* Misc fixes
detail:
* Fix de-serialisation for account leafs
* Update node recovery from unit tests
* Remove `LegacyAccount` from `PayloadRef` object
why:
Legacy accounts use a hash key as storage root which is detrimental
to the working of the Aristo database which uses a vertex ID.
* Dissolve `hashify_helper` into `aristo_utils` and `aristo_transcode`
why:
Functions are of general interest so they should live in first level
code files.
* Added left/right iterators over leaf nodes
* Some helper/wrapper functions that might be useful
* Slightly tighten some self-check conditions
* Redefined the database descriptor object as reference (to the object)
why:
The upcoming transaction wrapper will work with a database reference
rather than the object itself
* Append state before `save()` to the Aristo descriptor
why:
This stae was previously returned by the function. Appending it to
a field of the Aristo descriptor seems easier to handle.
* Fix include
why:
Eth67 not default yet so that got missed
* Rename `LeafKey` => `LeafTie`
why:
Name is a pen picture of what this object is for. Also, it avoids the
ubiquitous term `key`.
* Provided `getOrVoid()` wrapper for `getOrDefault()`
also:
Provide `isValid()` syntactic sugar for `.isNil.not`, `!= 0` etc.
Reorg descriptor source, split into sub-sources
* Bundled `NodeKey` objects with root ID and called it `HashLabel`
why:
`NodeKey` (aka repurposed Hash265) objects are unique only within a
particular sub-trie (e.g. storage slots) which are kept separated
(i.e non-interleaved) by design. This is not applied to the backend
as the map VertexID->NodeKey labelling the nodes needs not be injective.
For the in-memory database (transaction) layers, the injective map
VertexID->(VertexID,NodeKey) is used where the first field of the image
tuple is the root ID of the sub-trie the `NodeKey` object is valid. So
identical storage tries for different accounts can be represented.
* Exclude some storage tests
why:
These test running on external dumps slipped through. The particular
dumps were reported earlier as somehow dodgy.
This was changed in `#1457` but having a second look, the change on
hexary_interpolate.nim(350) might be incorrect.
* Redesign `Aristo DB` descriptor for transaction based layers
why:
Previous descriptor layout made it cumbersome to push/pop
database delta layers.
The new architecture keeps each layer with the full delta set
relative to the database backend.
* Keep root ID as part of the `Patricia Trie` leaf path
why;
That way, forests are supported
* Keep vertex ID generator state with each db-layer
why:
The vertex ID generator state is part of the difference to the below
layer
* Move otherwise unused source to test directory
* Add Merkle hash generator
also:
* Verification facility for debugging
* Empty Merkle key hashes encoded as `EMPTY_ROOT_HASH`