private HashSet <int> BigPercentageGenerateMethod(IUsedNumbersProvider usedNumbersProvider, int count)
{
var allNumbers = Enumerable.Range(From, (To - From) + 1);
var unusedNumbers = allNumbers.Except(usedNumbersProvider.GetUsedNumbers());
var returnedNumbers = unusedNumbers.ToList().TakeRandom(count);
usedNumbersProvider.SaveUsedNumbers(returnedNumbers);
return(new HashSet <int>(returnedNumbers));
}
public NumbersViewModel()
{
string dbName = ConfigurationManager.AppSettings["dbName"];
string serverName = ConfigurationManager.AppSettings["serverName"];
string tableName = ConfigurationManager.AppSettings["tableName"];
usedNumbersProvider = UsedNumbersProviderFactory.GetSQLUsedNumbersProvider(serverName, dbName, tableName);
generator = RandomUniqueGeneratorFactory.GetRandomUniqueGeneratorSQL(1000000, 9999999);
usedNumbersProvider.CachedMode = true;
}
/// <summary>
/// Generate list of random numbers in range [from, to].
/// </summary>
/// <param name="usedNumbersProvider"> Object implementing IUsedNumbersProvider that will return numbers to exclude.</param>
/// <param name="count">Number of random numbers to generate.</param>
/// <param name="shouldSave">If set to false</param>
/// <returns>List of random numbers, each in range [from, to].</returns>
#endregion
public HashSet <int> GenerateRandomUniqueNumbers(IUsedNumbersProvider usedNumbersProvider, int count)
{
if (count <= 0)
{
throw new ArgumentOutOfRangeException("count");
}
double countPercent = (double)count / (double)(To - From);
if (countPercent < _smallPercentageOffset)
{
return(SmallPercentageGenerateMethod(usedNumbersProvider, count));
}
else
{
return(BigPercentageGenerateMethod(usedNumbersProvider, count));
}
}
private HashSet <int> SmallPercentageGenerateMethod(IUsedNumbersProvider usedNumbersProvider, int count)
{
HashSet <int> usedNumbers = usedNumbersProvider.GetUsedNumbers();
HashSet <int> returnedNumbers = new HashSet <int>();
Random rnd = new Random();
int added = 0;
int currCandidate = 0;
do
{
currCandidate = rnd.Next(From, To);
if (!usedNumbers.Contains(currCandidate))
{
returnedNumbers.Add(currCandidate);
usedNumbers.Add(currCandidate);
added++;
}
} while (added != count);
usedNumbersProvider.SaveUsedNumbers(returnedNumbers);
return(returnedNumbers);
}