y-fdp-storage

fdp-storage database provider for Yjs

Abstract

This Yjs provider uses Swarm Feeds Sequential mechanism, which is more efficient than Swarm Feeds Epoch. This library contains a complete Typescript implementation from scratch.

We also added research technology from previous samples, in this case a simple wrapper which stores/read from a sequential feed. This can be extended to use Beeson, which in this Yjs provider we removed to avoid dependency complexity. Thus, the Yjs update data are stored as hex in the feed.

Because a Swarm Feed requires a Topic and Address, we need to provider a signing private key.

Further enhancements

• Enable WebSockets for Feeds either in a standalone server or in Swarm, this to avoid doing long-polling.
• Enable the provider to have a read (public key) and write (signing key) features.

Table of Contents

• Install
• Usage
• API
• References
• License

Install

npm install y-fdp-storage

Usage

import * as Y from 'yjs'
import { Bee } from '@ethersphere/bee-js'
import { hexToBytes, makePrivateKeySigner, FdpStoragePersistence } from 'y-fdp-storage'

const postageBatchId = process.env.BEE_POSTAGE || '1c082c5e642e15d49b6689f5437c2eb9e6aa9c546a8ed1d11d0024b043bca371'
const bee = new Bee('http://localhost:1633')

const testIdentity = {
  privateKey: '634fb5a872396d9693e5c9f9d7233cfa93f395c093371017ff44aa9ae6564cdd',
  publicKey: '03c32bb011339667a487b6c1c35061f15f7edc36aa9a0f8648aba07a4b8bd741b4',
  address: '8d3766440f0d7b949a5e32995d09619a7f86e632',
}
const wallet = makePrivateKeySigner(hexToBytes(testIdentity.privateKey))
const topic = '/crdt/document/test'

// Create FdpStoragePersistence object
const persistence = new FdpStoragePersistence(bee, wallet, topic, postageBatchId)

// Create Yjs document
const doc = new Y.Doc()

// On update event, store updates to bee
doc.on('update', async update => {
    await persistence.storeUpdate(update)
})

// Or use persistence.autoUpdate(doc, interval_milliseconds)

doc.getText('test').insert(0, 'Hello World')

const mostRecentDoc = await persistence.getYDoc()
// Hello World

const close = persistence.subscribe(doc);

Usage with fdp-storage

import * as Y from 'yjs'
import { FdpStorage } from '@fairdatasociety/fdp-storage'
const { hexToBytes } = Utils
import { hexToBytes, makePrivateKeySigner, FdpStoragePersistence } from 'y-fdp-storage'

const postageBatchId = process.env.BEE_POSTAGE || '1c082c5e642e15d49b6689f5437c2eb9e6aa9c546a8ed1d11d0024b043bca371'
const fdp = new FdpStorage('http://localhost:1633', postageBatchId)

const topic = '/crdt/document/test'

// Create FdpStoragePersistence object
const persistence = new FdpStoragePersistence(fdp.connection.bee, fdp.account.wallet, topic, fdp.connection.postageBatchId)

// Create Yjs document
const doc = new Y.Doc()

// On update event, store updates to bee
doc.on('update', async update => {
    await persistence.storeUpdate(update)
})

doc.getText('test').insert(0, 'Hello World')

const mostRecentDoc = await persistence.getYDoc()
// Hello World

API

FdpStoragePersistence

Creates a FdpStoragePersistence instance.

const persistence = new FdpStoragePersistence(fdp.connection.bee, fdp.account.wallet, topic, fdp.connection.postageBatchId)

storeUpdate

Writes the Yjs update to a feed. Handles any throws internally.

const update = Y.encodeStateAsUpdate(doc)
await persistence.storeUpdate(update)

store

Writes the Yjs update to a feed. Errors will be thrown if the update is not valid.

const update = Y.encodeStateAsUpdate(doc)
await persistence.store(update)

read

Reads the latest update from feed.

const update = await persistence.read()

getYDoc

Reads the last state as a YDoc.

const doc = await persistence.getYDoc()

subscribe

Subscribes to the feed and emits updates. Returns a function to cancel subscription interval.

const close = persistence.subscribe(doc, 30_000)

autoUpdate

Pushes updates. Returns a function to cancel push interval.

const close = persistence.autoUpdate(doc, 30_000)

Maintainers

molekilla

References

Yjs

License

Apache License 2.0