I initially wanted to keep a directory's block count and size as a
separate field so that exporting an in-memory tree to a JSON dump would
be easier to do, but that doesn't seem like a common operation to
optimize for. We'll probably need the algorithms to subtract sub-items
from directory counts anyway, so such an export can still be
implemented, albeit slower.
The new data model is supposed to solve a few problems with ncdu 1.x's
'struct dir':
- Reduce memory overhead,
- Fix extremely slow counting of hard links in some scenarios
(issue #121)
- Add support for counting 'shared' data with other directories
(issue #36)
Quick memory usage comparison of my root directory with ~3.5 million
files (normal / extended mode):
ncdu 1.15.1: 379M / 451M
new (unaligned): 145M / 178M
new (aligned): 155M / 200M
There's still a /lot/ of to-do's left before this is usable, however,
and there's a bunch of issues I haven't really decided on yet, such as
which TUI library to use.
Backporting this data model to the C version of ncdu is also possible,
but somewhat painful. Let's first see how far I get with Zig.
