Using it for catching corrupted files would be of secondary interest, but I can see some value doing that.
Quote:
Originally Posted by chaley
Problem 1: whatever checks the hash must know when to regenerate it. Calibre doesn't know when I edit an epub, when a viewer drops bookmarks in, or when other operations take place legitimately change the file. The user might know, though.
|
This sort of scenario would be the main reason I would want a feature like this. I don't really see it as a huge problem, just re-calculate the hash whenever the user performs a conversion/transfer/metadata manipulation of the book. Right now, if you convert from one format to another, and the destination format already exists, Calibre overwrites the destination format without any warning. If the destination format was one previously created by Calibre then no big deal, that means the user was just tweaking the conversion settings (or upgraded), and is attempting to create an improved conversion.
However, if I did go edit the file in Sigil or by hand then I don't want Calibre to silently destroy my work, which is exactly what happens today. It's extremely difficult to remember which files have been hand edited and which haven't. I've tried using a custom column to track this, but this is prone to user error. Using a checksum feature like this would allow Calibre to automatically recognize that the file was modified outside of Calibre since it was last manipulated. At that point the user could be warned and decide how to handle the situation.