Re: Architecture independence for rrd files

Today Steve Shipway wrote:

>
> I'm only guessing at what was in Tobi's mind when he designed it,
> but I think the idea was to sacrifice portability in exchange for
> speed (and maybe the idea of architecture independence didn't
> occur to him back in the 90s when he didn't realise how big
> RRDtool was going to be!).  Being able to write a struct directly
> to disk is always going to be more efficient than if you have to
> swap bytes of integers around first.  And, since (in the current
> code) we're writing the runtime data structure raw direct to
> disk, this means that word alignment in structs *is* an issue.

I simply was too ignorant back then, and all the nice people who
looked at the dataformat back then :-)

> Of course, there are ways around these problems, particularly
> since the headers structs are infrequently read and so can cope
> with translation and less efficient writing methods, but this
> would all require a more significant rewrite of how rrdtool works
> - and this brings us on to Tobi's RRDTool 2.x project which is
> going to address this issue, amongst others.

some time ago, I did some investigation into creating a portable
data format ... I just copied the page from the old rrdtool wiki
over to github.

https://github.com/oetiker/rrdtool-2.x/wiki/Portable-Dataformat

cheers
tobi

ps. please move the discussion to rrd-developers

-- 
Tobi Oetiker, OETIKER+PARTNER AG, Aarweg 15 CH-4600 Olten, Switzerland
http://it.oetiker.ch [email protected] ++41 62 775 9902 / sb: -9900