Improve performance of EObject.eContents() and Resource._index() by using caching.

Author: ghillairet

src/ecore.js

@@ -459,17 +459,36 @@ Ecore.EObjectPrototype = {
     eContents: function() {
         if (!this.eClass) return [];
 
-        var eAllFeatures = this.eClass.get('eAllStructuralFeatures'),
-            eContainments = _.filter(eAllFeatures, function(feature) {
+        if (_.isUndefined(this.__updateContents)) {
+            this.__updateContents = true;
+
+            var resource = this.eResource();
+            if (resource) {
+                var me = this;
+                resource.on('add remove', function() {
+                    me.__updateContents = true;
+                })
+            }
+        }
+
+        if (this.__updateContents) {
+            var eAllFeatures    = this.eClass.get('eAllStructuralFeatures');
+            var eContainments   = _.filter(eAllFeatures, function(feature) {
                 return feature.isTypeOf('EReference') &&
                     feature.get('containment') &&
                     this.isSet(feature.get('name'));
             }, this);
 
-        return _.flatten(_.map(eContainments, function(c) {
-            var value = this.get(c.get('name'));
-            return value instanceof Ecore.EList ? value.array() : value;
-        }, this));
+            var value = null;
+            this.__eContents = _.flatten(_.map(eContainments, function(c) {
+                value = this.get(c.get('name'));
+                return value ? (value.array ? value.array() : value) : [];
+            }, this));
+
+            this.__updateContents = false;
+        }
+
+        return this.__eContents;
     },
 
     // Returns the URI of the EObject.

src/resource.js

@@ -305,11 +305,7 @@ var EClassResource = Ecore.Resource = Ecore.EClass.create({
             _: function(fragment) {
                 if (!fragment) return null;
 
-                if (this.__index == null) {
-                    this.__index = buildIndex(this);
-                }
-
-                return this.__index[fragment];
+                return this._index()[fragment];
             }
         },
         {
@@ -403,7 +399,20 @@ var EClassResource = Ecore.Resource = Ecore.EClass.create({
             name: '_index',
             eType: JSObject,
             _: function() {
-                return buildIndex(this);
+                if (_.isUndefined(this.__updateIndex)) {
+                    var res = this;
+                    res.__updateIndex = true;
+                    res.on('add remove', function() {
+                        res.__updateIndex = true;
+                    })
+                }
+
+                if (this.__updateIndex) {
+                    this.__index = buildIndex(this);
+                    this.__updateIndex = false;
+                }
+
+                return this.__index;
             }
         }
     ]

test/index.test.js

@@ -0,0 +1,65 @@
+var Ecore   = require('../dist/ecore.js');
+var assert  = require('assert');
+var _       = require('underscore');
+
+describe('index', function() {
+
+    var resource;
+
+    beforeEach(function() {
+        var resourceSet = Ecore.ResourceSet.create();
+
+        var p = Ecore.EPackage.create({ name: 'p' });
+        var a = Ecore.EClass.create({ name: 'A' });
+        var b = Ecore.EClass.create({ name: 'B' });
+
+        p.get('eClassifiers')
+            .add(a)
+            .add(b);
+
+        resource = resourceSet.create('test');
+        resource.add(p);
+    });
+
+    it('should have index', function() {
+        var index = resource._index();
+        assert.ok(index);
+        assert.equal(3, _.keys(index).length);
+    })
+
+    it('should be updated when adding an element', function(done) {
+        assert.ok(resource._index());
+
+        resource.on('add', function(list) {
+            assert.ok(resource.__updateIndex === true);
+
+            var index = resource._index();
+            assert.equal(4, _.keys(index).length);
+
+            assert.strictEqual(index, resource.__index);
+
+            done();
+        })
+
+        var c = Ecore.EClass.create({ name: 'C' });
+        resource.get('contents').at(0).get('eClassifiers').add(c);
+    })
+
+    it('should be update when removing an element', function(done) {
+        var index = resource._index();
+        assert.equal(3, _.keys(index).length);
+
+        resource.on('remove', function(list) {
+            assert.ok(resource.__updateIndex === true);
+            index = resource._index();
+            assert.equal(2, _.keys(index).length);
+
+            done();
+        })
+
+        var root = resource.get('contents').at(0);
+        root.get('eClassifiers').remove(root.get('eClassifiers').at(1));
+    })
+
+})
+

test/resource.test.js

@@ -1,6 +1,6 @@
 var fs = require('fs');
 var Ecore = require('../dist/ecore.js');
-var assert = require("assert");
+var assert = require('assert');
 
 describe('Resource', function() {