Hi Mark,
On Mar 26, 2010, at 5:21 PM, Mark Miller wrote:
> Hmm. I know at least some of the VFD's in HDF5 maintain 'internal'
> knowledge of the file's current offset apart from the underlying FILE*
> stream or int fd desriptor to which they refer. So, if you did get in
> there and do a seek or read operation, you'd need to make sure you
> returned the FILE* stream of int fd to the state it was in BEFORE you
> did anything. Otherwise, HDF5 and the underlying file object wouldn't
> agree about where they are pointing.
Yes, that's true and falls under the "don't modify the file/file
handle" caveat, although we should probably make that more explicit.
> Out of curiosity, what does get_vfd_handle return for the core vfd? Does
> it return the actual buffer the core vfd is writing to? Is it even
> implemented for core?
Yes, it's implemented for the core VFD and returns the pointer to the
buffer.
Quincey
> Mark
>
> On Fri, 2010-03-26 at 13:26, Andrew Collette wrote:
>> Hi,
>>
>> Does anyone know if it's possible to read/modify the user block
>> associated with an open HDF5 file? The documentation for
>> H5Fget_vfd_handle says not to use the returned handle to modify the
>> file... is it safe to do things like seeking and reading?
>>
>> Thanks,
>> Andrew Collette
>>
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> --
> Mark C. Miller, Lawrence Livermore National Laboratory
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> [email protected] urgent: [email protected]
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>
>
> _______________________________________________
> Hdf-forum is for HDF software users discussion.
> [email protected]
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