public static HybridDbMessage Execute(Func <string, Type, object> deserializer, DocumentTransaction tx, DequeueCommand command)
{
var tablename = tx.Store.Database.FormatTableNameAndEscape(command.Table.Name);
var msg = (tx.SqlConnection.Query <(string Message, string Discriminator)>(@$ "
set nocount on;
delete top(1) from {tablename} with (rowlock, readpast)
output deleted.Message, deleted.Discriminator
where Topic = @Topic;
set nocount off;",
new { command.Topic },
tx.SqlTransaction
)).SingleOrDefault();
if (msg == default)
{
return(null);
}
var type = tx.Store.Configuration.TypeMapper.ToType(typeof(HybridDbMessage), msg.Discriminator);
return((HybridDbMessage)deserializer(msg.Message, type));
}
public static void UseMessageQueue(this Configuration config, string tablename = "messages")
{
config.GetOrAddTable(new QueueTable(tablename));
config.Decorate <Func <DocumentTransaction, DmlCommand, Func <object> > >((_, decoratee) => (tx, command) => () =>
Switch <object> .On(command)
.Match <EnqueueCommand>(enqueueCommand => EnqueueCommand.Execute(config.Serializer.Serialize, tx, enqueueCommand))
.Match <DequeueCommand>(dequeueCommand => DequeueCommand.Execute(config.Serializer.Deserialize, tx, dequeueCommand))
.Else(() => decoratee(tx, command)()));
}
