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. :(
Turns out that being able to open an empty directory actually has its
uses:
- If you delete the last file in a directory, you now won't be directed
to the parent directory anymore. This allows keeping 'd' pressed
without worrying that you'll delete stuff outside of the current dir.
(This is the primary motivation for doing this)
- You can now scan and later refresh an empty directory, as suggested by
#2 in http://dev.yorhel.nl/ncdu/bug/15
Tiny bug fix: The size of an excluded directory entry itself should not
be counted, either. This is consistent with what you'd expect: A cache
directory with thousands of files can easily take up several megabytes
for the dir entry - but from the perspective of a backup system that
recognizes cache dirs - the dir is empty, and therefore shouldn't take
any extra space at all.
POSIX defines ino_t to be of an unsigned integer type, and searching
around the net didn't tell me of any definitions conflicting that. So
every ino_t can be represented in an uint64_t. (Assuming that is the
largest integer type in use for an inode number, but I'm sure that
assumption will hold for a while)
(dev_t, on the other hand, is a bit messier. Still figuring out what to
do with that.)
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.
