Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Real-Time HTML5 and Ruby
Search
Luigi Ray-Montanez
March 24, 2012
Programming
3
650
Real-Time HTML5 and Ruby
Presented at RubyNation on March 24, 2012.
Luigi Ray-Montanez
March 24, 2012
Tweet
Share
More Decks by Luigi Ray-Montanez
See All by Luigi Ray-Montanez
A Decade under the Influence
luigi
0
45
Building Upworthy on Rails
luigi
1
140
You'll Never Believe Which Web Framework Powers Upworthy
luigi
0
10k
Server-Sent Events at Realtime Conf 2012
luigi
4
500
Developer Happiness & MongoDB
luigi
2
480
Other Decks in Programming
See All in Programming
Kubernetes History Inspector(KHI)を触ってみた
bells17
0
200
さいきょうのレイヤードアーキテクチャについて考えてみた
yahiru
3
730
Lottieアニメーションをカスタマイズしてみた
tahia910
0
120
テストをしないQAエンジニアは何をしているか?
nealle
0
130
データの整合性を保つ非同期処理アーキテクチャパターン / Async Architecture Patterns
mokuo
41
15k
Writing documentation can be fun with plugin system
okuramasafumi
0
120
CI改善もDatadogとともに
taumu
0
110
sappoRo.R #12 初心者セッション
kosugitti
0
230
AWSマネコンに複数のアカウントで入れるようになりました
yuhta28
2
160
定理証明プラットフォーム lapisla.net
abap34
1
1.7k
Amazon ECS とマイクロサービスから考えるシステム構成
hiyanger
2
490
Honoをフロントエンドで使う 3つのやり方
yusukebe
5
2.2k
Featured
See All Featured
Fontdeck: Realign not Redesign
paulrobertlloyd
82
5.4k
Practical Orchestrator
shlominoach
186
10k
The Cost Of JavaScript in 2023
addyosmani
47
7.3k
What's in a price? How to price your products and services
michaelherold
244
12k
Practical Tips for Bootstrapping Information Extraction Pipelines
honnibal
PRO
12
950
Java REST API Framework Comparison - PWX 2021
mraible
28
8.4k
A designer walks into a library…
pauljervisheath
205
24k
4 Signs Your Business is Dying
shpigford
182
22k
Measuring & Analyzing Core Web Vitals
bluesmoon
6
240
Automating Front-end Workflow
addyosmani
1367
200k
jQuery: Nuts, Bolts and Bling
dougneiner
63
7.6k
Performance Is Good for Brains [We Love Speed 2024]
tammyeverts
7
630
Transcript
Real-Time HTML5 and Ruby Luigi Montanez RubyNation 2012
Overview Part 1 - Real-time HTML5 Technologies Part 2 -
EventMachine Part 3 - Ruby frameworks
tl;dw You can do this stu! in Ruby, you don’t
need Node.js.
Part 1: Real-Time HTML5 Technologies
The Enemy: Page Refreshing
“Classic” Solutions AJAX AJAX Polling COMET (Long Polling)
“Classic” Solutions AJAX AJAX Polling COMET (Long Polling)
WebSockets TCP Socket between browser and server Bi-directional Remains open
until explicitly closed
In the Browser var connection = new WebSocket('ws://example.com/echo'); connection.onopen =
function () { connection.send('Ping'); }; connection.onerror = function (error) { // handle error }; connection.onmessage = function (e) { console.log('Server said: ' + e.data); }; connection.onclose = function () { // ensure you expected a close };
Just TCP A lower level than HTTP Developer de"nes protocol
Support XMPP, IRC, AMQP, VNC Some proxy servers not compatible
No JS Poly!ll Flash-based fallback Socket.IO falls back using di!erent
methods
Bi-directional communication usually overkill.
Server-Sent Events Forgotten little brother of WebSockets Downstream, server to
browser push Just HTTP Browser handles reconnections Pure JS Poly"ll by Remy Sharp
In the Browser var source = new EventSource('/stream'); source.addEventListener('message', function(e)
{ console.log(e.data); }); source.addEventListener('open', function(e) { ... }); source.addEventListener('error', function(e) { ... });
Data data: first line\n data: second line\n\n --- data: {\n
data: "msg": "hello world",\n data: "id": 12345\n data: }\n\n source.addEventListener('message', function(e) { var data = JSON.parse(e.data); console.log(data.id, data.msg); });
Data IDs and Events id: 12345\n data: AAPL\n data: 572.44\n\n
--- data: {"msg": "First message"}\n\n event: userlogon\n data: {"username": "John123"}\n\n event: update\n data: {"username": "John123", "emotion": "happy"}\n\n source.addEventListener('userlogon', function(e) { ... source.addEventListener('update', function(e) { ...
Part 2: EventMachine
Why EM? Many concurrent, long-held connections Addresses the C10K Problem
Can’t use Rails or Rack to support WebSockets and Server-Sent Events
Reactor Pattern Single-threaded event loop listens to many sources Dispatches
synchronous work to handlers Handlers report when done
Timebomb require 'eventmachine' EM.run do EM.add_timer(5) do puts "BOOM" EM.stop_event_loop
end EM.add_periodic_timer(1) do puts "Tick" end end $ ruby timer.rb Tick Tick Tick Tick BOOM
Other Constructs EM#next_tick EM#defer EM::Deferrable EM::Queue EM::Channel
Problem: Pyramid Code or Callback Spaghetti
Tip of the Pyramid EventMachine.run { page = EventMachine::HttpRequest.new('http://example.com/').get page.errback
{ p "Google is down! terminate?" } page.callback { about = EventMachine::HttpRequest.new('http://example2.com').get about.callback { # callback nesting, ad infinitum } about.errback { # error-handling code } } }
EM::Synchrony Ruby 1.9 Fibers Abstracts away callbacks and errbacks Code
looks synchronous but is actually asynchronous
EM + Fiber def http_get(url) f = Fiber.current http =
EM::HttpRequest.new(url).get # resume fiber once http call is done http.callback { f.resume(http) } http.errback { f.resume(http) } return Fiber.yield end EM.run do Fiber.new{ page = http_get('http://www.google.com/') puts "Fetched page: #{page.response_header.status}" if page page = http_get('http://www.google.com/search?q=eventmachine') puts "Fetched page 2: #{page.response_header.status}" end }.resume end
EM::Synchrony::Multi EventMachine.synchrony do multi = EventMachine::Synchrony::Multi.new multi.add :a, EventMachine::HttpRequest.new(uri1).aget multi.add
:b, EventMachine::HttpRequest.new(uri2).apost multi.add :c, EventMachine::HttpRequest.new(uri3).aget res = multi.perform p "Look ma, no callbacks, and parallel HTTP requests!" p res EventMachine.stop end
Part 3: Ruby Frameworks
All built on top of EventMachine
Servers Thin Rainbows!
Cramp Built by Pratik Naik, “lifo” http://cramp.in Supports Fibers $
cramp new myapp
Server-Sent Events class TimeAction < Cramp::Action self.transport = :sse on_start
:send_latest_time periodic_timer :send_latest_time, :every => 2 def send_latest_time data = {'time' => Time.now.to_i}.to_json render data end end
Goliath Built by Ilya Grigorik http://goliath.io Supports EM::Synchrony Both a
server and a framework
Goliath App class Websocket < Goliath::API use Goliath::Rack::Favicon, ‘favicon.ico') map
'/ws', WebsocketEndPoint end
WebSocket Endpoint class WebsocketEndPoint < Goliath::WebSocket def on_open(env) env.logger.info("WS OPEN")
env['subscription'] = env.channel.subscribe { |m| env.stream_send(m) } end def on_message(env, msg) env.logger.info("WS MESSAGE: #{msg}") env.channel << msg end def on_close(env) env.logger.info("WS CLOSED") env.channel.unsubscribe(env['subscription']) end def on_error(env, error) env.logger.error error end end
Frameworks AsyncRack Cramp Faye::WebSocket Goliath
Caveats Separate app Ports vs. Paths Automated Testing
Credits HTML5 Rocks Ilya Grigorik Dan Sinclair Peepcode
Questions?