[Pacemaker] SysInfo_mem_units()

[Simon Horman]

On Wed, Jul 07, 2010 at 11:16:21AM +0200, Andrew Beekhof wrote:
> On Wed, Jul 7, 2010 at 8:53 AM, Simon Horman <horms at verge.net.au> wrote:
> > On Wed, Jul 07, 2010 at 08:27:17AM +0200, Andrew Beekhof wrote:
> >> On Wed, Jul 7, 2010 at 6:17 AM, Simon Horman <horms at verge.net.au> wrote:
> >> > Hi,
> >> >
> >> > I am currently pondering the SysInfo_mem_units() function
> >> > of sources/SysInfo (with a view to turning it into awk to
> >> > avoid bashisms[1]).
> >> >
> >> > Basically the function seems to look at the unit of the input,
> >> > leave it as if if the unit is G, divide it by 1024 if its M[bB]?
> >> > or divide it by 1024^2 if the unit is k[B]?. It then does some rounding.
> >> >
> >> > On the unit handling side of things I am puzzled by the following code,
> >> > particularly the inner if [ $mem != ${mem/./} ] portion. It seems to
> >> > handle the x.yG case. But the logic seems to lead to the following result:
> >> >
> >> > xG => x
> >> > x.yG => 1024x + w*y
> >> >
> >> > Surely the latter should be x.yG => x + (w*y/1024).
> >> > Also, surely this logic also applies equally to other units.
> >
> > Can you comment on this?
> 
> Oh I probably just messed up. In any case, your awk version wont have
> this problem.

Ok, thats what I was thinking too.

> >> >    if [ ${mem:$memlen:1} = "G" ]; then
> >> >        mem="${mem:0:$memlen}"
> >> >        if [ $mem != ${mem/./} ]; then
> >> >            mem_before=${mem/.*/}
> >> >            mem_after=${mem/*./}
> >> >            mem=$[mem_before*1024]
> >> >            if [ ${#mem_after} = 0 ]; then
> >> >                :
> >> >            elif [ ${#mem_after} = 1 ]; then
> >> >                mem=$[mem+100*$mem_after]
> >> >            elif [ ${#mem_after} = 2 ]; then
> >> >                mem=$[mem+10*$mem_after]
> >> >            elif [ ${#mem_after} = 3 ]; then
> >> >                mem=$[mem+$mem_after]
> >> >            else
> >> >                mem_after=${mem_after:0:3}
> >> >                mem=$[mem+$mem_after]
> >> >            fi
> >> >        fi
> >> >    elif [ ${mem:$memlen:1} = "M" ]; then
> >> >
> >> >
> >> > [1] I also struggle to care about this bashism crusade. But its
> >>
> >> yeah, me too. but it also means that when people send patches I don't
> >> care enough to argue against them.
> >>
> >> >    something that Debian has decided matters, so I'm doing
> >> >    this with my debian-ha-maintainer member hat on.
> >> >
> >> >    The following hunk illustrates how I think SysInfo_hdd_units() can
> >> >    be handled. The awk version seems rather nicer or at least rather
> >> >    shorter than the original.
> >>
> >> agreed.  do you have a tree i can pull this from?
> >> that or can you resend as a hg export so you can get the proper attribution :-)
> >
> > I was planning to send it as part of a larger patch (a bit later).
> > But I can send it by itself (sooner) if you prefer.
> 
> No hurry, whenever you're ready :-)

I'll try to get something to you soon.