Ipfs-observed-remove-level NPM

IPFS Observed-Remove Set and Map

Eventually-consistent, conflict-free replicated data types (CRDT) implemented using IPFS and LevelDB.

This module and the IPFS PubSub system are experimental. If you encounter an issue, fork the repository, write tests demonstrating the issue, and create a pull request.

const os = require('os');
const path = require('path');
const uuid = require('uuid');
const level = require('level');
const ipfsAPI = require('ipfs-http-client');
const { IpfsObservedRemoveMap } = require('ipfs-observed-remove-level');

const run = async () => {

  const location = path.join(os.tmpdir(), uuid.v4());
  const db = level(location, { valueEncoding: 'json' });
  // IPFS nodes with PubSub enabled
  const ipfs1 = ipfsAPI('/ip4/127.0.0.1/tcp/5001'); 
  const ipfs2 = ipfsAPI('/ip4/127.0.0.1/tcp/5002');

  const topic = "CRDT_MAP";

  const alice = new IpfsObservedRemoveMap(db, ipfs1, topic, [], { namespace:'alice' });
  const bob = new IpfsObservedRemoveMap(db, ipfs2, topic, [], { namespace:'bob' });

  alice.on('set', (key, value) => {
    console.log(key, value); // logs [a, 1], [b, 2]
  });

  await alice.set('a', 1);
  await bob.set('b', 2);

  // Later

  await alice.get('b'); // 2
  await bob.get('a'); // 1
}

Install

yarn add ipfs-observed-remove-level

Map API

constructor

Create an observed-remove CRDT.

Parameters

db Object
ipfs Object? Object implementing the core IPFS API, most likely a js-ipfs or ipfs-http-client object.
topic String? IPFS pubub topic to use in synchronizing the CRDT.
entries Iterable\ Iterable of initial values (optional, default [])
options Object (optional, default {})
- options.maxAge String Max age of insertion/deletion identifiers (optional, default 5000)
- options.bufferPublishing String Interval by which to buffer 'publish' events (optional, default 20)
- options.chunkPubSub boolean Chunk pubsub messages for values greater than 1 MB (optional, default false)

ipfsSync

Publish an IPFS hash of an array containing all of the object's insertions and deletions.

Returns Array [Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)\<any>

getIpfsHash

Stores and returns an IPFS hash of the current insertions and deletions

Returns Promise [string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)

getIpfsHashes

Stores and returns an IPFS hash of the current insertions and deletions

Returns Promise [string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)

ipfsPeerCount

Current number of IPFS pubsub peers.

Returns number

shutdown

Gracefully shutdown

Returns void

IpfsObservedRemoveSet#readyPromise

Resolves when IPFS topic subscriptions are confirmed.

Type: Promise\

Signed Map API

constructor

Create an observed-remove CRDT.

Parameters

db Object
ipfs Object? Object implementing the core IPFS API, most likely a js-ipfs or ipfs-http-client object.
topic String? IPFS pubub topic to use in synchronizing the CRDT.
entries Iterable\ Iterable of initial values (optional, default [])
options Object (optional, default {})
- options.maxAge String Max age of insertion/deletion identifiers (optional, default 5000)
- options.bufferPublishing String Interval by which to buffer 'publish' events (optional, default 20)
- options.chunkPubSub boolean Chunk pubsub messages for values greater than 1 MB (optional, default false)