EnyimMemcached扩展 转载http://www.star2008.cn/blogview.asp?logID=1737

最近在看一些Memcached的资料，在.net下它的客户端比php等其他语言要少，我选择了EnyimMemcached(http://www.codeplex.com/enyimmemcached/ )，主要是前几天看大众点评网技术部博客时，发现他们用的是这个客户端(http://it.dianping.com/using_attribute_and_piab_to_hybrid_memcached_and_data_access_layer.htm )
Memcached本身对外提供的命令不多，也就add、get、set、incr、decr、replace、delete、stats等几个，客户端对这些操作进行了封装，总体来说调用还是很简单的。
初看了下EnyimMemcached结构，所有的操作都从Operation类继承，每个子类都实现自己的ExcuteAction

    操作：新窗口查看图片

所有的操作都由MemCachedClient这个门面提供

    操作：新窗口查看图片

在使用过程中，我需要遍历当前缓存，获取所有键值，EnyimMemCached却没有提供遍历的方法。在网上查了下，http://www.cnblogs.com/sunli/archive/2008/11/01/1324153.html 提供了遍历的思路，很简单，用"stats item"与"stats cachedump 1 0"命令即可实现遍历，我要做的只是把两个命令封装成上面提到的Operation，下面是实现代码：

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;

namespace Enyim.Caching.Memcached
{
    /// <summary>
    /// 扩展的获取所有键值操作 by wm
    /// </summary>
    internal class CacheDumpOperation : Operation
    {
        public CacheDumpOperation(ServerPool pool, string regex) : base(pool) 
        {
            this.regexquery = regex;
        }

        private ArrayList results;
        /// <summary>
        /// 结果键值集合
        /// </summary>
        public ArrayList Results
        {
            get { return results; }
        }

        private string regexquery = "";
        /// <summary>
        /// 查询条件正则表达式
        /// </summary>
        public string RegexQuery
        {
            get { return regexquery; }
            set { regexquery = value; }
        }
 

        protected override bool ExecuteAction()
        {
            List<string> lstParams = new List<string>();
            ArrayList arrKeys = new ArrayList();

            foreach (MemcachedNode server in this.ServerPool.WorkingServers)
            {
                using (PooledSocket ps = server.Acquire()) //step1
                {
                    if (ps != null)
                    {
                        ps.SendCommand("stats items");
                        while (true)
                        {
                            string line = ps.ReadResponse();

                            if (String.Compare(line, "END", StringComparison.Ordinal) == 0)
                                break;

                            if (line.Length < 6 || String.Compare(line, 0, "STAT ", 0, 5, StringComparison.Ordinal) != 0)
                            {
                                continue;
                            }

                            string para = line.Split(':')[1];
                            if (!lstParams.Contains(para))
                            {
                                lstParams.Add(para);
                            }
                        }
                    }

                }

                using (PooledSocket psDump = server.Acquire()) //step2
                {
                    if (psDump != null)
                    {
                        foreach (string para in lstParams)
                        {
                            psDump.SendCommand(string.Format("stats cachedump {0} {1}", para, 0));
                            while (true)
                            {
                                string lineDump = psDump.ReadResponse();
                                if (String.Compare(lineDump, "END", StringComparison.Ordinal) == 0)
                                    break;

                                if (lineDump.Length < 6 || String.Compare(lineDump, 0, "ITEM ", 0, 5, StringComparison.Ordinal) != 0)
                                {
                                    continue;
                                }

                                string key = lineDump.Split(' ')[1];
                                if (this.regexquery == "")
                                {
                                    arrKeys.Add(key);
                                }
                                else
                                {
                                    if (Regex.IsMatch(key, this.regexquery))
                                    {
                                        arrKeys.Add(key);
                                    }
                                }
                            }
                        }
                    }
                }

            }

            this.results = arrKeys;
            
            return true;

        }
    }
}
</string></string>

在MemcachedClient中添加方法

/// <summary>
/// 获取所有键值集合
/// </summary>
/// <returns></returns>
public System.Collections.ArrayList GetKeys()
{
    using (CacheDumpOperation g = new CacheDumpOperation(this.pool, ""))
    {
        g.Execute();
        return g.Results;
    } 
}

/// <summary>
/// 根据正则查找匹配缓存键值集合
/// </summary>
/// <param name="regex">
/// <returns></returns>
public System.Collections.ArrayList GetKeys(string regex)
{
    using (CacheDumpOperation g = new CacheDumpOperation(this.pool, regex))
    {
        g.Execute();
        return g.Results;
    }
}