Supersocket is Used in net5 - command

background ：Command Take out the command list and learn , In fact, it's just because it depends on your usage habits , If you don't want to use the built-in logic to process the message , You can do it yourself UsePackageHandler Method ; Or your TReceivePackage Package type does not inherit IKeyedPackageInfo<T>, There's no need to build in at this time Command Processing logic .

Of course ,Command And the use of filters still has many advantages , Make your business processing code more concise and clear , Make your code structure clearer , You can use filters to monitor business processing and add some processing isolated from business processing code ; Next, let's learn Command How to use it?

Now start the scenario defined in the article , Now create a Command To handle accepting and adding （Add） Business operations of user commands ; Data structures and filters are the same as above “ Startup ” In the same , But it should be noted that the data structure class should inherit IKeyedPackageInfo<T>

The message received is so long ：

1. The new name is Add Of Command

    [Command(Key = "add")]
    public class Add : IAsyncCommand<MyPackage>
    {
        public async ValueTask ExecuteAsync(IAppSession session, MyPackage package)
        {
            //TODO  Your business 
            string sql = $" insert into Users(UserName) values ('{package.UserName}')";
            Thread.Sleep(1000);
            await session.SendAsync(Encoding.UTF8.GetBytes(package.UserName));
        }
    }

Here's the thing to notice ：

（1）. characteristic Key There can be no , In no case Command The route of is according to key and Command Name to match

（2）. Appoint Comand Of key When , Just press key, Can't press Command Name to match

2. register Command

What we should pay attention to here is , Use Command To handle business , It can't be used anymore UsePackageHandler The method , Because use UsePackageHandler Will overwrite Command Related methods

            var host = SuperSocketHostBuilder.Create<MyPackage, MyFilter>()
    //.UsePackageHandler(async (s, p) =>
    //{
    //    // handle your package over here
    //    await s.SendAsync(Encoding.UTF8.GetBytes(p.Key + "\r\n"));
    //})
      .UseCommand((commandOptions) =>
      {
          // Register the add user command 
          commandOptions.AddCommand<Add>();
          //...add else command
      })
    .Build();
            await host.RunAsync();

Now you can test ：

Find out key yes “add” when , Will execute Add（ Created Command） The asynchronous method inside ExecuteAsync

3. Next, add Command Filter,Command Filter Equivalent to ASP.MVC Medium AOP Action filter , Will be called before or after the command is executed .

New inheritance AsyncCommandFilterAttribute perhaps CommandFilterAttribute Of CommandFilter

    /// <summary>
    /// Command filter 
    /// </summary>
    public class AddCommandFilterAttribute : CommandFilterAttribute
    {
        public override void OnCommandExecuted(CommandExecutingContext commandContext)
        {
            Console.WriteLine(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")+" After adding users ");
        }

        public override bool OnCommandExecuting(CommandExecutingContext commandContext)
        {
            Console.WriteLine(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + " Before adding users ");
            return true;
        }
    }

    /// <summary>
    ///  asynchronous Command filter 
    /// </summary>
    public class AsyncAddCommandFilterAttribute : AsyncCommandFilterAttribute
    {
        public override async ValueTask OnCommandExecutedAsync(CommandExecutingContext commandContext)
        {
            Console.WriteLine(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + " After adding users  Async");
            await Task.Delay(0);
        }

        public override async ValueTask<bool> OnCommandExecutingAsync(CommandExecutingContext commandContext)
        {
            Console.WriteLine(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + " Before adding users  Async");
            await Task.Delay(0);
            return true;
        }
    }

Add a property to the appropriate Command On ：

The test results ：

There are also global filters , Is defined in all Command What needs to be done before and after the execution of , The order of execution is specified elsewhere Filter Before

        public class AsyncMyGlobalFiterAttribute : AsyncCommandFilterAttribute
        {
            public override async ValueTask OnCommandExecutedAsync(CommandExecutingContext commandContext)
            {
                Console.WriteLine(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + " After processing the message  Async");
                await Task.Delay(0);
            }

            public override async ValueTask<bool> OnCommandExecutingAsync(CommandExecutingContext commandContext)
            {
                Console.WriteLine(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss") + " Before processing the message  Async");
                await Task.Delay(0);
                string commandName = commandContext.CurrentCommand.ToString();
                MyPackage myPackage = (MyPackage)commandContext.Package;
                if (myPackage.UserName == "Admin")
                {
                    // For example, the user name is Admin Not when Command Handle 
                    return false;
                }
                return true;
            }
        }

  Register global filter

      .UseCommand((commandOptions) =>
      {
          // Register the add user command 
          commandOptions.AddCommand<Add>();
          //...add else command

          // Register global filter 
          commandOptions.AddGlobalCommandFilter<AsyncMyGlobalFiterAttribute>();
      })

test

SuperSocket.Core Medium Command That's what I learned