Re: Asynchronous DNS resolving

[chad <yandros@gmail.com>]

Not what you asked, but related:

Modern browsers use a technique called DNS pre-fetching to increase
the responsiveness of their UI.  More or less, they pre-resolve the
DNS names of every link on a page when rendering it (usually with
some async technique). This helps with both images and links, which
can be a pretty big deal with a typical Web 2.0 page that has links
and images from many domains (for example: the host site, its CDN,
a comments site, and anywhere between a passel and a gaggle of
social media buttons).

There are some downsides to consider, unfortunately.  Many CDNs
really want a very short TTL on their resolves, and there are even
(I hear) some systems that use a system of ephemeral names in such
links to track users across sites (potentially bypassing cookies,
privacy policies, and anonymizing services). I suspect that eww
would like DNS pre-fetching anyway, but you might want a way to
turn it off.

I mention this now because it conflicts with the suggestion that
you can just make the entire open-network-stream (etc) process
async, and avoid the question at the level of eww.  Put another
way, you probably *can* do that, but youll be giving up a potentially
valuable browser speed-up.

I hope that helps,
~Chad