final patch for #510 -- new datastructure suggested and implemented by james for the events entry cache. speeds up all event operations

git-svn-id: http://svn.openlayers.org/trunk/openlayers@2896 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

doc/authors.txt

@@ -13,6 +13,7 @@ Tim Schaub
 Christopher Schmidt
 Cameron Shorter                                                              
 Paul Spencer                                                                 
+James Stembridge
 Erik Uzureau
 Bill Woodall
 Steve Woodbridge

lib/OpenLayers/Events.js

@@ -55,23 +55,40 @@ OpenLayers.Event = {
     return element;
   },
 
+  /** A hashtable cach of the event observers, keyed by element.id
+   * 
+   * @type Object
+   */
   observers: false,
 
   _observeAndCache: function(element, name, observer, useCapture) {
-    if (!this.observers) this.observers = [];
+    if (!this.observers) this.observers = new Object();
+
+    //if there is not yet a hash entry for this element, add one
+    if (!this.observers[element.id]) {
+        this.observers[element.id] = new Array();
+    }
+    //add a new observer to this element's list
+    this.observers[element.id].push([name, observer, useCapture]);
+
+    //add the actual browser event listener
     if (element.addEventListener) {
-      this.observers.push([element, name, observer, useCapture]);
       element.addEventListener(name, observer, useCapture);
     } else if (element.attachEvent) {
-      this.observers.push([element, name, observer, useCapture]);
       element.attachEvent('on' + name, observer);
     }
   },
 
   unloadCache: function() {
     if (!OpenLayers.Event.observers) return;
-    for (var i = 0; i < OpenLayers.Event.observers.length; i++) {
-      OpenLayers.Event.stopObserving.apply(this, OpenLayers.Event.observers[i]);
+    for (var elementId in OpenLayers.Event.observers) {
+        var elementObservers = OpenLayers.Event.observers[elementId];
+        if (elementObservers) {
+            for (var i = 0; i < elementObservers.length; i++) {
+                var args = new Array(elementId).concat(elementObservers[i]);            
+                OpenLayers.Event.stopObserving.apply(this, args);
+            }
+        }
     }
     OpenLayers.Event.observers = false;
   },
@@ -90,6 +107,8 @@ OpenLayers.Event = {
 
   stopObserving: function(elementParam, name, observer, useCapture) {
     var element = OpenLayers.Util.getElement(elementParam);
+    if (!element) return;
+
     useCapture = useCapture || false;
 
     if (name == 'keypress' &&
@@ -97,28 +116,37 @@ OpenLayers.Event = {
         || element.detachEvent))
       name = 'keydown';
 
-    // find entry in this.observers cache array and remove it
-    var observers = OpenLayers.Event.observers;
-    var entry = [element, name, observer, useCapture];
-    for (var i = 0; i < observers.length; i++) {
+    // find element's entry in this.observers cache and remove it
+    var elementObservers = OpenLayers.Event.observers[element.id];
+    if (elementObservers) {
+        var entry = [name, observer, useCapture];
 
-        //compare all 4 elements of entry with observer
-        var sameEntry = true;        
-        for (var j = 0; j < entry.length; j++) {
-            if (entry[j] != observers[i][j]) {
-                sameEntry = false;
-                break;
+        // find the specific event type in the element's list
+        for (var i = 0; i < elementObservers.length; i++) {
+            var cacheEntry = elementObservers[i];
+            
+            //compare all 3 elements of entry with observer
+            var sameEntry = true;        
+            for (var j = 0; j < entry.length; j++) {
+                if (entry[j] != cacheEntry[j]) {
+                    sameEntry = false;
+                    break;
+                }
+            }
+    
+            //if we've found it, remove it from the observers array
+            if (sameEntry) {
+                elementObservers.splice(i--, 1);
+                if (elementObservers.length == 0) {
+                    OpenLayers.Event.observers[element.id] = null;
+                }
+                break; 
             }
-        }
-
-        //if we've found it, remove it from the observers array
-        if (sameEntry) {
-            observers.splice(i--, 1);
-            break; 
         }
     }
 
-    if (element && element.removeEventListener) {
+    //actually remove the event listener from browser
+    if (element.removeEventListener) {
       element.removeEventListener(name, observer, useCapture);
     } else if (element && element.detachEvent) {
       element.detachEvent('on' + name, observer);

tests/test_Events.html

@@ -204,18 +204,19 @@
 
     function test_05_Event_destroy (t) {
         t.plan(2);
-        var start = OpenLayers.Event.observers.length;
+
         var div   = OpenLayers.Util.getElement('test');
         var obj   = {};
         var events = new OpenLayers.Events(obj, div);
         // +1 because of blocking dragstart in attachToElement()
-        t.eq(OpenLayers.Event.observers.length,
-             start + OpenLayers.Events.prototype.BROWSER_EVENTS.length + 1,
-             "construction increases the number of event observers");
+        t.eq(OpenLayers.Event.observers["test"].length,
+             OpenLayers.Events.prototype.BROWSER_EVENTS.length + 1,
+             "construction creates new arrayin hash, registers appropriate events");
+             
         events.destroy();
         events = null;
-        t.eq(OpenLayers.Event.observers.length, start,
-             "destruction restores the number of event observers");
+        t.eq(OpenLayers.Event.observers["test"], null,
+             "destruction removes the event observer from hash");
     }
    
   // -->