There may have been a thread about this before but is it conceivable to
smarten HDF5's open call and/or add a H5Pset_fapl_autovfd property that
will attempt to automatically detect which vfd to use to correctly open
a file by first opening the file and reading the superblock and, with
appropriate info encoded into the superblock, determine the correct vfd
to use to actually open and read the file?
It looks like some vfd's define additional superblock/userblock contents
while others do not.
I suppose another option is to after reading the superblock, pass its
contents to all an 'identify' function in all know vfd's asking each one
to indicate if it thinks it can open the file. If the resulting list of
positive answers is of size 0, can't open; size 1, use that vfd, size>1,
try in some kind of priority order.
Mark
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Mark C. Miller, Lawrence Livermore National Laboratory
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miller86@llnl.gov urgent: miller86@pager.llnl.gov
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Hi Mark,
There may have been a thread about this before but is it conceivable to
smarten HDF5's open call and/or add a H5Pset_fapl_autovfd property that
will attempt to automatically detect which vfd to use to correctly open
a file by first opening the file and reading the superblock and, with
appropriate info encoded into the superblock, determine the correct vfd
to use to actually open and read the file?
This is a very good idea and something we've intended on pursuing, but haven't gotten around to yet.
It looks like some vfd's define additional superblock/userblock contents
while others do not.
I suppose another option is to after reading the superblock, pass its
contents to all an 'identify' function in all know vfd's asking each one
to indicate if it thinks it can open the file. If the resulting list of
positive answers is of size 0, can't open; size 1, use that vfd, size>1,
try in some kind of priority order.
Yes, this sounds reasonable. Perhaps we can work it into the "VFD contract" document that I'll be starting in a couple of weeks.
Quincey
···
On Mar 11, 2010, at 12:52 PM, Mark Miller wrote:
