I have a very basic ajax slideshow on my website. On every scroll, the new images and response content continually increase the amount of memory used by the browser.
I've done my research and tried all suggestions to reset the XHR object on each new request, but this does absolutely nothing to help.
The slideshows are basic but may contain hundreds of slides. I want a user to be able to navigate the slideshow indefinitely without crashing their browser. Is this even possible?
Thanks, Brian
Increasing memory usage is normal. You are, after all, loading more data each time - the HTML from your AJAX response, as well as the images that are being displayed. Unless you're using Adobe Pagemill-generated HTML, that's only going to be a few hundreds of bytes of HTML/text. It's the images that will suck up the most space. Everything get stuffed into the browser's cache.
Since you're not doing anything fancy with the DOM (building sub-trees and whatnot) directly, just replacing a chunk of HTML repetitively, eventually the browser will do a cleanup and chuck some of the unused/old/stale image data from memory/cache and reclaim some of that memory.
Now, if you were doing some highly complex DOM manipulations and generating lots of new nodes on the fly, and were leaking some nodes here and there, THEN you'd have a memory problem, as those leaked nodes will eventually bury the browser.
But, just increasing memory usage by loading images is nothing to worry about, it's just like a normal extended surfing session, except you're just loading some new pictures.
If its a slideshow, are you only showing one image at a time? If you do only show one at a time and you're never getting rid of the last one you show, it will always increase the memory. If you remove the slides not being shown, it should help.
Related
On my website I need to toggle the visibility of complete articles.
When I make them visible (display:block), the text appears very fast while the space, where the image should be, is white. After a half or a second the image appears from once (it was loaded from the server before, so that's not the prob xD).
Now maybe there is a solution where I can hold the image in the RAM.
I don't even know how to call the Problem so I couldn't found much on google.
(Its important to take the article out of the DOM-Tree so setting opacity or visibility to 0 is not a solution).
It's up to the browser how it stores and fetches images from cache. There are a lot of factors, including what else the browser is doing, how many images, how big they are, etc. If it's taking that long, it's possible they are getting forced out of cache or they are too big or some other problem. Have you checked to make sure they are indeed being cached (again, this may be somewhat browser dependent)? Also make sure you don't have caching disabled (in your dev console or similar).
There are a lot of potential options to manage the image data, really depends on what you are doing as to the best solution.
This SO answer explains it clearly. In short,
If you render the HTML on the page, even if it's hidden, it's going to
load. If you want images to load only when they're needed, you're
going to have to dynamically set the source (src) on the image tag in
javascript.
I'm new to Ember. My first toy project is an cycling carousel of images.
I'm using an ArrayController to manage the images, and periodically rotating the underlying Array: http://jsbin.com/ePexEwom/14/edit?html,js,output
My question is: every time a rotation occurs (the first image moves to the end), my browser re-downloads the image which is slow and heavy.
This makes me think I should be just re-ordering the DOM elements in the view, rather than the objects in the controller's content, but not sure of the best way to do that...
Any ideas appreciated!
Update: I don't have control over the hosting site, so sending cache headers with the images won't work I'm afraid.
The best way to handle this is to set the cache expiry on the images. Both IE and FF don't send additional requests, but Chrome thinks you might want the latest and greatest each time, due to no caching values.
No caching of dynamically loaded images in Google Chrome
Cache Expiration On Static Images
Creating a custom worked pretty well: http://jsbin.com/ePexEwom/16/edit?html,js,output
Seems clean logically too, because the ordering of the pictures isn't changing in a meaningful way - it's just the presentation layer that needs to be changing.
We have a timer that removes the top item in an unordered list and moves it to the bottom of the list. Each item has images, custom fonts, rollovers, etc.
For some reason, the longer the page runs, the slower it gets. You can notice the latency when hovering over the ribbons. The ribbons are supposed to turn red on hover, but when it slows down you'll notice it can take several seconds to see the hover state.
I have no idea why this is happening. I believe we're properly cleaning everything up, but something is obviously wrong.
Here's the page in question...
http://gmfg.trailerparkinteractive.com/
Let me know if I can provide any additional detail.
It seems you have a memory leak and here's how you detect one.
It seems one of your scripts is allocating and deallocating a lot of memory over a short period of time.
Further drilling into the retaining tree we find that some HTML element nodes are being deleted from the DOM but not released.
My advice is, try running your site while disabling different scripts, and retest with this method to get a guestimate of which plugin is doing that.
I have a very basic ajax slideshow on my website. On every scroll, the new images and response content continually increase the amount of memory used by the browser.
I've done my research and tried all suggestions to reset the XHR object on each new request, but this does absolutely nothing to help.
The slideshows are basic but may contain hundreds of slides. I want a user to be able to navigate the slideshow indefinitely without crashing their browser. Is this even possible?
Thanks, Brian
Increasing memory usage is normal. You are, after all, loading more data each time - the HTML from your AJAX response, as well as the images that are being displayed. Unless you're using Adobe Pagemill-generated HTML, that's only going to be a few hundreds of bytes of HTML/text. It's the images that will suck up the most space. Everything get stuffed into the browser's cache.
Since you're not doing anything fancy with the DOM (building sub-trees and whatnot) directly, just replacing a chunk of HTML repetitively, eventually the browser will do a cleanup and chuck some of the unused/old/stale image data from memory/cache and reclaim some of that memory.
Now, if you were doing some highly complex DOM manipulations and generating lots of new nodes on the fly, and were leaking some nodes here and there, THEN you'd have a memory problem, as those leaked nodes will eventually bury the browser.
But, just increasing memory usage by loading images is nothing to worry about, it's just like a normal extended surfing session, except you're just loading some new pictures.
If its a slideshow, are you only showing one image at a time? If you do only show one at a time and you're never getting rid of the last one you show, it will always increase the memory. If you remove the slides not being shown, it should help.
I'm working on a HTML 5 game, it is already online, but it's currently small and everything is okay.
Thing is, as it grows, it's going to be loading many, many images, music, sound effects and more. After 15 minutes of playing the game, at least 100 different resources might have been loaded already. Since it's an HTML5 App, it never refreshes the page during the game, so they all stack in the background.
I've noticed that every resource I load - on WebKit at least, using the Web Inspector - remains there once I remove the <img>, the <link> to the CSS and else. I'm guessing it's still in memory, just not being used, right?
This would end up consuming a lot of RAM eventually, and lead to a downgrade in performance specially on iOS and Android mobiles (which I slightly notice already on the current version), whose resources are more limited than desktop computers.
My question is: Is it possible to fully unload a Resource, freeing space in the RAM, through JavaScript? Without having to refresh the whole page to "clean it".
Worst scenario: Would using frames help, by deleting a frame, to free those frames' resources?.
Thank you!
Your description implies you have fully removed all references to the resources. The behavior you are seeing, then, is simply the garbage collector not having been invoked to clean the space, which is common in javascript implementations until "necessary". Setting to null or calling delete will usually do no better.
As a common case, you can typically call CollectGarbage() during scene loads/unloads to force the collection process. This is typically the best solution when the data will be loaded for game "stages", as that is a time that is not time critical. You usually do not want the collector to invoke during gameplay unless it is not a very real-time game.
Frames are usually a difficult solution if you want to keep certain resources around for common game controls. You need to consider whether you are refreshing entire resources or just certain resources.
All you can do is rely on JavaScript's built in garbage collection mechanism.
This kicks in whenever there is no reference to your image.
So assuming you have a reference pointer for each image, if you use:
img.destroy()
or
img.parentNode.removeChild(img)
Worth checking out: http://www.ibm.com/developerworks/web/library/wa-memleak/
Also: Need help using this function to destroy an item on canvas using javascript
EDIT
Here is some code that allows you to load an image into a var.
<script language = "JavaScript">
var heavyImage = new Image();
heavyImage.src = "heavyimagefile.jpg";
......
heavyImage = null; // removes reference and frees up memory
</script>
This is better that using JQuery .load() becuase it gives you more control over image references, and they will be removed from memory if the reference is gone (null)
Taken from: http://www.techrepublic.com/article/preloading-and-the-javascript-image-object/5214317
Hope it helps!
There are 2 better ways to load images besides a normal <img> tag, which Google brilliantly discusses here:
http://www.youtube.com/watch?v=7pCh62wr6m0&list=UU_x5XG1OV2P6uZZ5FSM9Ttw&index=74
Loading the images in through an HTML5 <canvas> which is way way faster. I would really watch that video and implement these methods for more speed. I would imagine garbage collection with canvas would function better because it's breaking away from the DOM.
Embedded data urls, where the src attribute of an image tag is the actual binary data of the image (yeah it's a giant string). It starts like this: src="data:image/jpeg;base64,/9j/MASSIVE-STRING ... " After using this, you would of course want to use a method to remove this node as discussed in the other answers. (I don't know how to generate this base64 string, try Google or the video)
You said Worst scenario: Would using frames help, by deleting a frame, to free those frames' resources
It is good to use frame. Yes, it can free up resource by deleting the frames.
All right, so I've made my tests by loading 3 different HTML into an < article > tag. Each HTML had many, huge images. Somewhat about 15 huge images per "page".
So I used jQuery.load() function to insert each in the tag. Also had an extra HTML that only had an < h1 >, to see what happened when a page with no images was replacing the previous page.
Well, turns out the RAM goes bigger while you start scrolling, and shoots up when going through a particularly big image (big as in dimensions and size, not just size). But once you leave that behind and lighter images come to screen, the RAM consumption actually goes down. And whenever I replaced using JS the content of the page, the RAM consumption went really down when it was occupying to much. Virtual Memory remained always high and rarely went down.
So I guess the browser is quite smart about handling Resources. It does not seem to unload them if you leave it there for a long while, but as soon you start loading other pages or scrolling, it starts loading / freeing up.
I guess I don't have anything to worry about after all...
Thanks everyone! =)