Best way to handle huge strings in C#
I have to write the data below to a textfile after replacing two values with ##IP##, ##PORT##. What is the best way? Should I hold all in a string and use Replace and write to textfile?
Data:
[APP]
iVersion= 101
pcVersion= 1.01a
pcBuildDate=Mar 27 2009
[MAIN]
iFirstSetup= 0
rcMain.rcLeft= 676
rcMain.rcTop= 378
rcMain.rcRight= 1004
rcMain.rcBottom= 672
iShowLog= 0
iMode= 1
[GENERAL]
iTips= 1
iTrayAnimation= 1
iCheckColor= 1
iPriority= 1
iSsememcpy= 1
iAutoOpenRecv= 1
pcRecvPath= C:\Documents and Settings\karthikeyan\My Documents\Downloads\fremote101a\FantasyRemote101a\recv
pcFileName= FantasyRemote
iLanguage= 1
[SERVER]
iAcceptVideo= 1
iAcceptAudio= 1
iAcceptInput= 1
iAutoAccept= 1
iAutoTray= 0
iConnectSound= 1
iEnablePassword= 0
pcPassword=
pcPort= 7902
[CLIENT]
iAutoConnect= 0
pcPassword=
pcDefaultPort= 7902
[NETWORK]
pcConnectAddr=##IP##
pcPort=##Port##
[VIDEO]
iEnable= 1
pcFcc= AMV3
pcFccServer=
pcDiscription=
pcDiscriptionServer=
iFps= 30
iMouse= 2
iHalfsize= 0
iCapturblt= 0
iShared= 0
iSharedTime= 5
iVsync= 1
iCodecSendState= 1
iCompress= 2
pcPlugin=
iPluginScan= 0
iPluginAspectW= 16
iPluginAspectH= 9
iPluginMouse= 1
iActiveClient= 0
iDesktop1= 1
iDesktop2= 2
iDesktop3= 0
iDesktop4= 3
iScan= 1
iFixW= 16
iFixH= 8
[AUDIO]
iEnable= 1
iFps= 30
iVolume= 6
iRecDevice= 0
iPlayDevice= 0
pcSamplesPerSec= 44100Hz
pcChannels= 2ch:Stereo
pcBitsPerSample= 16bit
iRecBuffNum= 150
iPlayBuffNum= 4
[INPUT]
iEnable= 1
iFps= 30
iMoe= 0
iAtlTab= 1
[MENU]
iAlwaysOnTop= 0
iWindowMode= 0
iFrameSize= 4
iSnap= 1
[HOTKEY]
iEnable= 1
key_IDM_HELP= 0x00000070
mod_IDM_HELP= 0x00000000
key_IDM_ALWAYSONTOP= 0x00000071
mod_IDM_ALWAYSONTOP= 0x00000000
key_IDM_CONNECT= 0x00000072
mod_IDM_CONNECT= 0x00000000
key_IDM_DISCONNECT= 0x00000073
mod_IDM_DISCONNECT= 0x00000000
key_IDM_CONFIG= 0x00000000
mod_IDM_CONFIG= 0x00000000
key_IDM_CODEC_SELECT= 0x00000000
mod_IDM_CODEC_SELECT= 0x00000000
key_IDM_CODEC_CONFIG= 0x00000000
mod_IDM_CODEC_CONFIG= 0x00000000
key_IDM_SIZE_50= 0x00000074
mod_IDM_SIZE_50= 0x00000000
key_IDM_SIZE_100= 0x00000075
mod_IDM_SIZE_100= 0x00000000
key_IDM_SIZE_200= 0x00000076
mod_IDM_SIZE_200= 0x00000000
key_IDM_SIZE_300= 0x00000000
mod_IDM_SIZE_300= 0x00000000
key_IDM_SIZE_400= 0x00000000
mod_IDM_SIZE_400= 0x00000000
key_IDM_CAPTUREWINDOW= 0x00000077
mod_IDM_CAPTUREWINDOW= 0x00000004
key_IDM_REGION= 0x00000077
mod_IDM_REGION= 0x00000000
key_IDM_DESKTOP1= 0x00000078
mod_IDM_DESKTOP1= 0x00000000
key_IDM_ACTIVE_MENU= 0x00000079
mod_IDM_ACTIVE_MENU= 0x00000000
key_IDM_PLUGIN= 0x0000007A
mod_IDM_PLUGIN= 0x00000000
key_IDM_PLUGIN_SCAN= 0x00000000
mod_IDM_PLUGIN_SCAN= 0x00000000
key_IDM_DESKTOP2= 0x00000078
mod_IDM_DESKTOP2= 0x00000004
key_IDM_DESKTOP3= 0x00000079
mod_IDM_DESKTOP3= 0x00000004
key_IDM_DESKTOP4= 0x0000007A
mod_IDM_DESKTOP4= 0x00000004
key_IDM_WINDOW_NORMAL= 0x0000000D
mod_IDM_WINDOW_NORMAL= 0x00000004
key_IDM_WINDOW_NOFRAME= 0x0000000D
mod_IDM_WINDOW_NOFRAME= 0x00000002
key_IDM_WINDOW_FULLSCREEN= 0x0000000D
mod_IDM_WINDOW_FULLSCREEN= 0x00000001
key_IDM_MINIMIZE= 0x00000000
mod_IDM_MINIMIZE= 0x00000000
key_IDM_MAXIMIZE= 0x00000000
mod_IDM_MAXIMIZE= 0x00000000
key_IDM_REC_START= 开发者_JAVA百科 0x00000000
mod_IDM_REC_START= 0x00000000
key_IDM_REC_STOP= 0x00000000
mod_IDM_REC_STOP= 0x00000000
key_IDM_SCREENSHOT= 0x0000002C
mod_IDM_SCREENSHOT= 0x00000002
key_IDM_AUDIO_MUTE= 0x00000073
mod_IDM_AUDIO_MUTE= 0x00000004
key_IDM_AUDIO_VOLUME_DOWN= 0x00000074
mod_IDM_AUDIO_VOLUME_DOWN= 0x00000004
key_IDM_AUDIO_VOLUME_UP= 0x00000075
mod_IDM_AUDIO_VOLUME_UP= 0x00000004
key_IDM_CTRLALTDEL= 0x00000023
mod_IDM_CTRLALTDEL= 0x00000003
key_IDM_QUIT= 0x00000000
mod_IDM_QUIT= 0x00000000
key_IDM_MENU= 0x0000007B
mod_IDM_MENU= 0x00000000
[OVERLAY]
iIndicator= 1
iAlphaBlt= 1
iEnterHide= 0
pcFont= MS UI Gothic
[AVI]
iSound= 1
iFileSizeLimit= 100000
iPool= 4
iBuffSize= 32
iStartDiskSpaceCheck= 1
iStartDiskSpace= 1000
iRecDiskSpaceCheck= 1
iRecDiskSpace= 100
iCache= 0
iAutoOpen= 1
pcPath=C:\Documents and Settings\karthikeyan\My Documents\Downloads\fremote101a\FantasyRemote101a\avi
[SCREENSHOT]
iSound= 1
iAutoOpen= 1
pcPath= C:\Documents and Settings\karthikeyan\My Documents\Downloads\fremote101a\FantasyRemote101a\ss
pcPlugin= BMP
[CDLG_SERVER]
mrcWnd.rcLeft= 667
mrcWnd.rcTop= 415
mrcWnd.rcRight= 1013
mrcWnd.rcBottom= 634
[CWND_CLIENT]
miShowLog= 0
m_iOverlayLock= 0
[CDLG_CONFIG]
mrcWnd.rcLeft= 467
mrcWnd.rcTop= 247
mrcWnd.rcRight= 1213
mrcWnd.rcBottom= 802
miTabConfigSel= 2
Why does that look to me like an INI file? Try using Nini.
EDIT: Added sample
Here is the simple sample how you can use Nini library.
using System;
using Nini;
using Nini.Ini;
using Nini.Config;
using System.IO;
namespace CommandLine
{
class Test
{
static void Main(string[] Args)
{
string myIniTxt = Path.Combine(Environment.CurrentDirectory, "ini.txt");
IniConfigSource ini = new IniConfigSource(myIniTxt);
IConfig config = ini.Configs["NETWORK"];
config.Set("pcConnectAddr", "myValueForPcConnectAdd");
config.Set("pcPort", "myValueForPcPort");
ini.Save();
}
}
}
Remark: First link for "Nini" seems to do not work well but here is some others.
http://sourceforge.net/projects/nini/
http://nini.sourceforge.net/Manual/NiniManual.htm
I suggest you just read the file and replace. It should be fine. If you're worried about performance I suggest you measure the performance and try to fix later if it's a problem.
Example.
string file = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "foo.file");
string s = File.ReadAllText(file);
s = s.Replace("##IP##", "127.0.0.1");
s = s.Replace("##PORT##", "80");
File.WriteAllText(file, s);
I think you can use a StringBuilder here.
The StringBuilder lets you manipulate / replace a string in the same memory location.
Every time you manipulate a string, new memory is allocated to hold the result, and old string is garbage collected. The StringBuilder is specially designed to make mutable strings.
Edit after reading comment: The template (the text without the replacements) can be put in a project setting. The IDE will take care of the all the rest.
If it is really huge, it's better to put it in a file in the installation folder. Then you have to make sure the file is installed together with your appliation.
You put the file "MyTemplate.txt" in a StringBuilder like this:
var fileName = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().GetName().CodeBase )),
"MyTemplate.txt");
var stringBuilder = new StringBuilder(File.ReadAllText(fileName));
If you're dead sure about the size of the file and you know it won't exceed say a couple of hundred MB then read it in memory and do a regexp replace. However, for flexibility, I would ready the file one line at a time, make the replacement and write out to a second file.
Should I hold all in a string and use Replace and write to textfile?
That's the first thing to try. The string is pretty small (not megabytes), and I guess you won't be doing it often or in a loop (you'll only be doing it once), and that the delay will be only some fraction of a second which is alright for you, and that another more complicated solution using StringBuilder
would be no more than twice as quick.
You can also check this: Memory Efficiency and Performance of String.Replace .NET Framework.
You can do the following for reading from file, search, replace and then write again.
using System;
using System.IO;
using System.Text.RegularExpressions;
static public void ReplaceInFile( string filePath, string searchText, string replaceText )
{
StreamReader reader = new StreamReader( filePath );
string content = reader.ReadToEnd();
reader.Close();
content = Regex.Replace( content, searchText, replaceText );
StreamWriter writer = new StreamWriter( filePath );
writer.Write( content );
writer.Close();
}
See also this code from scratch: http://www.codeproject.com/KB/string/fastestcscaseinsstringrep.aspx
The best way is to manually parse the contents of the file and make replacements using StringBuilder.
精彩评论