TidHTTPServer "Out of memory" on large file upload - http

Question

I'm using Delphi 10.3.1 and Indy TIdHTTP / TIdHTTPServer
I created a client / server application to archive files.
The client uses a TIdHTTP component, the code is something like this:
procedure TForm1.SendFileClick (Sender: TObject);
var
Stream: TIdMultipartFormDataStream;
begin
Stream: = TIdMultipartFormDataStream.Create;
try
Stream.AddFormField ('field1', 'hello world');
Stream.AddFile ('field2', 'c:\temp\gigafile.mp4');
idHTTP.Post ('http://192.168.1.100:1717', Stream);
finally
Stream.Free;
end;
end;
The server uses a TIdHTTPServer component.
Everything seemed to work perfectly until I uploaded very large video files (>= 1GB), because I got the error "Out of memory".
By debugging, I saw that I get the error in function PreparePostStream (line 1229 of the IdCustomHTTPServer unit) when it calls LIOHandler.ReadStream, the event OnCommandGet is not fired yet.
The function LIOHandler.ReadStream goes wrong when it runs AdjustStreamSize (line 2013 of the IdIOHandler unit)
In my last test, with a large video file, in the AdjustStreamSize function, the value of ASize was 1091918544 and I got the error during the execution of
AStream.Size line: = ASize
I think that the origin point of the error is in the System.Classes unit in the following procedure when at the SetPointer ... line.
procedure TMemoryStream.SetCapacity (NewCapacity: NativeInt);
{$ IF SizeOf (LongInt) = SizeOf (NativeInt)}
begin
  SetPointer (Realloc (LongInt (NewCapacity)), FSize);
  FCapacity: = NewCapacity;
end;
I read many articles on the web but I didn't understand if there is something wrong in my code.
How can I solve it or is there a limit to the size of the files I can upload with TIdHTTPServer?

Answer 1

By default, TIdHTTPServer receives posted data using a TMemoryStream, which will obviously not work well for such large files. You can use the server's OnCreatePostStream event to provide an alternative TStream object to receive into, such as a TFileStream.

Answer 2

Delphi by default seems to have some kind of limit on memory usage, adding this lines to .DPR project file:
const
IMAGE_FILE_LARGE_ADDRESS_AWARE = $0020;
{$SetPEFlags IMAGE_FILE_LARGE_ADDRESS_AWARE}
applications can use up to 2.5 GB of RAM on the 32bit versions of Windows and up to 3.5 GB of RAM on the 64bit versions.
(https://cc.embarcadero.com/item/24309)
Anyway I think #RemyLebeau solution is the best