spdy

What is spdy?

The spdy npm package is designed to support the SPDY and HTTP/2 protocols in Node.js. It provides server and client functionality, allowing developers to create SPDY/HTTP2 servers and clients with ease. This package is particularly useful for improving web application performance by leveraging the advanced features of these protocols, such as multiplexing, server push, and header compression.

What are spdy's main functionalities?

Creating an SPDY/HTTP2 server

This code sample demonstrates how to create a simple SPDY/HTTP2 server using the spdy package along with Express. It sets up a server that listens on port 3000 and serves a simple message over SPDY/HTTP2.

const spdy = require('spdy');
const express = require('express');
const app = express();

app.get('/', (req, res) => {
  res.end('Hello over SPDY/HTTP2');
});

const options = {
  key: fs.readFileSync('<path-to-key>'),
  cert: fs.readFileSync('<path-to-cert>')
};

spdy.createServer(options, app).listen(3000, () => {
  console.log('Server is running on https://localhost:3000');
});

Creating an SPDY/HTTP2 client

This code sample shows how to create an SPDY/HTTP2 client that connects to a server. It demonstrates making a request to the server and handling the response, including reading response headers and data.

const spdy = require('spdy');
const http2 = require('http2');

const client = spdy.connect('https://localhost:3000', (err, socket) => {
  if (err) {
    throw new Error('Connection failed');
  }

  const req = http2.request({
    ':path': '/'
  });

  req.on('response', (headers) => {
    console.log('Response headers:', headers);
  });

  req.setEncoding('utf8');
  req.on('data', (chunk) => console.log(chunk));
  req.end();
});

Other packages similar to spdy

http2

The http2 package is a core module in Node.js that provides an implementation of the HTTP/2 protocol. It offers similar functionalities to spdy, such as creating servers and clients that can communicate over HTTP/2. However, spdy provides additional support for the SPDY protocol, which is not covered by the http2 module.

node-http2

node-http2 is an npm package that also implements the HTTP/2 protocol. It provides an API for creating HTTP/2 servers and clients. Compared to spdy, node-http2 focuses solely on HTTP/2 without support for SPDY. spdy might offer a more comprehensive solution for developers looking to support both protocols.

README

SPDY Server for node.js

With this module you can create SPDY servers in node.js with natural http module interface and fallback to regular https (for browsers that don't support SPDY yet).

Usage

Server:

var spdy = require('spdy'),
    fs = require('fs');

var options = {
  key: fs.readFileSync(__dirname + '/keys/spdy-key.pem'),
  cert: fs.readFileSync(__dirname + '/keys/spdy-cert.pem'),
  ca: fs.readFileSync(__dirname + '/keys/spdy-ca.pem'),

  // SPDY-specific options
  windowSize: 1024, // Server's window size
};

var server = spdy.createServer(options, function(req, res) {
  res.writeHead(200);
  res.end('hello world!');
});

server.listen(443);

Client:

var spdy = require('spdy');
var http = require('http');

var agent = spdy.createAgent({
  host: 'www.google.com',
  port: 443,

  // Optional SPDY options
  spdy: {
    plain: false or true,
    ssl: false or true,
    version: 3 // Force SPDY version
  }
});

http.get({
  host: 'www.google.com',
  agent: agent
}, function(response) {
  console.log('yikes');
  // Here it goes like with any other node.js HTTP request
  // ...
  // And once we're done - we may close TCP connection to server
  // NOTE: All non-closed requests will die!
  agent.close();
}).end();

And by popular demand - usage with express:

var spdy = require('spdy'),
    express = require('express'),
    fs = require('fs');

var options = { /* the same as above */ };

var app = express();

app.use(/* your favorite middleware */);

var server = spdy.createServer(options, app);

server.listen(443);

API

API is compatible with http and https module, but you can use another function as base class for SPDYServer.

spdy.createServer(
  [base class constructor, i.e. https.Server],
  { /* keys and options */ }, // <- the only one required argument
  [request listener]
).listen([port], [host], [callback]);

Request listener will receive two arguments: request and response. They're both instances of http's IncomingMessage and OutgoingMessage. But three custom properties are added to both of them: streamID, isSpdy, spdyVersion. The first one indicates on which spdy stream are sitting request and response. Second is always true and can be checked to ensure that incoming request wasn't received by HTTPS fallback and last one is a number representing used SPDY protocol version (2 or 3 for now).

Push streams

It is possible to initiate 'push' streams to send content to clients before the client requests it.

spdy.createServer(options, function(req, res) {
  var headers = { 'content-type': 'application/javascript' };
  var stream = res.push('/main.js', headers);
  stream.on('acknowledge', function() {
  });
  stream.on('error', function() {
  });
  stream.end('alert("hello from push stream!");');

  res.end('<script src="/main.js"></script>');
}).listen(443);

Push is accomplished via the push() method invoked on the current response object (this works for express.js response objects as well). The format of the push() method is:

.push('full or relative url', { ... headers ... }, optional priority, callback)

You can use either full ( http://host/path ) or relative ( /path ) urls with .push(). headers are the same as for regular response object. callback will receive two arguments: err (if any error is happened) and stream (stream object have API compatible with a net.Socket ).

Client usage:

var agent = spdy.createAgent({ /* ... */ });
agent.on('push', function(stream) {
  stream.on('error', function(err) {
    // Handle error
  });
  // Read data from stream
  // ...
  // stream.associated points to associated client-initiated stream
});

NOTE: You're responsible for the stream object once given it in .push() callback. Hence ignoring error events on it might result in uncaught exceptions and crash your program.

Trailing headers

Server usage:

function (req, res) {
  // Send trailing headers to client
  res.addTrailers({ header1: 'value1', header2: 'value2' });

  // On client's trailing headers
  req.on('trailers', function(headers) {
    // ...
  });
}

Client usage:

var req = http.request({ agent: spdyAgent, /* ... */ }).function (res) {
  // On server's trailing headers
  res.on('trailers', function(headers) {
    // ...
  });
});
req.write('stuff');
req.addTrailers({ /* ... */ });
req.end();

Options

All options supported by tls are working with node-spdy. In addition, maxStreams options is available. it allows you controlling maximum concurrent streams protocol option (if client will start more streams than that limit, RST_STREAM will be sent for each additional stream).

Additional options:

• plain - if defined, server will ignore NPN and ALPN data and choose whether to use spdy or plain http by looking at first data packet.
• ssl - if false and options.plain is true, http.Server will be used as a base class for created server.
• maxChunk - if set and non-falsy, limits number of bytes sent in one DATA chunk. Setting it to non-zero value is recommended if you care about interleaving of outgoing data from multiple different streams. (defaults to 8192)

Contributors

• Fedor Indutny
• Chris Strom
• François de Metz
• Ilya Grigorik
• Roberto Peon
• Tatsuhiro Tsujikawa
• Jesse Cravens

LICENSE

This software is licensed under the MIT License.

Copyright Fedor Indutny, 2013.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.