need more help with resume

Ok i want to resume a file from a client server setup and this is what i have so far,


client side gets file length of local file that is partially downloaded already and sends this info to server,

VB Code:

dim lengthfile as double
lengthfile = FileLen(.FileName)
Open .FileName For Binary As #1
xTransfer = True
            winsock1.SendData "|RESUME|" & lvFiles.SelectedItem.Key & lengthfile

server side recieves this,

VB Code:

Private Sub winsock1_DataArrival(ByVal bytesTotal As Long)
 Dim recievedataAs String
winsock1.GetData recievedata
 
resumesendFile ?????? ,winsock1
 
End sub

VB Code:

Public Sub ResumeSendFile(FileName As String, WinS As Winsock)
 
Dim FreeF As Integer
Dim LenFile As Long
Dim nCnt As Long
Dim LocData As String
Dim LoopTimes As Long
Dim i As Long
 
FreeF = FreeFile
 
Open FileName For Binary As #99
 
nCnt = 1
 
LenFile = LOF(99)
 
WinS.SendData "|FILESIZE|" & LenFile
DoEvents
 
Sleep (400)
 
 
Do Until nCnt >= (LenFile)
  
    LocData = Space$(1024)
 
  
  Get #99, nCnt, LocData
  
  
  If nCnt + 1024 > LenFile Then
      WinS.SendData Mid$(LocData, 1, (LenFile - nCnt))
  Else
  
    WinS.SendData LocData
  End If
  
  nCnt = nCnt + 1024
 
Loop
 
Close #99
 
End Sub

so according to this i think i have to make nct the value of the client side filelength. Could be way off but thats the way it looks to me.

any suggestions ?

Ok i added a delimiter "," so all i really have to do is parse this typical line to get the file length, any help on parsing this line would be great.

|resume|c:\program files\file1.exe,235043

Add proper splits in

[Resume], Filename, Start Point

VB Code:

Dim strData() as string
 
   'Splits into strings using the "," as a cut point
   strData = split(WinsockReturnedData, ",")
 
   'Get the right string and retrieve the requested files length
   FileLength = Filelen(strData(1))

You aren't guaranteed to receive a complete "request" from the client with one GetData call; your server code is assuming that you do.

You must check you have a complete request before using it. Also remember that you could feasibly receive more than a complete request from a GetData call; you need to account for this possibility aswell.

With TCP IP you should be ok :)

What do you mean by ok?

Data recieved comes in the order and size that you sent it in.

Make sure you have SP5 for VB though or winsock will be buggy :) :)

Uh, yes you receive the data that was sent in the correct order, but there are no guarantees about how much data a particular GetData call will return. Winsock doesn't know what you consider to be a "request" or "command" at the application level.

I have never had trouble before :)

Argh! That doesn't mean it's correct, I've seen apps break because of this when "out in the wild"!

To clarify before I go on more: what is your assumption on what a GetData call will return?

The receieved data :D :D

:rolleyes:

:lol:

Sorry that was just itching to come out :p

i rather suspected so ;) :o