concur-algorithm

Concur Algorithm

An implementation of the Concur algorithm.

There is a paper describing the algorithm which is (as they say) by no means inaccessible to the non-specialist:

• The First Correct Concurrency Control Algorithm

To summarise, the algorithm makes the following contributions:

• It includes a set of comprehensive stringwise operational transformations,
• has a recursive function that composes these transformations and is guaranteed to terminate,
• includes a protocol that makes use of this recursive function and
• can handle an arbitrary number of users and any amount of latency.

Installation

With npm:

npm install concur-algorithm

You can also clone the repository with Git...

git clone https://github.com/jecs-imperial/concur-algorithm.git

...and then install the necessary modules with npm from within the project's root directory:

npm install

You will need to do this if you want to look at the example.

Example

This encompasses a basic implementation of the algorithm. If you have cloned the repository, it can be run with the following command:

node ./bin/example.js

Once the server is running, launch a browser and the client will be available at http://localhost:8888.

Usage

const concur = require('concur-algorithm'),    ///
      { generateOperations, transformContent } = concur;

Not all the functionality required to implement the algorithm is exported by the package. If you want to implement the algorithm the only place to start is the example.

Compiling from source

Automation is done with npm scripts, have a look at the package.json file. The pertinent commands are:

npm run build-debug
npm run watch-debug

Running the tests

This can be done from the root of the repository:

./node_modules/.bin/mocha --recursive -R spec ./test

Contact

• [e-mail]
• http://djalbat.com