Common Node

This package implements a number of CommonJS proposals on top of Node.js using node-fibers. Fibers are used to emulate multi-threading within a single process, allowing one to use a synchronous programming style and as a result:

• write fast CRUD webapps that run on Node.js without messy callbacks and with very little overhead
• run webapps, middleware and libraries written for RingoJS, Narwhal, Akshell, Erbix, Wakanda, v8cgi and other implementations
• mix & match synchronous/asynchronous styles and use the best tool for the job by writing maintainable business logic in a synchronous manner
• write concise, legible shell scripts

For an example of a production app using Common Node, check out StartHQ.

If you have a spare 20 minutes, you can also check out this presentation (audio included). If you have any questions about Common Node, or mongo-sync, stick and other libraries built on top of it, please post them to the Common Node mailing list or IRC, channel #common-node on Freenode.

For a real world application using Common Node, take a look at the Minimal CMS.

The following modules are included:

• assert - Unit Testing/1.0 (available in Node) & a suite for running tests
• console - Console - partial implementation available in Node
• system - System/1.0
• binary - Binary/B
• io - IO/A, including a ByteArray backed MemoryStream
• fs - Filesystem/A
• httpserver - JSGI 0.3 compatible HTTP server
• httpclient - HTTP Client/A
• ringo/httpclient - RingoJS HttpClient wrapper for httpclient
• subprocess - methods for launching subprocesses modeled after Ringo
• socket - Sockets/A (work in progress)

Installation

If you don't already have them, install Node version 0.10.0 or later (previous versions for Node going back as far as 0.4.0 are also available in NPM) and Node Package Manager. It's also highly recommended that you have your $NODE_PATH variable set correctly.

Install common-node as a global package:

[sudo] npm -g install common-node

Run the "Hello World" example:

common-node $NODE_PATH/common-node/examples/hello.js

You shouldn't see any output. To test that it's working, make an HTTP request from another prompt:

curl http://localhost:8080/

Note: by default the port used is 8080 - to change this add the port number you want as the last command line argument.

Examples

A number of examples are available in common-node/examples:

• hello.js - Hello World webapp using JSGI to return a simple text response
• static.js - streams a static file as a response
• http.js - makes an HTTP request to another server and returns the result in the response
• sleep.js - sleeps for one second before returning a response
• spawn.js - spawns a new fiber which prints to stdout ten seconds after processing a request
• twitter.js - an example of using Twitter's streaming API, uses HttpClient & TextStream for reading one line at a time
• chat.js - Telnet chat server, compare this to an async implementation

For more usage examples, please refer to the tests in the common-node/test directory.

If you're looking for an Express like framework that works with Common Node, take a look at Stick. There's also the Notes example webapp which uses Stick and a MongoDB data store.

Common Node also works well with CoffeeScript, check out this example.

Documentation

The API reference is available at http://olegp.github.com/common-node/doc/

To generate the documentation, install RingoJS and run:

ringo-doc -n "Common Node" -s ./lib -d ./doc --file-urls

Tests

To run the unit tests run:

node test/all.js

You can also run individual tests or sets of tests, for example:

node test/io.js
node test/fs-base/all.js

Benchmarks

Although common-node is optimized for development efficiency rather than performance, a number of benchmarks are included in common-node/benchmarks. A common-node version, an asynchronous Node version using Connect & a RingoJS version of each benchmark is provided. The scripts are based on the Ringo/Node benchmark scripts, with a couple of additions.

The benchmarks have the following dependencies:

• connect for Node which can be installed via npm
• ringo which can be installed by following the instructions in the RingoJS repository
• ab - installed with sudo apt-get install apache2-utils on Debian/Ubuntu
• gnuplot - installed with sudo apt-get install gnuplot-nox

To run them and generate graphs, execute the following command:

cd benchmarks/; ./run; ./graph

This will generate PNG images of the graphs in benchmarks/results/graphs/. Some results are provided below:

• buffer-alloc - creates a number of byte arrays per request; the difference in performance compared to Node is due to the array being cleared
• hello-world - returns a dynamically generated string
• no-alloc
• parse-json
• set-timeout - sleep for 100ms before returning a response
• static-file - returns a file served from the file system
• string-alloc

As you can see from the results and given no profiling or optimization work has been done so far, there's room for improvement. Any patches or suggestions on how to improve performance would be greatly appreciated.

Embedding

You can use Common Node without invoking the common-node binary. There are two ways to do this:

• the bootstrapped approach allows you to run your Common Node code as is, but prevents you from accessing core Node modules such as fs (by over-riding that with Common Node's fs module instead)
• the mixed mode approach allows you to use Commo Node along side your existing Node specific code

Bootstrapped

To bootstrap Common Node & assuming your app's entry point is in main.js, simply add an index.js with the following contents to the same directory:

require('common-node').run('./main');

Then, instead of starting your app with common-node main.js, run node index.js.

Mixed Mode

To use Common Node alongside your existing Node code, you will need to:

• run your app with node instead of common-node
• change the way in which you require modules from var io = require('io'); to var io = require('common-node').io; or update your NODE_PATH to include common-node/lib (see bin/common-node for an example)
• make sure any synchronous code is inside a fiber that has been created with spawn (in the example below each call of exports.app runs in a new fiber)

For example the following modified version of examples/http.js can be run directly via node http.js

var HttpClient = require('common-node').httpclient.HttpClient;

exports.app = function(request) {
  return {
    status: 200,
    headers: {},
    body: new HttpClient({
      url: 'http://google.com'
    }).finish().body
  };
};

if (require.main == module) {
  require('common-node').run(exports);
}

Contributing

To contribute to this project, you can start by trying to run the tests on your system and posting any failures on the issue tracker. It is advised that you use the version in master for doing this, which you can install via:

npm install -g https://github.com/olegp/common-node/tarball/master

If you run into any issues along the way, whether related to using this library in your own project or to the documentation, please post your comments on the issue tracker. The tracker is also a great place to contribute ideas and find out what needs doing.

If you're coming from Ringo or Narwhal, please try running the tests for some of your existing packages. If the tests pass and the package is compatible with Common Node, feel free to add it to the wiki.

To find specific issues not listed on the tracker, you can run the following command from inside the common-node directory.

grep 'TODO' lib/*

To contribute code: fork the project, make and commit your changes and send a pull request.

A number of higher level goals, such as descriptions of packages that would complement Common Node are listed on the TODO wiki page.

Maintainers

• Alex Lam
• Oleg Podsechin

Acknowledgements

• Marcel Laverdet for node-fibers
• Hannes Wallnoefer and others from RingoJS - this project uses a number of its tests & the Ringo code was used as a starting point for some modules
• Kris Kowal, Tom Robinson, Isaac Schlueter for Narwhal - this project used a number of its modules as a starting point and some methods in e.g. Binary have been copied as is
• everybody on the CommonJS mailing list

License

(The MIT License)

Copyright (c) 2011+ Oleg Podsechin

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.