nimbus-eth1/nimbus/db/aristo/aristo_delta.nim

122 lines
4.4 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.
## Aristo DB -- Delta filter management
## ====================================
##
import
std/tables,
eth/common,
results,
./aristo_delta/[delta_merge, delta_reverse],
./aristo_desc/desc_backend,
"."/[aristo_desc, aristo_layers]
# ------------------------------------------------------------------------------
# Public functions, save to backend
# ------------------------------------------------------------------------------
proc deltaPersistentOk*(db: AristoDbRef): bool =
## Check whether the read-only filter can be merged into the backend
not db.backend.isNil and db.isCentre
proc deltaPersistent*(
db: AristoDbRef; # Database
nxtFid = 0u64; # Next filter ID (if any)
reCentreOk = false;
): Result[void,AristoError] =
## Resolve (i.e. move) the balancer into the physical backend database.
##
## This needs write permission on the backend DB for the descriptor argument
## `db` (see the function `aristo_desc.isCentre()`.) If the argument flag
## `reCentreOk` is passed `true`, write permission will be temporarily
## acquired when needed.
##
## When merging the current backend filter, its reverse will be is stored
## on other non-centre descriptors so there is no visible database change
## for these.
##
let be = db.backend
if be.isNil:
return err(FilBackendMissing)
# Blind or missing filter
if db.balancer.isNil:
# Add a blind storage frame. This will do no harm if `Aristo` runs
# standalone. Yet it is needed if a `Kvt` is tied to `Aristo` and has
# triggered a save cyle already which is to be completed here.
#
# There is no need to add a blind frame on any error return. If there
# is a `Kvt` tied to `Aristo`, then it must somehow run in sync and an
# error occuring here must have been detected earlier when (implicitely)
# registering `Kvt`. So that error should be considered a defect.
? be.putEndFn(? be.putBegFn())
return ok()
# Make sure that the argument `db` is at the centre so the backend is in
# read-write mode for this peer.
let parent = db.getCentre
if db != parent:
if not reCentreOk:
return err(FilBackendRoMode)
? db.reCentre()
# Always re-centre to `parent` (in case `reCentreOk` was set)
defer: discard parent.reCentre()
# Update forked balancers here do that errors are detected early (if any.)
if 0 < db.nForked:
let rev = db.revFilter(db.balancer).valueOr:
return err(error[1])
if not rev.isEmpty: # Can an empty `rev` happen at all?
var unsharedRevOk = true
for w in db.forked:
if not w.db.balancer.isValid:
unsharedRevOk = false
# The `rev` filter can be modified if one can make sure that it is
# not shared (i.e. only previously merged into the w.db.balancer.)
# Note that it is trivially true for a single fork.
let modLowerOk = w.isLast and unsharedRevOk
w.db.balancer = deltaMerge(
w.db.balancer, modUpperOk=false, rev, modLowerOk=modLowerOk)
let lSst = SavedState(
key: EMPTY_ROOT_HASH, # placeholder for more
serial: nxtFid)
# Store structural single trie entries
let writeBatch = ? be.putBegFn()
for rvid, vtx in db.balancer.sTab:
db.balancer.kMap.withValue(rvid, key) do:
be.putVtxFn(writeBatch, rvid, vtx, key[])
do:
be.putVtxFn(writeBatch, rvid, vtx, default(HashKey))
be.putTuvFn(writeBatch, db.balancer.vTop)
be.putLstFn(writeBatch, lSst)
? be.putEndFn writeBatch # Finalise write batch
# Copy back updated payloads
for accPath, vtx in db.balancer.accLeaves:
db.accLeaves.put(accPath, vtx)
for mixPath, vtx in db.balancer.stoLeaves:
db.stoLeaves.put(mixPath, vtx)
# Done with balancer, all saved to backend
db.balancer = LayerRef(nil)
ok()
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------