Small parentWays, parentRelations perf improvements

js/id/graph/graph.js

@@ -24,6 +24,7 @@ iD.Graph = function(other, mutable) {
 
     this.transients = {};
     this._childNodes = {};
+    this.getEntity = _.bind(this.entity, this);
 
     if (!mutable) {
         this.freeze();
@@ -48,19 +49,21 @@ iD.Graph.prototype = {
     },
 
     parentWays: function(entity) {
-        return _.map(this._parentWays[entity.id], _.bind(this.entity, this));
+        return _.map(this._parentWays[entity.id], this.getEntity);
     },
 
     isPoi: function(entity) {
-        return this.parentWays(entity).length === 0;
+        var parentWays = this._parentWays[entity.id];
+        return !parentWays || parentWays.length === 0;
+    },
+
+    isShared: function(entity) {
+        var parentWays = this._parentWays[entity.id];
+        return parentWays && parentWays.length > 1;
     },
 
     parentRelations: function(entity) {
-        return _.map(this._parentRels[entity.id], _.bind(this.entity, this));
-        var ent, id, parents;
-
-
-        return this._parentRels[entity.id] || [];
+        return _.map(this._parentRels[entity.id], this.getEntity);
     },
 
     childNodes: function(entity) {

js/id/renderer/map.js

@@ -64,7 +64,7 @@ iD.Map = function() {
             for (var i = 0; i < parents.length; i++) {
                 var parent = parents[i];
                 if (only[parent.id] === undefined) {
-                    only[parent.id] = graph.entity(parent.id);
+                    only[parent.id] = parent;
                     addParents(graph.parentRelations(parent));
                 }
             }

js/id/svg/vertices.js

@@ -36,7 +36,7 @@ iD.svg.Vertices = function(projection) {
         groups.attr('transform', iD.svg.PointTransform(projection))
             .call(iD.svg.TagClasses())
             .call(iD.svg.MemberClasses(graph))
-            .classed('shared', function(entity) { return graph.parentWays(entity).length > 1; });
+            .classed('shared', function(entity) { return graph.isShared(entity); });
 
         // Selecting the following implicitly
         // sets the data (vertix entity) on the elements