* bump rockdb
* Rename `KVT` objects related to filters according to `Aristo` naming
details:
filter* => delta*
roFilter => balancer
* Compulsory error handling if `persistent()` fails
* Add return code to `reCentre()`
why:
Might eventually fail if re-centring is blocked. Some logic will be
added in subsequent patch sets.
* Add column families from earlier session to rocksdb in opening procedure
why:
All previously used CFs must be declared when re-opening an existing
database.
* Update `init()` and add rocksdb `reinit()` methods for changing parameters
why:
Opening a set column families (with different open options) must span
at least the ones that are already on disk.
* Provide write-trigger-event interface into `Aristo` backend
why:
This allows to save data from a guest application (think `KVT`) to
get synced with the write cycle so the guest and `Aristo` save all
atomically.
* Use `KVT` with new column family interface from `Aristo`
* Remove obsolete guest interface
* Implement `KVT` piggyback on `Aristo` backend
* CoreDb: Add separate `KVT`/`Aristo` backend mode for debugging
* Remove `rocks_db` import from `persist()` function
why:
Some systems (i.p `fluffy` and friends) use the `Aristo` memory
backend emulation and do not link against rocksdb when building the
application. So this should fix that problem.
* Aristo: Generalise alien/guest interface for piggiback on database
* Aristo: Code cosmetics
* CoreDb+Kvt: Update transaction API
why:
Use single addressable function `forkTx(backLevel: int)` as used
in `Aristo`. So `Kvt` can be synced simultaneously to `Aristo`.
also:
Refactored `kvt_tx.nim` in a similar fashion to `Aristo`.
* Kvt: Replace `LayerDelta` object by reference
why:
Will be needed when introducing filters
* Kvt: Remodel backend filter facility similar to `Aristo`
why:
This allows to operate on several KVT instances simultaneously.
* CoreDb+Kvt: Fix on-disk storage
why:
Overlooked name change: `stow()` => `persist()` for permanent storage
* Fix copyright headers
Jordan Hrycaj