* Extract sub-tree deletion functions into separate sub-modules
* Move/rename `aristo_desc.accLruSize` => `aristo_constants.ACC_LRU_SIZE`
* Lazily delete sub-trees
why:
This gives some control of the memory used to keep the deleted vertices
in the cached layers. For larger sub-trees, keys and vertices might be
on the persistent backend to a large extend. This would pull an amount
of extra information from the backend into the cached layer.
For lazy deleting it is enough to remember sub-trees by a small set of
(at most 16) sub-roots to be processed when storing persistent data.
Marking the tree root deleted immediately allows to let most of the code
base work as before.
* Comments and cosmetics
* No need to import all for `Aristo` here
* Kludge to make `chronicle` usage in sub-modules work with `fluffy`
why:
That `fluffy` would not run with any logging in `core_deb` is a problem
I have known for a while. Up to now, logging was only used for debugging.
With the current `Aristo` PR, there are cases where logging might be
wanted but this works only if `chronicles` runs without the
`json[dynamic]` sinks.
So this should be re-visited.
* More of a kludge
* Extract `CoreDb` constructor helpers from `base.nim` into separate module
why:
This makes it easier to avoid circular imports.
* Extract `Ledger` constructor helpers from `base.nim` into separate module
why:
Move `accounts_ledger.nim` file to sub-folder `backend`. That way the
layout resembles that of the `core_db`.
* Updates and corrections
* Extract `CoreDb` configuration from `base.nim` into separate module
why:
This makes it easier to avoid circular imports, in particular
when the capture journal (aka tracer) is revived.
* Extract `Ledger` configuration from `base.nim` into separate module
why:
This makes it easier to avoid circular imports (if any.)
also:
Move `accounts_ledger.nim` file to sub-folder `backend`. That way the
layout resembles that of the `core_db`.
* CoreDb: Merged all sub-descriptors into `base_desc` module
* Dissolve `aristo_db/common_desc.nim`
* No need to export `Aristo` methods in `CoreDb`
* Resolve/tighten methods in `aristo_db` sub-moduled
why:
So they can be straihgt implemented into the `base` module
* Moved/re-implemented `KVT` methods into `base` module
* Moved/re-implemented `MPT` methods into `base` module
* Moved/re-implemented account methods into `base` module
* Moved/re-implemented `CTX` methods into `base` module
* Moved/re-implemented `handler_{aristo,kvt}` into `aristo_db` module
* Moved/re-implemented `TX` methods into `base` module
* Moved/re-implemented base methods into `base` module
* Replaced `toAristoSavedStateBlockNumber()` by proper base method
why:
Was the last for keeping reason for keeping low level backend access
methods
* Remove dedicated low level access to `Aristo` backend
why:
Not needed anymore, for debugging the descriptors can be accessed
directly
also:
some clean up stuff
* Re-factor `CoreDb` descriptor layout and adjust base methods
* Moved/re-implemented iterators into `base_iterator*` modules
* Update docu
* Remove `dirty` set from structural objects
why:
Not used anymore, the tree is dirty by default.
* Rename `aristo_hashify` -> `aristo_compute`
* Remove cruft, update comments, cosmetics, etc.
* Simplify `SavedState` object
why:
The key chaining have become obsolete after extra lazy hashing. There
is some available space for a state hash to be maintained in future.
details:
Accept the legacy `SavedState` object serialisation format for a
while (which will be overwritten by new format.)
* Normalised storage tree addressing in function prototypes
detail:
Argument list is always `<db> <account-path> <slot-path> ..` with
both path arguments as `openArray[]`
* Remove cruft
* CoreDb internally Use full account paths rather than addresses
* Update API logging
* Use hashed account address only in prototypes
why:
This avoids unnecessary repeated hashing of the same account address.
The burden of doing that is upon the application. In the case here,
the ledger caches all kinds of stuff anyway so it is common sense to
exploit that for account address hashes.
caveat:
Using `openArray[byte]` argument types for hashed accounts is inherently
fragile. In non-release mode, a length verification `doAssert` is
enabled by default.
* No accPath in data record (use `AristoAccount` as `CoreDbAccount`)
* Remove now unused `eAddr` field from ledger `AccountRef` type
why:
Is duplicate of lookup key
* Avoid merging the account record/statement in the ledger twice.
* Fix initialiser
why:
Possible crash (app profiling, tracer etc.)
* Update column family options processing
why:
Same for kvt as for aristo
* Move `AristoDbDualRocks` backend type to the test suite
why:
So it is not available for production
* Fix typos in API jump table
why:
Used for tracing and app profiling only. Needed some update
* Purged CoreDb legacy API
why:
Not needed anymore, was transitionary and disabled.
* Rename `flush` argument to `eradicate` in a DB close context
why:
The word `eradicate` leaves no doubt what is meant
* Rename `stoFlush()` -> `stoDelete()`
* Rename `core_apps_newapi` -> `core_apps` (not so new anymore)
* Bump nim-eth, nim-web3, nimbus-eth2
- Replace std.Option with results.Opt
- Fields name changes
* More fixes
* Fix Portal stream async raises and portal testnet Opt usage
* Bump eth + nimbus-eth2 + more fixes related to eth_types changes
* Fix in utp test app and nimbus-eth2 bump
* Fix test_blockchain_json rebase conflict
* Fix EVMC block_timestamp conversion plus commentary
---------
Co-authored-by: kdeme <kim.demey@gmail.com>
This PR consolidates the split header-body sequences into a single EthBlock
sequence and cleans up the fallout from that which significantly reduces
block processing overhead during import thanks to less garbage collection
and fewer copies of things all around.
Notably, since the number of headers must always match the number of bodies,
we also get rid of a pointless degree of freedom that in the future could
introduce unnecessary bugs.
* only read header and body from era file
* avoid several unnecessary copies along the block processing way
* simplify signatures, cleaning up unused arguemnts and returns
* use `stew/assign2` in a few strategic places where the generated
nim assignent is slow and add a few `move` to work around poor
analysis in nim 1.6 (will need to be revisited for 2.0)
```
stats-20240607_2223-a814aa0b.csv vs stats-20240608_0714-21c1d0a9.csv
bps_x bps_y tps_x tps_y bpsd tpsd timed
block_number
(498305, 713245] 1,540.52 1,809.73 2,361.58 2775.340189 17.63% 17.63% -14.92%
(713245, 928185] 730.36 865.26 1,715.90 2028.973852 18.01% 18.01% -15.21%
(928185, 1143126] 663.03 789.10 2,529.26 3032.490771 19.79% 19.79% -16.28%
(1143126, 1358066] 393.46 508.05 2,152.50 2777.578119 29.13% 29.13% -22.50%
(1358066, 1573007] 370.88 440.72 2,351.31 2791.896052 18.81% 18.81% -15.80%
(1573007, 1787947] 283.65 335.11 2,068.93 2441.373402 17.60% 17.60% -14.91%
(1787947, 2002888] 287.29 342.11 2,078.39 2474.179448 18.99% 18.99% -15.91%
(2002888, 2217828] 293.38 343.16 2,208.83 2584.77457 17.16% 17.16% -14.61%
(2217828, 2432769] 140.09 167.86 1,081.87 1296.336926 18.82% 18.82% -15.80%
blocks: 1934464, baseline: 3h13m1s, contender: 2h43m47s
bpsd (mean): 19.55%
tpsd (mean): 19.55%
Time (total): -29m13s, -15.14%
```
* Add persistent last state stamp feature
why:
This allows to run `CoreDb` without journal
* Start `CoreDb` without journal
* Remove journal related functions from `CoredDb`
This PR extends the `nimbus import` command to also allow reading from
era files - this command allows creating or topping up an existing
database with data coming from era files instead of network sync.
* add `--era1-dir` and `--max-blocks` options to command line
* make `persistBlocks` report basic stats like transactions and gas
* improve error reporting in several API
* allow importing multiple RLP files in one go
* clean up logging options to match nimbus-eth2
* make sure database is closed properly on shutdown
* Update TDD suite logger output format choices
why:
New format is not practical for TDD as it just dumps data across a wide
range (considerably larder than 80 columns.)
So the new format can be turned on by function argument.
* Update unit tests samples configuration
why:
Slightly changed the way to find the `era1` directory
* Remove compiler warnings (fix deprecated expressions and phrases)
* Update `Aristo` debugging tools
* Always update the `storageID` field of account leaf vertices
why:
Storage tries are weekly linked to an account leaf object in that
the `storageID` field is updated by the application.
Previously, `Aristo` verified that leaf objects make sense when passed
to the database. As a consequence
* the database was inconsistent for a short while
* the burden for correctness was all on the application which led
to delayed error handling which is hard to debug.
So `Aristo` will internally update the account leaf objects so that
there are no race conditions due to the storage trie handling
* Aristo: Let `stow()`/`persist()` bail out unless there is a `VertexID(1)`
why:
The journal and filter logic depends on the hash of the `VertexID(1)`
which is commonly known as the state root. This implies that all
changes to the database are somehow related to that.
* Make sure that a `Ledger` account does not overwrite the storage trie reference
why:
Due to the abstraction of a sub-trie (now referred to as column with a
hash describing its state) there was a weakness in the `Aristo` handler
where an account leaf could be overwritten though changing the validity
of the database. This has been changed and the database will now reject
such changes.
This patch fixes the behaviour on the application layer. In particular,
the column handle returned by the `CoreDb` needs to be updated by
the `Aristo` database state. This mitigates the problem that a storage
trie might have vanished or re-apperaed with a different vertex ID.
* Fix sub-trie deletion test
why:
Was originally hinged on `VertexID(1)` which cannot be wholesale
deleted anymore after the last Aristo update. Also, running with
`VertexID(2)` needs an artificial `VertexID(1)` for making `stow()`
or `persist()` work.
* Cosmetics
* Activate `test_generalstate_json`
* Temporarily `deactivate test_tracer_json`
* Fix copyright header
---------
Co-authored-by: jordan <jordan@dry.pudding>
Co-authored-by: Jacek Sieka <jacek@status.im>
* Update some docu & messages
* Remove cruft from the ledger modules
* Must not overwrite genesis data on an initialised database
why:
This will overwrite the global state of the Aristo single state DB.
Otherwise resuming at the last synced state becomes impossible.
* Provide latest block number from journal
why:
This relates the global state of the DB directly to the corresponding
block number.
* Implemented unit test providing DB pre-load and resume
* Code cosmetics
* Aristo+Kvt: Fix api wrappers
why:
Api setup killed the backend descriptor when backend mapping was
disabled.
* Aristo: Implement masked profiling entries
why:
Database backend should be listed but not counted in tally
* CoreDb: Simplify backend() methods
why:
DBMS backend access Was provided very early and over engineered. Now
there are only two backend machines, one for `Kvt` and the other one
for an `Mpt` available only via new API.
* CoreDb: Code cleanup regarding descriptor types
* CoreDb: Refactor/redefine `persistent()` methods
why:
There were `persistent()` methods for any type of caching storage
facilities `Kvt`, `Mpt`, `Phk`, and `Acc`. Now there is only a single
`persistent()` method storing all facilities in tandem (similar to
how transactions work.)
For non shared `Kvt` tables, there is now an extra storage method
`saveOffSite()`.
* CoreDb lingo update: `trie` becomes `column`
why:
Notion of a `trie` is pretty much hidden by the new `CoreDb` api.
Revealed are sort of database columns for accounts an storage data,
any of which have an internal state represented by a Keccack hash.
So a `trie` or `MPT` becomes a `column` and a `rootHash` becomes a
column state.
* Aristo: rename backend filed `filters` => `journal`
* Update full sync logging
details:
+ Disable eth handler noise while syncing
+ Log journal depth (if available)
* Fix copyright year
* Fix cruft and unwanted imports
* Aristo: Remove cruft
* Prettifying profile statistics printing & source code cosmetics
* Aristo/Kvt: API tools update
* CoreDb: Corrections, mostly API related
* CoreDb: Changed the tracer `logDb()` result
why:
Only the key-value table is used from the logger database
* CoreDb: Update legacy tracer
why:
The `contains()` directive did not correspond to `0 < get().len`
also:
Copy `CoreDb` meta settings like `trackLegaApi`, `trackNewApi`, etc. to
overlay tracer descriptor
* CoreDb: Extend/update tracer API
why:
Get ready for accommodating `Aristo` tracer
* Fix missing import
why:
Some CI compilers might have (cached?) a different NIM patch level
* Ditto
* Aristo/Kvt: Provide function hooks APIs
why:
These APIs can be used for installing tracers, profiling functoinality,
and other niceties on the databases.
* Aristo: Provide optional API profiling
details:
It basically is a re-implementation of the `CoreDb` profiling
implementation
* Kvt: Provide optional API profiling similar to `Aristo`
* CoreDb: Re-implementing profiling using `aristo_profile`
* Ledger: Re-implementing profiling using `aristo_profile`
* CoreDb: Update unit tests for maintainability
* update copyright dates
* Aristo: Reorg `hashify()` using different schedule algorithm
why:
Directly calculating the search tree top down from the roots turns
out to be faster than using the cached structures left over by `merge()`
and `delete()`.
Time gains is short of 20%
* Aristo: Remove `lTab[]` leaf entry object type
why:
Not used anymore. It was previously needed to build the schedule for
`hashify()`.
* Aristo: Avoid unnecessary re-org of the vertex ID recycling list
why:
This list can become quite large so a heuristic is employed whether
it makes sense to re-org.
Also, re-org check is only done by `delete()` functions.
* Aristo: Remove key/reverse lookup table from tx layers
why:
It is ignored except for handling proof nodes and costs unnecessary
run time resources.
This feature was originally needed to accommodate the mental transition
from the legacy MPT to the `Aristo` trie :).
* Fix copyright year
* CoreDb: update test suite
* Aristo: Simplify reverse key map
why:
The reverse key map `pAmk: (root,key) -> {vid,..}` as been simplified to
`pAmk: key -> {vid,..}` as the state `root` domain argument is not used,
anymore
* Aristo: Remove `HashLabel` object type and replace it by `HashKey`
why:
The `HashLabel` object attaches a root hash to a hash key. This is
nowhere used, anymore.
* Fix copyright
* CoreDb: Test module with additional sample selector cmd line options
* Aristo: Do not automatically remove a storage trie with the account
why:
This is an unnecessary side effect. Rather than using an automatism, a
a storage root must be deleted manually.
* Aristo: Can handle stale storage root vertex IDs as empty IDs.
why:
This is currently needed for the ledger API supporting both, a legacy
and the `Aristo` database backend.
This feature can be disabled at compile time by re-setting the
`LOOSE_STORAGE_TRIE_COUPLING` flag in the `aristo_constants` module.
* CoreDb+Aristo: Flush/delete storage trie when deleting account
why:
On either backend, a deleted account leave a dangling storage trie on
the database.
For consistency nn the legacy backend, storage tries must not be
deleted as they might be shared by several accounts whereas on `Aristo`
they are always unique.
* Remove custom block chain unit tests
why:
The custom block chain unit test functionality is superseded by
`test_coredb`.
All the custom block chains used here are hopelessly out of date and
the configs were never updated regarding fork and ttd settings (while
the production code has moved on.)
* CoreDb: Update unit tests suite
details:
Can accommodate non-built in network dumps. Inherited some functionality
from the now retired `test_custom_network` test.
* CoreDb: Improve API and API tracking
why:
Now logs state roots where appropriate
* CoreDb: re-implement `CoreDbVidRef` => `CoreDbTrieRef`
why:
Instead of a root vertex ID wrapper, the purpose of this object type
has been upgrades to a sub-trie prototype.
caveat:
`Aristo` backend not fully functional, yet.
* CoreDb: Update `Aristo` backend
why:
Supports virtual sub-tries
* CoreDb: Account address tracking for `StorageTrie` virtual tries
details:
Supported with API tracking/logging
* CoreDb: Keep account address in payload object
why:
No need to provide extra address argument for `merge()`, also
provides tracking possibility for account debugging.
* Ledger: Update new API for `Aristo` specific storage trie handling
* CoreDb+Ledger: Update unit tests
* Fix copyright headers
* Aristo: Re-phrase `LayerDelta` and `LayerFinal` as object references
why:
Avoids copying in some cases
* Fix copyright header
* Aristo: Verify `leafTie.root` function argument for `merge()` proc
why:
Zero root will lead to inconsistent DB entry
* Aristo: Update failure condition for hash labels compiler `hashify()`
why:
Node need not be rejected as long as links are on the schedule. In
that case, `redo[]` is to become `wff.base[]` at a later stage.
This amends an earlier fix, part of #1952 by also testing against
the target nodes of the `wff.base[]` sets.
* Aristo: Add storage root glue record to `hashify()` schedule
why:
An account leaf node might refer to a non-resolvable storage root ID.
Storage root node chains will end up at the storage root. So the link
`storage-root->account-leaf` needs an extra item in the schedule.
* Aristo: fix error code returned by `fetchPayload()`
details:
Final error code is implied by the error code form the `hikeUp()`
function.
* CoreDb: Discard `createOk` argument in API `getRoot()` function
why:
Not needed for the legacy DB. For the `Arsto` DB, a lazy approach is
implemented where a stprage root node is created on-the-fly.
* CoreDb: Prevent `$$` logging in some cases
why:
Logging the function `$$` is not useful when it is used for internal
use, i.e. retrieving an an error text for logging.
* CoreDb: Add `tryHashFn()` to API for pretty printing
why:
Pretty printing must not change the hashification status for the
`Aristo` DB. So there is an independent API wrapper for getting the
node hash which never updated the hashes.
* CoreDb: Discard `update` argument in API `hash()` function
why:
When calling the API function `hash()`, the latest state is always
wanted. For a version that uses the current state as-is without checking,
the function `tryHash()` was added to the backend.
* CoreDb: Update opaque vertex ID objects for the `Aristo` backend
why:
For `Aristo`, vID objects encapsulate a numeric `VertexID`
referencing a vertex (rather than a node hash as used on the
legacy backend.) For storage sub-tries, there might be no initial
vertex known when the descriptor is created. So opaque vertex ID
objects are supported without a valid `VertexID` which will be
initalised on-the-fly when the first item is merged.
* CoreDb: Add pretty printer for opaque vertex ID objects
* Cosmetics, printing profiling data
* CoreDb: Fix segfault in `Aristo` backend when creating MPT descriptor
why:
Missing initialisation error
* CoreDb: Allow MPT to inherit shared context on `Aristo` backend
why:
Creates descriptors with different storage roots for the same
shared `Aristo` DB descriptor.
* Cosmetics, update diagnostic message items for `Aristo` backend
* Fix Copyright year
* Activate `LedgerRef` wrapper for `AccountsCache`
details:
`accounts_cache.nim` methods are indirectly processed by the wrapper
methods from `ledger.nim`.
This works for all sources except `test_state_db.nim` where the source
`accounts_cache.nim` is included (rather than imported) in order to
access objects privy to the very source.
* Provide facility to switch to a preselected `LedgerRef` type
details:
Can be set as suggestion when initialising `CommonRef`
* Update `CoreDb` test suite for better time tracking
details:
+ Allow time logging by pre-defined block intervals
+ Print `CoreDb`/`Ledger`profiling results (if enabled)
* Explicitly use shared `Kvt` table on `Ledger` and `Clique` lookup.
why:
Speeds up lookup time with `Aristo` backend. For writing `Clique` data,
the `Companion` model allows to write `Clique` data past the database
locked by evm transactions.
* Implement `CoreDb` profiling with API tracking
why:
Chasing time spent per APT procs ...
* Implement `Ledger` profiling with API tracking
why:
Chasing time spent per APT procs ...
* Always hashify when commiting or storing
why:
A dirty cache makes no sense when committing
* Make sure that a zero key is created when adding/updating vertices
why:
This is an error fix mainly for edge cases. A typical error was
that the root key got deleted when there were only a few vertices
left on the DB.
* Need all created and changed vertices zero-keyed on the cache
why:
A zero key (i.e. empty Merkle hash) indicates that a vertex key
needs to be updated. This would not be needed immediately after
a merge as there is an actual leaf path on the cache layer. But
after subsequent merge and delete operations this information
might get blurred.
* Re-org hashing algorithm
why:
Apart from errors, the previous implementation was too slow for
two reasons:
+ some control hashes were calculated for debugging (now all
verification is done in `aristo_check` module)
+ the leaf paths stored on the cache are used to build the
labelling (aka hashing) schedule; there paths were accumulated
over successive hash sessions although it is clear that all
keys were generated, already
* Fix copyright year
* Show elapsed times with enabled `CoreDb` API tracking
* Show elapsed times with enabled `LedgerRef` API tracking
* Reorg `CoreDb` auto destructors for `Aristo` DB
why:
While `Aristo` supports some parallelism for concurrent database access,
this comes with a price of management overhead. With a naive approach,
the auto-destructor will slow down execution because the ledger and
evm treat the database in a shared mode where a DB descriptor is just
created and thrown away shortly after.
This is reflected in the `Coredb` abstraction layer above `Aristo`/`Kvt`
where a few `Shared` type descriptors are cached and a shared reference
is returned rather than a disposable new object.
* For `CoreDb` support transaction level tracking
details:
This is mainly an extra for the legacy DB as `Aristo` and `Kvt` support
this already.
Also return an error on the legacy DB backend when `persistent()` is
called while there are transactions pending (the `persistent()` call
does nothing otherwise on the legacy backend.)
* Clear compiler warnings (remove unused variables etc.)
* Using different `tmp` directories for `Kvt` and `Aristo`
why:
Closing one database would leave the other set of directories
incomplete.
* Code cosmetics, silence compiler
* Fix typo `EMPTY_ROOT_HASH` vs. `EMPTY_CODE_HASH`
* Fix copyright years
* Disable `TransactionID` related functions from `state_db.nim`
why:
Functions `getCommittedStorage()` and `updateOriginalRoot()` from
the `state_db` module are nowhere used. The emulation of a legacy
`TransactionID` type functionality is administratively expensive to
provide by `Aristo` (the legacy DB version is only partially
implemented, anyway).
As there is no other place where `TransactionID`s are used, they will
not be provided by the `Aristo` variant of the `CoreDb`. For the
legacy DB API, nothing will change.
* Fix copyright headers in source code
* Get rid of compiler warning
* Update Aristo code, remove unused `merge()` variant, export `hashify()`
why:
Adapt to upcoming `CoreDb` wrapper
* Remove synced tx feature from `Aristo`
why:
+ This feature allowed to synchronise transaction methods like begin,
commit, and rollback for a group of descriptors.
+ The feature is over engineered and not needed for `CoreDb`, neither
is it complete (some convergence features missing.)
* Add debugging helpers to `Kvt`
also:
Update database iterator, add count variable yield argument similar
to `Aristo`.
* Provide optional destructors for `CoreDb` API
why;
For the upcoming Aristo wrapper, this allows to control when certain
smart destruction and update can take place. The auto destructor works
fine in general when the storage/cache strategy is known and acceptable
when creating descriptors.
* Add update option for `CoreDb` API function `hash()`
why;
The hash function is typically used to get the state root of the MPT.
Due to lazy hashing, this might be not available on the `Aristo` DB.
So the `update` function asks for re-hashing the gurrent state changes
if needed.
* Update API tracking log mode: `info` => `debug
* Use shared `Kvt` descriptor in new Ledger API
why:
No need to create a new descriptor all the time
* Fix debug noise in `hashify()` for perfectly normal situation
why:
Was previously considered a fixable error
* Fix test sample file names
why:
The larger test file `goerli68161.txt.gz` is already in the local
archive. So there is no need to use the smaller one from the external
repo.
* Activate `accounts_cache` module from `db/ledger`
why:
A copy of the original `accounts_cache.nim` source to be integrated
into the `Ledger` module wrapper which allows to switch between
different `accounts_cache` implementations unser tha same API.
details:
At a later state, the `db/accounts_cache.nim` wrapper will be
removed so that there is only one access to that module via
`db/ledger/accounts_cache.nim`.
* Fix copyright headers in source code
* Make sure that storage tries are not pruned (by default) on the new Ledger API
why:
Pruning might kill some unwanted entries from storage tries ending up with an unstable database
leading to crashes.
* Implement `CoreDb` and `LedgerRef` API tracing
details:
+ Locally enabled at compile time via constants `ProvideCoreDbLegacyAPI`
and `EnableApiTracking` in either `base.nim` source
+ If enabled it can be selectively turned on/off via public switches in
the `CoreDb` descriptor.
* Allow suppressing opportunistic `ifNecessaryGetXxx()` functions
why:
Better troubleshooting when the system crashes (assertions will then
most probably happen outside an `async` function.)
* Provide TDD/debug facility for inspecting `persistBlocks()` working
detail:
+ Make sure that the last block of a test sample is the first batch
item in `persistBlocks()`.
+ Additionally, allow `AccountsCache` API tracing by setting the flag
`extraTraceMessages = true` in the file `accounts_cache.nim`
* Overload AccountsCache by abstraction wrapper
details:
Can facilitate CoreDb API switch, details in `ledger/README.md`.
* CoreDB: Re-org API
details:
Legacy API internally uses vertex ID for root node abstraction
* Cosmetics: Move some unit test helpers to common sub-directory
* Extract constant from `accouns_cache.nim` => `constants.nim`
* Fix tracer methods
why:
Logger dump data were wrongly dumped from the production database. This
caused an assert exception when iterating over the persistent database
(instead of the memory logger.) This event in turn was enabled after
fixing another inconsistency which just set up an empty iterator. Unit
tests failed to detect that.
* Aristo: remove obsolete functions
* Aristo: Fix error code for non-available hash keys
why:
Must not return `not-found` when the key is not available (i.e. the
current changes were not hashified, yet.)
* CoreDB: Provide TDD and test framework