- From: Dave Singer <singer@apple.com>
- Date: Tue, 29 Jul 2008 17:13:29 -0700
The situation is a lot better for archives (like MPEG-21 files) that have a directory at the front... At 20:10 -0400 29/07/08, Russell Leggett wrote: >That is a performance killer. > > >I don't think it is as much of a performance killer as you say it >is. Correct me if I'm wrong, but the standard connection limit is >two. It is not as though every external file could be loaded at >once. Additionally, as I said, you could split resources into >multiple archives to take advantage of multiple connections, because >they can be loaded asynchronously without issue. Remember, the use >case for this would be when there are likely dozens of different >files that need to be loaded. > >So you get nondeterministic load behaviour anyway. This is not good. > > >This is not so different than directly requesting a file from >multiple tabs. Let's say page 1 and page 2 each use the same image. >If I load page 2 first, it will go directly to the server. If I load >page 1 first, page 2 will get the image from cache. > > >Clearly, there are other ways of performing this task, but I think >this way is simple and I know that I would gladly accept it as a >possibility. It falls within the same realm that any caching >behavior does. It is meant purely for performance, but if you are >relying on it for a given behavior then you are on a road to trouble. > >The archived resources should be static, and also available as >individual files. Pre-fetching them should only be used for >performance gains, and if it would not be performant, it should not >be used. However, I think there is a fairly wide range of sites or >applications that could benefit from this feature. If there are >other ways of improving it, or making it work better for certain >edge cases, that would be great, but don't throw the baby out with >the bath water. > >Off the top of my head, I can think of a couple of ways to refine >the feature and deal with the issues raised. > >Only blocking the loading of files that could logically be inside >the archive: if the archive is located at "/js/resources.zip", then >the only files that should be blocked would have to be located under >"/js". <img src="/images/lolcat.jpg"/> would not be blocked. >To go a step further, there could even be some kind of "pattern" >attribute that would block the loading of files that matched a url >pattern. For example, if the archive were located at "/", but had a >pattern of "**.js,**.css,/images/*", only js, css, and files under >the "/images" directory would be blocked. > >On Tue, Jul 29, 2008 at 2:13 PM, Robert O'Callahan ><<mailto:robert at ocallahan.org>robert at ocallahan.org> wrote: > >On Tue, Jul 29, 2008 at 5:59 AM, Russell Leggett ><<mailto:russell.leggett at gmail.com>russell.leggett at gmail.com> wrote: > >Yes, the one major hang up that I foresee is how a browser should >handle asynchronous loading. How would it know the contents of the >archive before it loaded the archive so it did not try to load the >same files directly? The simple answer would be to load the >archive(s) synchronously. > > >That is a performance killer. > >As for references in a different tab, if the separate tab/document >did not reference the zip archive first, it would operate as normal. >It would check the cache and then attempt to load. If the zip had >been loaded from the first page already, the file would be present >in the cache, and if not, then the browser would attempt to retrieve >it from the server. > > >So you get nondeterministic load behaviour anyway. This is not good. > >Rob > >-- >"He was pierced for our transgressions, he was crushed for our >iniquities; the punishment that brought us peace was upon him, and >by his wounds we are healed. We all, like sheep, have gone astray, >each of us has turned to his own way; and the LORD has laid on him >the iniquity of us all." [Isaiah 53:5-6] -- David Singer Apple/QuickTime -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.whatwg.org/pipermail/whatwg-whatwg.org/attachments/20080729/7e25bfac/attachment.htm>
Received on Tuesday, 29 July 2008 17:13:29 UTC