Poor nnrpd xhdr performance

[meow]

In nnmh:inn-workers, George Lindholm <George.Lindholm at ubc.ca> wrote:

> I just noticed that XHDR with inn 2.3 is significantly slower compared to
> inn 1.7. I would say it is close to an order of magnitude slower.

Not surprising, since you're grabbing a non-overview header.  The new
overview code is not optimized for this, and indeed XHDR for non-NOV
headers was an add-on to the new code.  Olaf Titz' patch that enabled
this is very sane, so I'd look deeper.

Article retrieval by token has generally been plenty fast, so a likely
place to play around with profiling is probably going to be the
*search functions in the overview code.  A quick scan suggests it's
really made for the article/body/head/stat case, and building
up/tearing down lots of things that don't look healthy for a search
loop.