From ce05e8e8b0af2aa00b60d656126fc418d4b8fd9f Mon Sep 17 00:00:00 2001
From: Nick Fitzgerald <fitzgen@gmail.com>
Date: Thu, 21 Apr 2011 16:13:04 -0700
Subject: [PATCH] Moving the ui updating in to the main loop to fix the bug
 that I mention in the TODO, and fix the client/server communication

---
 apply.js  |   4 +-
 client.js | 108 ++++++++++++++++++++++++++----------------------------
 2 files changed, 54 insertions(+), 58 deletions(-)

diff --git a/apply.js b/apply.js
index 153822f..2bfcfa8 100644
--- a/apply.js
+++ b/apply.js
@@ -27,11 +27,11 @@ define(["./operations"], function (operations) {
                 if ( doc.indexOf(operations.val(op[i])) !== 0 ) {
                     throw new TypeError("Expected '" + operations.val(op[i])
                                         + "' to delete, found '" + doc.slice(0, 10)
-                                        + "...'");
+                                        + "'");
                 } else {
                     doc = doc.slice(operations.val(op[i]).length);
-                    break;
                 }
+                break;
             default:
                 throw new TypeError("Unknown operation: "
                                     + operations.type(op[i]));
diff --git a/client.js b/client.js
index 25bfcf9..b3328c6 100644
--- a/client.js
+++ b/client.js
@@ -29,7 +29,7 @@ define([
             msg = outgoing[i];
             xform(messages.operation(msg), ops, function (aPrime, bPrime) {
                 messages.operation(msg, aPrime);
-                messages.document(msg, apply(messages.document(msg), aPrime));
+                messages.document(msg, aPrime, apply(aPrime, messages.document(msg)));
                 messages.revision(msg, messages.revision(msg)+1);
                 ops = bPrime;
             });
@@ -49,7 +49,30 @@ define([
         });
     }
 
-    function init (outgoing, socket, ui, initialData) {
+    // Might need to start sending client id's back and forth. Don't really want
+    // to have to do a deep equality test on every check here.
+    function isOurOutgoing (msg, outgoing) {
+        var top = outgoing[0],
+            topOps = messages.operation(top),
+            msgOps = messages.operation(msg),
+            i = 0,
+            len = msgOps.length;
+        if ( messages.id(msg) !== messages.id(top) ) {
+            return false;
+        }
+        if ( messages.revision(msg) !== messages.revision(top) ) {
+            return false;
+        }
+        if ( len !== topOps.length ) {
+            return false;
+        }
+        if ( topOps.join() !== msgOps.join() ) {
+            return false;
+        }
+        return true;
+    }
+
+    function init (outgoing, incoming, socket, ui, initialData) {
         var previousDoc = messages.document(initialData),
             previousRevision = messages.revision(initialData),
             id = messages.id(initialData);
@@ -60,6 +83,7 @@ define([
             var msg,
                 oldOutgoingLength = outgoing.length,
                 uiDoc = ui.getDocument();
+
             if ( uiDoc !== previousDoc ) {
                 msg = {};
                 messages.operation(msg, operations.operation(previousDoc, uiDoc));
@@ -69,46 +93,42 @@ define([
 
                 outgoing.push(msg);
                 previousDoc = uiDoc;
+            }
 
-                if ( oldOutgoingLength === 0 ) {
-                    socket.send({
-                        type: "update",
-                        data: outgoing[0]
-                    });
+            while ( (msg = incoming.shift()) ) {
+                if ( outgoing.length && isOurOutgoing(msg, outgoing) ) {
+                    outgoing.shift();
+                } else {
+                    // TODO: need to handle cursor selection and index
+                    xformEach(outgoing, messages.operation(msg));
+                    previousRevision++;
+
+                    // TODO: cursor position
+                    if ( outgoing.length ) {
+                        ui.update(previousDoc = messages.document(outgoing[outgoing.length-1]));
+                    } else {
+                        ui.update(previousDoc = messages.document(msg));
+                    }
                 }
             }
+
+            if ( outgoing.length ) {
+                socket.send({
+                    type: "update",
+                    data: outgoing[0]
+                });
+            }
+
             setTimeout(loop, 1000);
         }
 
         setTimeout(loop, 10);
     }
 
-    // Might need to start sending client id's back and forth. Don't really want
-    // to have to do a deep equality test on every check here.
-    function isOurOutgoing (msg, outgoing) {
-        var top = outgoing[0],
-            topOps = messages.operation(top),
-            msgOps = messages.operation(msg),
-            i = 0,
-            len = msgOps.length;
-        if ( messages.id(msg) !== messages.id(top) ) {
-            return false;
-        }
-        if ( messages.revision(msg) !== messages.revision(top) ) {
-            return false;
-        }
-        if ( len !== topOps.length ) {
-            return false;
-        }
-        if ( topOps.join() !== msgOps.join() ) {
-            return false;
-        }
-        return true;
-    }
-
     return {
         OTDocument: function (opts) {
             var outgoing = [],
+                incoming = [],
                 socket = opts.socket || error("socket is required"),
                 ui = opts.ui || error("ui is required"),
                 docId = opts.id,
@@ -116,43 +136,19 @@ define([
 
             connect(socket, docId);
 
-            // TODO: what happens if we receive an update message from the
-            // server and we update the client and they lose what they were just
-            // typeing because we havent saved the operations in the outgoing
-            // buffer yet? Do I need to merge the main loop and handling of
-            // socket messages? Maybe just have the socket's receive handler
-            // queue events in an inbox and have the main loop process one
-            // change that the client is creating, then one message from the
-            // inbox.
-
             socket.onMessage(function (event) {
-                var msg;
-
                 switch ( event.type ) {
 
                 case "connect":
                     if ( ! initialized ) {
-                        init(outgoing, socket, ui, event.data);
+                        init(outgoing, incoming, socket, ui, event.data);
                     } else {
                         error("Already initialized");
                     }
                     break;
 
                 case "update":
-                    msg = event.data;
-                    if ( outgoing.length && isOurOutgoing(msg, outgoing) ) {
-                        outgoing.shift();
-                    } else {
-                        // TODO: need to handle cursor selection and index
-                        xformEach(outgoing, messages.operation(msg));
-
-                        // TODO: cursor position
-                        if ( outgoing.length ) {
-                            ui.update(messages.document(outgoing[outgoing.length-1]));
-                        } else {
-                            ui.update(messages.document(msg));
-                        }
-                    }
+                    incoming.push(event.data);
                     break;
 
                 default: