Share a string replace Method

ArticleDirectory

• String data for testing
• Test related methods
• Specific test code

In the previous article, I shared the custom implementation of an efficient string split method. Next I will share the string-related operation function replace. by decompiling the string replace method, the built-in implementation cannot view the specific implementation source code, so it cannot be inferred how the string replace method is implemented. However, out of curiosity, you can manually implement a corresponding replace function, from the test results, the efficiency is relatively better than the string replace method.

Test Description

To make the test more comprehensive, different content replacement and processing times are added to the test.

• String data for testing

Cache-control: public, Max-age = 0

Content-encoding: Gzip

Content-Length: 9480

Content-Type: text/html; charset = UTF-8

Date: Wed, 31 Oct 2012 14:17:06 GMT

Expires: Wed, 31 Oct 2012 14:17:05 GMT

Last-modified: Wed, 31 Oct 2012 14:17:05 GMT

P3p: Cp = non DSP cor ADM cur Dev Tai our ind nav pre sta

P3p: Cp = non DSP cor ADM cur Dev Tai our ind nav pre sta

Server: Microsoft-Microsoft IIS/7.5

Set-COOKIE: Smark = branch = default & isproject = 1; domain = .codeplex.com; expires = Fri, 31-oct-2042 14:17:06 GMT; Path =/

Vary: Accept-Encoding

X-ASPnet-version: 4.0.30319

X-aspnetmvc-version: 4.0

X-powered-by: ASP. NET

• Test related methods

Static void stringreplace (string value, string olddata, string newdata) {for (INT I = 0; I <count; I ++) {value. replace (olddata, newdata) ;}} static void stringextendreplace (string value, string olddata, string newdata) {for (INT I = 0; I <count; I ++) {stringextend. replace (value, olddata, newdata );}}
 

• TestCode

Static void main (string [] ARGs) {value. replace ("1", "010"); stringextend. replace (value, "1", "010"); console. setout (new system. io. streamwriter ("test.txt"); Count = 1; testreplace (value, "1", "010"); Count = 10; testreplace (value, "C ", "010"); Count = 100; testreplace (value, "W", "010"); Count = 1000; testreplace (value, "A", "010 "); count = 10000; testreplace (value, "0", "010"); Count = 100000; testreplace (value, ":", "010"); Count = 1; testreplace (value, "ASP. net "," aspx "); Count = 10; testreplace (value," 2012 "," 2048 "); Count = 100; testreplace (value," wed ", "MVC"); Count = 1000; testreplace (value, "content", "testopq"); Count = 10000; testreplace (value, "ASP. net "," aspx "); Count = 100000; testreplace (value," our "," BBQ "); console. out. flush (); console. read ();} static void testreplace (string value, string olddata, string newdata) {console. writeline ("========== [count: {0} \ t ({1} to {2})] ================ ", Count, olddata, newdata); system. diagnostics. stopwatch Sw = new system. diagnostics. stopwatch (); Sw. reset (); Sw. start (); stringextendreplace (value, olddata, newdata); Sw. stop (); console. writeline ("stringextendreplace: \ t {0} ms", SW. elapsed. totalmilliseconds); Sw. reset (); Sw. start (); stringreplace (value, olddata, newdata); Sw. stop (); console. writeline ("stringreplace: \ t {0} ms", SW. elapsed. totalmilliseconds); console. writeline ("");}

• Test Results

========= [Count: 1 (1 to 010)] ======================

Stringextendreplace: 0.1728 Ms

Stringreplace: 0.1654 Ms

 

========= [Count: 10 (C to 010)] ======================

Stringextendreplace: 0.0538 Ms

Stringreplace: 0.1002 Ms

 

========= [Count: 100 (W to 010)] ====================

Stringextendreplace: 0.4561 Ms

Stringreplace: 0.9015 Ms

 

========= [Count: 1000 (A to 010)] ====================

Stringextendreplace: 5.4919 Ms

Stringreplace: 11.0184 Ms

 

========= [Count: 10000 (0 to 010)] ====================

Stringextendreplace: 52.7016 Ms

Stringreplace: 96.3369 Ms

 

========= [Count: 100000 (: to 010)] ======================

Stringextendreplace: 633.8311 Ms

Stringreplace: 1025.9258 Ms

 

========= [Count: 1 (ASP. NET to aspx)] ================

Stringextendreplace: 0.0067 Ms

Stringreplace: 0.0084 Ms

 

========= [Count: 10 (2012 to 2048)] ======================

Stringextendreplace: 0.0424 Ms

Stringreplace: 0.0889 Ms

 

========= [Count: 100 (Wed to MVC)] ====================

Stringextendreplace: 0.4074 Ms

Stringreplace: 0.8477 Ms

 

========= [Count: 1000 (content to testopq)] ==================

Stringextendreplace: 4.5297 Ms

Stringreplace: 7.6571 Ms

 

========= [Count: 10000 (ASP. NET to aspx)] ================

Stringextendreplace: 43.2199 Ms

Stringreplace: 82.9951 Ms

 

========= [Count: 100000 (Our to BBQ)] ==================

Stringextendreplace: 442.286 Ms

Stringreplace: 841.7506 Ms

 

Method Source code

[Threadstatic] Static char [] mtempchars; protected static char [] gettempdata () {If (mtempchars = NULL) mtempchars = new char [1024*64]; return mtempchars ;} public static string Replace (string value, string olddata, string newdata) {char [] tmpchars = gettempdata (); int newpostion = 0; int oldpostion = 0; int length = value. length; int oldlength = olddata. length; int newlength = newdata. length; Int Index = 0; int copylength = 0; bool eq = false; while (index <value. length) {eq = true; For (int K = 0; k <oldlength; k ++) {If (value [index + k]! = Olddata [k]) {eq = false; break ;}} if (EQ) {copylength = index-oldpostion; value. copyto (oldpostion, tmpchars, newpostion, copylength); newpostion + = copylength; index + = oldlength; oldpostion = index; newdata. copyto (0, tmpchars, newpostion, newlength); newpostion + = newlength;} else {index ++ ;}} if (oldpostion <length) {copylength = index-oldpostion; value. copyto (oldpostion, tmpchars, newpostion, copylength); newpostion + = copylength;} return new string (tmpchars, 0, newpostion );}

Summary

[Threadstatic] is used to allocate a group of char [] to each thread to minimize the overhead of char. careful friends should find that the char [] size analyzed by each thread is 64 K. In other words, if this method is replaced with 64 K, it will be abnormal, but you can also set a maximum value for analysis. if necessary, add case-insensitive replacement for the function