Re: some netcdf contributions you may be interested in

Hi Russ,

> Although I included your v2i.c patch in 3.6.2, we haven't determined
> whether to include your other patches in that release.  However in the
> meantime, I've made them accessible to other users from here:

        understandable enough .. some of them are rather large ;-)

        (especially the fileinf one .. it occurs to me that I didn't 
really explain that one sufficiently .. to preempt a couple of likely
questions:

  * why SXP? 
    It originally was for "SX Profiling", until someone wanted
    to use it on a HP machine, so the patch became more portable.

  * why is putget.m4 so wildly different?
    I "unwound" the original putget.m4 a bit while working out
    where and how to add profiling hooks to the interface 
    routines (the VARM_upper etc were particularly tricky). 
    To rewind it I pulled out some common code into macros,
    mostly with the criteria of "doesn't overlap awkwardly
    with the profiling hooks", so it came out a bit differently
    to how it started. I also moved the v2 routines so that my
    diff tools would better highlight the commonalities in the 
    v3 ones. The outcome should be the same C routines (but not
    all in the same order), with profiling hooks added.

  * What does the profiling do to performance?
    As far as I've seen, very little. When the environment
    variable is not set the overhead is only one "if" test per
    hook, and even when NC_DETAIL is used the overhead appears 
    to be negligible. You do get rather a lot of stdout though.

  * another notable change is in nc.c and posixio.c, a lot of 
    the early-return statements have been changed into "goto end"
    statements, so that the profiling for the routine can be 
    gracefully stopped before returning, even when an error is
    discovered

        If you have any other "why did you do this/what is this 
code meant to do?" questions please don't hesitate to ask ..
(mostly where I've done something surprising or upsetting it
should be commented with the tag "sjl")

        cheers,

        Stephen

(ps: one more request: where the patches are published on the 
web site, could you please mangle my email address (eg 
leak@sx => leak (at) sx) to slow down the spam-bots a little ;-)
thanks!

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| Stephen Leak                        email:  address@hidden  |
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