js-crdt

Introduction

CRDT Conflict-free Replication Data Type in JavaScript.

Development

npm install
npm run build
npm test
npm run lint
npm run dist

How crdt/Text type with order/discrete should work? (WIP)

Consider two actors a and b working concurrently on some document. Actor a and b have same origin of the document origin:0. For simplification, origin is not shown here.

a:0
b:0

First actor started working on version a:0, and did some changes xxx. Actor b did not start working on document.

a:0  xxx
b:0

Actor a decided to send his version a:1 to actor b, but before that, he want to be sure that regardless if b receives his changes, he can continue on working his version of document. so he created a snapshot a:1 of his version of document and send changes to actor b.

a:0  xxx  a:1
b:0

Actor b sees incoming changes a:0 of the actor a, so he merge them with his current state and create new version it b:1 a:0

a:0  xxx  a:1
            |
b:0      b:1 a:0

Actor b decides to add something to document yyy, and send his changes to actor a. Actor b in the same manner, before sending his changes to actor a he creates snapshot of his version of document b:2 a:0 and send changes b:1 a:0 to a.

a:0  xxx  a:1
            |
b:0      b:1 a:0  yyy  b:2 a:0

When actor a sees incoming changes, he merge them with his document.

a:0  xxx  a:1          a:2 b:1
            |             |
b:0      b:1 a:0  yyy  b:2 a:0