added utilities to make and recover snapshots

provider/websocket/WebSocketProvider.js

@@ -97,8 +97,8 @@ const broadcastUpdate = (y, transaction) => {
 }
 
 class WebsocketsSharedDocument extends Y.Y {
-  constructor (url) {
-    super()
+  constructor (url, opts) {
+    super(opts)
     this.url = url
     this.wsconnected = false
     this.mux = Y.createMutex()
@@ -112,7 +112,7 @@ class WebsocketsSharedDocument extends Y.Y {
       const encoder = readMessage(this, data) // already muxed
       this.mux(() => {
         if (Y.encoding.length(encoder) > 1) {
-            bc.publish(url, Y.encoding.toBuffer(encoder))
+          bc.publish(url, Y.encoding.toBuffer(encoder))
         }
       })
     }
@@ -173,10 +173,10 @@ export class WebsocketProvider {
    * @param {string} name
    * @return {WebsocketsSharedDocument}
    */
-  get (name) {
+  get (name, opts) {
     let doc = this.docs.get(name)
     if (doc === undefined) {
-      doc = new WebsocketsSharedDocument(this.url + name)
+      doc = new WebsocketsSharedDocument(this.url + name, opts)
     }
     return doc
   }

provider/websocket/server.js

@@ -12,6 +12,8 @@ const http = require('http')
 
 const port = process.env.PORT || 1234
 
+// disable gc when using snapshots!
+const gcEnabled = process.env.GC !== 'false' && process.env.GC !== '0'
 const persistenceDir = process.env.YPERSISTENCE
 let persistence = null
 if (typeof persistenceDir === 'string') {
@@ -44,7 +46,7 @@ const afterTransaction = (doc, transaction) => {
 
 class WSSharedDoc extends Y.Y {
   constructor () {
-    super({ gc: true })
+    super({ gc: gcEnabled })
     this.mux = Y.createMutex()
     /**
      * Maps from conn to set of controlled user ids. Delete all user ids from awareness when this conn is closed
@@ -150,4 +152,4 @@ server.on('upgrade', (request, socket, head) => {
 
 server.listen(port)
 
-console.log('running on port', port)
+console.log('running on port', port)