Delphi fast file copy

Question

I\'m writing an app that supposed to copy a bunch of files from one place to another. When I\'m using TFileStream for the copy it is 3-4 times slower than copying the files

Answer 1

Or you can do it the "dirty" way ... I have found some old code that does the job (not sure if it is fast):

procedure CopyFile(const FileName, DestName: string);
var
   CopyBuffer   : Pointer; { buffer for copying }
   BytesCopied  : Longint;
   Source, Dest : Integer; { handles }
   Destination  : TFileName; { holder for expanded destination name }

const
     ChunkSize  : Longint = 8192; { copy in 8K chunks }

begin
     Destination := DestName;
     GetMem(CopyBuffer, ChunkSize); { allocate the buffer }
     try
       Source := FileOpen(FileName, fmShareDenyWrite); { open source file }
       if Source < 0
          then raise EFOpenError.CreateFmt('Error: Can''t open file!', [FileName]);
       try
         Dest := FileCreate(Destination); { create output file; overwrite existing }
         if Dest < 0
            then raise EFCreateError.CreateFmt('Error: Can''t create file!', [Destination]);
         try
           repeat
             BytesCopied := FileRead(Source, CopyBuffer^, ChunkSize); { read chunk }
             if BytesCopied > 0  {if we read anything... }
                then FileWrite(Dest, CopyBuffer^, BytesCopied); { ...write chunk }
           until BytesCopied < ChunkSize; { until we run out of chunks }

         finally
           FileClose(Dest); { close the destination file }
         end;

       finally
         FileClose(Source); { close the source file }
       end;

     finally
       FreeMem(CopyBuffer, ChunkSize); { free the buffer }
     end;
end;