* 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.
* Provide transaction based interface for standard operations
* Provide unit tests for new Aristo interface using transactions
details:
These new tests combine and replace several single-purpose tests.
The now unused test sources will be kept for a while to be eventually
removed.
* 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
* Added missing deferred cleanup directive to sub-test functions
why:
Rocksdb keeps the files locked for a short while leading to errors. This
was previously solved my using different db sub-directories
* Provide vertex deep-copy function globally.
why:
is just handy
* Avoid unnecessary vertex caching when merging proof nodes
also:
Run all merge tests on the rocksdb backend
Previously, proof node tests were run without backend
* Fix vertex ID generator state handling for rocksdb backend
why:
* Key error in walk iterator
* Needs to be loaded when opening the database
* Use non-zero sub-table prefixes for rocksdb
why:
Handy for debugging
* Fix error code for missing key on rocksdb backend
why:
Previously returned `VOID_HASH_KEY` rather than `GetKeyNotFound`
* Explicitly copy vertex data between internal table and function/result argument
why:
Function argument or return reference may still refer to the same data
object.
* Updated error symbols
why:
Error symbol names for the hike module now start with the prefix `Hike`.
* Write back modified branch node into local top layer cache
why:
With the backend available, the source of the branch node references
might not be the top layer cache. So any change must be explicitely
recorded.
* 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)
* 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`
* Cosmetics, renamed fields (eVtx, bVtx) -> (eVid, bVid)
* Multilayered delta architecture for Aristo DB
details:
Any VertexID or data retrieval needs to go down the rabbit hole and
fetch/get/manipulate the bottom layer -- even without explicit
backend.
* Direct reference to backend from top-level layer
why:
Some services as the vid management needs to be synchronised among all
layers. So access is optimised.
Jordan Hrycaj