nimbus-eth1/nimbus/db/aristo/aristo_merge/merge_proof.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.
{.push raises: [].}
import
std/[algorithm, sets, tables],
eth/common,
results,
stew/keyed_queue,
../../../sync/protocol/snap/snap_types,
".."/[aristo_desc, aristo_get, aristo_layers, aristo_serialise, aristo_vid]
# ------------------------------------------------------------------------------
# Private functions: add Merkle proof node
# ------------------------------------------------------------------------------
proc mergeNodeImpl(
db: AristoDbRef; # Database, top layer
hashKey: HashKey; # Merkel hash of node (or so)
node: NodeRef; # Node derived from RLP representation
rootVid: VertexID; # Current sub-trie
): Result[void,AristoError] =
## The function merges the argument hash key `lid` as expanded from the
## node RLP representation into the `Aristo Trie` database. The vertex is
## split off from the node and stored separately. So are the Merkle hashes.
## The vertex is labelled `locked`.
##
## The `node` argument is *not* checked, whether the vertex IDs have been
## allocated, already. If the node comes straight from the `decode()` RLP
## decoder as expected, these vertex IDs will be all zero.
##
## This function expects that the parent for the argument `node` has already
## been installed.
##
## Caveat:
## Proof of concept, not in production yet.
##
# Check for error after RLP decoding
doAssert node.error == AristoError(0)
# Verify arguments
if not rootVid.isValid:
return err(MergeRootKeyInvalid)
if not hashKey.isValid:
return err(MergeHashKeyInvalid)
# Make sure that the `vid<->key` reverse mapping is updated.
let vid = db.layerGetProofVidOrVoid hashKey
if not vid.isValid:
return err(MergeRevVidMustHaveBeenCached)
# Use the vertex ID `vid` to be populated by the argument root node
let key = db.layersGetKeyOrVoid vid
if key.isValid and key != hashKey:
return err(MergeHashKeyDiffersFromCached)
# Set up vertex.
let (vtx, newVtxFromNode) = block:
let vty = db.getVtx vid
if vty.isValid:
(vty, false)
else:
(node.to(VertexRef), true)
# The `vertexID <-> hashKey` mappings need to be set up now (if any)
case node.vType:
of Leaf:
# Check whether there is need to convert the payload to `Account` payload
if rootVid == VertexID(1) and newVtxFromNode:
try:
let
# `aristo_serialise.read()` always decodes raw data payloaf
acc = rlp.decode(node.lData.rawBlob, Account)
pyl = PayloadRef(
pType: AccountData,
account: AristoAccount(
nonce: acc.nonce,
balance: acc.balance,
codeHash: acc.codeHash))
if acc.storageRoot.isValid:
var sid = db.layerGetProofVidOrVoid acc.storageRoot.to(HashKey)
if not sid.isValid:
sid = db.vidFetch
db.layersPutProof(sid, acc.storageRoot.to(HashKey))
pyl.account.storageID = sid
vtx.lData = pyl
except RlpError:
return err(MergeNodeAccountPayloadError)
of Extension:
if node.key[0].isValid:
let eKey = node.key[0]
if newVtxFromNode:
vtx.eVid = db.layerGetProofVidOrVoid eKey
if not vtx.eVid.isValid:
# Brand new reverse lookup link for this vertex
vtx.eVid = db.vidFetch
elif not vtx.eVid.isValid:
return err(MergeNodeVidMissing)
else:
let yEke = db.getKey vtx.eVid
if yEke.isValid and eKey != yEke:
return err(MergeNodeVtxDiffersFromExisting)
db.layersPutProof(vtx.eVid, eKey)
of Branch:
for n in 0..15:
if node.key[n].isValid:
let bKey = node.key[n]
if newVtxFromNode:
vtx.bVid[n] = db.layerGetProofVidOrVoid bKey
if not vtx.bVid[n].isValid:
# Brand new reverse lookup link for this vertex
vtx.bVid[n] = db.vidFetch
elif not vtx.bVid[n].isValid:
return err(MergeNodeVidMissing)
else:
let yEkb = db.getKey vtx.bVid[n]
if yEkb.isValid and yEkb != bKey:
return err(MergeNodeVtxDiffersFromExisting)
db.layersPutProof(vtx.bVid[n], bKey)
# Store and lock vertex
db.layersPutProof(vid, key, vtx)
ok()
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
proc mergeProof*(
db: AristoDbRef; # Database, top layer
proof: openArray[SnapProof]; # RLP encoded node records
rootVid = VertexID(0); # Current sub-trie
): Result[int, AristoError]
{.gcsafe, raises: [RlpError].} =
## The function merges the argument `proof` list of RLP encoded node records
## into the `Aristo Trie` database. This function is intended to be used with
## the proof nodes as returened by `snap/1` messages.
##
## If there is no root vertex ID passed, the function tries to find out what
## the root hashes are and allocates new vertices with static IDs `$2`, `$3`,
## etc.
##
## Caveat:
## Proof of concept, not in production yet.
##
proc update(
seen: var Table[HashKey,NodeRef];
todo: var KeyedQueueNV[NodeRef];
key: HashKey;
) {.gcsafe, raises: [RlpError].} =
## Check for embedded nodes, i.e. fully encoded node instead of a hash.
## They need to be treated as full nodes, here.
if key.isValid and key.len < 32:
let lid = key.data.digestTo(HashKey)
if not seen.hasKey lid:
let node = key.data.decode(NodeRef)
discard todo.append node
seen[lid] = node
let rootKey = block:
if rootVid.isValid:
let vidKey = db.getKey rootVid
if not vidKey.isValid:
return err(MergeRootKeyInvalid)
# Make sure that the reverse lookup for the root vertex key is available.
if not db.layerGetProofVidOrVoid(vidKey).isValid:
return err(MergeProofInitMissing)
vidKey
else:
VOID_HASH_KEY
# Expand and collect hash keys and nodes and parent indicator
var
nodeTab: Table[HashKey,NodeRef]
rootKeys: HashSet[HashKey] # Potential root node hashes
for w in proof:
let
key = w.Blob.digestTo(HashKey)
node = rlp.decode(w.Blob,NodeRef)
if node.error != AristoError(0):
return err(node.error)
nodeTab[key] = node
rootKeys.incl key
# Check for embedded nodes, i.e. fully encoded node instead of a hash.
# They will be added as full nodes to the `nodeTab[]`.
var embNodes: KeyedQueueNV[NodeRef]
discard embNodes.append node
while true:
let node = embNodes.shift.valueOr: break
case node.vType:
of Leaf:
discard
of Branch:
for n in 0 .. 15:
nodeTab.update(embNodes, node.key[n])
of Extension:
nodeTab.update(embNodes, node.key[0])
# Create a table with back links
var
backLink: Table[HashKey,HashKey]
blindNodes: HashSet[HashKey]
for (key,node) in nodeTab.pairs:
case node.vType:
of Leaf:
blindNodes.incl key
of Extension:
if nodeTab.hasKey node.key[0]:
backLink[node.key[0]] = key
rootKeys.excl node.key[0] # predecessor => not root
else:
blindNodes.incl key
of Branch:
var isBlind = true
for n in 0 .. 15:
if nodeTab.hasKey node.key[n]:
isBlind = false
backLink[node.key[n]] = key
rootKeys.excl node.key[n] # predecessor => not root
if isBlind:
blindNodes.incl key
# If it exists, the root key must be in the set `mayBeRoot` in order
# to work.
var roots: Table[HashKey,VertexID]
if rootVid.isValid:
if rootKey notin rootKeys:
return err(MergeRootKeyNotInProof)
roots[rootKey] = rootVid
elif rootKeys.len == 0:
return err(MergeRootKeysMissing)
else:
# Add static root keys different from VertexID(1)
var count = 2
for key in rootKeys.items:
while true:
# Check for already allocated nodes
let vid1 = db.layerGetProofVidOrVoid key
if vid1.isValid:
roots[key] = vid1
break
# Use the next free static free vertex ID
let vid2 = VertexID(count)
count.inc
if not db.getKey(vid2).isValid:
doAssert not db.layerGetProofVidOrVoid(key).isValid
db.layersPutProof(vid2, key)
roots[key] = vid2
break
if LEAST_FREE_VID <= count:
return err(MergeRootKeysOverflow)
# Run over blind nodes and build chains from a blind/bottom level node up
# to the root node. Select only chains that end up at the pre-defined root
# node.
var
accounts: seq[seq[HashKey]] # This one separated, to be processed last
chains: seq[seq[HashKey]]
for w in blindNodes:
# Build a chain of nodes up to the root node
var
chain: seq[HashKey]
nodeKey = w
while nodeKey.isValid and nodeTab.hasKey nodeKey:
chain.add nodeKey
nodeKey = backLink.getOrVoid nodeKey
if 0 < chain.len and chain[^1] in roots:
if roots.getOrVoid(chain[0]) == VertexID(1):
accounts.add chain
else:
chains.add chain
# Process over chains in reverse mode starting with the root node. This
# allows the algorithm to find existing nodes on the backend.
var
seen: HashSet[HashKey]
merged = 0
# Process the root ID which is common to all chains
for chain in chains & accounts:
let chainRootVid = roots.getOrVoid chain[^1]
for key in chain.reversed:
if key notin seen:
seen.incl key
let node = nodeTab.getOrVoid key
db.mergeNodeImpl(key, node, chainRootVid).isOkOr:
return err(error)
merged.inc
ok merged
proc mergeProof*(
db: AristoDbRef; # Database, top layer
rootHash: Hash256; # Merkle hash for root
rootVid = VertexID(0); # Optionally, force root vertex ID
): Result[VertexID,AristoError] =
## Set up a `rootKey` associated with a vertex ID for use with proof nodes.
##
## If argument `rootVid` is unset then a new dybamic root vertex (i.e.
## the ID will be at least `LEAST_FREE_VID`) will be installed.
##
## Otherwise, if the argument `rootVid` is set then a sub-trie with root
## `rootVid` is checked for. An error is returned if it is set up already
## with a different `rootHash`.
##
## Upon successful return, the vertex ID assigned to the root key is returned.
##
## Caveat:
## Proof of concept, not in production yet.
##
let rootKey = rootHash.to(HashKey)
if rootVid.isValid:
let key = db.getKey rootVid
if key.isValid:
if rootKey.isValid and key != rootKey:
# Cannot use installed root key differing from hash argument
return err(MergeRootKeyDiffersForVid)
# Confirm root ID and key for proof nodes processing
db.layersPutProof(rootVid, key) # note that `rootKey` might be void
return ok rootVid
if not rootHash.isValid:
return err(MergeRootArgsIncomplete)
if db.getVtx(rootVid).isValid:
# Cannot use verify root key for existing root vertex
return err(MergeRootKeyMissing)
# Confirm root ID and hash key for proof nodes processing
db.layersPutProof(rootVid, rootKey)
return ok rootVid
if not rootHash.isValid:
return err(MergeRootArgsIncomplete)
# Now there is no root vertex ID, only the hash argument.
# So Create and assign a new root key.
let vid = db.vidFetch
db.layersPutProof(vid, rootKey)
return ok vid
proc mergeProof*(
db: AristoDbRef; # Database, top layer
rootVid: VertexID; # Root ID
): Result[VertexID,AristoError] =
## Variant of `mergeProof()` for missing `rootHash`
db.mergeProof(EMPTY_ROOT_HASH, rootVid)
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------