4b82

4b82 Continuity Trustcenter Framework

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Readme

4b82 - Continuity Trustcenter Framework

Based on GIT and Merkle Tree

ps. 4B82 is the first four symbols of the hash value for the GIT empty-tree "tree 0\0" 4b825dc642cb6eb9a060e54bf8d69288fbee4904

4B82 Project Key Technical Details

The goal of this project is to allow a straightforward and robust way to establish abstract, provably immutable sequences of digital events.

Currently existing methods for attaining this rely on highly specialized software, are computationally demanding, or both.

We have decided to use GIT’s architectural framework as the core implementing this functionality because of its versatility, robustness, strong safeguards against corruption, as well as its self-evidential flexibility.

Strict linearity was achieved by leveraging hash functionality typical to all git-like solutions while eschewing branching functionality, and was done in a manner that minimizes unnecessary (for our purposes) overhead of typical git object behaviors (but does not compromise the formal integrity of the git structures involved).

Read more about 4b82 Continuity Trustcenter Framework at 4b82.com

How to Use it?

Initialize an empty git repository:

mkdir git-repo && cd git-repo
git init
cd ..

Create the new node.js project:

mkdir 4b82-server && cd 4b82-server
npm init

Add 4b82 code from npm:

npm install 4b82 --save

Now, you can use 4b82 functions and make your own 4b82 server.

API Functions

Note: all callback functions are function (err, result) or function (err). if an error occurs then err object will be passed to callback function. Otherwise, err object is null and result object will be passed to the callback function (if result is exists).

Initialization

First, it is necessary to initialize the application.

During initialization, it is necessary to pass a configuration object. Currently, this object is simple and includes a git field. This field is an object with the path field which stores the path to the GIT repository. For example:

Configuration Object

{
    git: {
        path: 'path-to-git'
    }
}

Application Initialization

function init (conf)

Arguments Description
conf Configuration object (see above)

Exclusive Access

Before you make any changes to the GIT-repository, you must obtain an exclusive access to GIT-repository at the application level.

Important: please, do not forget to call releaseAccess() and to release exclusive access to the repository at the end of the operation.

Important: exclusive access is provided only at the application logic level, not the system level.

Obtain the Exclusive Access

function getAccess (callback)

Arguments Description
callback (err) Callback function that calls immediately after receiving
the exclusive access to the GIT repository

Release the Exclusive Access

function releaseAccess ()

Arguments Description
none Releases the exclusive access to the GIT repository

Adding and Reading Commits

Add a Commit to the Repository

function addCommit (message, author, committer, callback)

Arguments Description
message Commit message
author Commit author
committer Committer (your system)
callback (err, commit) Callback function that receives commit object after adding or error

Get the Recently Added Commit

function getRecentCommit (callback)

Arguments Description
callback (err, commit) Callback function that receives commit object after adding or error.
If there is no commits, null is returned.

Get the Commit With Hash Value

function getCommit (hash, callback)

Arguments Description
hash The hash value for the desired commit
callback (err, commit) Callback function that receives commit object after adding or error.
If there is no commits, null is returned.

Display the Commit Data

function prettyPrint (commit) - show information about commit

Arguments Description
commit Commit object returned by addCommit, getRecentCommit or getCommit functions

Examples

A simple application that adds commit to our fresh 4b82 git repository:

var _4b82 = require('4b82');

var config = {
    git: { path: '~/git-path/' } // Path to git repository
}

// Initialize 4b82
_4b82.init(config, function (err) {
    if (err) return console.error(err);

    // Get exclusive access to GIT
    _4b82.getAccess(function () {

        // Add commit
        _4b82.addCommit('test commit', 'me <me@localhost>', 'me <me@localhost>',
                function (err, commit) {

            if (err) {
                _4b82.releaseAccess();
                return console.error(err);
            }

            // Print commit data
            _4b82.prettyPrint(commit);

            // Release access
            _4b82.releaseAccess();

        });
    });
});

When you run this application it adds new commit to 4b82 git repository and prints the commit hash, data and deflated bytes.

To get specific commit use getCommit function:

// Initialize 4b82
_4b82.init(config, function (err) {
    if (err) return console.error(err);

    // Get commit data
    _4b82.getCommit(hash, function (err, commit) {
        if (err) return console.error(err);

        // Print commit data
        _4b82.prettyPrint(commit);

    })
});

This function returns commit object (with tag field).

commit contains whole git commit data, you can parse it for author, committer, e.t.c.

tag field uses for backward navigation (read more about backward navigation).


That's all.

If you find any bugs or have a feature request, please open an issue on github!

The npm package download data comes from npm's download counts api and package details come from npms.io.