nimbus-eth1/nimbus/db/kvt/kvt_init/memory_db.nim
Jacek Sieka 768307d91d
Cache code and invalid jump destination tables (fixes #2268) (#2404)
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.
2024-06-21 09:44:10 +02:00

187 lines
5.1 KiB
Nim

# nimbus-eth1
# Copyright (c) 2023-2024 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
# http://www.apache.org/licenses/LICENSE-2.0)
# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
# http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed
# except according to those terms.
## In-memory backend for Kvt DB
## ============================
##
## The iterators provided here are currently available only by direct
## backend access
## ::
## import
## kvt/kvt_init,
## kvt/kvt_init/kvt_memory
##
## let rc = newKvtDbRef(BackendMemory)
## if rc.isOk:
## let be = rc.value.to(MemBackendRef)
## for (n, key, vtx) in be.walkVtx:
## ...
##
{.push raises: [].}
import
std/tables,
chronicles,
eth/common,
results,
stew/byteutils,
../kvt_desc,
../kvt_desc/desc_backend,
./init_common
type
MemDbRef = ref object
## Database
tab: Table[Blob,Blob] ## Structural key-value table
MemBackendRef* = ref object of TypedBackendRef
## Inheriting table so access can be extended for debugging purposes
mdb: MemDbRef ## Database
MemPutHdlRef = ref object of TypedPutHdlRef
tab: Table[Blob,Blob]
# ------------------------------------------------------------------------------
# Private helpers
# ------------------------------------------------------------------------------
template logTxt(info: static[string]): static[string] =
"MemoryDB " & info
proc newSession(db: MemBackendRef): MemPutHdlRef =
new result
result.TypedPutHdlRef.beginSession db
proc getSession(hdl: PutHdlRef; db: MemBackendRef): MemPutHdlRef =
hdl.TypedPutHdlRef.verifySession db
hdl.MemPutHdlRef
proc endSession(hdl: PutHdlRef; db: MemBackendRef): MemPutHdlRef =
hdl.TypedPutHdlRef.finishSession db
hdl.MemPutHdlRef
# ------------------------------------------------------------------------------
# Private functions: interface
# ------------------------------------------------------------------------------
proc getKvpFn(db: MemBackendRef): GetKvpFn =
result =
proc(key: openArray[byte]): Result[Blob,KvtError] =
if key.len == 0:
return err(KeyInvalid)
var data = db.mdb.tab.getOrVoid @key
if data.isValid:
return ok(move(data))
err(GetNotFound)
proc lenKvpFn(db: MemBackendRef): LenKvpFn =
result =
proc(key: openArray[byte]): Result[int,KvtError] =
if key.len == 0:
return err(KeyInvalid)
var data = db.mdb.tab.getOrVoid @key
if data.isValid:
return ok(data.len)
err(GetNotFound)
# -------------
proc putBegFn(db: MemBackendRef): PutBegFn =
result =
proc(): Result[PutHdlRef,KvtError] =
ok db.newSession()
proc putKvpFn(db: MemBackendRef): PutKvpFn =
result =
proc(hdl: PutHdlRef; kvps: openArray[(Blob,Blob)]) =
let hdl = hdl.getSession db
if hdl.error == KvtError(0):
for (k,v) in kvps:
if k.isValid:
hdl.tab[k] = v
else:
hdl.error = KeyInvalid
proc putEndFn(db: MemBackendRef): PutEndFn =
result =
proc(hdl: PutHdlRef): Result[void,KvtError] =
let hdl = hdl.endSession db
if hdl.error != KvtError(0):
debug logTxt "putEndFn: key/value failed", error=hdl.error
return err(hdl.error)
for (k,v) in hdl.tab.pairs:
db.mdb.tab[k] = v
ok()
# -------------
proc closeFn(db: MemBackendRef): CloseFn =
result =
proc(ignore: bool) =
discard
proc canModFn(db: MemBackendRef): CanModFn =
result =
proc(): Result[void,KvtError] =
ok()
proc setWrReqFn(db: MemBackendRef): SetWrReqFn =
result =
proc(kvt: RootRef): Result[void,KvtError] =
err(RdbBeHostNotApplicable)
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
proc memoryBackend*: BackendRef =
let db = MemBackendRef(
beKind: BackendMemory,
mdb: MemDbRef())
db.getKvpFn = getKvpFn db
db.lenKvpFn = lenKvpFn db
db.putBegFn = putBegFn db
db.putKvpFn = putKvpFn db
db.putEndFn = putEndFn db
db.closeFn = closeFn db
db.canModFn = canModFn db
db.setWrReqFn = setWrReqFn db
db
proc dup*(db: MemBackendRef): MemBackendRef =
## Duplicate descriptor shell as needed for API debugging
new result
init_common.init(result[], db[])
result.mdb = db.mdb
# ------------------------------------------------------------------------------
# Public iterators (needs direct backend access)
# ------------------------------------------------------------------------------
iterator walk*(
be: MemBackendRef;
): tuple[key: Blob, data: Blob] =
## Walk over all key-value pairs of the database.
for (key,data) in be.mdb.tab.pairs:
if data.isValid:
yield (key, data)
else:
debug logTxt "walk() skip empty", key
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------