Small tdb optimization

[Rusty Russell]

On Thu, 15 Dec 2011 12:18:57 +0100, Volker Lendecke <Volker.Lendecke at SerNet.DE> wrote:
Non-text part: multipart/mixed
> Hi, Rusty!
> 
> Attached find a small modification that might show some
> speedup for large (i.e. ldb index) records.
> 
> The same would need to be applied to tdb2/tdb1_tdb.c if
> accepted.
> 
> With best regards,

I like it; I think saving the malloc & copy is better than avoiding two
copies into the mmap.  I think the dbuf.dsize != 0 check is unnecessary
though.

Thanks!
Rusty.