From a5f55359c32c62d4ed69c0147bfcb04a8061a019 Mon Sep 17 00:00:00 2001
From: Kevin Jahns <kevin.jahns@rwth-aachen.de>
Date: Fri, 15 Jan 2016 17:57:06 +0100
Subject: [PATCH] improve data exchange performance

---
 src/Connector.js   | 42 ++++++++++++++++++++++++++++++++----------
 src/Transaction.js | 15 +++------------
 2 files changed, 35 insertions(+), 22 deletions(-)

diff --git a/src/Connector.js b/src/Connector.js
index bc55ccf2..4d537ede 100644
--- a/src/Connector.js
+++ b/src/Connector.js
@@ -50,6 +50,7 @@ module.exports = function (Y/* :any */) {
       this.debug = opts.debug === true
       this.broadcastedHB = false
       this.syncStep2 = Promise.resolve()
+      this.broadcastOpBuffer = []
     }
     reconnect () {
     }
@@ -166,6 +167,31 @@ module.exports = function (Y/* :any */) {
         console.log(`send ${this.userId} -> ${uid}: ${message.type}`, message) // eslint-disable-line
       }
     }
+    /*
+      Buffer operations, and broadcast them when ready.
+    */
+    broadcastOps (ops) {
+      var self = this
+      function broadcastOperations () {
+        if (self.broadcastOpBuffer.length > 0) {
+          self.broadcast({
+            type: 'update',
+            ops: self.broadcastOpBuffer
+          })
+          self.broadcastOpBuffer = []
+        }
+      }
+      if (this.broadcastOpBuffer.length === 0) {
+        this.broadcastOpBuffer = ops
+        if (this.y.db.transactionInProgress) {
+          this.y.db.whenTransactionsFinished().then(broadcastOperations)
+        } else {
+          setTimeout(broadcastOperations, 0)
+        }
+      } else {
+        this.broadcastOpBuffer = this.broadcastOpBuffer.concat(ops)
+      }
+    }
     /*
       You received a raw message, and you know that it is intended for Yjs. Then call this function.
     */
@@ -226,15 +252,14 @@ module.exports = function (Y/* :any */) {
           db.requestTransaction(function * () {
             var ops = yield* this.getOperations(m.stateSet)
             if (ops.length > 0) {
-              var update /* :MessageUpdate */ = {
-                type: 'update',
-                ops: ops
-              }
               if (!broadcastHB) { // TODO: consider to broadcast here..
-                conn.send(sender, update)
+                conn.send(sender, {
+                  type: 'update',
+                  ops: ops
+                })
               } else {
                 // broadcast only once!
-                conn.broadcast(update)
+                conn.broadcastOps(ops)
               }
             }
             defer.resolve()
@@ -256,10 +281,7 @@ module.exports = function (Y/* :any */) {
             return o.struct === 'Delete'
           })
           if (delops.length > 0) {
-            this.broadcast({
-              type: 'update',
-              ops: delops
-            })
+            this.broadcastOps(delops)
           }
         }
         this.y.db.apply(message.ops)
diff --git a/src/Transaction.js b/src/Transaction.js
index 0d0b609d..da82223c 100644
--- a/src/Transaction.js
+++ b/src/Transaction.js
@@ -123,10 +123,7 @@ module.exports = function (Y/* :any */) {
       }
       if (!this.store.y.connector.isDisconnected() && send.length > 0) { // TODO: && !this.store.forwardAppliedOperations (but then i don't send delete ops)
         // is connected, and this is not going to be send in addOperation
-        this.store.y.connector.broadcast({
-          type: 'update',
-          ops: send
-        })
+        this.store.y.connector.broadcastOps(send)
       }
     }
 
@@ -522,10 +519,7 @@ module.exports = function (Y/* :any */) {
         var ops = deletions.map(function (d) {
           return {struct: 'Delete', target: [d[0], d[1]]}
         })
-        this.store.y.connector.broadcast({
-          type: 'update',
-          ops: ops
-        })
+        this.store.y.connector.broadcastOps(ops)
       }
     }
     * isGarbageCollected (id) {
@@ -563,10 +557,7 @@ module.exports = function (Y/* :any */) {
       yield* this.os.put(op)
       if (!this.store.y.connector.isDisconnected() && this.store.forwardAppliedOperations && op.id[0] !== '_') {
         // is connected, and this is not going to be send in addOperation
-        this.store.y.connector.broadcast({
-          type: 'update',
-          ops: [op]
-        })
+        this.store.y.connector.broadcastOps([op])
       }
     }
     * getOperation (id/* :any */)/* :Transaction<any> */ {