ayu.rb

## currently mostly a fruity fish soup for h2o
module Ayu

  #Resource, currently non stackable
  class Resource

    HTTPMethods = %i(get post put delete head options trace connect).uniq

    class << self
      def http_methods
        @http_methods ||= Array.new
      end
    end

    HTTPMethods.each { |http_method|
      define_singleton_method(http_method) { |&blk|

        bmname = :"__#{http_method}"
        define_method(bmname, &blk)
        define_method(http_method) { |*args|
          response = send(bmname, *args)
          case response
          when Array #, Rack::Response
            resp
          else
            response = response.to_s 
            [200, {'Content-Type' => 'text/plain'}, [response]] #TODO: check if h2o adds Content-Length
          end

        }
      }
      define_method(http_method) { |*args| default_http_method(*args) }
    }

    # Every resource, on being instantiated, is given the Rack env.
    def initialize(env, app = nil, params = nil)
      @env, @app, @params = env, app, params
    end


    #bounce back to h2o
    def default_http_method(*args)
      [399,{},[]]
    end


  end
  
	class App
		Errors = {
			400 => [400, {'Content-Type' => 'text/plain'}, ["400 Bad Request.\n"]],
			404 => [404, {'Content-Type' => 'text/plain'}, ["404 Not Found\n"]],
			501 => [501, {'Content-Type' => 'text/plain'},["501 Not Implemented.\n"]],
      399 => [399,{}, []], #bounce to h2o
		}

    Routes = R3::Tree.new(100) 

    # Method name cache.  Maps HTTP methods to object methods.
    # not 100% sure if this is really faster compared to .downcase.to_sym
    HttpMethods = Hash.new { |h,k| h[k] = k.downcase.to_sym }
    # Prefill MNCache above with the likely culprits:
    %w(GET PUT POST DELETE OPTIONS HEAD TRACE CONNECT PATCH).each{ |m| HttpMethods[m] }


    def self.resource(path, res = nil, &blk)
      Routes.add(path, R3::ANY, res )
    end

    def initialize
      Routes.compile
    end


    # Rack handlerß
    # TODO: define behaviour if method is not defined or no handler is found. 
    # either bounce back to h2o or return an item from Errors
    def call env, req_path = nil
      rm = HttpMethods[env['REQUEST_METHOD']]
      return(Errors[501]) unless rm

      params, handler = Routes.match env['PATH_INFO']
      return Errors[399] unless handler

      res = handler.new(env, self, params)
      res.send(rm)
    end
	end #App

end #module

error.json

{"msg": "FAILOMATICS"}

h2o.conf

listen:
  port: 8080

num-threads: 1
hosts:
  "*":
    paths:
      /:
        mruby.handler-file: sample.rb
        file.file: error.json

sample.rb

require 'ayu'

class MyApp < Ayu::App 

	class UserResource < Ayu::Resource
		get do 
			{msg: "hello world from ayu!", params: @params, env: @env }.to_json 
		end
	end

	resource('/users/{user_id}', UserResource)
end

MyApp.new