Checksum

Even though this is not strictly necessary in order to decode compressed Zstandard files, it is advised to implement checksum verification. Remember, you have already [read the checksum value][whole-frame.md#building-the-type] if it is present.

You can compute the checksum as you decode data by adding an appropriate hasher to the decoding context and update it every time you decode a byte. The XxHash64 type of the twox_hash crate implements the right algorithm. You can truncate the final result to 32 bit, and compare it to the value found in the compressed Zstandard file: if they match, the data is likely not corrupt.

✅ Implement the checksum verification.