* Update docu
* Update Aristo/Kvt constructor prototype
why:
Previous version used an `enum` value to indicate what backend is to
be used. This was replaced by using the backend object type.
* Rewrite `hikeUp()` return code into `Result[Hike,(Hike,AristoError)]`
why:
Better code maintenance. Previously, the `Hike` object was returned. It
had an internal error field so partial success was also available on
a failure. This error field has been removed.
* Use `openArray[byte]` rather than `Blob` in functions prototypes
* Provide synchronised multi instance transactions
why:
The `CoreDB` object was geared towards the legacy DB which used a single
transaction for the key-value backend DB. Different state roots are
provided by the backend database, so all instances work directly on the
same backend.
Aristo db instances have different in-memory mappings (aka different
state roots) and the transactions are on top of there mappings. So each
instance might run different transactions.
Multi instance transactions are a compromise to converge towards the
legacy behaviour. The synchronised transactions span over all instances
available at the time when base transaction was opened. Instances
created later are unaffected.
* Provide key-value pair database iterator
why:
Needed in `CoreDB` for `replicate()` emulation
also:
Some update of internal code
* Extend API (i.e. prototype variants)
why:
Needed for `CoreDB` geared towards the legacy backend which has a more
basic API than Aristo.
* Reorg of distributed backend access
details:
Now handled via API provided in `aristo_desc`.
* Rename `checkCache()` => `checkTop()`
why:
Better naming for top layer cache checker
also:
Provide cascaded fifos checker
* Provide `eq` directive for finding filter by exact filter ID (think block number)
* Some code beautification (for better code reading)
* State root reposition and reorg
details:
Repositioning is supported by forking a new descriptor. Reorg is then
accomplished by writing this forked state on the backend database.
* 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)
* 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.
* 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 missing branch checks in transcoder
why:
Symmetry problem. `Blobify()` allowed for encoding degenerate branch
vertices while `Deblobify()` rejected decoding wrongly encoded data.
* Update memory backend so that it rejects storing bogus vertices.
why:
Error behaviour made similar to the rocks DB backend.
* Make sure that leaf vertex IDs are not repurposed
why:
This makes it easier to record leaf node changes
* Update error return code for next()/right() traversal
why:
Returning offending vertex ID (besides error code) helps debugging
* Update Merkle hasher for deleted nodes
why:
Not implemented, yet
also:
Provide cache & backend consistency check functions. This was
partly re-implemented from `hashifyCheck()`
* Simplify some unit tests
* Fix delete function
why:
Was conceptually wrong
Jordan Hrycaj