nimbus-eth1/nimbus/db/aristo/aristo_delta/delta_siblings.nim
Jacek Sieka 81e75622cf
storage: store root id together with vid, for better locality of refe… (#2449)
The state and account MPT:s currenty share key space in the database
based on that vertex id:s are assigned essentially randomly, which means
that when two adjacent slot values from the same contract are accessed,
they might reside at large distance from each other.

Here, we prefix each vertex id by its root causing them to be sorted
together thus bringing all data belonging to a particular contract
closer together - the same effect also happens for the main state MPT
whose nodes now end up clustered together more tightly.

In the future, the prefix given to the storage keys can also be used to
perform range operations such as reading all the storage at once and/or
deleting an account with a batch operation.

Notably, parts of the API already supported this rooting concept while
parts didn't - this PR makes the API consistent by always working with a
root+vid.
2024-07-04 15:46:52 +02:00

118 lines
4.0 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.
import
results,
eth/common,
../aristo_desc,
"."/[delta_merge, delta_reverse]
type
UpdateState = enum
Initial = 0
Updated,
Finished
UpdateSiblingsRef* = ref object
## Update transactional context
state: UpdateState
db: AristoDbRef ## Main database access
balancers: seq[(AristoDbRef,LayerDeltaRef)] ## Rollback data
rev: LayerDeltaRef ## Reverse filter set up
# ------------------------------------------------------------------------------
# Public contructor, commit, rollback
# ------------------------------------------------------------------------------
proc rollback*(ctx: UpdateSiblingsRef) =
## Rollback any changes made by the `update()` function. Subsequent
## `rollback()` or `commit()` calls will be without effect.
if ctx.state == Updated:
for (d,f) in ctx.balancers:
d.balancer = f
ctx.state = Finished
proc commit*(ctx: UpdateSiblingsRef): Result[void,AristoError] =
## Accept updates. Subsequent `rollback()` calls will be without effect.
if ctx.state != Updated:
ctx.rollback()
return err(FilSiblingsCommitUnfinshed)
ctx.db.balancer = LayerDeltaRef(nil)
ctx.state = Finished
ok()
proc commit*(
rc: Result[UpdateSiblingsRef,AristoError];
): Result[void,AristoError] =
## Variant of `commit()` for joining with `update()`
(? rc).commit()
proc init*(
T: type UpdateSiblingsRef; # Context type
db: AristoDbRef; # Main database
): Result[T,AristoError] =
## Set up environment for installing the reverse of the `db` argument current
## read-only filter onto every associated descriptor referring to the same
## database.
if not db.isCentre:
return err(FilBackendRoMode)
if db.nForked == 0:
return ok T(db: db) # No need to do anything
func fromVae(err: (VertexID,AristoError)): AristoError =
err[1]
# Filter rollback context
ok T(
db: db,
rev: ? db.revFilter(db.balancer).mapErr fromVae) # Reverse filter
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
proc update*(ctx: UpdateSiblingsRef): Result[UpdateSiblingsRef,AristoError] =
## This function installs the reverse of the `init()` argument `db` current
## read-only filter onto every associated descriptor referring to the same
## database. If the function fails, a `rollback()` is called automatically.
##
## This function might do some real work so it was detached from `init()` so
## it can be called late but before the physical database is updated.
##
if ctx.state == Initial:
ctx.state = Updated
if not ctx.rev.isNil:
let db = ctx.db
# Update distributed filters. Note that the physical backend database
# must not have been updated, yet. So the new root key for the backend
# will be `db.balancer.kMap[$1]`.
let trg = db.balancer.kMap.getOrVoid((VertexID(1), VertexID(1)))
for w in db.forked:
let rc = db.deltaMerge(w.balancer, ctx.rev, trg)
if rc.isErr:
ctx.rollback()
return err(rc.error[1])
ctx.balancers.add (w, w.balancer)
w.balancer = rc.value
ok(ctx)
proc update*(
rc: Result[UpdateSiblingsRef,AristoError]
): Result[UpdateSiblingsRef,AristoError] =
## Variant of `update()` for joining with `init()`
(? rc).update()
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------