Smart checksumming

[ihatehydras]

When utorrent starts again after an unclean shutdown it seems to go through all the files and checksum them. With large files this can take quite a while. It would be nice if it could

1) Not checksum files you've successfully downloaded already

2) Only checksum the parts of incomplete files that you've downloaded data for

Both of these could make the checksumming stage a whole lot faster.

[Firon]

There's no real way for it to know if the files -really- were successfully written to disk, although I admit, it could be smart and ignore any file that was finished more than 10-15 minutes before the crash, or something.

[ihatehydras]

Could you just call FlushFileBuffers once a file is complete? Once it returns you know the file has been written to the disk and you can mark it as not needing to be checksummed anymore. Or since there might be some performance issues with this if you were downloading lots of small files, instead it could flush all completed file buffers every X minutes, and then mark them as not needing to be checksummed.