Merge pull request #3013 from gberaudo/performance_vector_source_clear

Improve vector source clear() performance

src/ol/source/vectorsource.js

@@ -36,8 +36,16 @@ ol.source.VectorEventType = {
    */
   CHANGEFEATURE: 'changefeature',
 
+  /**
+   * Triggered when the clear method is called on the source.
+   * @event ol.source.VectorEvent#clear
+   * @api
+   */
+  CLEAR: 'clear',
+
   /**
    * Triggered when a feature is removed from the source.
+   * See {@link ol.source.Vector#clear source.clear()} for exceptions.
    * @event ol.source.VectorEvent#removefeature
    * @api stable
    */
@@ -227,15 +235,32 @@ ol.source.Vector.prototype.addFeaturesInternal = function(features) {
 
 /**
  * Remove all features from the source.
+ * @param {boolean=} opt_fast Skip dispatching of {@link removefeature} events.
  * @api stable
  */
-ol.source.Vector.prototype.clear = function() {
-  this.rBush_.forEach(this.removeFeatureInternal, this);
+ol.source.Vector.prototype.clear = function(opt_fast) {
+  if (opt_fast) {
+    for (var featureId in this.featureChangeKeys_) {
+      var keys = this.featureChangeKeys_[featureId];
+      goog.array.forEach(keys, goog.events.unlistenByKey);
+    }
+    this.featureChangeKeys_ = {};
+    this.idIndex_ = {};
+    this.undefIdIndex_ = {};
+  } else {
+    var rmFeatureInternal = this.removeFeatureInternal;
+    this.rBush_.forEach(rmFeatureInternal, this);
+    goog.object.forEach(this.nullGeometryFeatures_, rmFeatureInternal, this);
+    goog.asserts.assert(goog.object.isEmpty(this.featureChangeKeys_));
+    goog.asserts.assert(goog.object.isEmpty(this.idIndex_));
+    goog.asserts.assert(goog.object.isEmpty(this.undefIdIndex_));
+  }
+
   this.rBush_.clear();
-  goog.object.forEach(
-      this.nullGeometryFeatures_, this.removeFeatureInternal, this);
-  goog.object.clear(this.nullGeometryFeatures_);
-  goog.asserts.assert(goog.object.isEmpty(this.featureChangeKeys_));
+  this.nullGeometryFeatures_ = {};
+
+  var clearEvent = new ol.source.VectorEvent(ol.source.VectorEventType.CLEAR);
+  this.dispatchEvent(clearEvent);
   this.changed();
 };
 

src/ol/structs/rbush.js

@@ -74,7 +74,7 @@ ol.structs.RBush.prototype.load = function(extents, values) {
   }
   goog.asserts.assert(extents.length === values.length);
 
-  var items = [];
+  var items = new Array(values.length);
   for (var i = 0, l = values.length; i < l; i++) {
     var extent = extents[i];
     var value = values[i];
@@ -86,7 +86,7 @@ ol.structs.RBush.prototype.load = function(extents, values) {
       extent[3],
       value
     ];
-    items.push(item);
+    items[i] = item;
     goog.object.add(this.items_, goog.getUid(value).toString(), item);
   }
   this.rbush_.load(items);
@@ -228,7 +228,7 @@ ol.structs.RBush.prototype.isEmpty = function() {
  */
 ol.structs.RBush.prototype.clear = function() {
   this.rbush_.clear();
-  goog.object.clear(this.items_);
+  this.items_ = {};
 };
 
 

test/spec/ol/source/vectorsource.test.js

@@ -85,11 +85,31 @@ describe('ol.source.Vector', function() {
 
     describe('#clear', function() {
 
-      it('removes all features', function() {
+      it('removes all features using fast path', function() {
         var changeSpy = sinon.spy();
         goog.events.listen(vectorSource, 'change', changeSpy);
         var removeFeatureSpy = sinon.spy();
         goog.events.listen(vectorSource, 'removefeature', removeFeatureSpy);
+        var clearSourceSpy = sinon.spy();
+        goog.events.listen(vectorSource, 'clear', clearSourceSpy);
+        vectorSource.clear(true);
+        expect(vectorSource.getFeatures()).to.eql([]);
+        expect(vectorSource.isEmpty()).to.be(true);
+        expect(changeSpy).to.be.called();
+        expect(changeSpy.callCount).to.be(1);
+        expect(removeFeatureSpy).not.to.be.called();
+        expect(removeFeatureSpy.callCount).to.be(0);
+        expect(clearSourceSpy).to.be.called();
+        expect(clearSourceSpy.callCount).to.be(1);
+      });
+
+      it('removes all features using slow path', function() {
+        var changeSpy = sinon.spy();
+        goog.events.listen(vectorSource, 'change', changeSpy);
+        var removeFeatureSpy = sinon.spy();
+        goog.events.listen(vectorSource, 'removefeature', removeFeatureSpy);
+        var clearSourceSpy = sinon.spy();
+        goog.events.listen(vectorSource, 'clear', clearSourceSpy);
         vectorSource.clear();
         expect(vectorSource.getFeatures()).to.eql([]);
         expect(vectorSource.isEmpty()).to.be(true);
@@ -97,6 +117,8 @@ describe('ol.source.Vector', function() {
         expect(changeSpy.callCount).to.be(1);
         expect(removeFeatureSpy).to.be.called();
         expect(removeFeatureSpy.callCount).to.be(features.length);
+        expect(clearSourceSpy).to.be.called();
+        expect(clearSourceSpy.callCount).to.be(1);
       });
 
     });