今天看到Google PageRank Checksumphp代碼才發現上次發布的庫寫的很爛，我根本沒有去理解里面的意思，有很多函數是沒有必要的，如<< >>位操作都已經是現成的，我怎么還照著vb代碼改寫，真是愚蠢。
　　為了彌補我的愚蠢，把php代碼改編成的.net庫,發布出來。

　　Google PageRank 鏈接庫下載地址：http://code.VeVb.com/down/2847.html

　　演示地址：http://PR.csharphack.org/checkpr.aspx

　　使用實例：
　　//得到Pagerank值
　　Console.WriteLine(PRCrack.PageRank.CheckPR("　　//得到pagerank checksum
　　Console.WriteLine(PRCrack.PageRank.OutputCheckSum("));

　　包含函數：
　　//輸出指定網址的pagerank checksum
　　//參數m_Version指定１，表示得到新版本checksum，Google Toolbar版本>>=2.0.114
　　//參數m_Version指定０，表示得到老版本checksum，Google Toolbar版本<2.0.114
　　public static string OutputCheckSum(string m_Url,int m_Version)

　　//輸出制定網址的pagerank
　　public static string CheckPR(string m_Url)
　　Checksum 算法源代碼請看詳細內容

1using System;
2
3namespace PRCrack
4{
5 /// <summary>
6 /// Google PageRank的Checksum算法。
7 /// 作者:4111y80y
8 /// 日期:2005年1月22日
9 /// email:sillyboy@china.com
10 /// </summary>
11 class CheckSum
12 {
13  public CheckSum()
14  {
15   //
16   // TODO: 在此處添加構造函數邏輯
17   //
18  }
19
20  uint GOOGLE_MAGIC=0xE6359A60;
21
22  private uint zeroFill(uint a, int b)
23  {
24   checked
25   {
26    uint z = 0x80000000;
27    if (Convert.ToBoolean(z & a))
28    {
29     a = (a>>1);
30     a &= (~z);
31     a |= 0x40000000;
32     a = (a>>(b-1));
33    }
34    else
35    {
36     a = (a>>b);
37    }
38   }
39   return a;
40  }
41
42  private uint[] mix(uint a,uint b,uint c)
43  {
44   a -= b;  a -= c; a ^= (uint)(zeroFill(c,13));
45   b -= c; b -= a; b ^= (uint)(a<<8);
46   c -= a; c -= b; c ^= (uint)(zeroFill(b,13));
47   a -= b; a -= c; a ^= (uint)(zeroFill(c,12));
48   b -= c; b -= a; b ^= (uint)(a<<16);
49   c -= a; c -= b; c ^= (uint)(zeroFill(b,5));
50   a -= b; a -= c; a ^= (uint)(zeroFill(c,3)); 
51   b -= c; b -= a; b ^= (uint)(a<<10);
52   c -= a; c -= b; c ^= (uint)(zeroFill(b,15));
53  
54   return new uint[3]{a,b,c};
55  }
56
57  private uint GoogleCH(uint[] url, uint length, uint init)
58  {
59   if(length==0)
60   {
61    length = (uint)url.Length;
62   }
63   uint a ,b;
64   a=b= 0x9E3779B9;
65   uint c = init;
66   int k = 0;
67   uint len = length;
68   uint[] m_mix=new uint[3];
69   while(len >= 12)
70   {
71    a += (uint)(url[k+0] +(url[k+1]<<8) +(url[k+2]<<16) +(url[k+3]<<24));
72    
73    b += (uint)(url[k+4] +(url[k+5]<<8) +(url[k+6]<<16) +(url[k+7]<<24));
74    c += (uint)(url[k+8] +(url[k+9]<<8) +(url[k+10]<<16)+(url[k+11]<<24));
75    m_mix = mix(a,b,c);
76    a = m_mix[0]; b = m_mix[1]; c = m_mix[2];
77 
78    k += 12;
79    len -= 12;
80   }
81
82   c += length;
83
84   switch(len)              /* all the case statements fall through */
85   {
86    case 11:
87    {
88     c+=(uint)(url[k+10]<<24);
89     c+=(uint)(url[k+9]<<16);
90     c+=(uint)(url[k+8]<<8);
91     b+=(uint)(url[k+7]<<24);
92     b+=(uint)(url[k+6]<<16);
93     b+=(uint)(url[k+5]<<8);
94     b+=(uint)(url[k+4]);
95     a+=(uint)(url[k+3]<<24);
96     a+=(uint)(url[k+2]<<16);
97     a+=(uint)(url[k+1]<<8);
98     a+=(uint)(url[k+0]);
99     break;
100    }
101    case 10:
102    {
103     c+=(uint)(url[k+9]<<16);
104     c+=(uint)(url[k+8]<<8);
105     b+=(uint)(url[k+7]<<24);
106     b+=(uint)(url[k+6]<<16);
107     b+=(uint)(url[k+5]<<8);
108     b+=(uint)(url[k+4]);
109     a+=(uint)(url[k+3]<<24);
110     a+=(uint)(url[k+2]<<16);
111     a+=(uint)(url[k+1]<<8);
112     a+=(uint)(url[k+0]);
113     break;
114    }
115    case 9 :
116    {
117     c+=(uint)(url[k+8]<<8);
118     b+=(uint)(url[k+7]<<24);
119     b+=(uint)(url[k+6]<<16);
120     b+=(uint)(url[k+5]<<8);
121     b+=(uint)(url[k+4]);
122     a+=(uint)(url[k+3]<<24);
123     a+=(uint)(url[k+2]<<16);
124     a+=(uint)(url[k+1]<<8);
125     a+=(uint)(url[k+0]);
126     break;
127    }
128     /* the first byte of c is reserved for the length */
129    case 8 :
130    {
131     b+=(uint)(url[k+7]<<24);
132     b+=(uint)(url[k+6]<<16);
133     b+=(uint)(url[k+5]<<8);
134     b+=(uint)(url[k+4]);
135     a+=(uint)(url[k+3]<<24);
136     a+=(uint)(url[k+2]<<16);
137     a+=(uint)(url[k+1]<<8);
138     a+=(uint)(url[k+0]);
139     break;
140    }
141    case 7 :
142    {
143     b+=(uint)(url[k+6]<<16);
144     b+=(uint)(url[k+5]<<8);
145     b+=(uint)(url[k+4]);
146     a+=(uint)(url[k+3]<<24);
147     a+=(uint)(url[k+2]<<16);
148     a+=(uint)(url[k+1]<<8);
149     a+=(uint)(url[k+0]);
150     break;
151    }
152    case 6 :
153    {
154     b+=(uint)(url[k+4]);
155     a+=(uint)(url[k+3]<<24);
156     a+=(uint)(url[k+2]<<16);
157     a+=(uint)(url[k+1]<<8);
158     a+=(uint)(url[k+0]);
159     break;
160    }
161    case 5 :
162    {
163     b+=(uint)(url[k+4]);
164     a+=(uint)(url[k+3]<<24);
165     a+=(uint)(url[k+2]<<16);
166     a+=(uint)(url[k+1]<<8);
167     a+=(uint)(url[k+0]);
168     break;
169    }
170    case 4 :
171    {
172     a+=(uint)(url[k+3]<<24);
173     a+=(uint)(url[k+2]<<16);
174     a+=(uint)(url[k+1]<<8);
175     a+=(uint)(url[k+0]);
176     break;
177    }
178    case 3 :
179    {
180     a+=(uint)(url[k+2]<<16);
181     a+=(uint)(url[k+1]<<8);
182     a+=(uint)(url[k+0]);
183     break;
184    }
185    case 2 :
186    {
187     a+=(uint)(url[k+1]<<8);
188     a+=(uint)(url[k+0]);
189     break;
190    }
191    case 1 :
192    {
193     a+=(uint)(url[k+0]);
194     break;
195    }
196     /* case 0: nothing left to add */
197   }
198   m_mix = mix(a,b,c);
199   /*-------------------------------------------- report the result */
200   return m_mix[2];
201  }
202
203  private uint GoogleCH(string url, uint length)
204  {
205   uint[] m_urluint=new uint[url.Length];
206   for(int i=0;i<url.Length;i++)
207   {
208    m_urluint[i]=url[i];
209   }
210   return GoogleCH(m_urluint,length,GOOGLE_MAGIC);
211  }
212
213  private uint GoogleCH(string sURL)
214  {
215   return GoogleCH(sURL,0);
216  }
217
218  private uint GoogleCH(uint[] url, uint length)
219  {
220   return GoogleCH(url, length, GOOGLE_MAGIC);
221  }
222
223  private uint[] c32to8bit(uint[] arr32)
224  {
225   uint[] arr8=new uint[arr32.GetLength(0)*4+3];
226
227   for(int i=0;i<arr32.GetLength(0);i++)
228   {
229    for (int bitOrder=i*4;bitOrder<=i*4+3;bitOrder++)
230    {
231     arr8[bitOrder]=arr32[i]&255;
232     arr32[i]=zeroFill(arr32[i], 8);
233    }   
234   }
235   return arr8;
236  }
237
238  //新算法,ToolBar 版本>>=2.0.114
239  public string CalculateChecksum(string sURL)
240  { 
241   uint ch=GoogleCH("info:" + sURL);
242   
243   ch = (((ch/7) << 2) | (((uint)(ch%13))&7));
244
245   uint[] prbuf = new uint[20];
246   prbuf[0] = ch;
247   for(int i = 1; i < 20; i++) {
248    prbuf[i] = prbuf[i-1]-9;
249   }
250   ch = GoogleCH(c32to8bit(prbuf), 80);
251
252   return string.Format("6{0}",ch);
253  }
254
255  //老算法,ToolBar 版本<2.0.114
256  public string CalculateChecksumOld(string sURL)
257  { 
258   uint ch=GoogleCH("info:" + sURL);
259   
260   string CalculateChecksum = "6" + Convert.ToString((ch));
261   return CalculateChecksum;
262  }
263 }
264}