whosonmodule.cs

asp.net技术内幕的书配源码

using System;
using System.Web;
using System.Collections;
using System.Configuration;

namespace WhosOn {

	public class WhosOnModule : IHttpModule {

		void IHttpModule.Init(HttpApplication myApp) {
			myApp.BeginRequest += new EventHandler(this.OnEnter);
		}

		void IHttpModule.Dispose() {

		}
	
		public void OnEnter(object s, EventArgs e) {
			HttpApplication objApp;		
			HttpContext objContext;
			String strPath;
			Queue colPageStats;
			StatsEntry objStatsEntry;
			int intMaxEntries;
	
			objApp = (HttpApplication)s;
			objContext = objApp.Context;
			strPath = objContext.Request.Path.ToLower();

			// Don't keep stats on .axd pages
			if (strPath.Substring(strPath.Length-4, 4 ) == ".axd")
				return;
		
			strPath = strPath.Substring( 0, strPath.LastIndexOf(".") - 1 );
			// Get Max Entries From Web.Config
			intMaxEntries = Convert.ToInt32(ConfigurationSettings.AppSettings["whoson"]);

			// Check whether Cache object exists
			colPageStats = (Queue)objContext.Cache["whoson_" + strPath];
			if (colPageStats == null)
				colPageStats = new Queue();

			// Add Current Request to the Queue
			objStatsEntry = new StatsEntry(
				objContext.Timestamp,
				objContext.Request.Browser.Type,
				objContext.Request.UserHostName,
				objContext.Request.ServerVariables["HTTP_REFERER"]
				);
			colPageStats.Enqueue( objStatsEntry );

			// Delete Previous Entries
			if (intMaxEntries > 0) {
				while (colPageStats.Count > intMaxEntries) {			
					colPageStats.Dequeue();
				}
			}

			// Update the Cache
			objContext.Cache["whoson_" + strPath] = colPageStats;
		}

	}

	public class StatsEntry {
		public DateTime TimeStamp;
		public string BrowserType;
		public string UserHostName;
		public string Referrer;
		public StatsEntry(DateTime TimeStamp, string BrowserType, string userHostName, string Referrer) {
			this.TimeStamp = TimeStamp;
			this.BrowserType = BrowserType;
			this.UserHostName = UserHostName;
			this.Referrer = Referrer;
		}

	}
}