127 lines
3.5 KiB
JavaScript
127 lines
3.5 KiB
JavaScript
/**
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* @module provider/websocket/server
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*/
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const Y = require('../../build/yjs.js')
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const WebSocket = require('ws')
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const http = require('http')
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const port = process.env.PORT || 1234
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const server = http.createServer((req, res) => {
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res.writeHead(200, { 'Content-Type': 'text/plain' })
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res.end('okay')
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})
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const wss = new WebSocket.Server({ noServer: true })
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const docs = new Map()
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const messageSync = 0
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const messageAwareness = 1
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const afterTransaction = (doc, transaction) => {
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if (transaction.encodedStructsLen > 0) {
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const encoder = Y.createEncoder()
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Y.writeVarUint(encoder, messageSync)
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Y.writeUpdate(encoder, transaction.encodedStructsLen, transaction.encodedStructs)
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const message = Y.toBuffer(encoder)
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doc.conns.forEach((_, conn) => conn.send(message))
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}
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}
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class WSSharedDoc extends Y.Y {
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constructor () {
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super({ gc: true })
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this.mux = Y.createMutex()
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/**
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* Maps from conn to set of controlled user ids. Delete all user ids from awareness when this conn is closed
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* @type {Map<Object, Set<number>>}
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*/
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this.conns = new Map()
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this.awareness = new Map()
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this.on('afterTransaction', afterTransaction)
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}
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}
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const messageListener = (conn, doc, message) => {
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const encoder = Y.createEncoder()
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const decoder = Y.createDecoder(message)
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const messageType = Y.readVarUint(decoder)
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switch (messageType) {
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case messageSync:
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Y.writeVarUint(encoder, messageSync)
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Y.readSyncMessage(decoder, encoder, doc)
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if (Y.length(encoder) > 1) {
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conn.send(Y.toBuffer(encoder))
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}
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break
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case messageAwareness: {
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Y.writeVarUint(encoder, messageAwareness)
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const updates = Y.forwardAwarenessMessage(decoder, encoder)
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updates.forEach(update => {
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doc.awareness.set(update.userID, update.state)
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doc.conns.get(conn).add(update.userID)
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})
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const buff = Y.toBuffer(encoder)
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doc.conns.forEach((_, c) => {
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c.send(buff)
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})
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break
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}
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}
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}
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const setupConnection = (conn, req) => {
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conn.binaryType = 'arraybuffer'
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// get doc, create if it does not exist yet
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let doc = docs.get(req.url.slice(1))
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if (doc === undefined) {
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doc = new WSSharedDoc()
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docs.set(req.url.slice(1), doc)
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}
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doc.conns.set(conn, new Set())
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// listen and reply to events
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conn.on('message', message => messageListener(conn, doc, message))
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conn.on('close', () => {
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const controlledIds = doc.conns.get(conn)
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doc.conns.delete(conn)
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const encoder = Y.createEncoder()
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Y.writeVarUint(encoder, messageAwareness)
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Y.writeUsersStateChange(encoder, Array.from(controlledIds).map(userID => {
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doc.awareness.delete(userID)
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return { userID, state: null }
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}))
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const buf = Y.toBuffer(encoder)
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doc.conns.forEach((_, conn) => conn.send(buf))
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})
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// send sync step 1
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const encoder = Y.createEncoder()
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Y.writeVarUint(encoder, messageSync)
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Y.writeSyncStep1(encoder, doc)
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conn.send(Y.toBuffer(encoder))
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if (doc.awareness.size > 0) {
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const encoder = Y.createEncoder()
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const userStates = []
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doc.awareness.forEach((state, userID) => {
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userStates.push({ state, userID })
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})
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Y.writeVarUint(encoder, messageAwareness)
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Y.writeUsersStateChange(encoder, userStates)
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conn.send(Y.toBuffer(encoder))
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}
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}
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wss.on('connection', setupConnection)
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server.on('upgrade', (request, socket, head) => {
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// You may check auth of request here..
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wss.handleUpgrade(request, socket, head, ws => {
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wss.emit('connection', ws, request)
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})
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})
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server.listen(port)
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console.log('running on port', port)
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