[lNet] LHTTPClient - upload file. Buffer problem.
lazarus / 38-Networking and Web Programming

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Dibo · 2010-11-17 11:33

Hi,

I'm trying to upload file with LHTTPClient. There is no demo in
examples, so I'm doing the same way as with LTCPClient in this topic:
http://lazarus.firmos.at/index.php?topic=5146.0
But I have problem with buffer. Above example presents how to send
large text, so we can easily offset sended chunk with String[Position]
index, but how do this with file buffer? I'm not familiar with
streams. This is fragment of my code:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i private  {
private declarations }  FFile: TFileStream;  FBuff: Pointer; 
FBuffReaded, FBuffSended: Integer;   const  ChunkSize: Longint = 8192;
{ copy in 8K chunks } procedure TForm1.FormCreate(Sender:
TObject);begin  FBuff := GetMem(ChunkSize);  FBuffReaded := 0; 
FBuffSended := 0;end; procedure TForm1.FormDestroy(Sender:
TObject);begin  Freemem(FBuff);  FreeThenNil(FFile);end;   procedure
TForm1.http_clientCanWrite(ASocket: TLHTTPClientSocket;  var
OutputEof: TWriteBlockStatus);var  n: Integer;begin  AddLog('Can
write: ' + IntToStr(integer(OutputEof)));   OutputEof :=
wsPendingData;  repeat    // Next chunk if whole sended    if
(FBuffSended>=FBuffReaded) and (FFile.Position<FFile.Size) then begin 
    FBuffReaded := FFile.Read(FBuff^, ChunkSize);      FBuffSended :=
0;      if (FBuffReaded=0) then Break;    end;        n :=
ASocket.Send(FBuff^, FBuffReaded);    Inc(FBuffSended, n);  // Loop
until filled the OS send buffer or sended whole file  until (n=0) or
((FBuffSended>=FBuffReaded) and (FFile.Position>=FFile.Size));   if
(FBuffSended>=FBuffReaded) and (FFile.Position>=FFile.Size) then   
OutputEof := wsDone;end;  Line 39. How offset buffer (FBuff^) position
to FBuffSended? Because in each loop cycle it send buffer from
begining. Can I somehow strip first FBuffSended bytes from FBuff?

Regards and sorry for my English