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.
* 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+RocksDB: Update backend drivers
why:
RocksDB update allows use some of the newly provided methods which
were previously implemented by using the very C backend (for the lack
of NIM methods.)
* Aristo+RocksDB: Simplify drivers wrapper
* Kvt: Update backend drivers and wrappers similar to `Aristo`
* Aristo+Kvm: Use column families for RocksDB
* Aristo+MemoryDB: Code cosmetics
* Aristo: Provide guest column family for export
why:
So `Kvt` can piggyback on `Aristo` so there avoiding to run a second
DBMS system in parallel.
* Kvt: Provide import mechanism for RoksDB guest column family
why:
So `Kvt` can piggyback on `Aristo` so there avoiding to run a second
DBMS system in parallel.
* CoreDb+Aristo: Run persistent `Kvt` DB piggybacked on `Aristo`
why:
Avoiding to run two DBMS systems in parallel.
* Fix copyright year
* Ditto
* 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.)
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