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.