* Rewrite remaining `AristoError` return code into `Result[void,AristoError]`
why:
Better code maintenance
* Update import sections
* Update Aristo DB paths
why:
More systematic so directory can be shared with other DB types
* More cosmetcs
* Update unit tests runners
why:
Proper handling of persistent and mem-only DB. The latter can be
consistently triggered by an empty DB path.
* Set scheduler state as part of the backend descriptor
details:
Moved type definitions `QidLayoutRef` and `QidSchedRef` to
`desc_structural.nim` so that it shares the same folder as
`desc_backend.nim`
* Automatic filter queue table initialisation in backend
details:
Scheduler can be tweaked or completely disabled
* Updated backend unit tests
details:
+ some code clean up/beautification, reads better now
+ disabled persistent filters so that there is no automated filter
management which will be implemented next
* Prettify/update unit tests source code
details:
Mostly replacing the `check()` paradigm by `xCheck()`
* Somewhat simplified backend type management
why:
Backend objects are labelled with a `BackendType` symbol where the
`BackendVoid` label is implicitly assumed for a `nil` backend object
reference.
To make it easier, a `kind()` function is used now applicable to
`nil` references as well.
* Fix DB storage layout for filter objects
why:
Need to store the filter ID with the object
* Implement reverse [] index on fifo
why:
An integer index argument on `[]` retrieves the QueueID (label) of the
fifo item while a QueueID argument on `[]` retrieves the index (so
it is inverse to the former variant).
* Provide iterator over filters as fifo
why:
This iterator goes along the cascased fifo structure (i.e. in
historical order)
* Rename FilterID => QueueID
why:
The current usage does not identify a particular filter but uses it as
storage tag to manage it on the database (to be organised in a set of
FIFOs or queues.)
* Split `aristo_filter` source into sub-files
why:
Make space for filter management API
* Store filter queue IDs in pairs on the backend
why:
Any pair will will describe a FIFO accessed by bottom/top IDs
* Reorg some source file names
why:
The "aristo_" prefix for make local/private files is tedious to
use, so removed.
* Implement filter slot scheduler
details:
Filters will be stored on the database on cascaded FIFOs. When a FIFO
queue is full, some filter items are bundled together and stored on the
next FIFO.
* Remove concept of empty/blind filters
why:
Not needed. A non-existent filter is is coded as a nil reference.
* Slightly generalised backend iterators
why:
* VertexID as key for the ID generator state makes no sense
* there will be more tables addressed by non-VertexID keys
* Store serialised/blobified vertices on memory backend
why:
This is more in line with the RocksDB backend so more appropriate
for testing when comparing behaviour. For a speedy memory database,
a backend-less variant should be used.
* Drop the `Aristo` prefix from names `AristoLayerRef`, etc.
* Suppress compiler warning
why:
duplicate imports
* Add filter serialisation transcoder
why:
Will be used as storage format
* Renamed type `NoneBackendRef` => `VoidBackendRef`
* Clarify names: `BE=filter+backend` and `UBE=backend (unfiltered)`
why:
Most functions used full names as `getVtxUnfilteredBackend()` or
`getKeyBackend()`. After defining abbreviations (and its meaning) it
seems easier to use `getVtxUBE()` and `getKeyBE()`.
* Integrate `hashify()` process into transaction logic
why:
Is now transparent unless explicitly controlled.
details:
Cache changes imply setting a `dirty` flag which in turn triggers
`hashify()` processing in transaction and `pack()` directives.
* Removed `aristo_tx.exec()` directive
why:
Inconsistent implementation, functionality will be provided with a
different paradigm.
* Provide deep copy for each transaction layer
why:
Localising changes. Selective deep copy was just overlooked.
* Generalise vertex ID generator state reorg function `vidReorg()`
why:
makes it somewhat easier to handle when saving layers.
* Provide dummy back end descriptor `NoneBackendRef`
* Optional read-only filter between backend and transaction cache
why:
Some staging area for accumulating changes to the backend DB. This
will eventually be an access layer for emulating a backend with
multiple/historic state roots.
* Re-factor `persistent()` with filter between backend/tx-cache => `stow()`
why:
The filter provides an abstraction from the physically stored data on
disk. So, there can be several MPT instances using the same disk data
with different state roots. Of course, all the MPT instances should
not differ too much for practical reasons :).
TODO:
Filter administration tools need to be provided.
* Better error handling
why:
Bail out on some error as early as possible before any changes.
* Implement `fetch()` as opposite of `merge()`
rationale:
In the `Aristo` realm, the action named `fetch()` and `merge()` indicate
leaf value related actions on the MPT, while actions `get()` and `put()`
handle vertex or hash key related operations that constitute the MPT.
* Re-factor `merge()` prototypes
why:
The most used variant of `merge()` should have the simplest prototype.
* Persistent DB constructor needs to import `aristo/aristo_init/persistent`
why:
Most applications use memory DB anyway. This avoids linking `-lrocksdb`
or any other back end libraries by default.
* Re-factor transaction module
why:
Got the paradigm wrong. The transaction descriptor did replace the
database one but should be handled separately.