Updating the read process upon change

[neodammer]

Ive figured out a way to read a text file while in use and read each line when two files are not the same (the one being used by another process and duplicate one i made for vb access.) The problem lies in this text file being somewhat large >1MB and you know when my timer keeps checking for changes and loading the text file all over again it MAJORLY hogs up cycles. My question is: Is there a way to keep it so the text file in question is loaded into the ram or something? Maybe buffering if i understand what that means correctly.

 

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

'check to see if file exists if so delete and recopy

Dim checkfile As String

checkfile = Dir$("C:\access2.log")

If checkfile = "C:\access2.log" Then

Kill("C:\access2.log")

End If

System.IO.File.Copy("C:\access.log", "C:\access2.log") 'copy file because its in use

'end check

Timer1.Enabled = False

End Sub

 

Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick

Dim fileDetails_new As System.IO.FileInfo = New System.IO.FileInfo("C:\access2.log")

Dim fileDetails_reg As System.IO.FileInfo = New System.IO.FileInfo("C:\access.log")

If fileDetails_new.Length.ToString() <> fileDetails_reg.Length.ToString() Then

 

 

Dim sr As StreamReader = New StreamReader("C:\access2.log")

Dim line As String

 

 

Do 'looping reading each line at a time

line = sr.ReadLine()

If TextBox1.Text = "" Then 'make sure you dont have a blank line at start

TextBox1.Text = Mid(line, 1, 13)

Else

TextBox1.Text = TextBox1.Text & vbCrLf & Mid(line, 1, 13)

End If

 

 

Loop Until line = Nothing 'loop until the end

Me.Show() 'set the caret and redraw to scroll to bottom

TextBox1.SelectionStart = TextBox1.Text.Length

TextBox1.ScrollToCaret()

 

sr.Close() 'close the streamreader

 

End If

 

Private Sub Form1_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing

Kill("C:\access2.log")

End Sub

 

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Timer1.Enabled = True

 

End Sub

 

 

As you can see the access file is constantly being changed so the program is completely copying and reloading the text file into the textbox which again is chewing cycles. anyway to stop it from such a huge lag and just write

Edited August 4, 2005 by neodammer

[PlausiblyDamp]

Just out of interest what is generating the file in the first place? Also instead of just looping in a timer you could use a FileSystemWatcher component from the toolbar to notify you on changes to the file.

Also rather than reading the file line by line you could do a sr.ReadToEnd() to read the entire file into memory in one hit andthen process it. Possibly even skipping to the last read line and only appending new data to the textbox rather than reloading the entire thing.

 

Although it won't solve your problem you might want to replace some of the VB6 code (Dir etc) with the .Net equivalent

   Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
       'check to see if file exists if so delete and recopy
       If File.Exists("C:\access2.log") Then
           File.Delete("C:\access2.log")
       End If
       System.IO.File.Copy("C:\access.log", "C:\access2.log") 'copy file because its in use
       'end check
       Timer1.Enabled = False
   End Sub

   Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick

       Dim fileDetails_new As FileInfo = New FileInfo("C:\access2.log")
       Dim fileDetails_reg As FileInfo = New FileInfo("C:\access.log")
       If fileDetails_new.Length.ToString() <> fileDetails_reg.Length.ToString() Then

           Dim sr As StreamReader = New StreamReader("C:\access2.log")
           Dim line As String

           Do 'looping reading each line at a time
               line = sr.ReadLine()
               If TextBox1.Text = "" Then 'make sure you dont have a blank line at start
                   TextBox1.Text = line.Substring(1, 13)
               Else
                   TextBox1.Text = TextBox1.Text & vbCrLf & line.Substring(1, 13)
               End If
           Loop Until line = Nothing 'loop until the end

           Me.Show() 'set the caret and redraw to scroll to bottom
           TextBox1.SelectionStart = TextBox1.Text.Length
           TextBox1.ScrollToCaret()

           sr.Close() 'close the streamreader

       End If
   End Sub

   Private Sub Form1_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
       File.Delete("C:\access2.log")
   End Sub

   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
       Timer1.Enabled = True
   End Sub

[neodammer]

Could you give a sample code on how I would append a .txt file with readtoend followed by appending? I know how to use readtoend just to import a file etc. not sure exactly how to tell it to append the difference between the files.

 

 

 

It is Apache's access file im trying to create a simple monitor for :D

 

 

 

 

Hmmm what about if I find the # of lines in the file and then compare it and then if different just goto the last line of the old file and write whatever is new to a stored variable and display that? seems then it wouldnt have to to load the entire .txt file everytime.

Edited August 5, 2005 by neodammer

[neodammer]

Here is the project in zip file. You can see what im trying to do better this way and hopefully help me come up with a solution lol i can get it to work just it keeps reloading a huge text file sometimes and all i need it to is update the new data.

 

eeek sorry bout the binaries forgot to remove them thanks ;)

APACHEREADER.zip

Edited August 5, 2005 by neodammer

[neodammer]

err just a thought and a bump as well (im still without a solution to this rofl) but this error is it a memory leak as well? Seems possible but not sure i havent tested it yet.