It is common for many accounts to share the same code - at the database
level, code is stored by hash meaning only one copy exists per unique
program but when loaded in memory, a copy is made for each account.
Further, every time we execute the code, it must be scanned for invalid
jump destinations which slows down EVM exeuction.
Finally, the extcodesize call causes code to be loaded even if only the
size is needed.
This PR improves on all these points by introducing a shared
CodeBytesRef type whose code section is immutable and that can be shared
between accounts. Further, a dedicated `len` API call is added so that
the EXTCODESIZE opcode can operate without polluting the GC and code
cache, for cases where only the size is requested - rocksdb will in this
case cache the code itself in the row cache meaning that lookup of the
code itself remains fast when length is asked for first.
With 16k code entries, there's a 90% hit rate which goes up to 99%
during the 2.3M attack - the cache significantly lowers memory
consumption and execution time not only during this event but across the
board.
* 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 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+Kvt: Fix backend `dup()` function in api setup
why:
Backend object is subject to an inheritance cascade which was not
taken care of, before. Only the base object was duplicated.
* Kvt: Simplify DB clone/peers management
* Aristo: Simplify DB clone/peers management
* Aristo: Adjust unit test for working with memory DB only
why:
This currently causes some memory corruption persumably in the
`libc` background layer.
* CoredDb+Kvt: Simplify API for KVT
why:
Simplified storage models (was over engineered) for better performance
and code maintenance.
* CoredDb+Aristo: Simplify API for `Aristo`
why:
Only single database state needed here. Accessing a similar state will
be implemented from outside this module using a context layer. This
gives better performance and improves code maintenance.
* Fix Copyright headers
* CoreDb: Turn off API tracking
why:
CI would ot go through. Was accidentally turned on.
* 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
* Fix kvt headers
* Provide differential layers for KVT transaction stack
why:
Significant performance improvement
* Provide abstraction layer for database top cache layer
why:
This will eventually implemented as a differential database layers
or transaction layers. The latter is needed to improve performance.
behavioural changes:
Zero vertex and keys (i.e. delete requests) are not optimised out
until the last layer is written to the database.
* Provide differential layers for Aristo transaction stack
why:
Significant performance improvement
* 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.
why:
Additional tables needed for the `CoreDB` object with separate
key-value table and MPT.
details:
+ Stripped down copy of Aristo DB to have a similar look'n feel. Otherwise
it is just a posh way for accessing `Table` objects or `RocksDB` data.
+ No unit tests yet, will be tested on the go.
Jacek Sieka
Jordan Hrycaj