JS everywhere 2011

The Future of Server Side JavaScript

/me #startups #akshell #ringojs #moscowjs #dailyjs

Node.js Ideal use cases Real time apps, infrastructure duct tape Badly suited for CRUD, command line tools, CPU heavy loads Easy to get started with Difficult to get into production

Akshell NarwhalJS RingoJS Wakanda GPSEE v8cgi

“ async style is kicking sync style's back end”

sync is “on top of” async – a higher level of abstraction

Sync vs. Async function add(callback) { http.get(url1, function(response1) { var part1 = response1.data; http.get(url2, function(response2) { var part2 = response2.data; callback(part1 + part2); } } }

Sync vs. Async http.get(url1).data + http.get(url2).data

Interoperability Pure JavaScript modules run anywhere Templating, parsing, formatting, encoding Anything doing I/O exposes sync or async API Defines the interface exposed by higher level packages

CommonJS /1 Modules/1.1 Packages/1.0 Assert Console System/1.0

CommonJS /2 Binary/B IO/A JSGI 0.3 Filesystem/A

CommonJS /3 HTTP Client /A Sockets/A Subprocess

common-node Implements synchronous CommonJS proposals using node-fibers Traceur to support latest language features Bridges the gap between platforms, sync and async

What's it actually good for? Business logic Lots of state, fine grained error handling CRUD Java, Rails, PHP, Python Command line tools Cross platform portability

On Threads & Fibers “ Threads suck” - Brendan Eich, creator of JavaScript “ Fibers introduce interleaving hazards — Any function call can cause a yield and then your closure invariants *may be* broken.” - Kris Kowal, creator of CommonJS/Modules

Concurrency in JavaScript “ You shouldn’t think that event-based concurrency eliminates synchronization, or shared memory, or anything other than preemption” - Sam Tobin-Hochstadt, member of the Ecma TC39 committee on JavaScript

fibers /1 Co routine implementation using libcoro Co-operative multitasking Implicit synchronization

fibers /2 Not a fork or a hack of Node No wrapper script required V8 Context and 64KB stack per fiber Will run on Windows

Node.js process [ closure closure t ->

RingoJS (0.8) process thread stack process thread stack t ->

Common Node (fibers) process fiber stack fiber stack [ t ->

Node.js Common Node RingoJS Process Count Single Single Multiple State Closure Fiber Stack Thread Stack Multitasking User (co-op) Library (co-op) OS (pre-empt) Memory Usage Low Low High “ Jitter” High High Low

Internals - sleep exports.sleep = function(milliseconds) { var fiber = Fiber.current; setTimeout(function() { fiber.run(); }, milliseconds); yield(); } ;

Internals – HttpClient /1 var req = http.request(options, function(r) { fiber.run(r); }); req.on('error', function(error) { fiber.run(error); }); this.guts.body.forEach(function(block) { req.write(block.buffer || block); }); req.end();

Internals – HttpClient /2 var result = yield(); if(result instanceof Error) throw new Error(result.message); return { status: result.statusCode, headers: result.headers, body: new Stream(result) };

Internals - IO // on 'data', 'end', 'error' // pause when draining var listeners = attach(this.stream); var data = yield(); detach(this.stream, listeners);

JSGI exports.app = function(request) { return { status: 200, headers: {}, body: ['Hello World!'] // openRaw(module.filename) }; };

Spawn & Sleep exports.app = function(request) { spawn(function() { sleep(10000); console.log('Hello Server!'); }); return { status: 200, headers: {}, body: ['Hello Client!'] }; };

HTTP Proxy var HttpClient = require('httpclient').HttpClient; exports.app = function(req) { req.url = 'http://nodejs.org'; return new HttpClient(req).finish(); };

Twitter Streaming /1 var stream = new TextStream( new HttpClient({ method: 'POST', url: '...', headers: {} body: ['track='+system.args[4]], timeout: 10000 }).finish().body);

Twitter Streaming /2 var line; while(true) { line = stream.readLine(); if(!line.length) break; if(line.length > 1) { var message = JSON.parse(line); console.log(message.text); } }

hello-world exports.app = function() { return { status: 200, headers: { 'Content-Type': 'text/plain' }, body: ['Hello World!\n'] }; };

string-alloc exports.app = function(request) { for( var i = 1; i <= 50; i++) b.decodeToString("ascii"); return { status: 200, headers: {}, body: [b] }; };

parse-json exports.app = function(request) { JSON.parse(json); return { status: 200, headers: {}, body: [json] }; };

static-file exports.app = function() { return { status: 200, headers: {}, body: openRaw('../README.md') }; };

set-timeout exports.app = function() { sleep(100); return { status: 200, headers: {}, body: [] }; };

Contributing Google “ common node ” github.com/olegp/common-node/ npm -g install common-node

Next Steps Stick backport Database access selectjs.com Higher level packages (wiki)

common-utils base64: encode, decode hash: sha1 etc. url: parse, format, resolve string: format, trim etc. date: format, add, before, after etc. array: contains etc. object: clone, merge etc.

One more thing ... Third party services & APIs olegp/rest-wrapper thelockerproject.org Browser based IDEs (Cloud9, Akshell) Social hosting PINF, automatic redeployment, continuous integration etc.

Summary sync and async will co-exist toolkits instead of frameworks implementation driven de-facto standards we are just getting started!

JS everywhere 2011

More Related Content

What's hot

Viewers also liked

Similar to JS everywhere 2011

More from Oleg Podsechin

Recently uploaded

JS everywhere 2011