supersockets命令过滤器

关键字: 命令过滤器, 命令, 过滤器, OnCommandExecuting, OnCommandExecuted

SuperSocket 中的命令过滤器看起来有些像 ASP.NET MVC 中的 Action Filter，你可以用它来做命令执行的拦截，命令过滤器会在命令执行前和执行后被调用。

命令过滤器必须继承于 Attribute 类 CommandFilterAttribute:

/// <summary>

/// Command filter attribute

/// </summary>

[AttributeUsage(AttributeTargets.Class, AllowMultiple = true)]

public abstract class CommandFilterAttribute : Attribute

{

/// <summary>

/// Gets or sets the execution order.

/// </summary>

/// <value>

/// The order.

/// </value>

public int Order { get; set; }

/// <summary>

/// Called when [command executing].

/// </summary>

/// <param name="commandContext">The command context.</param>

public abstract void OnCommandExecuting(CommandExecutingContext commandContext);

/// <summary>

/// Called when [command executed].

/// </summary>

/// <param name="commandContext">The command context.</param>

public abstract void OnCommandExecuted(CommandExecutingContext commandContext);

}

你需要为你的命令过滤器实现下面两个方法:

OnCommandExecuting: 此方法将在命令执行前被调用;

OnCommandExecuted: 此方法将在命令执行后被调用;

Order: 此属性用于设置多个命令过滤器的执行顺序;

下面的代码定义了一个命令过滤器 LogTimeCommandFilterAttribute 用于记录执行时间超过5秒钟的命令:

public class LogTimeCommandFilter : CommandFilterAttribute

{

public override void OnCommandExecuting(CommandExecutingContext commandContext)

{

commandContext.Session.Items["StartTime"] = DateTime.Now;

}

public override void OnCommandExecuted(CommandExecutingContext commandContext)

{

var session = commandContext.Session;

var startTime = session.Items.GetValue<DateTime>("StartTime");

var ts = DateTime.Now.Subtract(startTime);

if (ts.TotalSeconds > 5 && session.Logger.IsInfoEnabled)

{

session.Logger.InfoFormat("A command '{0}' took {1} seconds!", commandContext.CurrentCommand.Name, ts.ToString());

}

}

}

然后通过增加属性的方法给命令 "QUERY" 应用此过滤器:

[LogTimeCommandFilter]

public class QUERY : StringCommandBase<TestSession>

{

public override void ExecuteCommand(TestSession session, StringCommandInfo commandData)

{

//Your code

}

}

如果你想应用次过滤器给所有的命令, 你可以向下面的代码这样将此命令过滤器的属性加到你的 AppServer 类上面去:

[LogTimeCommandFilter]

public class TestServer : AppServer<TestSession>

{

}

你可以通过将 commandContext's 的 Cancel 属性设为 True 来取消当前命令的执行:

public class LoggedInValidationFilter : CommandFilterAttribute

{

public override void OnCommandExecuting(CommandExecutingContext commandContext)

{

var session = commandContext.Session as MyAppSession;

//If the session is not logged in, cancel the executing of the command

if (!session.IsLoggedIn)

commandContext.Cancel = true;

}

public override void OnCommandExecuted(CommandExecutingContext commandContext)

{

}

}

ServerConfig配置内没有对ipRange的配置，只有ConnectionFilter属性，但完全不起作用，难道只能使用BootstrapFactory启动才能使用连接过滤吗？