On Fri, Jun 29, 2012 at 04:30:49PM -0600, Kshitij Mehta wrote:
> Hello, 
> HDF5 stores all information about objects in memory in a B-tree. When it 
> writes data out to a file on disk, there should be a mapping between the 
> b-tree and the actual offsets in file where the objects are stored. Is there 
> some documentation where this mapping is explained? For example, if I have an 
> HDF5 file with a root group and two datasets,
> what are the exact offsets in the hdf5 file where the datasets get stored? At 
> what offsets can I find their headers?
> 
> I looked (briefly) at the file format specification, it talks about the 
> various header formats etc., but I dont think it talks about object-->offset 
> mapping.

It must be there somewhere.  'h5ls -v -a' gives an 'address'.  

If you trace h5ls you quickly come to H5Ddebug() with the comment
"This function is not to be documented in the API at this time."  

I guess if we talk about H5Debug, Quincey will "pay us a visit" and we
won't be heard from again? 

Well, take a look at H5Ddebug and I think you'll find the information
you need.  It involves directly de-referencing internal hdf5
structures, but hey that's just another way of saying "adventure".

==rob


-- 
Rob Latham
Mathematics and Computer Science Division
Argonne National Lab, IL USA

_______________________________________________
Hdf-forum is for HDF software users discussion.
[email protected]
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org

Reply via email to