yjs/provider/websocket/server.js
2018-10-30 00:51:09 +01:00

54 lines
1.4 KiB
JavaScript

const Y = require('../../build/node/index.js')
const WebSocket = require('ws')
const wss = new WebSocket.Server({ port: 1234 })
const docs = new Map()
const afterTransaction = (doc, transaction) => {
if (transaction.encodedStructsLen > 0) {
const encoder = Y.createEncoder()
Y.writeUpdate(encoder, transaction.encodedStructsLen, transaction.encodedStructs)
const message = Y.toBuffer(encoder)
doc.conns.forEach(conn => conn.send(message))
}
}
class WSSharedDoc extends Y.Y {
constructor () {
super()
this.mux = Y.createMutex()
this.conns = new Set()
this.on('afterTransaction', afterTransaction)
}
}
const messageListener = (conn, doc, message) => {
const encoder = Y.createEncoder()
const decoder = Y.createDecoder(message)
Y.readMessage(decoder, encoder, doc)
if (Y.length(encoder) > 0) {
conn.send(Y.toBuffer(encoder))
}
}
const setupConnection = (conn, req) => {
conn.binaryType = 'arraybuffer'
// get doc, create if it does not exist yet
let doc = docs.get(req.url.slice(1))
if (doc === undefined) {
doc = new WSSharedDoc()
docs.set(req.url.slice(1), doc)
}
doc.conns.add(conn)
// listen and reply to events
conn.on('message', message => messageListener(conn, doc, message))
conn.on('close', () =>
doc.conns.delete(conn)
)
// send sync step 1
const encoder = Y.createEncoder()
Y.writeSyncStep1(encoder, doc)
conn.send(Y.toBuffer(encoder))
}
wss.on('connection', setupConnection)