* Generalised Aristo DB constructor for any type of backend
details:
* Records to be deleted are represented as key-void (rather than
key-value) pairs by the put-function arguments
* Allow direct driver access, iterators as example implementation and
for testing.
* Provide backend storage interface
details:
Stores the top layer onto backend tables
* Implemented Rocks DB backend
details:
Transaction based `put()` functionality
Iterators (based on direct RocksDB access)
* 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.
Jordan Hrycaj