转自Discuz！NT代震军的blog，修改名字为Regex的效率的奇怪的问题，哈哈

zoukankan html css js c++ java

转自Discuz！NT代震军的blog，修改名字为Regex的效率的奇怪的问题，哈哈

在.net1.4322 和.net2.0下，如下代码运行速度差近50倍，至今还未找到原因，目前的解决方法是在静态构造函数中直接进行声明，以提升速度，如果大家有兴趣可以看一下

RegexOptions.Compiled 这个正则项，我猜在vs2005下的框架有一些变化。

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

using System.Text;
using System.Text.RegularExpressions;

public partial class admin_RetTest2 : System.Web.UI.Page
{

    public static Regex[] r=new Regex[10];

    static admin_RetTest2()
    {
        r[0]=new Regex(@"<%template ([^\[\]\{\}\s]+)%>", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Singleline);
        r[1]=new Regex(@"<%template ([^\[\]\{\}\s]+)%>", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Singleline);
        r[2]=new Regex(@"<%loop ([^\[\]\{\}\s]+) ([^\[\]\{\}\s]+)%>", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Singleline);
        r[3]= new Regex(@"<%\/loop%>", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Singleline);
        r[4] = new Regex(@"<%if ([^\s]+)%>", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Singleline);
        r[5] = new Regex(@"<%else%>", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Singleline);
        r[6] = new Regex(@"<%\/if%>", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Singleline);
        r[7] = new Regex(@"(\{strtoint\(([^\s]+?)\)\})", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Singleline);
        r[8] = new Regex(@"(\{urlencode\(([^\s]+?)\)\})", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Singleline);
        r[9] = new Regex(@"(\{([^\.\[\]\{\}\s]+)\.([^\[\]\{\}\s]+)\})", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.Singleline);

    }

    public string strTemplate = "adfadsf ,adfadf aasdfadfwfadf adfadfwacx adfrafdda swfdfad";


    protected void Page_Load(object sender, EventArgs e)
    {



        ShowTime("有 RegexOptions.Compiled 开始");
        for (int i = 0; i < 100; i++)
        {
            for (m = r[0].Match(strTemplate); m.Success; m = m.NextMatch())
            {
                strTemplate = strTemplate.Replace(m.Groups[0].ToString(), "\r\n");
            }

            for (m = r[2].Match(strTemplate); m.Success; m = m.NextMatch())
            {
                strTemplate = strTemplate.Replace(m.Groups[0].ToString(),
                   "\r\n\tint " + m.Groups[1].ToString() + "__loop__id=0;\r\n\tforeach(DataRow " + m.Groups[1].ToString() + " in " + m.Groups[2].ToString() + ".Rows)\r\n\t{\r\n\t\t" + m.Groups[1].ToString() + "__loop__id++;\r\n");
            }

            for (m = r[3].Match(strTemplate); m.Success; m = m.NextMatch())
            {
                strTemplate = strTemplate.Replace(m.Groups[0].ToString(),
                    "\r\n\t}\t//end loop\r\n");
            }

            for (m = r[4].Match(strTemplate); m.Success; m = m.NextMatch())
            {
                strTemplate = strTemplate.Replace(m.Groups[0].ToString(),
                    "\r\n\tif(" + m.Groups[1].ToString() + ")\r\n\t{\r\n");
            }

            for (m = r[5].Match(strTemplate); m.Success; m = m.NextMatch())
            {
                strTemplate = strTemplate.Replace(m.Groups[0].ToString(),
                    "\r\n\t}\r\n\telse\r\n\t{\r\n");
            }

            for (m = r[6].Match(strTemplate); m.Success; m = m.NextMatch())
            {
                strTemplate = strTemplate.Replace(m.Groups[0].ToString(),
                    "\r\n\t}\t//end if\r\n");
            }

            for (m = r[7].Match(strTemplate); m.Success; m = m.NextMatch())
            {
                strTemplate = strTemplate.Replace(m.Groups[0].ToString(), ", 0)");
            }

            for (m = r[8].Match(strTemplate); m.Success; m = m.NextMatch())
            {
                strTemplate = strTemplate.Replace(m.Groups[0].ToString(),
                    "Utils.UrlEncode(" + m.Groups[2].ToString() + ")");
            }

            //解析{var.a}
            for (m = r[9].Match(strTemplate); m.Success; m = m.NextMatch())
            {

                strTemplate = strTemplate.Replace(m.Groups[0].ToString(),
                    "\" + " + m.Groups[2].ToString() + ".ToString().Trim() + \"");

            }
        }
        ShowTime("有 RegexOptions.Compiled 结束");


    }

    public void ShowTime(string name)
    {
        DateTime dt = DateTime.Now;
        Response.Write("<br>" + name + dt.Minute.ToString() +"分"+ dt.Second.ToString() +"秒" + dt.Millisecond.ToString()+"毫秒");
    }
}

查看全文

相关阅读:
SSH深度历险（五）深入浅出-----IOC AND AOP
Hbuilder X下载及安装教程
 如何用Prometheus监控十万container的Kubernetes集群
 使用并部署Flutter Web的步骤实例
 回顾 Android 11 中的存储机制更新
 移动端UI一致性解决方案
 使用 tail 结合 grep 查找日志关键字并高亮及显示所在行上下文
 Nginx PHP 报504 Gateway time-out错误的解决方法
 SPSS 24 安装详细教程及下载
 CoRL 2020奖项公布，斯坦福获最佳论文奖，华为等摘得最佳系统论文奖

原文地址：https://www.cnblogs.com/kokoliu/p/610925.html