Change maxSize on RequestHeaderParser

[RuslanHimikEvchev]

Hello!
You make a wonderful project, which we use in production. But we have a moment that has to be constantly maintained and remembered about it. This is the maximum size of the buffer, when parsing the request. Now it's 4096 characters, which is not very convenient. Is it possible to make this parameter configurable or get rid of it?
React\Http\RequestHeaderParser, line 18 on v0.7.4

[WyriHaximus]

Hey why is the 4096 length limit an issue for you? It is only used for the limiting the request header size and not the body. Are your headers exceeding that size and if so by how much?

[clue]

Thanks for filing this! I think it makes sense to provide a way to configure this limit and I suppose we would welcome PRs for this 👍

For the reference: Note that this limit only applies to the total maximum size of the incoming request headers, it does not limit the size of the (much bigger) message bodies or the outgoing response headers.

[RuslanHimikEvchev]

In some cases, we have a more than 4k headers bag. Maximum is 16k

[WyriHaximus]

Dang that is a lot , as @clue suggests would you mind creating a PR for it? :)

[christoph-kluge]

I'm willing to help here but I'm not sure how we should get the stuff to the right place.. any preferences here?

// Option#1 inject via optional parameter in __construct() OR via setter
$config = new ServerConfiguration($options);
$config->setRequestHeaderBufferSize($maxSize);

$server = new Server($callback, $config);
$server->setServerConfiguration($config);

// Option#2 inject server configuration via environment variables (default: 4096)
setenv('REACTPHP_REQUEST_HEADER_BUFFER_SIZE', $maxSize);
$server = new Server($callback);

// Option#3 setter inside the server
$server = new Server($callback);
$server->setRequestHeaderBufferSize($maxSize);

[WyriHaximus]

Tbh I would rather see an extra argument to the constructor with options, like:

$config = [];
$config['max_header_size'] = 1024 * 16;
$server = new Server($callback, $config);

[clue]

Small status update: We've raised the hard-coded default request header size to 8 KIB via #253 for the v0.8.0 release. This means that this will be less of an issue for most consumers of this package.

That being said, I think we all agree that offering a way to configure this limit is the goal here. We will look into coordinating efforts to get this in in one of the next releases