private static ScheduledCommand CreateStoredScheduledCommand <TAggregate>(
IScheduledCommand <TAggregate> scheduledCommand,
DateTimeOffset domainTime,
Clock schedulerClock)
where TAggregate : class =>
new ScheduledCommand
{
AggregateId = ScheduledCommand <TAggregate> .TargetGuid(scheduledCommand),
SequenceNumber = scheduledCommand
.IfTypeIs <IEvent>()
.Then(e => e.SequenceNumber)
.Else(() => - DateTimeOffset.UtcNow.Ticks),
AggregateType = Command.TargetNameFor(scheduledCommand.Command.GetType()),
SerializedCommand = scheduledCommand.ToJson(),
CreatedTime = domainTime,
DueTime = scheduledCommand.DueTime ?? schedulerClock.Now(),
Clock = schedulerClock
};
private async Task Enqueue(IScheduledCommand scheduledCommand)
{
var message = new BrokeredMessage(scheduledCommand.ToJson())
{
SessionId = scheduledCommand.AggregateId.ToString()
};
if (scheduledCommand.DueTime != null)
{
message.ScheduledEnqueueTimeUtc = scheduledCommand.DueTime.Value.UtcDateTime.Add(MessageDeliveryOffsetFromCommandDueTime);
}
messageSubject.OnNext(scheduledCommand);
using (new TransactionScope(TransactionScopeOption.Suppress))
{
await queueClient.SendAsync(message);
}
}
private async Task <ScheduledCommand> StoreScheduledCommand(IScheduledCommand <TAggregate> scheduledCommandEvent)
{
ScheduledCommand storedScheduledCommand;
using (var db = createCommandSchedulerDbContext())
{
var domainTime = Domain.Clock.Now();
// store the scheduled command
var clockName = await ClockNameForEvent(scheduledCommandEvent, db);
var schedulerClock = await db.Clocks.SingleOrDefaultAsync(c => c.Name == clockName);
if (schedulerClock == null)
{
Debug.WriteLine(string.Format("SqlCommandScheduler: Creating clock '{0}' @ {1}", clockName, domainTime));
schedulerClock = new Clock
{
Name = clockName,
UtcNow = domainTime,
StartTime = domainTime
};
db.Clocks.Add(schedulerClock);
await db.SaveChangesAsync();
}
storedScheduledCommand = new ScheduledCommand
{
AggregateId = scheduledCommandEvent.AggregateId,
SequenceNumber = scheduledCommandEvent.SequenceNumber,
AggregateType = eventStreamName,
SerializedCommand = scheduledCommandEvent.ToJson(),
CreatedTime = domainTime,
DueTime = scheduledCommandEvent.DueTime,
Clock = schedulerClock
};
if (storedScheduledCommand.ShouldBeDeliveredImmediately() &&
!scheduledCommandEvent.Command.RequiresDurableScheduling)
{
storedScheduledCommand.NonDurable = true;
return(storedScheduledCommand);
}
Debug.WriteLine(string.Format("SqlCommandScheduler: Storing command '{0}' ({1}:{2}) on clock '{3}'",
scheduledCommandEvent.Command.CommandName,
scheduledCommandEvent.AggregateId,
scheduledCommandEvent.SequenceNumber,
clockName));
db.ScheduledCommands.Add(storedScheduledCommand);
while (true)
{
try
{
db.SaveChanges();
break;
}
catch (DbUpdateException exception)
{
if (exception.IsConcurrencyException())
{
if (storedScheduledCommand.SequenceNumber < 0)
{
// for scheduler-assigned sequence numbers, decrement and retry
storedScheduledCommand.SequenceNumber--;
}
else
{
// this is not a scheduler-assigned sequence number, so the concurrency exception indicates an actual issue
break;
}
}
else
{
throw;
}
}
}
}
return(storedScheduledCommand);
}
internal static async Task <ScheduledCommand> StoreScheduledCommand <TAggregate>(
IScheduledCommand <TAggregate> scheduledCommand,
Func <CommandSchedulerDbContext> createDbContext,
Func <IScheduledCommand <TAggregate>, CommandSchedulerDbContext, Task <string> > clockNameForEvent) where TAggregate : class, IEventSourced
{
ScheduledCommand storedScheduledCommand;
using (var db = createDbContext())
{
var domainTime = Domain.Clock.Now();
// get or create a clock to schedule the command on
var clockName = await clockNameForEvent(scheduledCommand, db);
var schedulerClock = await db.Clocks.SingleOrDefaultAsync(c => c.Name == clockName);
if (schedulerClock == null)
{
Debug.WriteLine(String.Format("Creating clock '{0}' @ {1}", clockName, domainTime));
schedulerClock = new Clock
{
Name = clockName,
UtcNow = domainTime,
StartTime = domainTime
};
db.Clocks.Add(schedulerClock);
await db.SaveChangesAsync();
}
storedScheduledCommand = new ScheduledCommand
{
AggregateId = scheduledCommand.AggregateId,
SequenceNumber = scheduledCommand.SequenceNumber,
AggregateType = AggregateType <TAggregate> .EventStreamName,
SerializedCommand = scheduledCommand.ToJson(),
CreatedTime = domainTime,
DueTime = scheduledCommand.DueTime,
Clock = schedulerClock
};
if (scheduledCommand.IsDue(storedScheduledCommand.Clock) &&
!scheduledCommand.Command.RequiresDurableScheduling)
{
storedScheduledCommand.NonDurable = true;
return(storedScheduledCommand);
}
Debug.WriteLine(String.Format("Storing command '{0}' ({1}:{2}) on clock '{3}'",
scheduledCommand.Command.CommandName,
scheduledCommand.AggregateId,
scheduledCommand.SequenceNumber,
clockName));
db.ScheduledCommands.Add(storedScheduledCommand);
while (true)
{
try
{
db.SaveChanges();
scheduledCommand.Result = new CommandScheduled(scheduledCommand)
{
ClockName = schedulerClock.Name
};
break;
}
catch (DbUpdateException exception)
{
if (exception.IsConcurrencyException())
{
if (storedScheduledCommand.SequenceNumber < 0)
{
// for scheduler-assigned sequence numbers, decrement and retry
storedScheduledCommand.SequenceNumber--;
}
else
{
// this is not a scheduler-assigned sequence number, so the concurrency exception indicates an actual issue
break;
}
}
else
{
throw;
}
}
}
}
return(storedScheduledCommand);
}
private ScheduledCommand StoreScheduledCommand(IScheduledCommand <TAggregate> scheduledCommandEvent)
{
ScheduledCommand storedScheduledCommand;
using (var db = createCommandSchedulerDbContext())
{
var domainTime = Domain.Clock.Now();
// store the scheduled command
var clockName = ClockNameForEvent(scheduledCommandEvent, db);
var schedulerClock = db.Clocks.SingleOrDefault(c => c.Name == clockName);
if (schedulerClock == null)
{
schedulerClock = new Clock
{
Name = clockName,
UtcNow = domainTime,
StartTime = domainTime
};
db.Clocks.Add(schedulerClock);
db.SaveChanges();
}
storedScheduledCommand = new ScheduledCommand
{
AggregateId = scheduledCommandEvent.AggregateId,
SequenceNumber = scheduledCommandEvent.SequenceNumber,
AggregateType = eventStreamName,
SerializedCommand = scheduledCommandEvent.ToJson(),
CreatedTime = domainTime,
DueTime = scheduledCommandEvent.DueTime,
Clock = schedulerClock
};
if (storedScheduledCommand.ShouldBeDeliveredImmediately() &&
!scheduledCommandEvent.Command.RequiresDurableScheduling)
{
storedScheduledCommand.NonDurable = true;
return(storedScheduledCommand);
}
db.ScheduledCommands.Add(storedScheduledCommand);
while (true)
{
try
{
db.SaveChanges();
break;
}
catch (DbUpdateException exception)
{
if (exception.IsConcurrencyException())
{
if (storedScheduledCommand.SequenceNumber < 0)
{
// for scheduler-assigned sequence numbers, decrement and retry
storedScheduledCommand.SequenceNumber--;
}
else
{
// this is not a scheduler-assigned sequence number, so the concurrency exception indicates
break;
}
}
else
{
throw;
}
}
}
}
return(storedScheduledCommand);
}
private async Task Enqueue(IScheduledCommand scheduledCommand)
{
var message = new BrokeredMessage(scheduledCommand.ToJson())
{
SessionId = scheduledCommand.AggregateId.ToString()
};
if (scheduledCommand.DueTime != null)
{
message.ScheduledEnqueueTimeUtc = scheduledCommand.DueTime.Value.UtcDateTime.Add(MessageDeliveryOffsetFromCommandDueTime);
}
messageSubject.OnNext(scheduledCommand);
using (new TransactionScope(TransactionScopeOption.Suppress, TransactionScopeAsyncFlowOption.Enabled))
{
await queueClient.SendAsync(message);
}
}
