Feature #11266: [PATCH] WEBrick: allow subclassing of Response and Request

• Status: Closed
• Assignee: -
• Target version: -

[julik (Julik Tarkhanov)]

To properly support the Rack specification features introduced in 2013, a number of features is needed in HTTPResponse.

• The Response should be able to handle it's socket to the given proc for writing (the socket control should be transferred to another routine). This is required for rack.hijack to work.
• The Response assumes an "IO pull" model via read()/readpartial() for grabbing data from the body. Rack assumes a "push" model for writing the response, so having the ability to take over the socket is better for Rack as well. We can make a Fiber-based adapter to let an iterable object present itself like an IO to WEBrick but having direct socket control is much easier.
• The Response should be able to take control of the chunking. This is currently done as a monkeypatch in Rack, but we much rather have it contained in the Response objects used by the Rack-supplied server handler.

Rack currently solves it by giving WEBrick the read end of an IO pipe, which has a side effect of buffering the entire response even when direct socket operation is needed. This creates a situation where no Rack-based streaming servers can function (no long-polling, no server-sent-events, no large streamed responses via HTTP/FTP adapters etc.)

Since all the three of those require patches to the HTTPResponse, a better approach would be to let the Server object create the right Response and let that response deal with the socket in a way it sees fit. This, however, is impossible at the moment because HTTPResponse and HTTPRequest are hardcoded in the main Server loop code, so if you want to override them with your implementations you have to override the entire service() method.

If we let the Server object instantiate the Response and Request in it's own separate method a Server subclass could use customized versions of those. Pretty much the only downside is one extra method call per HTTP request. Rack could then use it's own Server subclass with the right Response and Request objects in place.

I will be happy to provide a patch.

[julik (Julik Tarkhanov)]

• File custom_req_response.patch custom_req_response.patch added

Patch against current trunk, should be backportable.

[julik (Julik Tarkhanov)]

• Subject changed from WEBrick: allow subclassing of Response and Request to [PATCH] WEBrick: allow subclassing of Response and Request

[nobu (Nobuyoshi Nakada)]

Any reason to create both together in create_request_and_response?

[julik (Julik Tarkhanov)]

No specific reason, only to make the changes to the library smaller. They certainly can be separate methods.

[julik (Julik Tarkhanov)]

• File req_response_sub2.patch req_response_sub2.patch added

Version with separate methods

[julik (Julik Tarkhanov)]

Nobu, is there something else I can do?

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Assigned
• Assignee set to nahi (Hiroshi Nakamura)

[julik (Julik Tarkhanov)]

Is there still anything I can do/change?

[julik (Julik Tarkhanov)]

It has been a year. Is there still anything I can do/change?

[naruse (Yui NARUSE)]

• Assignee changed from nahi (Hiroshi Nakamura) to 11083

[rosenfeld (Rodrigo Rosenfeld Rosas)]

+1 Since WEBrick is part of stdlib, being able to use it in a generic test server which supported Rack hijack would be great as such requests could be tested without any sort of mocking.

[julik (Julik Tarkhanov)]

It has been... a very long time. Nobu, is there something else I can do?

[normalperson (Eric Wong)]

• Status changed from Assigned to Closed

Applied in changeset trunk|r66452.

---

webrick: add the ability to override res, req creation

So that a customized HTTPServer subclass can use it's own
Request/Response classes.

To apply the override, make a subclass of WEBrick::HTTPServer
and override the
create_request_and_response(with_webrick_config) method. The
method should return an Array of [request, response].

To check whether the Server supports this method (i.e. when
using older versions of WEBrick when needing this
functionality), you can ask the server if it responds to the
method

server.respond_to?(:create_request_and_response)

This is backportable.

[ruby-core:69604] [Feature #11266]

From: Julik Tarkhanov [e-mail]

[normalperson (Eric Wong)]

[e-mail] wrote:

It has been... a very long time. Nobu, is there something else I can do?

https://bugs.ruby-lang.org/issues/11266#change-74992

Committed as r66452. Sorry for the delays, I wasn't webrick
maintainer at the time this was brought up so I missed it.

In the future, ping us every week or so to get more people to notice
it. And feel free to Cc: me on webrick or any changes I've been
responsible for in the past. Thanks.