106 lines
3.1 KiB
JavaScript
106 lines
3.1 KiB
JavaScript
/**
|
|
* @module provider/websocket
|
|
*/
|
|
|
|
const Y = require('../../build/yjs.umd.js')
|
|
const WebSocket = require('ws')
|
|
const wss = new WebSocket.Server({ port: 1234 })
|
|
const docs = new Map()
|
|
|
|
const messageSync = 0
|
|
const messageAwareness = 1
|
|
|
|
const afterTransaction = (doc, transaction) => {
|
|
if (transaction.encodedStructsLen > 0) {
|
|
const encoder = Y.createEncoder()
|
|
Y.writeVarUint(encoder, messageSync)
|
|
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()
|
|
/**
|
|
* Maps from conn to set of controlled user ids. Delete all user ids from awareness when this conn is closed
|
|
* @type {Map<Object, Set<number>>}
|
|
*/
|
|
this.conns = new Map()
|
|
this.awareness = new Map()
|
|
this.on('afterTransaction', afterTransaction)
|
|
}
|
|
}
|
|
|
|
const messageListener = (conn, doc, message) => {
|
|
const encoder = Y.createEncoder()
|
|
const decoder = Y.createDecoder(message)
|
|
const messageType = Y.readVarUint(decoder)
|
|
switch (messageType) {
|
|
case messageSync:
|
|
Y.writeVarUint(encoder, messageSync)
|
|
Y.readSyncMessage(decoder, encoder, doc)
|
|
if (Y.length(encoder) > 1) {
|
|
conn.send(Y.toBuffer(encoder))
|
|
}
|
|
break
|
|
case messageAwareness: {
|
|
Y.writeVarUint(encoder, messageAwareness)
|
|
const updates = Y.forwardAwarenessMessage(decoder, encoder)
|
|
updates.forEach(update => {
|
|
doc.awareness.set(update.userID, update.state)
|
|
doc.conns.get(conn).add(update.userID)
|
|
})
|
|
const buff = Y.toBuffer(encoder)
|
|
doc.conns.forEach((_, c) => {
|
|
c.send(buff)
|
|
})
|
|
break
|
|
}
|
|
}
|
|
}
|
|
|
|
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.set(conn, new Set())
|
|
// listen and reply to events
|
|
conn.on('message', message => messageListener(conn, doc, message))
|
|
conn.on('close', () => {
|
|
const controlledIds = doc.conns.get(conn)
|
|
doc.conns.delete(conn)
|
|
const encoder = Y.createEncoder()
|
|
Y.writeVarUint(encoder, messageAwareness)
|
|
Y.writeUsersStateChange(encoder, Array.from(controlledIds).map(userID => {
|
|
doc.awareness.delete(userID)
|
|
return { userID, state: null }
|
|
}))
|
|
const buf = Y.toBuffer(encoder)
|
|
doc.conns.forEach((_, conn) => conn.send(buf))
|
|
})
|
|
// send sync step 1
|
|
const encoder = Y.createEncoder()
|
|
Y.writeVarUint(encoder, messageSync)
|
|
Y.writeSyncStep1(encoder, doc)
|
|
conn.send(Y.toBuffer(encoder))
|
|
if (doc.awareness.size > 0) {
|
|
const encoder = Y.createEncoder()
|
|
const userStates = []
|
|
doc.awareness.forEach((state, userID) => {
|
|
userStates.push({ state, userID })
|
|
})
|
|
Y.writeVarUint(encoder, messageAwareness)
|
|
Y.writeUsersStateChange(encoder, userStates)
|
|
conn.send(Y.toBuffer(encoder))
|
|
}
|
|
}
|
|
|
|
wss.on('connection', setupConnection)
|