Managed ArrayLists are deprecated in 0.15. "ArrayList" in 0.15 is the
same as "ArrayListUnmanaged" in 0.14. The latter alias is still
available in 0.15, so let's stick with that for now. When dropping
support for 0.14, we can do s/ArrayListUnmanaged/ArrayList/.
Fixes#215.
delete.zig's item replacement/refresh code is pretty awful and may be
buggy in some edge cases. Existing refresh infrastructure wasn't
designed to update an individual file.
Which is, AFAIK, a recommended practice. Reduces the number of times
translate-c is being run and (most likely) simplifies a possible future
transition if/when @cImport is thrown out of the language.
Also uses zstd.h instead of my own definitions, mainly because I plan to
use the streaming API as well and those need more definitions.
Code is more hacky than I prefer, but this approach does work and isn't
even as involved as I had anticipated.
Still a few known bugs and limitations left to resolve.
Still using a few embedded packed structs for those fields that benefit
from bit packing. This isn't much cleaner than using packed structs for
everything, but it does have better semantics. In particular, all fields
(except those inside nested packed structs) are now guaranteed to be
byte-aligned and I don't have to worry about the memory representation
of integers when pointer-casting between the different Entry types.
As aluded to in the previous commit. This approach keeps track of hard
links information much the same way as ncdu 1.16, with the main
difference being that the actual /counting/ of hard link sizes is
deferred until the scan is complete, thus allowing the use of a more
efficient algorithm and amortizing the counting costs.
As an additional benefit, the links listing in the information window
now doesn't need a full scan through the in-memory tree anymore.
A few memory usage benchmarks:
1.16 2.0-beta1 this commit
root: 429 162 164
backup: 3969 1686 1601
many links: 155 194 106
many links2*: 155 602 106
(I'm surprised my backup dir had enough hard links for this to be an
improvement)
(* this is the same as the "many links" benchmarks, but with a few
parent directories added to increase the tree depth. 2.0-beta1 doesn't
like that at all)
Performance-wise, refresh and delete operations can still be improved a
bit.
While this simplifies the code a bit, it's a regression in the sense
that it increases memory use.
This commit is yak shaving for another hard link counting approach I'd
like to try out, which should be a *LOT* less memory hungry compared to
the current approach. Even though it does, indeed, add an extra cost of
these parent node pointers.
