fix several sync issues. improve performance a bit by removing ds from first sync step

src/Connector.js

@@ -59,7 +59,6 @@ export default function extendConnector (Y/* :any */) {
       this.syncingClients = []
       this.forwardToSyncingClients = opts.forwardToSyncingClients !== false
       this.debug = opts.debug === true
-      this.syncStep2 = Promise.resolve()
       this.broadcastOpBuffer = []
       this.protocolVersion = 11
       this.authInfo = opts.auth || null
@@ -146,6 +145,9 @@ export default function extendConnector (Y/* :any */) {
         isSynced: false,
         role: role
       }
+      let defer = {}
+      defer.promise = new Promise(function (resolve) { defer.resolve = resolve })
+      this.connections[user].syncStep2 = defer
       for (var f of this.userEventListeners) {
         f({
           action: 'userJoined',
@@ -187,7 +189,7 @@ export default function extendConnector (Y/* :any */) {
           var answer = {
             type: 'sync step 1',
             stateSet: stateSet,
-            deleteSet: deleteSet,
+            // deleteSet: deleteSet,
             protocolVersion: conn.protocolVersion,
             auth: conn.authInfo
           }
@@ -289,12 +291,23 @@ export default function extendConnector (Y/* :any */) {
           if (message.type === 'sync step 1' && canRead(auth)) {
             let conn = this
             let m = message
-
+            let wait // wait for sync step 2 to complete
+            if (this.role === 'slave') {
+              wait = Promise.all(Object.keys(this.connections)
+                .map(uid => this.connections[uid])
+                .filter(conn => conn.role === 'master')
+                .map(conn => conn.syncStep2.promise)
+              )
+            } else {
+              wait = Promise.resolve()
+            }
+            wait.then(() => {
               this.y.db.requestTransaction(function * () {
                 var currentStateSet = yield * this.getStateSet()
-              if (canWrite(auth)) {
-                yield * this.applyDeleteSet(m.deleteSet)
-              }
+                // TODO: remove
+                // if (canWrite(auth)) {
+                //  yield * this.applyDeleteSet(m.deleteSet)
+                // }
 
                 var ds = yield * this.getDeleteSet()
                 var answer = {
@@ -326,14 +339,11 @@ export default function extendConnector (Y/* :any */) {
                   })
                 }
               })
+            })
           } else if (message.type === 'sync step 2' && canWrite(auth)) {
             var db = this.y.db
-            var defer = {}
-            defer.promise = new Promise(function (resolve) {
-              defer.resolve = resolve
-            })
-            this.syncStep2 = defer.promise
-            let m /* :MessageSyncStep2 */ = message
+            let defer = this.connections[sender].syncStep2
+            let m = message
             // apply operations first
             db.requestTransaction(function * () {
               yield * this.applyDeleteSet(m.deleteSet)
@@ -344,18 +354,17 @@ export default function extendConnector (Y/* :any */) {
               }
               defer.resolve()
             })
-            /*
-            then apply ds
+            /*/ then apply ds
             db.whenTransactionsFinished().then(() => {
               db.requestTransaction(function * () {
                 yield * this.applyDeleteSet(m.deleteSet)
               })
               defer.resolve()
             })*/
-            return this.syncStep2
+            return defer.promise
           } else if (message.type === 'sync done') {
             var self = this
-            this.syncStep2.then(function () {
+            this.connections[sender].syncStep2.promise.then(function () {
               self._setSyncedWith(sender)
             })
           } else if (message.type === 'update' && canWrite(auth)) {

tests-lib/helper.js

@@ -93,9 +93,19 @@ export async function initArrays (t, opts) {
   var chance = opts.chance || new Chance(t.getSeed() * 1000000000)
   var connector = Object.assign({ room: 'debugging_' + t.name, testContext: t, chance }, opts.connector)
   for (let i = 0; i < opts.users; i++) {
+    let dbOpts
+    let connOpts
+    if (i === 0) {
+      // Only one instance can gc!
+      dbOpts = Object.assign({ gc: true }, opts.db)
+      connOpts = Object.assign({ role: 'master' }, connector)
+    } else {
+      dbOpts = Object.assign({ gc: false }, opts.db)
+      connOpts = Object.assign({ role: 'slave' }, connector)
+    }
     let y = await Y({
-      connector: connector,
-      db: Object.assign({ gc: i === 0 }, opts.db), // Only one instance can gc!
+      connector: connOpts,
+      db: dbOpts,
       share: share
     })
     result.users.push(y)

tests-lib/test-connector.js

@@ -1,4 +1,5 @@
 /* global Y */
+import { wait } from './helper.js'
 
 var rooms = {}
 
@@ -13,8 +14,8 @@ export class TestRoom {
       connector.setUserId('' + (this.nextUserId++))
     }
     Object.keys(this.users).forEach(uid => {
-      this.users[uid].userJoined(connector.userId, 'master')
-      connector.userJoined(uid, 'master')
+      this.users[uid].userJoined(connector.userId, connector.role)
+      connector.userJoined(uid, this.users[uid].role)
     })
     this.users[connector.userId] = connector
   }
@@ -43,6 +44,7 @@ export class TestRoom {
       users = allUserIds.map(id => this.users[id].y)
     }
     while (flushing) {
+      await wait(10)
       let res = await Promise.all(allUserIds.map(id => this.users[id]._flushAll(users)))
       flushing = res.some(status => status === 'flushing')
     }
@@ -65,7 +67,6 @@ export default function extendTestConnector (Y) {
       if (options.room == null) {
         throw new Error('You must define a room name!')
       }
-      options.role = 'slave'
       super(y, options)
       this.options = options
       this.room = options.room