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

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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 -- a Patricia Trie with labeled edges
## ===============================================
##
## These data structures allow to overlay the *Patricia Trie* with *Merkel
## Trie* hashes. See the `README.md` in the `aristo` folder for documentation.
##
## Some semantic explanations;
##
## * HashKey, NodeRef etc. refer to the standard/legacy `Merkle Patricia Tree`
## * VertexID, VertexRef, etc. refer to the `Aristo Trie`
##
{.push raises: [].}
import
std/[hashes, sets, tables],
eth/common,
results,
./aristo_constants,
./aristo_desc/[desc_error, desc_identifiers, desc_nibbles, desc_structural],
minilru
from ./aristo_desc/desc_backend
import BackendRef
# Not auto-exporting backend
export
tables, aristo_constants, desc_error, desc_identifiers, desc_nibbles,
desc_structural, minilru, common
type
AristoTxRef* = ref object
## Transaction descriptor
db*: AristoDbRef ## Database descriptor
parent*: AristoTxRef ## Previous transaction
txUid*: uint ## Unique ID among transactions
level*: int ## Stack index for this transaction
AristoDbRef* = ref object
## Three tier database object supporting distributed instances.
top*: LayerRef ## Database working layer, mutable
stack*: seq[LayerRef] ## Stashed immutable parent layers
balancer*: LayerRef ## Balance out concurrent backend access
backend*: BackendRef ## Backend database (may well be `nil`)
txRef*: AristoTxRef ## Latest active transaction
txUidGen*: uint ## Tx-relative unique number generator
accLeaves*: LruCache[Hash32, VertexRef]
## Account path to payload cache - accounts are frequently accessed by
## account path when contracts interact with them - this cache ensures
## that we don't have to re-traverse the storage trie for every such
## interaction
## TODO a better solution would probably be to cache this in a type
## exposed to the high-level API
stoLeaves*: LruCache[Hash32, VertexRef]
## Mixed account/storage path to payload cache - same as above but caches
## the full lookup of storage slots
# Debugging data below, might go away in future
xMap*: Table[HashKey,RootedVertexID] ## For pretty printing/debugging
Leg* = object
## For constructing a `VertexPath`
wp*: VidVtxPair ## Vertex ID and data ref
nibble*: int8 ## Next vertex selector for `Branch` (if any)
Hike* = object
## Trie traversal path
root*: VertexID ## Handy for some fringe cases
legs*: ArrayBuf[NibblesBuf.high + 1, Leg] ## Chain of vertices and IDs
tail*: NibblesBuf ## Portion of non completed path
# ------------------------------------------------------------------------------
# Public helpers
# ------------------------------------------------------------------------------
template mixUp*(accPath, stoPath: Hash32): Hash32 =
# Insecure but fast way of mixing the values of two hashes, for the purpose
# of quick lookups - this is certainly not a good idea for general Hash32
# values but account paths are generated from accounts which would be hard
# to create pre-images for, for the purpose of collisions with a particular
# storage slot
var v {.noinit.}: Hash32
for i in 0..<v.data.len:
# `+` wraps leaving all bits used
v.data[i] = accPath.data[i] + stoPath.data[i]
v
func getOrVoid*[W](tab: Table[W,VertexRef]; w: W): VertexRef =
tab.getOrDefault(w, VertexRef(nil))
func getOrVoid*[W](tab: Table[W,NodeRef]; w: W): NodeRef =
tab.getOrDefault(w, NodeRef(nil))
func getOrVoid*[W](tab: Table[W,HashKey]; w: W): HashKey =
tab.getOrDefault(w, VOID_HASH_KEY)
func getOrVoid*[W](tab: Table[W,RootedVertexID]; w: W): RootedVertexID =
tab.getOrDefault(w, default(RootedVertexID))
func getOrVoid*[W](tab: Table[W,HashSet[RootedVertexID]]; w: W): HashSet[RootedVertexID] =
tab.getOrDefault(w, default(HashSet[RootedVertexID]))
# --------
func isValid*(vtx: VertexRef): bool =
vtx != VertexRef(nil)
func isValid*(nd: NodeRef): bool =
nd != NodeRef(nil)
func isValid*(pid: PathID): bool =
pid != VOID_PATH_ID
func isValid*(layer: LayerRef): bool =
layer != LayerRef(nil)
func isValid*(root: Hash32): bool =
root != EMPTY_ROOT_HASH
func isValid*(key: HashKey): bool =
assert key.len != 32 or key.to(Hash32).isValid
0 < key.len
func isValid*(vid: VertexID): bool =
vid != VertexID(0)
func isValid*(rvid: RootedVertexID): bool =
rvid.vid.isValid and rvid.root.isValid
func isValid*(sqv: HashSet[RootedVertexID]): bool =
sqv.len > 0
# ------------------------------------------------------------------------------
# Public functions, miscellaneous
# ------------------------------------------------------------------------------
# Hash set helper
func hash*(db: AristoDbRef): Hash =
## Table/KeyedQueue/HashSet mixin
cast[pointer](db).hash
# ------------------------------------------------------------------------------
# Public helpers
# ------------------------------------------------------------------------------
iterator rstack*(db: AristoDbRef): LayerRef =
# Stack in reverse order
for i in 0..<db.stack.len:
yield db.stack[db.stack.len - i - 1]
proc deltaAtLevel*(db: AristoDbRef, level: int): LayerRef =
if level == 0:
db.top
elif level > 0:
doAssert level <= db.stack.len
db.stack[^level]
elif level == -1:
doAssert db.balancer != nil
db.balancer
elif level == -2:
nil
else:
raiseAssert "Unknown level " & $level
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------