Bumping the minor version of the file format to '2'.
The "ino" field is only interesting for hardlinks, so we can save space
by not exporting it for other entries.
The hlink count will be interesting later on when I implement tracking
of shared data between directories. It's currently ignored on import.
The "nlink" field makes the "hlnkc" field redundant, but let's keep
including that field anyway for backwards compatibility.
Unfortunately, there wasn't a single bit free in struct dir.flags, so I
had to increase its size to 16 bit. This commit is just the initial
preparation, there's still a few things to do:
- Add "extended information" cli flag to enable/disable this
functionality.
- Export and import extended information when requested
- Do something with the data.
I also did a few memory measurements on a file list with 12769842 items:
before this commit: 1.239 GiB
without extended info: 1.318 GiB
with extended info: 1.698 GiB
It's surprising what adding a single byte to a struct can do to the
memory usage. :(
!WARNING! The export option is experimental, and the file format is not
final. I make no promise that a future version of ncdu will be able to
read the current format. There's also quite a few TODO's left.
2 billion files should be enough for everyone. You probably won't have
enough memory to scan such a filesystem. int is a better choice than
long, as sizeof(int) is 4 on pretty much any system where ncdu runs.
This allows scanning stuff without initializing ncurses. Not too useful
at this point since ncdu will switch to an ncurses environment when it's
done anyway, but this will become more useful when the export-to-file
feature has been implemented.
The architecture is explained in dir.h. The reasons for these changes is
two-fold:
- calc.c was too complex, it simply did too many things. 399ccdeb is a
nice example of that: Should have been an easy fix, but it introduced
a segfault (fixed in 0b49021a), and added a small memory leak.
- This architecture features a pluggable input/output system, which
should make a file export/import feature relatively simple.
The current commit does not feature any user interface, so there's no
feedback yet when scanning a directory. I'll get to that in a bit.
I've also not tested the new scanning code very well yet, so I might
have introduced some bugs.
