how to increase max_request_size at request level

[rmallah]

We want to increase max_request_size only for the requests that
handle the file upload in a certain controller.

sub upload {
    my $c = shift ;

  # how do i increase max_request_size here.
   ......
  ......
}

https://docs.mojolicious.org/Mojolicious#max_request_size

above describes how to do in startup {} , but we do not want
to increase the limit for the entire app.

regds
Rajesh Mallah.

[Grinnz]

It's possible you'd be able to increase instead $c->req->max_message_size in the action, but it would have to occur before anything attempts to parse the request body or it may already have been applied.

[kraih]

It has to be done earlier. From an event that triggers before the message body is received. https://docs.mojolicious.org/Mojolicious/Guides/Cookbook#Streaming-multipart-uploads

[rmallah]

the below works (i have tested the code for positive and negative cases)

sub startup {
 my $app =  shift;

 ........

 $app->hook(after_build_tx => sub  {
    my $tx =  shift;
    $tx->on(request => sub  {
      my $url = shift->req->url ;
      if ($url =~ /upload/) {
        $app->max_request_size(104857600);
      }   
    }); 
  });

  ........
}

Q: how do i restore the limit after the request is done ?

[Grinnz]

You can set it only for that request by setting max_message_size on $c->req instead of on the application. Requests may not happen sequentially so if you set it on the app it may affect other requests no matter how soon you change it back.

[rmallah]

I checked below does not work.

 $app->hook(after_build_tx => sub  {
    my $tx =  shift;
    my $app = shift;
    $tx->on(request => sub  {
      my $req = shift->req ;
      if ($req->url =~ /upload/) {
        $req-> max_message_size (104857600);
      }   
    }); 
  }); 

[rmallah]

You can set it only for that request by setting max_message_size on $c->req instead of on the application. Requests may not happen sequentially so if you set it on the app it may affect other requests no matter how soon you change it back.

I am not sure if a strict control is possible, but an eventually consistent threshold converging to default value is still better
and having it (app level setting) raised till lifetime of the process.