From e3520ac711834fb5ca7b587ad5075ad054ecac27 Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonygarnockjones@gmail.com>
Date: Sun, 7 Aug 2016 21:04:32 -0400
Subject: [PATCH] Coalesce adjacent patch actions from a given pid

---
 js/src/actor.js     | 5 +----
 js/src/dataspace.js | 9 +++++++++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/js/src/actor.js b/js/src/actor.js
index d458f8f..4e767cc 100644
--- a/js/src/actor.js
+++ b/js/src/actor.js
@@ -86,12 +86,9 @@ Actor.prototype.quiesce = function() {
       var facet = subjectId[0];
       var endpoint = subjectId[1];
       withCurrentFacet(facet, function () {
-        // TODO: coalesce patches within a single actor
-        var aggregate = Patch.emptyPatch;
         var patch = Patch.retract(__).andThen(endpoint.subscriptionFn.call(facet.fields));
         var r = facet.actor.mux.updateStream(endpoint.eid, patch);
-        aggregate = aggregate.andThen(r.deltaAggregate);
-        Dataspace.stateChange(aggregate);
+        Dataspace.stateChange(r.deltaAggregate);
       });
     });
   }
diff --git a/js/src/dataspace.js b/js/src/dataspace.js
index 6d9af72..f892abc 100644
--- a/js/src/dataspace.js
+++ b/js/src/dataspace.js
@@ -203,6 +203,15 @@ Dataspace.prototype.step = function () {
 };
 
 Dataspace.prototype.enqueueAction = function (pid, action) {
+  if (action.type === 'stateChange') {
+    var newestEntry = this.pendingActions.last();
+    if (newestEntry && newestEntry[0] === pid && newestEntry[1].type === 'stateChange') {
+      var combinedPatch = newestEntry[1].patch.andThen(action.patch);
+      this.pendingActions = this.pendingActions.pop().push([pid, stateChange(combinedPatch)]);
+      return;
+    }
+    /* fall through */
+  }
   this.pendingActions = this.pendingActions.push([pid, action]);
 };