Demonstration of reel (0.4.0.pre) http responses returning incorrect reel (0.4.0.pre)

app.rb

require 'rubygems'
require 'bundler/setup'
require 'celluloid/autostart'
require 'reel'
require 'json'

module Test
  APP_LOGGER = Logger.new('log.txt');

  Celluloid.logger = APP_LOGGER
  APP_LOGGER.debug "hello"

  class WebServer < Reel::Server
    EXTRA_HEADERS = { :'Access-Control-Allow-Origin' => '*' }
    def initialize
      @silly_counter = 10000
      @data = []
      host = '0.0.0.0'
      port = 8091
      APP_LOGGER.debug "---\n---\n---\nWebServer starting host #{host} port #{port}"
      super(host, port, &method(:on_connection))
    end
    def on_connection(connection)
      while request = connection.request
        @silly_counter += 1
        @data << @silly_counter.to_s
        payload = @data.to_json
        APP_LOGGER.debug "respond with length #{payload.length} payload |#{payload}|"
        connection.respond :ok, EXTRA_HEADERS, payload
      end
    end
  end

  Celluloid::Actor[:web_server] = WebServer.new
  sleep
end
=begin
Author: Craig Anderson craig@coot.net

Demonstrate a reel (0.4.0.pre), celluloid (0.15.0.pre2) application
where a series of get's are done with a text body returned.  The text
body is increased in size on ezch get.  The Content-Length:9 of the first
response body is correct, but the same Content-Length:9 is returned with
each subsequent response, so the body is truncated by the browser.


$ which jruby
/opt/ruby/jruby/bin/jruby

$ which bundle
/opt/ruby/jruby/bin/bundle

$ jruby -v
jruby 1.7.4 (1.9.3p392) 2013-05-16 2390d3b on Java HotSpot(TM) 64-Bit Server VM 1.7.0_25-b15 [linux-amd64]

$ bundle install

$ bundle list
Gems included by the bundle:
  * bundler (1.3.5)
  * celluloid (0.15.0.pre2)
  * celluloid-io (0.14.1)
  * certified (0.1.1)
  * http (0.4.0)
  * http_parser.rb (0.5.3)
  * nio4r (0.5.0)
  * rack (1.5.2)
  * reel (0.4.0.pre)
  * timers (1.1.0)
  * websocket_parser (0.1.4)

$ jruby app.rb

Using developer tools in chromium browser:
Version 28.0.1500.71 Ubuntu 13.04 (28.0.1500.71-0ubuntu1.13.04.1)

The following log mixes the browser request, browser output, response headers and log file text.

--- request
http://localhost:8091/

--- response
Access-Control-Allow-Origin:*
Connection:Keep-Alive
Content-Length:9

["10001"]

--- log
D, [2013-08-30T20:26:23.927000 #4331] DEBUG -- : respond with length 9 payload |["10001"]|

--- request
http://localhost:8091/

--- response
Access-Control-Allow-Origin:*
Connection:Keep-Alive
Content-Length:9

["10001",

--- log
D, [2013-08-30T20:29:45.530000 #4331] DEBUG -- : respond with length 17 payload |["10001","10002"]|

--- request
http://localhost:8091/

--- response
Access-Control-Allow-Origin:*
Connection:Keep-Alive
Content-Length:9

["10001",

--- log
D, [2013-08-30T20:31:44.061000 #4331] DEBUG -- : respond with length 25 payload |["10001","10002","10003"]|

=end

Gemfile

source 'https://rubygems.org'
gem "celluloid", "~> 0.15.0.pre"
gem "reel", "~> 0.4.0.pre"

Gemfile.lock

GEM
  remote: https://rubygems.org/
  specs:
    celluloid (0.15.0.pre2)
      timers (>= 1.0.0)
    celluloid-io (0.14.1)
      celluloid (>= 0.14.1)
      nio4r (>= 0.4.5)
    certified (0.1.1)
    http (0.4.0)
      certified
      http_parser.rb
    http_parser.rb (0.5.3-java)
    nio4r (0.5.0-java)
    rack (1.5.2)
    reel (0.4.0.pre)
      celluloid-io (>= 0.8.0)
      http (>= 0.2.0)
      http_parser.rb (>= 0.5.3)
      rack (>= 1.4.0)
      websocket_parser (>= 0.1.2)
    timers (1.1.0)
    websocket_parser (0.1.4)
      http

PLATFORMS
  java

DEPENDENCIES
  celluloid (~> 0.15.0.pre)
  reel (~> 0.4.0.pre)

proposed_fix.txt

With this change headers[CONTENT_LENGTH] is not present when the check/assignment
of length is done.  The example works correctly.

$ diff response.rb.orig response.rb
  21c21
  <         headers = body_or_headers
  ---
  >         headers = {}.merge body_or_headers

This code is setting the headers[CONTENT_LENGTH] on the first call
and then leaving it alone on subsequent calls

jruby-1.7.4/lib/ruby/gems/shared/gems/reel-0.4.0.pre/lib/reel/response.rb:

module Reel
class Response
...
def initialize(status, body_or_headers = nil, body = nil)
...
case @Body
when String
headers[CONTENT_LENGTH] ||= @body.bytesize
when IO
headers[CONTENT_LENGTH] ||= @Body.stat.size