nimbus-eth2/beacon_chain/spec/eth2_merkleization.nim

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# beacon_chain
# Copyright (c) 2018-2023 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: [].}
disentangle eth2 types from the ssz library (#2785) * reorganize ssz dependencies This PR continues the work in https://github.com/status-im/nimbus-eth2/pull/2646, https://github.com/status-im/nimbus-eth2/pull/2779 as well as past issues with serialization and type, to disentangle SSZ from eth2 and at the same time simplify imports and exports with a structured approach. The principal idea here is that when a library wants to introduce SSZ support, they do so via 3 files: * `ssz_codecs` which imports and reexports `codecs` - this covers the basic byte conversions and ensures no overloads get lost * `xxx_merkleization` imports and exports `merkleization` to specialize and get access to `hash_tree_root` and friends * `xxx_ssz_serialization` imports and exports `ssz_serialization` to specialize ssz for a specific library Those that need to interact with SSZ always import the `xxx_` versions of the modules and never `ssz` itself so as to keep imports simple and safe. This is similar to how the REST / JSON-RPC serializers are structured in that someone wanting to serialize spec types to REST-JSON will import `eth2_rest_serialization` and nothing else. * split up ssz into a core library that is independendent of eth2 types * rename `bytes_reader` to `codec` to highlight that it contains coding and decoding of bytes and native ssz types * remove tricky List init overload that causes compile issues * get rid of top-level ssz import * reenable merkleization tests * move some "standard" json serializers to spec * remove `ValidatorIndex` serialization for now * remove test_ssz_merkleization * add tests for over/underlong byte sequences * fix broken seq[byte] test - seq[byte] is not an SSZ type There are a few things this PR doesn't solve: * like #2646 this PR is weak on how to handle root and other dontSerialize fields that "sometimes" should be computed - the same problem appears in REST / JSON-RPC etc * Fix a build problem on macOS * Another way to fix the macOS builds Co-authored-by: Zahary Karadjov <zahary@gmail.com>
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# Import this module to get access to `hash_tree_root` for spec types
import
ssz_serialization/[merkleization, proofs],
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./ssz_codec
from ./datatypes/phase0 import HashedBeaconState, SignedBeaconBlock
from ./datatypes/altair import HashedBeaconState, SignedBeaconBlock
from ./datatypes/bellatrix import HashedBeaconState, SignedBeaconBlock
from ./datatypes/capella import HashedBeaconState, SignedBeaconBlock
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export ssz_codec, merkleization, proofs
type
DepositsMerkleizer* = SszMerkleizer[DEPOSIT_CONTRACT_LIMIT]
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# 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) {.
error: "HashedBeaconState should not be hashed".}
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func hash_tree_root*(
x: phase0.SignedBeaconBlock | altair.SignedBeaconBlock |
bellatrix.SignedBeaconBlock | capella.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