nimbus-eth2/beacon_chain/spec/deposit_snapshots.nim

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from std/sequtils import all
from stew/objects import isZeroMemory
import ./eth2_merkleization
from ./datatypes/base import Eth1Data, DepositContractState
from ./digest import Eth2Digest
export
depositCountBytes, depositCountU64
type
OldDepositContractSnapshot* = object
eth1Block*: Eth2Digest
depositContractState*: DepositContractState
DepositTreeSnapshot* = object
## https://eips.ethereum.org/EIPS/eip-4881
eth1Block*: Eth2Digest
depositContractState*: DepositContractState
blockHeight*: uint64
func toDepositTreeSnapshot*(d: OldDepositContractSnapshot,
blockHeight: uint64): DepositTreeSnapshot =
DepositTreeSnapshot(
eth1Block: d.eth1Block,
depositContractState: d.depositContractState,
blockHeight: blockHeight)
func toOldDepositContractSnapshot*(d: DepositTreeSnapshot): OldDepositContractSnapshot =
OldDepositContractSnapshot(eth1Block: d.eth1Block,
depositContractState: d.depositContractState)
template getDepositCountU64*(d: OldDepositContractSnapshot |
DepositTreeSnapshot): uint64 =
depositCountU64(d.depositContractState.deposit_count)
func getDepositRoot*(d: OldDepositContractSnapshot |
DepositTreeSnapshot): Eth2Digest =
let merk = DepositsMerkleizer.init(d.depositContractState)
let hash = merk.getFinalHash()
# TODO: mixInLength should accept unsigned int instead of int as
# this right now cuts in half the theoretical number of deposits.
return mixInLength(hash, int(merk.totalChunks))
func isValid*(d: DepositTreeSnapshot, wantedDepositRoot: Eth2Digest): bool =
## `isValid` requires the snapshot to be self-consistent and
## to point to a specific Ethereum block
return not (d.eth1Block.isZeroMemory or
d.blockHeight == 0 or
d.getDepositRoot() != wantedDepositRoot)
func matches*(snapshot: DepositTreeSnapshot, eth1_data: Eth1Data): bool =
snapshot.getDepositCountU64() == eth1_data.deposit_count and
snapshot.getDepositRoot() == eth1_data.deposit_root