[Solved] What are the alternatives to URLOpenBlockingStream.
lazarus / 38-Networking and Web Programming

----------------------------------------------------------------------
loaded · 2021-11-06 08:29

Hi All,
With the code in the example, I am downloading an image from the https
site using the URLOpenBlockingStream method.
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 procedure
TForm1.Button1Click(Sender: TObject);var    //  add uses
activex,comobj,urlmon,  ExchangeStream: IStream;  Pngstream:
TOleStream;  crono:Cardinal;  furl:string;begincrono:=GetTickCount; 
 furl:='https://tile.openstreetmap.de/7/63/42.png';   //
 https://wiki.openstreetmap.org/wiki/Tile_servers   if
(URLOpenBlockingStream(nil, pchar(furl),ExchangeStream,0,nil)=0) then 
 begin   Pngstream:=TOleStream.Create(ExchangeStream); 
 image1.picture.LoadFromStream(Pngstream); 
 end; TButton(sender).Caption:=FloatToStr((GetTickCount-crono)/1000);
 // about 0.031~ secondsend;
This code downloads the image in the link in about 0.031~ seconds,
uploads the Image and displays it.
I have an application like leaflet  https://leafletjs.com/in my mind,
for this, while I'm just at the beginning, I want to discover the
fastest download method suitable for thread use. I will lay the
groundwork for this today
What alternatives to URLOpenBlockingStream can be used for this?
Any ideas you share will be very valuable to me. Respects.

----------------------------------------------------------------------
Thaddy · 2021-11-06 09:32

A pure blocking alternative is synapse 4.1
There are more alternatives:
packages:
fcl-web/fcl-net
gnutls
Indy
libcurl

and probably more.

All the packages mentioned are cross platform and all come with
examples.

You may want to choose one of these anyway, because they are not tied
to windows.
I guess the speed is more likely to be dependent on connection and
internet speed. Less so on which method you use.

My own preference is currently fcl-web/fcl-net because it is
maintained by the core fpc team and pure Pascal. (or synapse, but fcl-
web/fcl-net is very similar).

Except for synapse all come with FPC/Lazarus as standard.

Note that on windows only URLOpenBlockingStream  may be slightly
faster, but still x-platform is a better option to me.

----------------------------------------------------------------------
loaded · 2021-11-06 16:17

Thaddy Master, thank you for spending your valuable time and sharing
your valuable experience.
This information became like lights on the road. They're pretty good
for a start.

----------------------------------------------------------------------
trev · 2021-11-06 21:29

For Windows, my favourite is the WinInet API because it avoids OpenSSL
DLL hell.

----------------------------------------------------------------------
loaded · 2021-11-12 13:48

Thaddy and trev who replied, thank you as much as the number of
letters in your messages.
After extensive experimentation, I decided to use WinINet.
-Almost the same speed as Chrome.
-In different windows versions, also different http and https servers
work without problems.
-No Dll dependencies
For now, these are very, very good enough for me.
Also, what I learned was extra.