524957 - Load order based on content types instead of tabs

Status: RESOLVED INVALID

(Firefox :: General, enhancement)

Description

[The 8472]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.4) Gecko/20091016 Firefox/3.5.4
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.4) Gecko/20091016 Firefox/3.5.4

When reopening a session with many many tabs (80+) firefox seems to load the pages mostly on a tab-by-tab basis instead of fetching all HTML/CSS/JS first and then loading the heavy-weight content (images, flash, pdfs).

Since i have many image-heavy pages in my session it can take several minutes until everything is loaded. I'd like to browse the remaining (mostly text-based) pages before everything is done loading.

I propose an option to queue the requests globally based on expected content-type instead of queueing things tab by tab. Or if it's not possible to do based on content-type then at least load images last, globally.

Reproducible: Always

Steps to Reproduce:
1. Open many tabs
2. Enable session restore
3. Restart Firefox
4. Trace the order in which content is fetched (e.g. with the live http headers extension)

Actual Results:  
Watch how not even the HTML is fetched for some tabs until other tabs have loaded completely

Expected Results:  
The basic page being fetched/rendered first before the fluff is loaded

Comment 1

[Paul O'Shannessy [:zpao] (not bugmail, email directly)]

This is true, and probably something that belongs elsewhere. I think this would would need to be implemented in the network component.

That said, bug 514490 should help marginally. When you switch to a different tab we'll switch network priority so that the focus tab gets higher priority for new network requests.

Comment 2

[Boris Zbarsky [:bzbarsky]]

>  think this would would need to be implemented in the network component.

Er... why?  The browser is setting explicit priorities here, which necko then follows.  When the priority is identical, Necko does basic FIFO scheduling.  But again, the browser is doing manual priority-setting, and we do in fact prioritize some sorts of content over others (e.g scripts are higher priority than images).

Comment 3

[Boris Zbarsky [:bzbarsky]]

"we" above is mostly the application layer, and to some small extent the direct necko consumers in the DOM.  Necko itself, again, just follows the loading priorities it's given.

Comment 4

[Paul O'Shannessy [:zpao] (not bugmail, email directly)]

(In reply to comment #2)
> Er... why?

I figured something had to happen at a point lower in the stack than session restore for us to be able to do it. I didn't know where, and wasn't even 100% sure we had the capability. But we do, so cool.

Comment 5

[The 8472]

Closing it since tabs are now lazy-loaded on session restore, thus avoiding the problem.