File checksum

[tritemio]

Would be nice to have to option to create a checksum when creating a Photon-HDF5 files.

Why?

The checksum can be used to verify that the data file is the original unmodified one. It protects against accidental modifications (such as editing in HDFView, or other programs). Could be also a protection against disk corruptions of download errors, but in general these error would be detected anyways because the file would become illegible.

How?

A checksum (for example SHA1) can be saved in a sidecar text file like this:

my_photon_hdf5_file.hdf5
my_photon_hdf5_file.sha1

The checksum can be distributed with the data file to verify the data file was not modified.

Phconvert can create this checksum automatically when creating a file and can provide a function to verify a file against its checksum.