[h5md-user] generic API for H5MD libraries

[Felix Höfling]

Hi,

At the time being we have already a bunch of libraries that support  
reading and writing H5MD [1], specifically for Fortran, Python, C (thanks  
to Pierre), a second one for C (Jonas, see VMD plugin), and Lua (Peter).  
For myself, I'm planning a C++ version.

My proposal is to specify a (generic) API for H5MD libraries which then  
can be implemented in the various languages. I didn't inspect all the  
different libraries more closely, but I suspect that the essential  
functions have similar interfaces.

Such a specification would be helpful to define a set of core  
functionality that any H5MD library should provide. Of course, it has to  
be written as pseudo-prototypes, e.g. it does not say whether output is  
passed by return value, reference or pointers, etc. Examples are given  
below.

Please let me know, what you think.

Best regards,

Felix


function validate_file
        Input: filename (or HDF5 group?)
        Output: boolean, true if "filename" (HDF5 tree) is in H5MD format

function read_h5md_element
        Input: HDF5 group (e.g., "/particles/A")
        Input: field name (e.g., "position", "id")
        Input (optional): step
        Output: data at given step
        Output (optional): boolean, true upon success

function write_h5md_data
        Input: HDF5 group
        Input: field name
        Input (optional): step
        Output: boolean, true upon success

[1] http://nongnu.org/h5md/software.html#reading-and-writing-h5md-files