Is there any way to view (not just recompute) the Fletcher32 checksum in a file?
My use case is basically this: I have a database of my H5 files, and I want to be sure that none of the files have changed without the database knowing about it. Computing the MD5 sum of the entire file takes much too long, and I actually don’t care if — say — a new attribute has been added, or the file’s mtime has changed; but I do want to know if the datasets themselves have the same data. For example, I might realize that some scaling was off by a factor of 2, go in and change those bits in one dataset without changing the shape, or possibly even the number of bytes in the file — and then fail to update the database for one reason or another. I need to be able to detect such a change. And since Fletcher32 is already being computed by HDF5 with every change to our data, it would be very convenient.