On Wed, 21 Apr 2010 17:10:00 +0200, Torsten Förtsch
<torsten.foert...@gmx.net> wrote:
On Wednesday 21 April 2010 16:59:01 Perrin Harkins wrote:
In both cases you have the same drawback: it's impossible to read
anything from the shared data without copying the data you read into
perl variables.
[...]
no, MMapDB creates read-only variables that reference the mmapped block.
It manipulates SvPVX directly:
SvPV_set(sv, pointer);
SvLEN_set(sv, 0); # this makes sure perl won't try to free() the
space
[...]
You can then pass around references to that variable and nothing will be
copied.
Cool!
So, if I understand correctly: using something like Cache::FastMmap
creates copy of your strings/values/... in your process memory.
See the "fc_read" function. Is this correct?
http://cpansearch.perl.org/src/ROBM/Cache-FastMmap-1.35/Cache-FastMmap-CImpl/CImpl.xs
I guess pretty much anything else works that way, not just Cache::FastMmap.
--
Cosimo
