortLength} bytes!");
}
var x = I2PConstants.ElGamalPMinusOne.Subtract(pkey.ToBigInteger());
var reader = new BufRefLen(data);
var readlen = zeropad
? EncryptedPaddedLength / 2
: EncryptedShortLength / 2;
var a = reader.ReadBigInteger(readlen);
var b = reader.ReadBigInteger(readlen);
var m2 = b.Multiply(a.ModPow(x, I2PConstants.ElGamalP));
var m1 = m2.Mod(I2PConstants.ElGamalP);
var m = m1.ToByteArrayUnsigned();
var payload = new BufLen(m, 33, ClearTextLength);
var hash = I2PHashSHA256.GetHash(payload);
if (!BufUtils.Equal(m, 1, hash, 0, 32))
{
throw new HashCheckFailException();
}
return(payload);
}
public static KeyValuePair <K, V> Random <K, V>(this IDictionary <K, V> dic)
{
return(dic.Skip(BufUtils.RandomInt(dic.Keys.Count - 1))
.Take(1).FirstOrDefault());
}
public static V RandomValue <K, V>(this IDictionary <K, V> dic)
{
return(dic[dic.Keys.Skip(BufUtils.RandomInt(dic.Keys.Count - 1))
.Take(1).FirstOrDefault()]);
}