Class: Rack::WASI::IncomingHandler

Inherits:
Object
  • Object
show all
Defined in:
lib/rack/wasi/incoming_handler.rb

Overview

wasi:http/proxy-like handler implementation for Rack apps

Instance Method Summary collapse

Constructor Details

#initialize(app, base_url: "http://localhost:3000", skip_data_uri_uploads: false) ⇒ IncomingHandler

Returns a new instance of IncomingHandler.



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# File 'lib/rack/wasi/incoming_handler.rb', line 128

def initialize(app, base_url: "http://localhost:3000", skip_data_uri_uploads: false)
  @app = app

  @app = Rack::DataUriUploads.new(@app) unless skip_data_uri_uploads

  @base_url = base_url
end

Instance Method Details

#handle(req, res) ⇒ Object

Takes Wasi request, converts it to Rack request, calls the Rack app, and write Rack response back to the Wasi response.

Parameters:

  • req (Rack::WASI::HTTP::IncomingRequest)
  • res (Rack::WASI::HTTP::ResponseOutparam) 


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# File 'lib/rack/wasi/incoming_handler.rb', line 141

def handle(req, res)
  uri = URI.join(base_url, req.path_with_query || "")
  headers = req.headers.each.with_object({}) do |(key, value), headers|
    headers["HTTP_#{key.upcase.gsub("-", "_")}"] = value
    headers
  end

  http_method = req.method.upcase
  headers[:method] = http_method

  body = req.consume
  headers[:input] = StringIO.new(body) if body

  request = Rack::MockRequest.env_for(uri.to_s, headers)
  begin
    response = Rack::Response[*@app.call(request)]
    response_status, response_headers, bodyiter = *response.finish

    out_response = OutgoingResponse.new(headers: response_headers, status_code: response_status)

    body = ""
    body_is_set = false

    bodyiter.each do |part|
      body += part
      body_is_set = true
    end

    # Serve images as base64 from Ruby and decode back in JS
    # FIXME: extract into a separate middleware and add a header to indicate the transformation
    if response_headers["Content-Type"]&.start_with?("image/")
      body = Base64.strict_encode64(body)
    end

    out_response.write(body) if body_is_set
    res.set(Result.new(out_response, nil))
  rescue Exception => e
    res.set(Result.new(e.message, 503))
  end
end