无侵入方面编程用HttpModule+SoapExtension监视页面执行参数(一）

    先简单介绍一下项目吧,我们这个项目是用VS2003开发的，老早一个项目。WEB前端机+业务处理（WebService层）+数据库分别布置在不同的计算机上。

    现在老总有一个需求，要统计出每个页面的执行时间，以及每次调用过哪些WebService方法，调用的时间等参数。

    可行的方案有好多，但我感觉使用HttpModule+SoapExtension，可以不在改变目标系统源码的基础上，完成这项工作。也许有一天，老总说，现在不需要再统计了，我就直接配置一下，不再统计就行了。

    由于要调用WebService，我们采用编写一个SoapExtension，在它的ProcessMessage函数中，在message.Stage是 BeforeSerialize 时，记一个开始时间，并采集一些数据，在message.Stage＝＝AfterDeserialize时，再采集一些时间等数据。最后通过HttpContext.Current.Items[WSInvokeMonitorKey]获取HttpModule的对象，把采集到的数据放在HttpModule里面。

    在HttpModule层，我们可以context的BeginRequest、PreRequestHandlerExecute、PreSendRequestContent、EndRequest中采集数据，最后写入通过Log4net写入日志文件。

    具体实现起来，应该很简单，高手可以略过了。

先看看如何使用吧，只需在Web.Config中加一条配置：

<configuration>
  <system.web>
     <httpModules>
        <add name="WSInvokeMonitorHttpModule" type="Hebmc.WebTools.WSInvokeMonitor.WSInvokeMonitorHttpModule,WSInvokeMonitor"/>
    </httpModules>
    <webServices>
        <soapExtensionTypes>
            <add type="Hebmc.WebTools.WSInvokeMonitor.SimpleWSInvokeMonitorExtension,WSInvokeMonitor"
                priority="1"
                group="0" />
        </soapExtensionTypes>
    </webServices>
 </system.web>
</configuration>

SoapExtension实现：

    public class SimpleWSInvokeMonitorExtension : SoapExtension
    {
        private const string WSInvokeMonitorKey = "__WSInvokeMonitorKey__";
        private WSInvokeInfo invokeInfo = new WSInvokeInfo();
        public override System.IO.Stream ChainStream(System.IO.Stream stream)
        {
            return stream;
        }

        public override object GetInitializer(Type serviceType)
        {
            return null;
        }

        public override object GetInitializer(LogicalMethodInfo methodInfo, SoapExtensionAttribute attribute)
        {
            return null;
        }

        public override void Initialize(object initializer)
        {

        }


        public override void ProcessMessage(SoapMessage message)
        {
            if(message is SoapClientMessage)
            {
                switch (message.Stage) 
                {
                    case SoapMessageStage.BeforeSerialize:

                        //采集时间
                        this.invokeInfo.BeginInvokeTime = DateTime.Now;
                        //采集WebService方法名
                        this.invokeInfo.MethodName = message.MethodInfo.Name;
                        break;


                    case SoapMessageStage.AfterSerialize:
                        break;


                    case SoapMessageStage.BeforeDeserialize:
                        break;

                        // About to call methods
                    case SoapMessageStage.AfterDeserialize:

                        //采集时间
                        this.invokeInfo.EndInvokeTime = DateTime.Now;

                        PageInfo pageInfo = (PageInfo)HttpContext.Current.Items[WSInvokeMonitorKey] ;
                        if(pageInfo != null)
                        {
                            //添加到Module记录
                            pageInfo.AppendInvokeInfo(this.invokeInfo);
                        }

                        break;

                        // After Method call

                    default:
                        throw new Exception("No stage such as this");
                }

            }
            else if(message is SoapServerMessage)
            {
                switch (message.Stage) 
                {
                    case SoapMessageStage.BeforeDeserialize:
                        break;

                    case SoapMessageStage.AfterDeserialize:
                        break;

                    case SoapMessageStage.BeforeSerialize:
                        break;

                    case SoapMessageStage.AfterSerialize:
                        break;

                    default:
                        throw new Exception("No stage such as this");
                }

            }
        }


    }

HttpModule实现：

    public class WSInvokeMonitorHttpModule : IHttpModule    
    {
        private static ILog log  = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
        private const string WSInvokeMonitorKey = "__WSInvokeMonitorKey__";
        HttpApplication httpApp = null;

        #region IHttpModule 成员

        public void Init(HttpApplication webApp)
        {
            this.httpApp = webApp;

            //注册事件 
            this.httpApp.BeginRequest+=new EventHandler(context_BeginRequest);
            this.httpApp.PreRequestHandlerExecute+=new EventHandler(httpApp_PreRequestHandlerExecute);
            this.httpApp.PreSendRequestContent+=new EventHandler(context_PreSendRequestContent);
            this.httpApp.EndRequest+=new EventHandler(context_EndRequest);
        }

        public void Dispose()
        {
            this.httpApp.BeginRequest-=new EventHandler(context_BeginRequest);
            this.httpApp.PreSendRequestContent-=new EventHandler(context_PreSendRequestContent);
            this.httpApp.EndRequest-=new EventHandler(context_EndRequest);
        }

        #endregion







        private void context_BeginRequest(object sender, EventArgs e)
        {
            HttpApplication webApp = sender as HttpApplication;
            if(webApp != null)
            {
                PageInfo pageInfo = null;
                
                //开始时，设置数据对象，将来采集到的数据都放在这里
                webApp.Context.Items[WSInvokeMonitorKey] = pageInfo = new PageInfo();

                //采集路径
                pageInfo.PageUri = webApp.Context.Request.Url.ToString();
            }
            
        }

        private void httpApp_PreRequestHandlerExecute(object sender, EventArgs e)
        {
            HttpApplication webApp = sender as HttpApplication;
            if(webApp != null)
            {
                Page page = webApp.Context.Handler as Page;
                if(page != null)
                {
                    PageInfo pageInfo = (PageInfo)webApp.Context.Items[WSInvokeMonitorKey];
                    if(pageInfo != null)
                    {
                        //采集处理类名，及时间
                        pageInfo.TypeName = page.GetType().FullName;
                        pageInfo.PreRequestHandlerExecuteTime = DateTime.Now;
                    }
                }

            }
        }

        private void context_PreSendRequestContent(object sender, EventArgs e)
        {
            HttpApplication webApp = sender as HttpApplication;
            if(webApp != null)
            {
                Page page = webApp.Context.Handler as Page;
                if(page != null)
                {
                    PageInfo pageInfo = (PageInfo)webApp.Context.Items[WSInvokeMonitorKey];
                    if(pageInfo != null)
                    {
                        try
                        {
                            //采集时间
                            pageInfo.PreSendRequestContentTime = DateTime.Now;

                            if(log.IsInfoEnabled)
                            {
                                //记日志
                                string xmlData = string.Empty;
                                XmlSerializer xs = new XmlSerializer(typeof(PageInfo));
                                StringBuilder sb = new StringBuilder();
                                using(MemoryStream ms = new MemoryStream())
                                {
                                    XmlTextWriter xtw = new XmlTextWriter(ms, Encoding.UTF8);
                                    xtw.Formatting = Formatting.None;
                                    xs.Serialize(xtw, pageInfo);
                                    

                                    ms.Position = 0;

                                    StreamReader sr = new StreamReader(ms, Encoding.UTF8);
                                    xmlData = sr.ReadToEnd();
                                }

                                TimeSpan tsExecute = pageInfo.EndRequestTime - pageInfo.BeginRequestTime;
                                log.InfoFormat("{0},{1},{2}MS,{3},{4},{5}", 
                                    pageInfo.BeginRequestTime, 
                                    pageInfo.TypeName, 
                                    tsExecute.TotalMilliseconds, 
                                    pageInfo.WSInvokeCount,
                                    pageInfo.PageUri, 
                                    xmlData);

                            }
                        }
                        catch (System.Exception ex)
                        {
                            log.Error(ex);
                        }
                    }
                }
            }
        }

        private void context_EndRequest(object sender, EventArgs e)
        {
            HttpApplication webApp = sender as HttpApplication;
            if(webApp != null)
            {
                Page page = webApp.Context.Handler as Page;
                if(page != null)
                {
                    PageInfo pageInfo = (PageInfo)webApp.Context.Items[WSInvokeMonitorKey];
                    if(pageInfo != null)
                    {
                        //采集时间
                        pageInfo.EndRequestTime = DateTime.Now;
                    }


                }
            }
        }

    }

用到的数据类：

namespace Hebmc.WebTools.WSInvokeMonitor.Data
{
    [Serializable]
    public class PageInfo
    {
        private string typeName;
        private string pageUri;
        private DateTime beginRequestTime = DateTime.Now;
        private DateTime preRequestHandlerExecuteTime = DateTime.Now;
        private DateTime endRequestTime = DateTime.Now;
        private DateTime preSendRequestContentTime = DateTime.Now;
        private ArrayList wsInvokeInfoList = new ArrayList();

        /// <summary>
        /// 类名
        /// </summary>
        public string TypeName
        {
            get { return typeName; }
            set { typeName = value; }
        }

        /// <summary>
        /// 页面URI
        /// </summary>
        public string PageUri
        {
            get { return pageUri; }
            set { pageUri = value; }
        }

        /// <summary>
        /// 开始时间
        /// </summary>
        public System.DateTime BeginRequestTime
        {
            get { return beginRequestTime; }
            set { beginRequestTime = value; }
        }

        /// <summary>
        /// 开始处理时间
        /// </summary>
        public System.DateTime PreRequestHandlerExecuteTime
        {
            get { return preRequestHandlerExecuteTime; }
            set { preRequestHandlerExecuteTime = value; }
        }

        /// <summary>
        /// 结束处理时间
        /// </summary>
        public System.DateTime EndRequestTime
        {
            get { return endRequestTime; }
            set { endRequestTime = value; }
        }


        /// <summary>
        /// 向客户端发送数据开始时间
        /// </summary>
        public System.DateTime PreSendRequestContentTime
        {
            get { return preSendRequestContentTime; }
            set { preSendRequestContentTime = value; }
        }

        /// <summary>
        /// 调用次数
        /// </summary>
        [XmlIgnore]
        public int WSInvokeCount
        {
            get
            {
                return this.wsInvokeInfoList.Count;
            }
        }


        /// <summary>
        /// 该页面调用的WebService信息
        /// </summary>
        public WSInvokeInfo[] WSInvokeInfos
        {
            get
            {
                return (WSInvokeInfo[])wsInvokeInfoList.ToArray(typeof(WSInvokeInfo));
            }
            set
            {
                wsInvokeInfoList.AddRange(value);
            }
        }

        /// <summary>
        /// 添加一个调用WebService日志
        /// </summary>
        /// <param name="info"></param>
        public void AppendInvokeInfo(WSInvokeInfo info)
        {
            wsInvokeInfoList.Add(info);
        }

        /// <summary>
        /// 序列化需要
        /// </summary>
        public PageInfo()
        {}
    }

    [Serializable]
    public class WSInvokeInfo
    {
        private string methodName;
        private DateTime beginInvokeTime = DateTime.Now;
        private DateTime endInvokeTime = DateTime.Now;

        /// <summary>
        /// 函数名
        /// </summary>
        public string MethodName
        {
            get { return methodName; }
            set { methodName = value; }
        }

        /// <summary>
        /// 开始调用时间
        /// </summary>
        public System.DateTime BeginInvokeTime
        {
            get { return beginInvokeTime; }
            set { beginInvokeTime = value; }
        }

        /// <summary>
        /// 结束调用时间
        /// </summary>
        public System.DateTime EndInvokeTime
        {
            get { return endInvokeTime; }
            set { endInvokeTime = value; }
        }




    }
}

OK了，这个方案还可以继续深入，可以使用SoapExtension把WebService层的采集到的数据，也拉到前端。这样便可以知道一个WebService方法执行几次数据库连接。嘿嘿。