Added extra bool in Window object to know about its Mutation Observers

This commit is contained in:
Nupur Baghel 2018-02-14 02:11:58 +05:30
parent 7945dff8ea
commit a1fd6c39a2
3 changed files with 64 additions and 1 deletions

View file

@ -9,7 +9,7 @@ use dom::bindings::codegen::Bindings::MutationObserverBinding::MutationCallback;
use dom::bindings::codegen::Bindings::MutationObserverBinding::MutationObserverBinding::MutationObserverMethods;
use dom::bindings::codegen::Bindings::MutationObserverBinding::MutationObserverInit;
use dom::bindings::error::{Error, Fallible};
use dom::bindings::reflector::{Reflector, reflect_dom_object};
use dom::bindings::reflector::{Reflector, reflect_dom_object, DomObject};
use dom::bindings::root::DomRoot;
use dom::bindings::str::DOMString;
use dom::mutationrecord::MutationRecord;
@ -67,6 +67,7 @@ impl MutationObserver {
}
pub fn Constructor(global: &Window, callback: Rc<MutationCallback>) -> Fallible<DomRoot<MutationObserver>> {
global.set_exists_mut_observer();
let observer = MutationObserver::new(global, callback);
ScriptThread::add_mutation_observer(&*observer);
Ok(observer)
@ -105,6 +106,9 @@ impl MutationObserver {
/// <https://dom.spec.whatwg.org/#queueing-a-mutation-record>
pub fn queue_a_mutation_record(target: &Node, attr_type: Mutation) {
if !target.global().as_window().get_exists_mut_observer() {
return;
}
// Step 1
let mut interestedObservers: Vec<(DomRoot<MutationObserver>, Option<DOMString>)> = vec![];
// Step 2 & 3

View file

@ -285,9 +285,20 @@ pub struct Window {
/// The Webrender Document id associated with this window.
#[ignore_malloc_size_of = "defined in webrender_api"]
webrender_document: DocumentId,
/// Flag to identify whether mutation observers are present(true)/absent(false)
exists_mut_observer: Cell<bool>,
}
impl Window {
pub fn get_exists_mut_observer(&self) -> bool {
self.exists_mut_observer.get()
}
pub fn set_exists_mut_observer(&self) {
self.exists_mut_observer.set(true);
}
#[allow(unsafe_code)]
pub fn clear_js_runtime_for_script_deallocation(&self) {
unsafe {
@ -1814,6 +1825,7 @@ impl Window {
test_worklet: Default::default(),
paint_worklet: Default::default(),
webrender_document,
exists_mut_observer: Cell::new(false),
});
unsafe {

View file

@ -0,0 +1,47 @@
<!DOCTYPE html>
<html>
<head>
<meta charset='utf-8'>
</head>
<body>
<script>
window.onload = function(){
var script = document.createElement("script");
script.setAttribute("attr", "val");
var start_test = function(targetNode,attr) {
var start = performance.now();
for( val = 1; val <= 1000; val++) {
targetNode.setAttribute(attr, val);
}
var stop = performance.now();
console.log('Time taken:'+ (stop - start)/1000.0);
};
var config = { attributes: true, childList: true };
console.log('Mutation Observer Algorithm performance testing...');
console.log('\nMutation performed without observer ->');
start_test(script,"attr");
console.log('\nMutation performed with observer ->');
var callback = function(mutationsList) {
for(var mutation of mutationsList) {
if (mutation.type == 'childList') {
// Uncomment below line to see changes
// console.log('A child node has been added or removed.');
}
else if (mutation.type == 'attributes') {
// Uncomment below line to see changes
// console.log('The ' + mutation.attributeName + ' attribute was modified.');
}
}
};
var observer = new MutationObserver(callback);
observer.observe(script, config);
start_test(script,"attr");
}
</script>
</body>
</html>