mirror of
https://github.com/nodejs/node.git
synced 2024-11-30 07:27:22 +01:00
244 lines
9.2 KiB
HTML
244 lines
9.2 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|
<html xmlns="http://www.w3.org/1999/xhtml">
|
|
<head>
|
|
<style type="text/css">
|
|
ul {
|
|
padding: 0;
|
|
margin: 0;
|
|
}
|
|
</style>
|
|
<script type="text/javascript" src="sh_main.js"></script>
|
|
<script type="text/javascript" src="sh_javascript.min.js"></script>
|
|
<link type="image/x-icon" rel="icon" href="favicon.ico" />
|
|
<link type="image/x-icon" rel="shortcut icon" href="favicon.ico" />
|
|
<link type="text/css" rel="stylesheet" href="pipe.css" />
|
|
<link type="text/css" rel="stylesheet" href="sh_vim-dark.css" />
|
|
<link rel="alternate"
|
|
type="application/rss+xml"
|
|
title="node blog"
|
|
href="http://feeds.feedburner.com/nodejs/123123123"/>
|
|
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
|
|
<title>node.js</title>
|
|
</head>
|
|
<body>
|
|
<div id="toc">
|
|
<ol>
|
|
<li><a href="#download">Download</a></li>
|
|
<li><a href="https://github.com/joyent/node/wiki/ChangeLog">ChangeLog</a></li>
|
|
<li><a href="#about">About</a></li>
|
|
<li><a href="http://nodejs.org/docs/v0.4.12/api">v0.4.12 docs</a></li>
|
|
<li><a href="http://nodejs.org/docs/v0.5.7/api">v0.5.7 docs</a></li>
|
|
<br/>
|
|
<li><a href="https://github.com/joyent/node/wiki">Wiki</a></li>
|
|
<li><a href="http://blog.nodejs.org/">Blog</a></li>
|
|
<li><a href="https://github.com/joyent/node/wiki/Community">Community</a></li>
|
|
<li><a href="http://chat.nodejs.org/">Demo</a></li>
|
|
<li><a href="/logos/">Logos</a></li>
|
|
<li><a href="http://jobs.nodejs.org/">Jobs</a></li>
|
|
<ol><!-- JOBS --><!-- JOBS --></ol>
|
|
</ol>
|
|
</div>
|
|
<div id="content">
|
|
|
|
<!-- <h1><a href="http://nodejs.org/">Node</a></h1> -->
|
|
<br /><br />
|
|
<img id="logo" src="logo.png" alt="node.js"/>
|
|
|
|
<p id="introduction">
|
|
Evented I/O for
|
|
<a href="http://code.google.com/p/v8/">V8 JavaScript</a>.
|
|
</p>
|
|
|
|
<p>
|
|
An example of a web server written in Node which responds with
|
|
"Hello World" for every request.
|
|
</p>
|
|
|
|
<pre>
|
|
var http = require('http');
|
|
http.createServer(function (req, res) {
|
|
res.writeHead(200, {'Content-Type': 'text/plain'});
|
|
res.end('Hello World\n');
|
|
}).listen(1337, "127.0.0.1");
|
|
console.log('Server running at http://127.0.0.1:1337/');
|
|
</pre>
|
|
|
|
<p>
|
|
To run the server, put the code into a file
|
|
<code>example.js</code> and execute it with the <code>node</code>
|
|
program:
|
|
</p>
|
|
<pre class="sh_none">
|
|
% node example.js
|
|
Server running at http://127.0.0.1:1337/</pre>
|
|
|
|
<p>
|
|
Here is an example of a simple TCP server which listens on port 1337
|
|
and echoes whatever you send it:
|
|
</p>
|
|
|
|
<pre>
|
|
var net = require('net');
|
|
|
|
var server = net.createServer(function (socket) {
|
|
socket.write("Echo server\r\n");
|
|
socket.pipe(socket);
|
|
});
|
|
|
|
server.listen(1337, "127.0.0.1");
|
|
</pre>
|
|
|
|
<p>
|
|
See the <a href="/docs">API documentation</a> for more
|
|
examples.
|
|
</p>
|
|
|
|
|
|
<p>
|
|
Go to <a href="https://github.com/joyent/node/wiki">the Wiki</a> for lots more information.
|
|
</p>
|
|
|
|
<h2 id="video">Introduction</h2>
|
|
|
|
<iframe title="YouTube video player" width="640" height="390"
|
|
src="http://www.youtube.com/embed/jo_B4LTHi3I" frameborder="0"
|
|
allowfullscreen></iframe>
|
|
|
|
<h2 id="download">Download</h2>
|
|
|
|
<p>
|
|
<a href="http://github.com/joyent/node/tree/master">git repo</a>
|
|
</p>
|
|
|
|
<p>2011.09.15 v0.4.12 (stable)
|
|
<ul class="release">
|
|
<li><a href="http://nodejs.org/dist/node-v0.4.12.tar.gz"><code>node-v0.4.12.tar.gz</code> Source Code</a>
|
|
<li><a href="http://nodejs.org/docs/v0.4.12/api/index.html">Documentation</a>
|
|
</ul>
|
|
|
|
<p>2011.09.16 v0.5.7 (unstable)
|
|
<ul class="release">
|
|
<li><a href="http://nodejs.org/dist/v0.5.7/node-v0.5.7.tar.gz"><code>node-v0.5.7.tar.gz</code> Source code</a>
|
|
<li><a href="http://nodejs.org/dist/v0.5.7/node.exe"><code>node.exe</code> Windows executable</a>
|
|
<li><a href="http://nodejs.org/docs/v0.5.7/api/index.html">Documentation</a>
|
|
</ul>
|
|
|
|
|
|
<p>Historical: <a href="http://nodejs.org/dist">versions</a>, <a href="http://nodejs.org/docs">docs</a></p>
|
|
|
|
<p>
|
|
For build instructions see
|
|
<a href="https://github.com/joyent/node/wiki/Installation">https://github.com/joyent/node/wiki/Installation</a>
|
|
</p>
|
|
|
|
|
|
<h2 id="about">About</h2>
|
|
|
|
<p>
|
|
Node's goal is to provide an easy way to build scalable network
|
|
programs. In the "hello world" web server example above, many
|
|
client connections can be handled concurrently. Node tells the
|
|
operating system (through <code>epoll</code>, <code>kqueue</code>,
|
|
<code class="sh_none">/dev/poll</code>, or <code>select</code>)
|
|
that it should be notified when a new connection is made, and
|
|
then it goes to sleep. If someone new connects, then it executes
|
|
the callback. Each connection is only a small heap allocation.
|
|
</p>
|
|
|
|
<p>
|
|
This is in contrast to today's more common concurrency model where
|
|
OS threads are employed. Thread-based networking is relatively
|
|
inefficient and very difficult to use. See:
|
|
<a href="http://www.kegel.com/c10k.html">this</a> and
|
|
<a href="http://bulk.fefe.de/scalable-networking.pdf">this.</a>
|
|
|
|
Node will show much better memory efficiency under high-loads
|
|
<!-- TODO benchmark -->
|
|
than systems which allocate 2mb thread stacks for each connection.
|
|
|
|
Furthermore, users of Node are free from worries of dead-locking
|
|
the process—there are no locks. Almost no function in Node
|
|
directly performs I/O, so the process never blocks. Because
|
|
nothing blocks, less-than-expert programmers are able to develop
|
|
fast systems.
|
|
</p>
|
|
|
|
<p>
|
|
Node is similar in design to and influenced by systems like Ruby's <a
|
|
href="http://rubyeventmachine.com/">Event Machine</a> or Python's <a
|
|
href="http://twistedmatrix.com/">Twisted</a>. Node takes the event
|
|
model a bit further—it presents the event loop as a language
|
|
construct instead of as a library. In other systems there is always
|
|
a blocking call to start the event-loop. Typically one defines
|
|
behavior through callbacks at the beginning of a script and at the
|
|
end starts a server through a blocking call like
|
|
<code>EventMachine::run()</code>. In Node there is no such
|
|
start-the-event-loop call. Node simply enters the event loop after
|
|
executing the input script. Node exits the event loop when there are
|
|
no more callbacks to perform. This behavior is like browser
|
|
javascript—the event loop is hidden from the user.
|
|
</p>
|
|
|
|
<p>
|
|
HTTP is a first class protocol in Node. Node's HTTP library has
|
|
grown out of the author's experiences developing and working with
|
|
web servers. For example, streaming data through most web frameworks
|
|
is impossible. Node attempts to correct these problems in its HTTP
|
|
<a href="http://github.com/ry/http-parser/tree/master">parser</a>
|
|
and API. Coupled with Node's purely evented infrastructure, it makes
|
|
a good foundation for web libraries or frameworks.
|
|
</p>
|
|
|
|
<p>
|
|
<i>
|
|
But what about multiple-processor concurrency? Aren't threads
|
|
necessary to scale programs to multi-core computers?
|
|
</i>
|
|
You can start new processes via <code>child_process.fork()</code>
|
|
these other processes will be scheduled in parallel.
|
|
</p>
|
|
|
|
<p>
|
|
See also:
|
|
<ul>
|
|
<li><a href="http://s3.amazonaws.com/four.livejournal/20091117/jsconf.pdf">slides</a> from JSConf 2009</li>
|
|
<li><a href="http://nodejs.org/jsconf2010.pdf">slides</a> from JSConf 2010</li>
|
|
<li><a href="http://www.yuiblog.com/blog/2010/05/20/video-dahl/">video</a> from a talk at Yahoo in May 2010</li>
|
|
</ul>
|
|
</p>
|
|
|
|
|
|
</div>
|
|
|
|
<div style="float: right;">
|
|
<a
|
|
href='https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String'
|
|
title='JS String match'><img
|
|
src='http://static.jsconf.us/promotejsh.gif' height='150' width='180'
|
|
alt='JS String match'/></a>
|
|
</div>
|
|
|
|
<a href="http://no.de/"><img src="sponsored.png" height="58" width="120"/></a>
|
|
|
|
<div style="clear: both; font-size: 8pt">
|
|
Copyright 2010 Joyent, Inc
|
|
<br/>
|
|
Node.js is a trademark of Joyent, Inc.
|
|
See the <a href="trademark-policy.pdf">trademark policy</a>
|
|
for more information.
|
|
</div>
|
|
|
|
<script type="text/javascript">
|
|
var gaJsHost = (("https:" == document.location.protocol) ?
|
|
"https://ssl." : "http://www.");
|
|
document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
|
|
</script>
|
|
<script type="text/javascript">
|
|
try {
|
|
var pageTracker = _gat._getTracker("UA-10874194-2");
|
|
pageTracker._trackPageview();
|
|
} catch(err) {}</script>
|
|
<script type="text/javascript">highlight(undefined, undefined, 'pre');</script>
|
|
</body>
|
|
</html>
|