Node Js and ruby

7/28/2019 Node Js and ruby

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& Ruby

Saturday, April 17, 2010


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@mbleigh



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present.ly



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Whats Node?



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Evented I/OforJavascript



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Runs onGoogles V8



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var sys = require('sys'),

http = require('http');

http.createServer(function (req, res) {

setTimeout(function () {

res.writeHead(200, {'Content-Type': 'text/plain'});

res.end('Hello World\n');

}, 2000);

}).listen(8000);

sys.puts('Server running at http://127.0.0.1:8000/');



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Supported By Node

HTTP, TCP File I/O

Redis, Mongo, SQL (DBSlayer)



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Express: Nodes Sinatra

RESTful DSL for Node webapps Cookies, sessions, caching, etc.

expressjs.com



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require.paths.unshift('path/to/express/lib')

require('express')

get('/', function(){

this.redirect('/hello/world')

})

get('/hello/world', function(){

return'Hello World'

})

run()



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Why Node?



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Generally Speedy



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> summary(node1$ttime)Min. 1st Qu. Median Mean 3rd Qu. Max.

0.0000 0.0000 1.0000 0.7437 1.0000 106.0000

> summary(thin1$ttime)Min. 1st Qu. Median Mean 3rd Qu. Max.0.000 1.000 1.000 1.122 1.000 74.000

> summary(narwhal1$ttime)Min. 1st Qu. Median Mean 3rd Qu. Max.15.00 22.00 23.00 23.74 24.00 88.00

> summary(v8cgi1$ttime)Min. 1st Qu. Median Mean 3rd Qu. Max.12.00 13.00 13.00 14.49 18.00 39.00

four.livejournal.com/1019177.html

http://four.livejournal.com/1019177.htmlhttp://four.livejournal.com/1019177.htmlhttp://four.livejournal.com/1019177.htmlhttp://four.livejournal.com/1019177.html


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Great atConcurrency



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AsynchronousEverything



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functionupload_file(req, res) {req.setBodyEncoding('binary');

var stream = new multipart.Stream(req);stream.addListener('part', function(part) {part.addListener('body', function(chunk) {

var progress = (stream.bytesReceived / stream.bytesTotal *100).toFixed(2);

var mb = (stream.bytesTotal / 1024 / 1024).toFixed(1);

sys.print("Uploading "+mb+"mb ("+progress+"%)\015");

// chunk could be appended to a file if the uploaded file needs tobe saved

});});stream.addListener('complete', function() {res.sendHeader(200, {'Content-Type': 'text/plain'});res.sendBody('Thanks for playing!');res.finish();sys.puts("\n=> Done");

});}

bit.ly/nodejs-fstream



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Javascript isgreat for this.



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Browser and server,together at last



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Why Ruby?



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Are you at theright conf?



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When to Node



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Real-TimeApplications



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WebSockets

Persistent server connections Part of HTML5 True real-time for web apps Deprecate to Flash Sockets



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Why Real-Time?

Better on your server Better for your user

You need more buzzwords



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var socket = new WebSocket("ws://www.websocket.org");

socket.onopen = function(evt) { alert("Open."); };

socket.onmessage = function(evt) { alert(evt.data); };socket.onclose = function(evt) { alert("Closed."); };

socket.send("Hello Web Socket!");

socket.close();

http://www.websocket.org/http://www.websocket.org/


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Why JS for WebSockets?

You already write your client

interaction code in Javascript

Just an extension of that

Same interface throughout



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Hazards of aYoung Tool



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node.websocket.js

Framework-like approach Includes fun examples Node version headaches github.com/guille/node.websocket.js/

http://github.com/guille/node.websocket.js/http://github.com/guille/node.websocket.js/http://github.com/guille/node.websocket.js/


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Socket.IO

Multi-transport socket for Node Comes with client JS library For production usage github.com/rosepad/socket.io-node

http://github.com/rosepad/socket.io-nodehttp://github.com/rosepad/socket.io-nodehttp://github.com/rosepad/socket.io-node


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node.ws.js

Minimal Node WebSocket server

Talk to your browser clientsJavascript all the way down

Mostly for experimentation github.com/ncr/node.ws.js

http://github.com/ncr/node.ws.jshttp://github.com/ncr/node.ws.jshttp://github.com/ncr/node.ws.js


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How can weactually use it?



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Redis is the Bridge

Super-fast, super-awesome PUBSUB = WIN!

Swiss-army knife for your app.



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Example

Twitter-esque status streams

Want to update web interface inreal time

Rails, Node, Redis, and Chrome



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The Ruby Code



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classUser < ActiveRecord::Base# Include default devise modules. Others available are:# :token_authenticatable, :lockable and :timeoutabledevise :database_authenticatable, :registerable, :rememberable, :validatable

# Setup accessible (or protected) attributes for your model

attr_accessible:email, :password, :password_confirmation

deffollow(other_user) Red.sadd "user:#{other_user.id}:followers", self.id Red.sadd "user:#{self.id}:follows", other_user.id end

deffollower_ids Red.smembers "user:#{self.id}:followers" end

deffollow_ids Red.smembers "user:#{self.id}:follows" enddefupdate(text)

(follower_ids + [self.id]).each do |uid| Red.lpush "user:#{uid}:timeline", text Red.lpush "user:#{uid}:updates", text Red.publish "user:#{uid}:timeline", text end endend



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defupdate(text)

(follower_ids + [self.id]).each do |uid|

Red.lpush "user:#{uid}:timeline", text

Red.lpush "user:#{uid}:updates", text

Red.publish "user:#{uid}:timeline", text

end

end



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The Node Code



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var sys = require("sys"),ws = require("./ws"),redis = require("./redis-client");

var pubsub = redis.createClient();

pubsub.stream.addListener('connect', function() {pubsub.subscribeTo("user:*:timeline", function(channel, data) {

var uid = channel.toString().split(':')[1];

if (clients[uid]) {sys.debug("Writing " + data + " to " + uid)clients[uid].write(data);

} else {

sys.debug("User " + clients[uid] + " is not connected.");}

});});

ws.createServer(function (websocket) { var user_id = null; var websocket = websocket;

websocket.addListener("connect", function (resource) {user_id = resource.match(/timeline\/([0-9]+)$/i)[1]clients[user_id] = websocket;

}).addListener("close", function() {sys.debug("User " + user_id + " disconnected.")

});

}).listen(8080);



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ws.createServer(function (websocket) { var user_id = null;

var websocket = websocket;

websocket.addListener("connect", function (resource) {

user_id = resource.match(/timeline\/([0-9]+)$/i)[1]

clients[user_id] = websocket;

}).addListener("close", function() {

sys.debug("User " + user_id + " disconnected.")

});}).listen(8080);



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pubsub.stream.addListener('connect', function() {pubsub.subscribeTo("user:*:timeline", function(channel, data) {

var uid = channel.toString().split(':')[1];

if (clients[uid]) {

sys.debug("Writing " + data + " to " + uid)clients[uid].write(data);

} else {

sys.debug("User " + clients[uid] + " is not connected.");

}

});});



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The Browser Code



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if ("WebSocket" in window) { var ws = new WebSocket("ws://127.0.0.1:8080/timeline/" +current_user);

ws.onmessage = function(evt) {$('ul.timeline').prepend("" + evt.data + "");

}}



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How else can weuse Node?



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AsynchronousApplications



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PushAPIs

Want to notify API subscribers inreal-time

Utilize Webhooks

Example: GitHubs Service Hooks



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File Transcoding



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Online Gaming



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EphemeralPeer-to-Peer



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Wrapping up...



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Tip of the Iceberg

Nodes libraries and use casesare expanding rapidly

Async means thinking differently

Still at the early stages



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howtonode.org



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Node for Ruby?



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EventMachine



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Use what feels right.



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I dont knowthe half of it.



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Questions?

Documents

Node Js and ruby