nimbus-eth2/beacon_chain/spec/eth2_merkleization.nim

112 lines
4.1 KiB
Nim

# beacon_chain
# Copyright (c) 2018-2024 Status Research & Development GmbH
# Licensed and distributed under either of
# * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
# * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
# at your option. This file may not be copied, modified, or distributed except according to those terms.
{.push raises: [].}
# Import this module to get access to `hash_tree_root` for spec types
import
stew/endians2,
std/sets,
ssz_serialization/[merkleization, proofs],
./ssz_codec
from ./datatypes/base import HashedValidatorPubKeyItem
from ./datatypes/phase0 import HashedBeaconState, SignedBeaconBlock
from ./datatypes/altair import HashedBeaconState, SignedBeaconBlock
from ./datatypes/bellatrix import HashedBeaconState, SignedBeaconBlock
from ./datatypes/capella import HashedBeaconState, SignedBeaconBlock
from ./datatypes/deneb import HashedBeaconState, SignedBeaconBlock
from ./datatypes/electra import HashedBeaconState, SignedBeaconBlock
from ./datatypes/fulu import HashedBeaconState, SignedBeaconBlock
export ssz_codec, merkleization, proofs
type
DepositsMerkleizer* = SszMerkleizer2[DEPOSIT_CONTRACT_TREE_DEPTH + 1]
# Can't use `ForkyHashedBeaconState`/`ForkyHashedSignedBeaconBlock` without
# creating recursive module dependency through `forks`.
func hash_tree_root*(
x: phase0.HashedBeaconState | altair.HashedBeaconState |
bellatrix.HashedBeaconState | capella.HashedBeaconState |
deneb.HashedBeaconState | electra.SignedBeaconBlock |
fulu.SignedBeaconBlock) {.
error: "HashedBeaconState should not be hashed".}
func hash_tree_root*(
x: phase0.SignedBeaconBlock | altair.SignedBeaconBlock |
bellatrix.SignedBeaconBlock | capella.SignedBeaconBlock |
deneb.SignedBeaconBlock | electra.SignedBeaconBlock |
fulu.SignedBeaconBlock) {.
error: "SignedBeaconBlock should not be hashed".}
func depositCountBytes*(x: uint64): array[32, byte] =
doAssert(x <= 4294967295'u64)
var z = x
for i in 0..3:
result[31-i] = byte(int64(z) %% 256'i64)
z = z div 256
func depositCountU64*(xs: openArray[byte]): uint64 =
## depositCountU64 considers just the first 4 bytes as
## MAX_DEPOSIT_COUNT is defined as 2^32 - 1.
for i in 0 .. 27:
doAssert xs[i] == 0
return uint64.fromBytesBE(xs[24..31])
func init*(T: type DepositsMerkleizer, s: DepositContractState): DepositsMerkleizer =
let count = depositCountU64(s.deposit_count)
DepositsMerkleizer.init(s.branch, count)
func toDepositContractState*(merkleizer: DepositsMerkleizer): DepositContractState =
# TODO There is an off by one discrepancy in the size of the arrays here that
# need to be investigated. It shouldn't matter as long as the tree is
# not populated to its maximum size.
result.branch[0..31] = merkleizer.getCombinedChunks[0..31]
result.deposit_count[24..31] = merkleizer.getChunkCount().toBytesBE
func getDepositsRoot*(m: var DepositsMerkleizer): Eth2Digest =
mixInLength(m.getFinalHash, int m.totalChunks)
func hash*(v: ref HashedValidatorPubKeyItem): Hash =
if not isNil(v):
hash(v[].key)
else:
default(Hash)
func `==`*(a, b: ref HashedValidatorPubKeyItem): bool =
if isNil(a):
isNil(b)
elif isNil(b):
false
else:
a[].key == b[].key
func init*(T: type HashedValidatorPubKey, key: ValidatorPubKey): HashedValidatorPubKey =
{.noSideEffect.}:
var keys {.threadvar.}: HashSet[ref HashedValidatorPubKeyItem]
let
tmp = (ref HashedValidatorPubKeyItem)(
key: key,
root: hash_tree_root(key)
)
cached =
if keys.containsOrIncl(tmp):
try:
# The interface of HashSet is such that we must construct a full
# instance to check if it's in the set - then we can return that
# instace and discard the one we just created temporarily
addr keys[tmp][]
except KeyError:
raiseAssert "just checked"
else:
addr tmp[]
HashedValidatorPubKey(value: cached) # https://github.com/nim-lang/Nim/issues/23505