static async Task <int> CreateOrder(int dayOffset)
{
using (var context = new SeqNumContext())
{
Order order;
using (var transaction = await context.Database.BeginTransactionAsync())
{
order = new Order()
{
Created = DateTime.UtcNow.AddDays(dayOffset),
};
context.Orders.Add(order);
await context.SaveChangesAsync();
transaction.Commit();
}
var firstDailyOrder =
((order.Created.Year % 100) * 100000000) +
order.Created.Month * 1000000 +
order.Created.Day * 10000 +
1;
var lastDailyOrder = firstDailyOrder + 9998;
await context.Database.ExecuteSqlCommandAsync($"update oo set oo.[Number] = isnull((select max([Number]) from [Orders] io where io.[Number] >= {firstDailyOrder} and io.[Number] <= {lastDailyOrder}) + 1, {firstDailyOrder}) from [Orders] oo (tablock) where oo.[Id] = {order.Id}");
return(order.Id);
}
}
static async Task Main(string[] args)
{
var numberOfOrders = 10000;
Console.WriteLine("Preparing database..");
using (var context = new SeqNumContext())
{
await context.Database.EnsureDeletedAsync();
await context.Database.EnsureCreatedAsync();
}
Console.WriteLine("Inserting data..");
var runningTasks = new Dictionary <int, Task>();
var random = new Random();
using (var throttle = new SemaphoreSlim(20, 20))
{
for (var i = 0; i < numberOfOrders; i++)
{
Console.Title = $"SeqNum {i + 1}/{numberOfOrders}";
await throttle.WaitAsync();
var dayOffset = random.Next(-1, 1);
Task task = null;
task = Task.Run(async() =>
{
try
{
await CreateOrder(dayOffset);
}
catch (Exception ex)
{
Console.Error.WriteLine($"Run failed: {ex.Message}");
}
finally
{
lock (runningTasks)
{
runningTasks.Remove(task.Id);
}
throttle.Release();
}
});
lock (runningTasks)
{
runningTasks.Add(task.Id, task);
}
}
await Task.WhenAll(runningTasks.Values);
}
Console.WriteLine("Printing statistics..");
using (var context = new SeqNumContext())
{
Console.WriteLine(" - created {0} orders", await context.Orders.CountAsync());
Console.WriteLine(" - created {0} numbers", await context.Orders.Select(x => x.Number).Distinct().CountAsync());
}
Console.ReadKey();
}