mschuler / uniqueidgenerator Goto Github PK

This lib has really cool hidden features.

After you have generated an ID, you can convert the ID into its parts:

• string Bits
• TimeSpan Time
• short GeneratorId
• long Sequence

I think it should be in the description.

I love this lib.

NextLong can return just long type since sql server don't support unsigned bigint type.

Hi,
Is this project dead? Can you provide a net core version?

I tried the generator (1 generator) for 1000 times for 3 threads, and it gives me duplicated values

// Create a new instance of the generator
      Generator gen1 = new Generator(128, new DateTime(2019, 05, 1));

      int max = 1000;
      List<string> ids = new List<string>();

      for (int i = 0; i < max; i++) {
        ids.Add(gen1.Next());
      }

      Task t1 = Task.Factory.StartNew(() => {
        for (int i = 0; i < max; i++) {
          ids.Add(gen1.Next());
        }
      });

      Task t2 = Task.Factory.StartNew(() => {
        for (int i = 0; i < max; i++) {
          ids.Add(gen1.Next());
        }
      });

      Task.WaitAll(t1, t2);

      var grouped = (from i in ids group i by i into g select new { Id = g.Key, Count = g.Count() });

      var duplicated = grouped.Count(g => g.Count > 1);
      Console.WriteLine("duplicated ids  " + duplicated);
      //Failed
      Debug.Assert(0 == duplicated);

I like this implementation. I've seen some that use a Stopwatch instead of DateTime.Now because it's more accurate. That is the only possible improvement I can think of.

var blockingCollection = new BlockingCollection();
List tasks = new List();
for (int i = 0; i < 100; i++)
{
var task = Task.Run(() =>
{

                for (int j = 0; j < 10000; j++)
                {

                    blockingCollection.Add(new Generator(1, DateTime.MinValue).Next());
                }
            });

            tasks.Add(task);
        }

        Task.WaitAll(tasks.ToArray());

        Console.WriteLine(blockingCollection.Distinct().Count());

        Console.ReadKey();

What is the best way to reduce the number of digits for the unique ID. Currently the result ID is often bigger than 2^53-1 or 9007199254740991, which make it impossible to work with JavaScript's number integer. Thanks.

Hi,

When I set today date, it is giving generate negative number.

Any idea why?

Might not be the best solution, but since I am using smaller sequence sizes and this could add significant os calls and context switches, it might be prudent to do something like this. 2 new 'spin' lines to SpinToNextSequence().

private void SpinToNextSequence()
{
    var spin = new SpinWait();   // create spin object
    var time = GetTime();

    while (time == _previousTime && _sequence >= _maxSequence)
    {
        spin.SpinOnce();    // spin locally in user space instead of forcing excess os calls to get next time.
        // Or maybe Thread.Sleep(0)?
        time = GetTime();
    }
    _sequence = time == _previousTime ? (short)(_sequence + 1) : (short)0;
    _previousTime = time;
 }

@mschuler