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Last active August 29, 2015 14:18
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aurelia-breeze-adapter: splice vs. null
Raw
index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge, chrome=1" />
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no" />
<title >Observer Fun</title>
</head>
<body>
<h1>Ta Da!</h1>
<div>
</div>
<script src="observer.js"></script>
<script>
var limit = 1000000;
var isSplicer = true;
for (var i = 0; i < 6; i++) {
if (isSplicer) {
runSplicer(limit);
isSplicer = false;
} else {
runNuller(limit);
isSplicer = true;
}
}
var doneEl = document.createElement('div');
doneEl.innerHTML = 'done!';
document.body.appendChild(doneEl);
/////////////////////////////////////////
function runSplicer(limit){
var observer = new Splicer({});
var firstUnsubscribe = observer.subscribe('first', function() {
// console.log('first event ');
});
var count = 0;
console.log("==Splicer start");
for (var i = 0; i<limit; i++){
doit();
}
firstUnsubscribe();
console.log("==Splicer done, iter="+i);
function doit() {
count++;
var unsubscribe = observer.subscribe('splicer', function() {
//console.log('splicer event '+count);
});
observer.subscription('splicer');
unsubscribe();
}
}
function runNuller(limit){
var observer = new Nuller({});
var firstUnsubscribe = observer.subscribe('first', function() {
// console.log('first event ');
});
var count = 0;
console.log("==Nuller start");
for (var i = 0; i<limit; i++){
doit();
}
firstUnsubscribe();
console.log("==Nuller done, iter="+i);
function doit() {
count++;
var unsubscribe = observer.subscribe('nuller', function() {
//console.log('Nuller event '+count);
});
observer.subscription('nuller');
unsubscribe();
}
}
</script>
</body>
</html>
Raw
observer.js
function Splicer(obj){
this.obj = obj;
this.observers = {};
this.callbacks = {};
this.callbackCount = 0;
}
Splicer.prototype = {
constructor: Splicer,
subscribe: subscribeSplice,
unsubscribe: unsubscribeSplice
}
function subscribeSplice(propertyName, callback){
var callbacks = this.callbacks[propertyName];
if (!callbacks) {
this.callbacks[propertyName] = [callback];
} else if (callbacks.indexOf(callback) === -1) {
callbacks.push(callback);
} else {
return; // already registered; ignore.
}
if (this.callbackCount === 0) {
// this.subscription = this.obj.entityAspect.propertyChanged.subscribe(this.handleChanges.bind(this));
this.subscription = handleChangesSplice.bind(this);
}
this.callbackCount += 1;
return this.unsubscribe.bind(this, propertyName, callback);
}
function unsubscribeSplice(propertyName, callback) {
var callbacks = this.callbacks[propertyName];
if (!callbacks) { return; } // no subscriptions for this property; ignore.
var index = callbacks.indexOf(callback);
if (index === -1) { return; } // this callback was not found; ignore.
callbacks.splice(index, 1);
this.callbackCount -= 1;
if (this.callbackCount === 0) {
// this.obj.entityAspect.propertyChanged.unsubscribe(this.subscription);
this.subscription = function() {};
this.callbacks={};
}
}
function handleChangesSplice(propertyName) {
var callbacks=this.callbacks[propertyName];
if (!callbacks) return;
for (var i = 0, ii = callbacks.length; i < ii; i++) {
callbacks[i]();
}
}
//////////////
function Nuller(obj){
this.obj = obj;
this.observers = {};
this.callbacks = {};
this.callbackCount = 0;
}
Nuller.prototype = {
constructor: Nuller,
subscribe: subscribeNull,
unsubscribe: unsubscribeNull
}
function subscribeNull(propertyName, callback){
var callbacks = this.callbacks[propertyName];
if (!callbacks) {
this.callbacks[propertyName] = [callback];
} else if (callbacks.indexOf(callback) === -1) {
var ix = callbacks.indexOf(null);
if (ix === -1) {
callbacks.push(callback);
} else {
callbacks[ix]=callback;
}
} else {
return; // already registered; ignore.
}
if (this.callbackCount === 0) {
// this.subscription = this.obj.entityAspect.propertyChanged.subscribe(this.handleChanges.bind(this));
this.subscription = handleChangesNull.bind(this);
}
this.callbackCount += 1;
return this.unsubscribe.bind(this, propertyName, callback);
}
function unsubscribeNull(propertyName, callback) {
var callbacks = this.callbacks[propertyName];
if (!callbacks) return;
var index = callbacks.indexOf(callback);
if (index === -1) return;
callbacks[index] = null;
this.callbackCount -= 1;
if (this.callbackCount === 0) {
// this.obj.entityAspect.propertyChanged.unsubscribe(this.subscription);
this.subscription = function() {};
this.callbacks={};
}
}
function handleChangesNull(propertyName) {
var callbacks=this.callbacks[propertyName];
if (!callbacks) return;
for (var i = 0, ii = callbacks.length; i < ii; i++) {
callbacks[i] && callbacks[i]();
}
}
/////////////////////////
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