* move pfx out of variant which avoids pointless field type panic checks
and copies on access
* make `VertexRef` a non-inheritable object which reduces its memory
footprint and simplifies its use - it's also unclear from a semantic
point of view why inheritance makes sense for storing keys
Compared to `keyed_queue`, `minilru` uses significantly less memory, in
particular for the 32-byte hash keys where `kq` stores several copies of
the key redundantly.
* Cleaning up, removing cruft and debugging statements
* Make `aristo_delta` fluffy compatible
why:
A sub-module that uses `chronicles` must import all possible
modules used by a parent module that imports the sub-module.
* update TODO
* Extract sub-tree deletion functions into separate sub-modules
* Move/rename `aristo_desc.accLruSize` => `aristo_constants.ACC_LRU_SIZE`
* Lazily delete sub-trees
why:
This gives some control of the memory used to keep the deleted vertices
in the cached layers. For larger sub-trees, keys and vertices might be
on the persistent backend to a large extend. This would pull an amount
of extra information from the backend into the cached layer.
For lazy deleting it is enough to remember sub-trees by a small set of
(at most 16) sub-roots to be processed when storing persistent data.
Marking the tree root deleted immediately allows to let most of the code
base work as before.
* Comments and cosmetics
* No need to import all for `Aristo` here
* Kludge to make `chronicle` usage in sub-modules work with `fluffy`
why:
That `fluffy` would not run with any logging in `core_deb` is a problem
I have known for a while. Up to now, logging was only used for debugging.
With the current `Aristo` PR, there are cases where logging might be
wanted but this works only if `chronicles` runs without the
`json[dynamic]` sinks.
So this should be re-visited.
* More of a kludge
