On Tue, Sep 28, 2010 at 9:39 AM, Boris Zbarsky <bzbar...@mit.edu> wrote:
> On 9/28/10 10:32 AM, Chris Marrin wrote: > >> I'd hate the idea of another flag in XHR. Why not just keep the raw bits >> and then convert when responseText is called? The only disadvantage of this >> is when the author makes multiple calls to responseText and I would not >> think that is a very common use case. >> > > It's actually reasonably common; Gecko had some performance bugs filed on > us until we started caching the responseText (before that we did exactly > what you just suggested). > > Oh, and some sites poll responseText from progress events for reasons I > can't fathom. > A number of sites check .responseText.length on every progress event in order to monitor how much data has been received. This came up as a performance hotspot when I was profiling WebKit's XHR implementation as well. - James > > -Boris > >