[RESOLVED] I need optimization/speed

[RS_Arm]

This is my code, which needs to be optimized

My function geral.ReadFile:

Public Function ReadFile(FileName As String) As String
Dim Container As String, Fich As Integer

Fich = FreeFile

Open FileName For Input As #Fich
Container = Input(LOF(Fich), Fich)
Close #Fich

ReadFile = Container

End Function

In my sub:

    Original = geral.ReadFile(OriginalFile)     
    ContainerTemp = geral.ReadFile(TempFile)              
    
    Original = Right(Original, Len(Original) - 25)  
    ContainerTemp = Right(ContainerTemp, Len(ContainerTemp) - 25)              
    
    
    If InStr(1, Original, ContainerTemp, vbBinaryCompare) >= 1 Then      
        Kill TempFile                                                           
    Else                                                                        
        Kill OriginalFile                                                       
        Name TempFile As OriginalFile                               
        ListNewRegs = ListNewRegs & OriginalFile & vbNewLine                
    
    End If

Thank you in advance for any given tip.

[Mr.Mac]

This is my code, which needs to be optimized

"Optimized"??

That implies that your code works perfectly, but it too slow, or uses too many instructions or storage space, etc.

What do you want to achieve? Speed it up? I don't see any reason it would run slowly.

Mac

[RS_Arm]

What i need is speed

If you are comparing about 60000 files, you will need it.

Thank you

[leinad31]

Depends largely on the contents of files... try to find other means of determining deletion without having to load most of the file, or other means aside from InStr().

[RS_Arm]

Thank you for your post.

I really need to compare entire file except the 1st 25 characters in the files.
So, do you think that I only can speed up my app using another way to determine the files that i need to delete?

Thank you

[Mr.Mac]

It appears that your program needs to input just the last 25 characters of a file. Your method is to read the entire file into a string and take the last 25 characters from that. Given a very large file, that would be problematic, so I guess that is your optimization problem.

Why not OPEN in BINARY, rather than INPUT?

Then you could input the last 25 characters immediately.

Mac

[RS_Arm]

It's not really that, but you are close.
I need to read from file system, lets say, file.txt.
This file contains exported data from a db.
What I do, is to recreate the content of that file in a temp file, based again in my db.

The 1st 25 characters are the date of creation (on boths files).
Then, I compare the files to check if there is any change.

Thank you

[leinad31]

Thank you for your post.

I really need to compare entire file except the 1st 25 characters in the files.
So, do you think that I only can speed up my app using another way to determine the files that i need to delete?

Thank you

Working with large strings is unavoidably slow due to memory allocation and other factors. You need other criteria... maybe the dates can be used as basis, such as skipping InStr(1, new_file, old_file) since InStr(1, old_file, new_file) is more likely to be performed.

[RS_Arm]

My files have, in average, 1054 bytes.
The date on file is only for tracking the last export, it does not refer to any field from db, so I can't take it as an valid criteria.

Is there any faster methods, I don't know, maybe using Windows API or something like that, or is my code just in its maximum performance?

Thank you

[Mr.Mac]

So if I get it right now, you are faced with two files, and you want to know whether they are identical, ignoring the first 25 characters.

This undebugged function might be more useful

Private Function Same(f1 As String, f2 As String) As Boolean
If Dir(f1) = "" Then Stop ' error in calling program
If Dir(f2) = "" Then Stop ' error in calling program
Dim ff1 As Integer: ff1 = FreeFile
Dim ff2 As Integer: ff2 = FreeFile
Open ff1 For Binary As #ff1
Open ff2 For Binary As #ff2
Dim L1 As Long: L1 = LOF(ff1)
Dim L2 As Long: L2 = LOF(ff2)
If L1 < 26 Or L1 <> L2 Then
  Close #ff1: Close #ff2
  Exit Function
End If
Dim p As Long: p = 26
Const BufSize = 100
Dim Content1 As String * BufSize
Dim Content2 As String * BufSize
Do
  Get #ff1, p, Content1
  Get #ff2, p, Content2
  If Content1 <> Content2 Then
    Close #ff1: Close #ff2
    Exit Function
  End If
  p = p + buffsize
Loop While p < L1
Close #ff1: Close #ff2
Same = True
End Function

[RS_Arm]

Got error 55 in line 7

Open ff2 For Binary As #ff2

Looks like vb6 doesn't like to open a 2nd file without closing the 1st.

[opus]

The code posted has a Typo, I think, f1 is the string with the name of the file and ff1 is the filenumber to be used!
It should read:

Open f1 For Binary As #ff1
Open f2 For Binary As #ff2

[RS_Arm]

same error even with your correction

[opus]

VB6 can open multiple files ( or better Windows can do that), so what is the error given, at which line, what are the values for f1,f2,ff1,ff2?

[RS_Arm]

Run-time error '55':
File already open
Line 7

f1=c:\log\teste.txt
f2=c:\log\teste2.txt

ff1=1
ff2=2

I've rebooted my computer and without doing nothing at all, still got error 55

[opus]

Are you sure that windows doesn't hold an opened file of your examples somewhere? If you not sure try to restart the PC and run the code again.

[edit]
just read the last lien of your post, so restart didn't help.
Then look through your other code, did you open one of the files before the code-lines are occuring?

[RS_Arm]

ok, restarting again...
2 minutes and i'm back

[Merri]

Freefile should be called again only after opening the first file.

[opus]

Good point merri, I was looking in the wrong direction, that should solve his problem!

[RS_Arm]

merri, you got it.
Now is running smoothly.

[RS_Arm]

Now I'm going to addapt it to my app. In some minutes I'll give you all more feedback about speed processing.

Thank you guys for your interest.

brb

[Code Doc]

Your files are rather small, so I believe reading them all in beyond the offset position in binary should be very fast. Consider modifying this alternative:

Dim FF1 As Integer, FF2 As Integer
Dim Data1 As String, Data2 As String
Const OffSet = 25

Private Sub Command1_Click()
Call CompareFiles
End Sub

Public Sub CompareFiles()
FF1 = FreeFile
Open "MyFirstFile" For Binary As #FF1
FF2 = FreeFile
Data1 = Space$(LOF(FF1) - OffSet)
Get #FF1, OffSet + 1, Data1
Open "MySecondFile" For Binary As #FF2
Data2 = Space$(LOF(FF2) - OffSet)
Get #FF2, OffSet + 1, Data1
Close
If Data1 <> Data2 Then
    MsgBox "Files are not the same after offset."
Else: MsgBox "Files match after offset."
End If
End Sub

[RS_Arm]

I'm pretty satisfied with the suggestion from Mr. Mac. It only takes 7 minutes to read 31001 files and compare to other 31001.

Although I'm gonna test your suggestion CodeDoc.

Thank you all guys.
I'm in debt to you all.

[Mr.Mac]

Thanks for your reply, RS_Arm.

Sorry to disconvenience you by posting untested code. I had a doctor appointment and it is snow/ice on the road, so I had to leave immediately.

I hate people that post untested code. Now I see why.

Glad everyone could patch it up.

Mac

[Code Doc]

I'm pretty satisfied with the suggestion from Mr. Mac. It only takes 7 minutes to read 31001 files and compare to other 31001.

Although I'm gonna test your suggestion CodeDoc.

Thank you all guys.
I'm in debt to you all.

Take a look at this while you are at it. CV Michael's code may run faster yet:
http://www.vbforums.com/showthread.php?t=498745

I tested it on a huge file and was rather amazed at the speed. Byte array comparison will probably outrun string comparison.

[opus]

Hi Mr.Mac
If only tested code would be allowed to be posted, none of those who are online but without their IDE on hand could be posting. And even tested code could have an error, we are all humans, we do make mistakes, but by helping each other we all will improve. (Posted in english without my english grammar- and wordbook on hand)

[RS_Arm]

Thank you Code Doc. Indeed, CV Michael's code use much less memory then the other codes (-120mb RAM).
About its speed, it takes the same time (7 mins for 31001 files).

Thank you once again.